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The use of a reference electrode and the analysis of Electrochemical Impedance Spectroscopy (EIS) data recorded in three-electrode configuration are beneficial for understanding the underlying electrochemical reaction mechanisms in Li-ion batteries. However, analysis of EIS data recorded both in two-electrode and especially three-electrode configurations is prone to misinterpretation due to presence of unidentified artifacts. Using the commercially available instrument (Biologic VMP3), EIS data is recorded simultaneously for both working and counter electrodes in three-electrode five-wire configuration and are algebraically summed to obtain the data for two-electrode configuration. This data is then compared to that recorded in two-electrode configuration. This arrangement of instrument helps in identifying the otherwise hidden and anomalous features, such as a high-frequency arc and extended solid electrolyte interphase (SEI) region, in the three-electrode configuration and the reason for their absence in the two-electrode configuration. Moreover, these additional features are found State-of-Charge (SoC) i.e., cell-electrochemistry dependent and can be highly influenced by the resistance of current/potential measuring leads. Additionally, a new methodology is established to rectify the EIS data and obtain 'artifact-free' electrochemical data. [Display omitted] [ABSTRACT FROM AUTHOR]

• Three novel linear PTO-based COPs was fabricated via Suzuki coupling reaction. • The P(PTODB)-2 shows a high initial specific capacity of 210 mA h g-1 at 0.1 A g-1. • Superior rate properties (150 mA h g-1 at 5 A g-1) could be achieved. • The ex-situ FT-IR and XPS tests have proved lithium storage mechanism with C=O groups. Conjugated organic polymers (COPs) have been emerged as a class of cathode materials for lithium-ion batteries (LIBs) because of the rigid structural units and tunable properties. Nonetheless, their applications are still limited due to the poor conductivity and low cycling life. Herein, we design a series of pyrene-4,5,9,10-tetraone-based COPs (P(PTODB)-1, P(PTODB)-2, P(PTODB)-3), containing different number of benzene rings as linking units. Consequently, prolonging the linker lengths could effectively improve structural stability and extend π-conjugation, leading to the enhanced charge-storage capability. When tested as cathode materials for LIBs, the P(PTODB)-2 electrode delivers a better electrochemical performance with high capacity of 203 mA h g-1 after 100 cycles at 0.1 A g-1 (coulombic efficiency almost 100%) and excellent rate performance (150 mA h g-1 at 5 A g-1). In addition, the Li+ storage mechanism was carried out by ex situ Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) analysis. Eventually, our study brings forward the appropriately extended linker lengths to fabricate COP cathodes with high electrochemical properties. [Display omitted] [ABSTRACT FROM AUTHOR]

The operation life is a key factor affecting the cost and application of lithium-ion batteries. This article investigates the changes in discharge capacity, median voltage, and full charge DC internal resistance of the 25Ah ternary (LiNi 0.5 Mn 0.3 Co 0.2 O 2 /graphite) lithium-ion battery during full life cycles at 45 °C and 2000 cycles at 25 °C for comparison. The batteries before and after cycling were disassembled, and the structure, morphology, interface characteristics, element content of the cathode and anode plates of the battery were characterized. By analyzing the failure factors of the performance of the ternary batteries during the 45 °C cycling, a reaction mechanism for the rapid decline of high-temperature cycling performance of ternary batteries has been proposed. The results show that the performance degradation of the ternary lithium-ion batteries in the whole life operated at high temperature is characterized by slow decline in the initial stage and rapid drop in the latter stage. Further analysis of physical and chemical performance revealed irreversible damage to both the cathode and anode. The dissolution of transition metal ions from the cathode and their deposition on the anode surface catalyze the decomposition of electrolyte solvents to produce a large amount of gas. Gassing, accompanied by the deposition of Li 2 CO 3 and the thickening of SEI, leads to an increase in the internal resistance of the battery. The coupling between gassing and increased internal resistance is responsible for the rapid drop in the performance of the ternary batteries during high-temperature cycling. [ABSTRACT FROM AUTHOR]

Direct recycling of cathode materials from spent Li-ion batteries (LIBs) or electrode scraps necessitates the efficient recovery of active materials from the aluminum foil. The variability in electrode types and recovery processes across previous studies complicates the comparative assessment of the recovery performance of green solvents. In this study, we evaluated the performance of three green solvents—triethyl phosphate (TEP), dihydrolevoglucosenone (Cyrene), and propylene carbonate (PC)—in recovering valuable active materials from industrial-grade cathode scraps. Using ultrasonication, we developed a standardized, energy-efficient recovery process that eliminated the need for conventional stirring and achieved complete cathode delamination from the aluminum foil. Furthermore, we successfully recovered the used green solvents after the process, ensuring their reuse and supporting a circular economy. The recovered materials retained their original morphology, chemical composition, and crystalline structure; however, the presence of surface impurities varied significantly depending on the green solvent used. These impurities had a considerable impact on the electrochemical performance of the recovered materials. TEP and PC yielded high-purity active materials and aluminum foils suitable for reuse or direct recycling, while Cyrene resulted in substantial residues of PVDF/solvent, requiring additional post-processing. Additionally, the recyclability of these green solvents was influenced by their solubility power for PVDF. This study provides valuable insights into the green solvent-based recycling process, laying the groundwork for future sustainable practices in LIB recycling. [ABSTRACT FROM AUTHOR]

Silicon stands out as an ideal anode material for the next generation of lithium-ion batteries (LIBs) due to its abundant sources, low lithiation/delithiation potential, and high specific capacity. However, its practical application is impeded by significant volume expansion, leading to electrode structure damage. In this study, the Porous silicon(PSi)@C/Ti 3 C 2 MXene composite was developed by dispersing porous micro-silicon@carbon (PSi@C) particles into layered stackable Ti 3 C 2 MXene sheets using ultrasonic and freeze drying. The Ti 3 C 2 MXene interlayer played a crucial role in enhancing the conductive crosslinking network between PSi@C particles, and providing efficient channels for electron transport/ion diffusion. Additionally, the Ti 3 C 2 MXene interlayer served as a buffer to accommodate the substantial volume changes in silicon during electrochemical cycling. Consequently, the PSi@C/Ti 3 C 2 MXene composite electrode demonstrated rapid electron/ion conduction and maintained structural stability. Remarkably, the electrode exhibited outstanding long cycle stability with 952 mAh g-1 at 0.5 A g-1 after 200 cycles and excellent rate performance with 542 mAh g-1 at 2 A g-1. [Display omitted] [ABSTRACT FROM AUTHOR]

• A systematic study on the effect of moisture in LiFSI based NMC622/graphite cells. • Intentionally added H 2 O (∼1000 ppm) improved NMC622/lithium half-cell performance • Moisture negatively affected graphite/lithium half and NMC622/graphite full cells. Lithium-ion battery (LIB) technology is state-of-the-art energy storage technology for portable electronics and electric vehicles (EVs). In this incumbent LIB technology, lithium hexafluorophosphate (LiPF 6) is the most widely used electrolyte salt to date. However, the challenges related to its chemical/thermal stability, sensitivity to moisture and the consequent formation of strong acids such as hydrogen fluoride (HF) need to be resolved with alternative salts. Due to its better chemical/thermal stability, resistance to moisture and HF formation, and better ionic conductivity, lithium bis(fluorosulfonyl)imide (LiFSI) has been considered as a promising alternative electrolyte salt to LiPF 6. In this study, the effect of addition of 1000 ppm water on LiFSI based electrolytes was systematically investigated by testing NMC622/lithium and artificial graphite/lithium half and NMC622/graphite full cells in four LiFSI based electrolytes; plain LiFSI, LiFSI + 1000 ppm H 2 O, LiFSI + 10 wt% FEC, and LiFSI + 1000 ppm H 2 O + 10 wt% FEC. Post mortem characterization of selected electrodes was also conducted with SEM imaging and XPS to study the surface chemistry and morphology of cycled electrodes. Overall, this study shows that 1000 ppm water can slightly improve the electrochemical performance of NMC622/lithium half cells; however, the same amount of moisture severly degrades the graphite half and NMC622/graphite full cells. [ABSTRACT FROM AUTHOR]

In order to improve the accuracy of predicting RUL of lithium-ion batteries, a lithium-ion battery RUL prediction method based on the DBO CNN-DSformer model is proposed. Firstly, the health characteristics of the battery are extracted and the local information of health features is mined using CNN. DSformer is utilized for global information, local information, and variable correlation learning of battery aging characteristics. The DBO is used to optimize the super-parameters of the CNN-DSformer model and build the DBO CNN-DSformer model. Finally, the battery aging data set was used for verification. The results show that DBO CNN-DSformer, which sets different prediction starting points, can extract sequence information from input data and establish long-term dependencies between sequences. The maximum average MRE error in the NASA data set was 0.05, the maximum average MAE was 0.018, and the maximum average AE error was within 5. The maximum average MRE error of the CALCE data set was 0.37, the maximum average MAE was 0.014, and the maximum average AE prediction error was within 10. Compared with LSTM, RNN, and Transformer models, it was found that DBO CNN-DSformer showed high prediction accuracy and good robustness. [Display omitted] [ABSTRACT FROM AUTHOR]

• Nb-LiNi0.55Mn0.25Co0.20O2 materials were prepared via the solvothermal method. • The Li+ /Ni2+ cation mixing degree was reduced with the Nb introduction. • Nb-doped cathodes exhibited higher specific capacity and better cyclic performance. • The capacity retention of 1% Nb-NMC cathode was 92.7% after 100 cycles at 1.0C. Ni-based layered oxide materials are among the most promising cathode materials for the next generation of lithium-ion batteries due to their higher energy capacity. However, capacity decay occurs due to degradation mechanisms that reduce the electrochemical performance of this type of material. This work aims to synthesize Nb-doped LiNi 0.55 Mn 0.25 Co 0.20 O 2 (Nb-NCM) materials via the solvothermal method to enhance the cyclability and energy density of the layered oxide cathode. The effects of Nb doping on the microstructure and the electrochemical performance of the cathodes are investigated. The introduction of the contents of Nb expands the structural lattice parameters and decreases the Li+/Ni2+ cation mixing degree of the NCM cathode. Furthermore, the Nb doping enhances the electrochemical activity of LiNi 0.55 Mn 0.25 Co 0.20 O 2 , increasing its initial discharge capacity to 169.61 mAhg−1 when 1% of Nb was used as a dopant (1%Nb-NCM) in contrast to the capacity of 149.45 mAhg−1 presented by the pristine material. The modified 1.0%Nb-NCM material also exhibits remarkable cycling performance with a capacity retention of 92.7% after 100 cycles at the rate of 1 C (2.8–4.3 V). This work suggests a rational strategy for high-performance cathode for lithium-ion batteries, proposing the extension of Nb doping to enhance Ni-mid material's cyclability. [Display omitted] [ABSTRACT FROM AUTHOR]

Polypropylene- grafted -maleic anhydride (PPMA) as a modifier of polypropylene (PP) at different contents and the corona radiation for surface ionization at various modification times were applied to promote the PP-based separator efficiency. The determined microstructural characteristics showed an improvement in the separator's porosity of 6–139 % at the tension amounts of 700–900 %, however, more stretching hurts the mechanical properties. The electrostatic interactions formed between the electrolytes and anhydrides increased the electrolyte sorption capacity in the samples and the surface wettability by 740 % and 25 %, respectively. The electrical test results indicated that the anhydrides led to capturing the electrolytes in the separator and created a resistance against the ion diffusion. This phenomenon reduced the separator resistance from 475 to 165 Ω, and enhanced the charge capacity and ion conductivity from 585 to 871 mAh/g and 0.29 to 0.34 S cm−1, respectively, while the PPMA content increased from 20 to 60 wt.%. The achieved FT-IR illustrated that the ionization caused the creation of more polar groups in the LIB separator, which increased the bulk and surface wettability by 420 % and 21 %, respectively, without any change in the microstructure of the separator. However, raising the exposure time in the radiation process decomposed the sample surface and led to damage in the separator microstructure. This issue reduced the separator porosity as well as the electrolyte absorption amount and ion conductivity. [Display omitted] [ABSTRACT FROM AUTHOR]

Micron-silicon based material is a promising anode material for high performance lithium batteries due to its ultra-high specific capacity. However, the volume expansion exceeds 300 % during charging and discharging, resulting in the collapse of the electrode structure and a rapid decline in electrochemical performance. Coating the surface of silicon-based materials with flexible ionic conductors is an effective method to maintain their high capacity and suppress swelling. Here, to further improve the electrochemical performance of silicon-based materials, we have deposited a titanate-type ionic conductor layer on a micron-sized silicon-carbon oxide (SiO X -C) material to synthesize the SiO X -C@TiO x (OH) y material. The TiO x (OH) y layer not only exhibits the elastic properties of a superpolymer to mitigate swelling strain, but also has a fast capacitance effect to improve its rate performance. In addition, the interfacial charge transport of SiO X -C@TiO x (OH) y is enhanced due to the structural diversity of the TiO x (OH) y layer. For the above mechanisms, the SiO X -C@TiO x (OH) y has a specific capacity of 278.3 mAh g −1 under high current of 3500 mA g −1. Meanwhile, the SiO X -C@TiO x (OH) y with the capacity retention of 67 % is achieved at 2000 mA g −1 after 100 cycles. [Display omitted] [ABSTRACT FROM AUTHOR]

• The optimal heating rate is a crucial factor in the preparation of LiNi 0.8 Co 0.1 Mn 0.1 O 2 materials. • The LiNi 0.8 Co 0.1 Mn 0.1 O 2 samples with different heating rates were systematically studied. • The optimal heating rate for LiNi 0.8 Co 0.1 Mn 0.1 O 2 has been determined to be 2 °C min-1. • An appropriate heating rate is beneficial for reducing cation mixing in the material and the residual alkali on the surface. • An appropriate heating rate is beneficial for improving the capacity retention and performance of the material. Nickel-rich layered oxides have attracted significant attention as promising cathode materials for lithium-ion batteries due to their high specific capacity, rate capability, and relatively low cost. However, the material still faces challenges such as harsh synthesis conditions, easy cation mixing and large residual alkali on the surface, severely limiting its practical applications. To overcome these drawbacks, this study successfully synthesized a series of LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM) cathode materials with different heating rates. The results indicate that appropriately reducing the heating rate can improve the cycling performance of the material and reduce cation mixing and surface residual alkalinity. Specifically, among the four samples, the LiNi 0.8 Co 0.1 Mn 0.1 O 2 sample (NCM-2 °C min-1) exhibites a lower Li⁺/Ni²⁺ mixed arrangement and fewer surface residual alkalis, demonstrating good cycling performance and rate capability. The NCM-2 °C min-1 sample provides an excellent initial discharge capacity of 210.4 mAh g⁻¹ under 0.1 C conditions, and it achieves the highest capacity retention rate (85.9%) after 100 cycles at 1 C, while the capacity retention rates for NCM-1 °C min-1, NCM-3 °C min-1, and NCM-4 °C min-1 are 75.4%, 75.2%, and 71.2%, respectively. NCM-2 °C min-1 sample also showed excellent rate performance, especially at high rates. The discharge capacity remains at 151.6 mAh g-1 at 10 C, which is much higher than that of other samples (149.3 mAh g-1 for NCM-1 °C min-1, 123.5 mAh g-1 for NCM-3 °C min-1, and 120.6 mAh g-1 for NCM-4 °C min-1). The research of synthesis technology has important guiding significance for the synthesis of high-stability high-nickel layered oxide materials. [ABSTRACT FROM AUTHOR]

Among the various materials investigated for use as anodes in lithium-ion batteries (LIBs), SnO 2 faces the significant challenge of substantial volume expansion, severely limiting its practical applications. To address this issue, this paper uses a simple co-precipitation method to synthesize ultrafine SnO 2 and TiO 2 encapsulated in cross-linked porous carbon (SnO 2 @TiO 2 @C), in which SnO 2 acts as the primary active material. At the same time, TiO 2 functions as a mechanical buffer to mitigate the large volume expansion of SnO 2. Additionally, developing (Sn, Ti)O 2 solid solution at the interface between TiO 2 and SnO 2 significantly enhances the bonding between these components, effectively preventing their separation. The cross-linked carbon enhances the conductivity of the SnO 2 @TiO 2 @C. The combination of TiO 2 and cross-linked carbon produces a synergistic effect that enhances the remarkable cycling performance of SnO 2 @TiO 2 @C (769.1 mAh/g after 100 cycles at 0.2 A/g), impressive rate performance (422.3 mAh/g at a discharge rate of 10 A/g) and extended cycle life (403.6 mAh/g after 2000 cycles at 5 A/g). Moreover, this study examined how various ratios of SnO 2 and TiO 2 influence the electrochemical performance of SnO 2 @TiO 2 @C. [ABSTRACT FROM AUTHOR]

The energy storage market necessitates an increase in the specific capacity of battery materials, particularly cathodes, to meet growing demands. Manganese (Mn) substitution of lithium iron phosphate (LFP) cathodes presents a promising avenue, offering high specific capacity and operability at elevated voltages. However, during cycling, the dissolution of Fe/Mn ions into the electrolyte leads to capacity fading. In this study, we enhance the specific capacity of LFP by Mn substitution in the iron position at various ratios (0.1, 0.2, 0.3, and 0.4). LiFe 0.6 Mn 0.4 PO 4 exhibits the highest capacity of 159.1 mAh g-1 at 0.1C with an initial Coulombic efficiency of 97.9 %. This improvement stems from an enhanced lithium diffusion coefficient, increasing from 1.86 × 10–14 cm2 s-1 for pristine LFP to 2.46 × 10–12 cm2 s-1 for LiFe 0.6 Mn 0.4 PO 4. However, LiFe 0.6 Mn 0.4 PO 4 demonstrates the poorest capacity retention among the substituted samples, reaching 78.4 % over 100 cycles due to severe Fe/Mn ion dissolution. To address this issue, we coat Mn-substituted LFP with poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and lithiated Nafion (LN) polymer, which offer high electronic and lithium-ion conductivity, respectively. This coating layer enhances the capacity retention of LiFe 0.6 Mn 0.4 PO 4 to 90.1 % at 0.2C after 100 cycles, effectively mitigating active material loss during charge-discharge processes. This study demonstrates that PEDOT:PSS-LN can improve the electronic and ionic conductivity of cathode materials and maintain high capacity retention during cycling. [Display omitted] [ABSTRACT FROM AUTHOR]

High-entropy oxides (HEOs), known for their high theoretical capacity and structural stability, are considered promising anode materials for next-generation lithium-ion batteries (LIBs). In this research, we synthesized a novel spinel-type HEO, (Cr 0.2 Mn 0.2 Co 0. 2 Ni 0.2 Zn 0.2) 3 O 4 , using a solution combustion method. By adjusting the quantity of the combustion agent, we produced samples with varying crystallite sizes. The crystallite size of the HEOs initially enlarges with an increased combustion agent, then diminishes. The enhancement of crystallite size correlates with improved electrochemical performance for lithium storage. Notably, the (Cr 0.2 Mn 0.2 Co 0. 2 Ni 0.2 Zn 0.2) 3 O 4 nanoparticles, with the largest crystallite size of 36.3 nm, demonstrated a reversible capacity of 343 mA h g-1 after 100 cycles at 100 mA g-1, a capacity retention to 319 mA h g-1 after 1000 cycles at 1 A g-1, and a commendable rate capability of 260 mA h g-1 at 2 A g-1. This study underscores the pivotal role of crystallite size in LIB performance and presents a viable strategy to enhance the lithium storage capabilities of HEOs and other metal oxides. [Display omitted] [ABSTRACT FROM AUTHOR]

Lithium cobalt oxide (LiCoO₂) and graphite are considered the optimal cathode and anode, respectively, for lithium-ion batteries (LIBs) in digital 3C products, including computers, communication devices, and consumer electronics. The underlying failure mechanism of commercial LiCoO₂/graphite LIBs at high temperatures has been elucidated through non-destructive and disassembling characterizations. The findings demonstrate that the capacity retention at 1 C following 800 cycles declines from 92% to 82%, and the associated interface film thickens by approximately 25% as the temperature rises from 25°C to 45°C. The Al₂O₃ coating layer is initially compromised, resulting in the formation of a spinel phase on the surface of LiCoO₂ and the dissolution of Co ions. The diffusion of Co ions and their deposition on graphite serve to accelerate the decomposition of the electrolyte. Following the disassembly of the LiCoO₂/graphite cell and the reassembly of half cells, it is observed that the capacity of LiCoO₂ can not be recovered, and the graphite exhibits a significant amount of electrolyte decomposition. However, following the removal of the interface films of LiCoO₂ and graphite and subsequent reassembly of half cells, it is observed that the capacity of LiCoO₂ remains unresponsive, whereas the capacity of graphite is recoverable. This indicates that both surface structural damage to the LiCoO₂ electrode and the thickening of the interface films on the graphite anode contribute to a deterioration in the electrochemical performance. [ABSTRACT FROM AUTHOR]

• Lithium bis(fluorosulfonyl)imide (LiFSI)-based electrolyte for high-voltage LIB. • LiFSI-based electrolyte leads to the corrosion of Al current collector. • New approach of in-situ EIS characterisation of corrosion of current collectors. LiFSI-based electrolytes are frontiers amongst candidates for future generation of high-voltage and high-temperature capable Li-ion batteries. Arguably, the biggest disadvantage of these electrolytes is their undesirable ability to corrode aluminium current collectors. Hence, suppressing the Al corrosion in such electrolytes has become a widely discussed topic. Despite that, there is a lack of studies focusing on in-situ approaches for the detection of such corrosion, even though such approaches are essential for the effective evaluation of the performance of Li-ion batteries containing novel LiFSI-based electrolytes. This work demonstrates the usage of EIS for the detection of corrosion of Al current collectors in NMC/Graphite cells containing 1.0 M LiFSI in EC:DMC (1:1, v/v). When cycled up to 4.2 V at 50 °C, cathode-side Nyquist plots displayed induction loops developing over the cycles, which were ascribed to the corrosion of Al current collectors, and whose presence was confirmed by SEM imaging. When the cut-off voltage was decreased to 3.7 V to maintain a native protective Al 2 O 3 layer and hence suppress the corrosion, neither the induction loops in Nyquist plots nor pitting holes in SEM images were observed, confirming the link between the induction loops and the corrosion. This work aims to support designing and understanding of future experiments focused on suppressing the corrosion of Al current collectors in LiFSI-based high-voltage Li-ion batteries capable of operation at higher temperatures. [Display omitted] [ABSTRACT FROM AUTHOR]

• The P3DPY material exhibits an excellent positive temperature coefficient (PTC) effect at 100 °C, which coincides with the dangerous occurrence temperature of lithium-ion batteries (100 °C). • The P3DPY material has remarkable electrochemical activity in the battery environment, further enhancing the electrochemical performance of the electrode. • The LCO-P3DPY cathode has a capacity output of only 1.7 mAh g−1 at 100 °C, demonstrating reliable thermal shutdown. • The capacity retention rate of the LCO-P3DPY cathode increased from 62.86 % to 91.83 % (vs LCO cathode) after 200 cycles at 0.25 C. Exploring a simple way that can accurately respond to abnormal temperature increase within battery and then promptly shut down the corresponding thermally abused battery is crucial to improving the thermal safety of lithium-ion batteries (LIBs), yet still faces challenges. To counter this, a temperature-sensitive LCO-P3DPY cathode was constructed with a new conductive polymer, i.e., poly(3-decylpyrrole): poly(4-styrenesulfonic acid) (P3DPY: PSS). Safety tests demonstrated that P3DPY exhibited an exceptional positive temperature coefficient (PTC) effect at 100 °C, coinciding with the dangerous occurrence temperature (100 °C) of most LIBs. Consequently, the LCO-P3DPY cathode displayed a significant thermal shutdown in the immediate aftermath of thermal abuse within the battery, showing a capacity output of only 1.7 mAh g−1. Furthermore, LCO-P3DPY cathode not only exhibited excellent electrochemical stability in the battery environment, but also enhanced electrochemical performance, as compared with the traditional batteries at room temperature. After 200 charging-discharging cycles at 0.25C, LCO-P3DPY cathode was able to maintain a reversible capacity of 142.8 mAh g−1, corresponding to a capacity retention rate of 91.83 % that is better than that of blank LCO (62.86 %). This work provides a potential strategy to solve the thermal safety problem and simultaneously improve the electrochemical stability of LIBs. [Display omitted] [ABSTRACT FROM AUTHOR]

• MnO/Mn 3 O 4 –600 anode was synthesized through a one-step pyrolysis of MOD. • The MnO/Mn 3 O 4 –600 anode shows structure-related performance towards li storage. • The (de)lithiated mechanism of MnO/Mn 3 O 4 –600 was probed by in situ XRD. • The LFP||MnO/Mn 3 O 4 –600 full cell shows outstanding electrochemical performance. Manganese oxides are considered a highly promising anode material in lithium ion batteries (LIBs) because of their high theoretical capacity, abundant sources, relatively low voltage hysteresis, nontoxic and cost-effectiveness. Nevertheless, the practical application of these materials faces many challenges such as poor lifespan and serious volume variation during operation. Herein, MnO/Mn 3 O 4 –600 composite was obtained based on a single-step pyrolysis procedure from commercial manganese(II) oxalate dihydrate (MOD, C 2 H 4 MnO 6). The MnO/Mn 3 O 4 –600 anode exhibits an exceptionally high reversible capacity of 1041.8 mAh g −1 at the current density of 200 mA g −1, and a remarkable lifespan at 1000 mA g −1. The outstanding performance benefits from the formation of porous structures on nanoparticles, which not only mitigate volume changes and prevent the aggregation of internal MnO/Mn 3 O 4 nanoparticles, but also enhance the ion diffusion. The in-depth insights into the (de)lithiated mechanism of the electrode are investigated by in situ X-ray diffraction (XRD) technique. Moreover, when applied in a full cell, the MnO/Mn 3 O 4 –600 anode demonstrates exceptional electrochemical property. The MnO/Mn 3 O 4 –600 was synthesized through a single-step pyrolysis process of commercial manganese(II) oxalate dihydrate. As the anode in LIBs, MnO/Mn 3 O 4 –600 demonstrates excellent performance, which can be attributed to the nanoengineering of MnO/Mn 3 O 4 nanoparticles and the porous architecture. (De)lithiated mechanism was proposed by in situ XRD. Moreover, the LFP||MnO/Mn 3 O 4 –600 full cell exhibits good electrochemical performances. [Display omitted] [ABSTRACT FROM AUTHOR]

In the present work, Z n -doped M n C O 3 i.e., M n 1 − x Z n x C O 3 (x = 0 t o 0.3) have been successfully synthesized by easy and commercial co-precipitation method at atmospheric pressure and temperature. The structural, morphological, chemical, and thermal properties of as-synthesized samples were examined by XRD, FESEM, EDX, XPS, FTIR and TGA techniques. Rietveld refinements of XRD patterns reveal the successful incorporation of Z n in the crystal lattice of MC (M n C O 3). Further, the L i -storage performance of all the samples have been examined from 0.005 to 3.0 V vs. L i / L i + by GCD at a constant current rate of 60 mA·g−1 and CV measurement techniques. The result shows that MZC-2 (M n 0.8 Z n 0.2 C O 3) exhibits a better L i -storage performance with the reversible capacity of 667 (±10) mA·h·g−1 and better cyclic stability at least for 100 cycles and superior rate performance. A plausible charge storage mechanism is proposed based on ex-situ XRD and TEM analysis. The results indicate the contribution of both the alloying-de-alloying and conversion reaction of Z n. Incorporation of Z n into M n C O 3 have been found beneficial to stabilize the cyclability of M n C O 3. [ABSTRACT FROM AUTHOR]

The LiNi 0.8 Co 0.15 Al 0.05 O 2 (NCA) nickel-rich layered cathode material is widely used for Li-ion batteries because of its excellent structural stability and high specific capacity. However, the Li/Ni mixing effect and the generation of interfacial secondary reactions in NCA cathode materials reduce the electrochemical properties of Li-ion batteries. Herein, we report a series of vanadium (V)-doped NCA cathode (VNCA) materials with different amounts of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) polymers in-situ coated on the surface using a liquid-phase method. The introduction of PEDOT:PSS coating not only improves the conductivity of NCA cathode materials but also protects the surface of cathode materials from cracking during the cycle. Electrochemical results show that the PEDOT:PSS (2 wt%) coating possesses high capacity retention rate (83.58%) after 200 cycles at 1 C, which is better than that of the sample without coating (66.7%). The PEDOT:PSS (2 wt%) coated cathode materials also display superior rate performance to VNCA at high magnification. This work provides new methods and theoretical guidance for the development of efficient ternary cathode materials for Li-ion batteries. [ABSTRACT FROM AUTHOR]

In this paper, WO 3 uniformly coated LiNi 0.9 Co 0.05 Mn 0.05 O 2 cathode materials are prepared by wet coating method using ammonium metatungstate as tungsten source. The XRD, SEM, and XPS tests show that the cladding process introduced W ions into the NCM lattice, increasing the layer spacing and improving the lithium diffusion rate. The charge/discharge test results indicate that a moderate amount of WO 3 coating can enhance the rate-discharge performance and increase the long cycle life. After 100 cycles at 1C (180 mAh g−1), the reversible capacity of the material containing 0.5wt% WO 3 coating is 157.9 mAh g−1, while that of the original material is only 130.9 mAh g−1, which indicates that the WO 3 coating protects the cathode material from HF corrosion, thus improving the stability of the structure. DFT calculations show that the dangling bonds of O on the NCM surface are highly susceptible to binding with W, which reduces the possibility of WO 3 coating exfoliation.WO 3 and NCM are p-type semiconductors and semi-metallic materials, respectively, which form ohmic contacts at heterogeneous interfaces thereby increasing the electronic conductivity of the materials, and due to the synergistic effect, the diffusion barrier of Li near the heterogeneous interfaces is lower than that of the pristine materials. [ABSTRACT FROM AUTHOR]

The theoretical specific capacity of tin dioxide (SnO 2) as a lithium-ion batteries (LIBs) anode material is up to 1494 mAh·g−1, far exceeding that of graphite. However, the low conductivity, volume expansion, crushing failure and particles agglomeration during charge/discharge cycles limit its application in LIBs. In this work, the SnO 2 /MoO 3- x /rGO composite material was synthesized by one-step hydrothermal method, with SnO 2 and amorphous MoO 3- x tightly and uniformly anchored at the surface of reduced graphene oxide (rGO). The results of structural characterization and electrochemical performance evaluation show that amorphous MoO 3- x can increase the reactive active sites, inhibit Sn particles aggregation, and promote the reversible reaction of SnO 2. rGO effectively improves the electrical conductivity of the composite and buffers the volume change of Li-Sn alloying/dealloying during cycles. In addition, due to introduction of MoO 3- x and rGO a stable SEI film can be formed at the material's surface to improve the cycle stability. SnO 2 /MoO 3- x /rGO exhibits excellent rate performance and cycle performance. When the rGO content is 10.9 wt%, the reversible capacity of the composite reach 813 mAh·g−1 after 800 cycles at current density of 1.0 A·g−1, and 450.6 mAh·g−1 after 1000 cycles at current density of 5.0 A·g−1, with the capacity retention rate of 96.9%. [ABSTRACT FROM AUTHOR]

The precise assessment of the kinetic properties of graphite is crucial for the design of the material and the development of electrochemical models for lithium-ion batteries. However, conventional evaluation methods using composite electrodes fall short in excluding the influence of its porous structure and evaluating the influence of particle shape on kinetic behavior. In this work, we elucidate the impact of non-spherical morphology on kinetic behavior of single artificial graphite particle, employing the single-particle microelectrode technique. Three single artificial graphite particles with different sizes are pre-cycled and exhibit outstanding rate capability, maintaining a maximum capacity retention of 78.1 % at 200 C. Further, exchange current density and diffusion coefficients are determined through Tafel plots and the potentiostatic intermittent titration technique (PITT), respectively. It is found that the particle with a higher exposure of edge planes present elevated exchange current density and diffusion coefficients. Considering that the graphite particles typically feature an ellipsoidal rather than spherical shape, we propose an approach based on an ellipsoidal diffusion model for extracting diffusion coefficients. This model takes into account the non-spherical morphology of graphite, addressing the limitations inherent in the geometric assumptions of previous methods. The average relative error between the diffusion coefficients derived from the ellipsoidal diffusion model and the previous method using spherical assumptions is 215 %, indicating that accurately depicting the shape of ellipsoidal graphite particles in the model is crucial for obtaining correct estimates of kinetic parameters. This study offers direct experimental evidence of superior kinetic behavior of edge planes over basal planes. To leverage this characteristic, it is recommended to employ an out-of-plane aligned architecture for composite electrodes using novel techniques, e.g., 3D printing or magnetic alignment techniques. [ABSTRACT FROM AUTHOR]

Perovskite ceramic oxides (ABO 3) have emerged as strong contenders against graphite anodes in non-aqueous metal-ion batteries. Exploring perovskites, we studied lithium insertion in barium lead oxide (BaPbO 3) and strontium lead oxide (SrPbO 3) perovskites, where lead (Pb4+) occupies the B-site. BaPbO 3 and SrPbO 3 , mass produced by solid-state or solution-combustion route, delivered reversible capacities upto 333 mAh/g and 339 mAh/g corresponding to 4.3 and 4.9 lithium uptake, respectively at room temperature. Among them, BaPbO 3 showed stable cycling for 50 cycles. Furthermore, at 50 ⁰C, BaPbO 3 delivers a first charge capacity of 382 mAh/g (or 5.6 lithium per formula unit) maintaining excellent stability beyond 50 cycles. Ex situ diffraction and microscopy studies confirm charge storage occurs via initial conversion (PbIV/PbII → Pb0) followed by reversible (de)alloying (Li–Pb) reaction. These results showcase perovskites as a promising family of Li-ion battery anodes. [ABSTRACT FROM AUTHOR]

In 2 O 3 , employed as an anode, demonstrates exceptional capacity in lithium-ion batteries (LIBs). Nonetheless, its propensity for significant volume expansion results in internal fracturing and reorganization. Two-dimensional double transition metal carbides and nitrides (MXenes), characterized by unique out-of-plane metal atom ordering, exhibit promising electrical properties due to their chemical versatility and intricate structure. However, MXenes' tendency to aggregate or stack into lamellar structures impedes their practical energy storage application. To address these issues, a hierarchical porous microrods In 2 O 3 @C@Ti 3 C 2 T X (HPMR-In 2 O 3 @C@Ti 3 C 2 T X) composite anode material was synthesized through electrostatic self-assembly of MIL-68 (In) and Ti 3 C 2 T X , followed by carbonization. This synthesis produced continuous one-dimensional microrods with hierarchical porous channels in HPMR-In 2 O 3 @C, offering a substantial specific surface area, numerous Li+ storage sites, and enhanced charge transfer rates. Moreover, the interlayer space within Ti 3 C 2 T X acts as an electrolyte reservoir, facilitating comprehensive electrochemical reactions and accommodating volume changes during charge-discharge cycles. Consequently, the HPMR-In 2 O 3 @C@Ti 3 C 2 T X anode exhibited remarkable properties, including a high initial discharge specific capacity of 1406 mAh g-1 at 0.1 C, outstanding cycling performance, and superior rate performance. This research presents a promising direction for the advancement of high-performance anode materials for lithium-ion batteries. [Display omitted] [ABSTRACT FROM AUTHOR]

• Synthesis of MIL-100 (Fe) from Fe(OH) 3 slag from hydrometallurgy. • Porous structure improves the rate-multiplying performance of PIBs. • The porous structure improves the K+ migration reaction kinetics. • Incomplete coordination leads to higher carbon content. Recycling spent cathode materials is crucial for sustainably developing lithium-ion battery technology. To achieve the high-value utilization of spent LiFePO 4 (LFP) cathodes, this paper proposes a method for preparing MIL-100(Fe) based on solid waste residues from spent LFP cathodes. R-FeS 2 @C derived from MIL-100(Fe) can serve as an anode material for potassium-ion batteries featuring a porous structure. Electrochemical tests demonstrate that the R-FeS 2 @C exhibits more stable cycling performance compared with the FeS 2 @C derived from the traditional MIL-100(Fe), reaching 525 mAh g−1 after 100 cycles at a current density of 100 mA g−1. Impressively, R-FeS 2 @C also showcases excellent rate performance (343 mAh g−1 specific capacity at 5 A g−1). Furthermore, full cells assembled with PI@rGO cathodes also exhibit excellent rate performance and stable cycling performance. The porous structure of R-FeS 2 @C provides numerous voids to accommodate volume changes and introduces sufficient channels for electrolyte penetration. The higher carbon content enhances the electrical conductivity improving the kinetics of the K+ migration reaction. These researches can provide guidance for the recycling of spent lithium-ion batteries and the design of sulfide electrodes for PIBs. [Display omitted] [ABSTRACT FROM AUTHOR]

As a sustainable, safe, and cost-effective alternative to conventional lithium-ion batteries, aqueous rechargeable zinc-metal-based batteries have attracted significant attention in large-scale energy storage. However, their practical application is hindered by zinc anode degradation, primarily dendrite growth and corrosion, which compromise battery performance and lifespan. Herein, we present an aluminum-doped silica (Al-SiO 2) aerogel coating layer to address these issues. The aluminum-doped silica aerogel coating layer offers improved hydrophilicity and zinc ion adsorption capabilities because of its porous structure, high surface area, and functional groups. By facilitating uniform zinc ion deposition and providing a physical barrier against corrosion, the Al-SiO 2 aerogel coating layer significantly mitigates dendrite formation and extends the electrochemical stability and operational lifespan of aqueous rechargeable zinc-metal-based batteries. Symmetric cell tests reveal that zinc anodes coated with Al-SiO 2 can achieve stable cycling over 3000 h, indicating exceptional reversibility and rate performance, much better than that of the bare Zn anode. Furthermore, the Al-SiO 2 aerogel-coated zinc anode coupled with MnO 2 cathode forms a stable rechargeable full battery. This work contributes to the body of knowledge on advanced materials for energy storage, highlighting the potential of aerogel coatings as a scalable and effective solution for improving the performance and durability of zinc metal anode for aqueous rechargeable zinc-metal-based batteries. [ABSTRACT FROM AUTHOR]

• SiO x thin film anodes with different oxygen contents were prepared by radio frequency PECVD. • A simple and effective method of rapid heat treatment is provided. • Modification of SiO x thin film anodes for better electrochemical properties using rapid heat treatment. SiO x (x = 0.61, 0.87 and 1.3) thin film anodes with different oxygen contents were prepared by radio frequency plasma enhanced chemical vapor deposition (PECVD) by adjusting the SiH 4 /N 2 O (R) gas flow ratio. The introduction of oxygen can alleviate the volume expansion during discharge/charging at the expense of the cycle-specific capacity. On this basis, rapid thermal process (RTP) of SiO x films at different temperatures was continued. A certain heat treatment is conducive to release the compressive stress accumulated in the deposition process of the film, reducing the impurity molecules in the film, breaking the hanging bonds attached to the film in the preparation process, and improving the overall mechanical properties of the film, so as to improve the cyclic stability and rate performance of the film. After the experiment, the SiO 0.61 film was used as the substrate for RTP of the film. The film after RTP at 600 °C had a discharge specific capacity of 1107 mAh g-1 after 100 cycles at 0.5 C current density, which was 352 mAh g-1 higher than that of SiO 0.61 without heat treatment. [Display omitted] [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) electrode design can provide improved capacities and rate capabilities over conventional two-dimensional electrodes by enhancing electrical and ionic transport. Expanding upon our previous modeling efforts for conversion chemistry lithium-ion batteries, we develop a pseudo-four-dimensional (P4D) approach that is subsequently used to investigate the design of a pillared FeS 2 electrode. The model considers transport in three dimensions with an additional "fourth" dimension corresponding to the solid-state lithium transport within the active material particles. Additionally, we allow for expansion of the active material during the conversion reaction to understand how internal stresses impact the electrochemical performance of the cell. By optimizing the model with respect to areal capacity, we are able to predict areal capacities up to 16.8 mAh/cm2 for an areal current density of 1.78 mA/cm2 and a 103% improvement for the three-dimensional electrodes over planar electrodes of equal volume. Despite the promising results, our simulations suggest that 3D design may be difficult for conversion cathode materials due to the large internal stresses that arise during conversion. Nevertheless, the model is robust and adaptable to other materials that may be more suitable for 3D electrodes due to a lesser change in volume during discharge. [ABSTRACT FROM AUTHOR]

The lithium-rich composite-layered oxide, xLi 2 MnO 3 •(1-x)LiM'O 2 , where M' represents transition metals, is a promising cathode material with excellent capacity at high working voltage for lithium-ion batteries (LIBs). Nevertheless, an unusual charge-discharge feature is observed for this material with sloping and plateau regions during the initial charging. In this work, ab initio calculations based on density functional theory were employed to examine the stability of x Li 2 MnO 3 •(1- x)Li(Ni 1/3 Co 1/3 Mn 1/3)O 2 composite-layered cathode materials during the first charging. Optimized atomistic models for different compositions (x = 0.0, 0.3, 0.4, 0.5, 0.7, and 1) unveil a pseudo-rhombohedral or monoclinic-like structure within the solid solution phase, with simulated X-ray diffraction patterns closely matching experimental data. Using these atomistic models, the first charging process of the 0.4Li 2 MnO 3 •0.6Li(Ni 1/3 Co 1/3 Mn 1/3)O 2 cathode were investigated. There exists phase transition from a layered to a spinel structure. Additionally, Bader charge analysis reveals intriguing trends during the first delithiation process, where the valence states of Ni and Co gradual increase, while that of Mn almost remains unchanged. Simultaneously, significant oxidation of O is observed. This finding leads to further evaluations on oxygen vacancy formation in comparison to the energy required for delithiation. Defect formation energy calculations demonstrate that the plateau in charging curve is resulted from oxygen vacancy formation during the first charging. By empirical fitting oxygen chemical potential at μ O = -1.200 eV, the calculated charging-discharging curves aligned well with experimental data during the first and second charging. Furthermore, the pathways of lithium and oxygen deintercalation are elucidated. This work contributes fundamental understandings on the x Li 2 MnO 3 •(1- x)LiM'O 2 composite-layered oxides as cathode for LIBs, providing valuable guidance for further developments in high-capacity Co-lean cathode materials. [Display omitted] [ABSTRACT FROM AUTHOR]

• A new three-dimensional conductive network composed of the sheath (TiO 2) / core structure (Sn) was fabricated successfully. • The sheath/core structure improves the electronic conductivity and provides a buffer for volumetric strain. • The fiber core Sn and sheath TiO 2 form a heterojunction interface, accelerating electron transport. Flexible Sn/TiO 2 carbon nanofiber (ST-NCF) composites were constructed by doping TiO 2 into tin-based carbon nanofibers via coaxial electrospinning. Sn/TiO 2 carbon nanofiber was directly used as an anode for Lithium-ion Batteries (LIBs) and Potassium-ion Batteries (PIBs), which show exceptional electrochemical performances. The layered sheath/core structure of the material lead to its good electrochemical properties, where the core Sn carbon nanofiber was encapsulated by the sheath layer of TiO 2 nanoparticles. In addition to enhancing its electrical conductivity, the outer TiO 2 and N-doped carbon fiber matrix also provide a buffer zone for volumetric strain during charging and discharging. The fiber core Sn and sheath TiO 2 form a heterojunction interface on the two-dimensional tube surface, which increases the diffusion rate of ions and electrons. After 100 cycles, TiO 2 -NCF and ST-NCF-40%TBT (40% TBT indicates the percentage of TiO 2 in shell solution to the total composition of shell spinning solution) show capacities of 386.6 mAh g−1 and 1336 mAh g-1, respectively, at 0.5A g-1. After 2000 cycles, ST-NCF-40%TBT in LIBs displayed a high capacity of 299 mAh g-1 at 10 A g-1. After 350 cycles at 1A g-1, the capacity of ST-NCF-40%TBT in PIBs is reserved at 307 mA h g-1. Due to the superior mechanical flexibility of ST-NCF-40%TBT films, it will be a promising anode candidate for flexible LIBs and PIBs. [Display omitted] [ABSTRACT FROM AUTHOR]

Disordered rocksalt cathodes exhibit high specific capacities and high energy density; however, their low electronic conductivity poses a great challenge. Herein, we explored an aqueous-solution-based synthesis route that involves controlling the surface charges of Li 1.2 Mn 0.6 Ti 0.2 O 1.8 F 0.2 (LMTOF) to be anchored by a few-layer reduced graphene oxide (rGO) for the first time. The uniform rGO wrapping on the surface of the LMTOF particles is achieved by electrostatic attraction between the negatively charged rGO and positively charged LMTOF particles. Although the initial specific capacity of rGO-LMTOF composite increased by 58 % compared to the pristine LMTOF, the composite experienced a severe capacity fade over cycling. The synthesis process in an aqueous medium resulted in Li+/ H + exchange and TM dissolution as evidenced from inductively coupled plasmon analysis and X-ray diffraction analysis. Therefore, this work suggests the search for alternative media or conditions for the synthesis of carbon-disordered rock salt cathode composite. [ABSTRACT FROM AUTHOR]

The use of composite solid-state electrolytes (CSEs) in Li-ion batteries presents a promising future for a new generation of solid-state battery technology. These composites address current limitations like poor room temperature ionic conductivity, low mechanical strength, and unstable interfaces. In this study, a NASICON-type Li 1.5 Al 0.5 Ti 1.5 (PO 4) 3 (LATP) ceramic was prepared using a cold sintering process (CSP), incorporating LATP, poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (PVDF-TrFE-CFE), and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][TFSI]). This three-component CSE demonstrated reduced sintering temperature, energy, time, and operational costs compared to traditional methods. The LATP-based pellet achieved high density and a prismatic structure without impurities. The addition of a polymeric binder and an ionic liquid improved the nanostructuration, dispersion, mechanical properties, and relative density of the CSEs. Small-angle neutron scattering revealed nanostructuration changes, decreasing air pore size. Notably, room temperature ionic conductivities between 10–4 – 10–3 S cm-1 were achieved, with a maximum conductivity of 7.02 × 10–3 S cm-1 and lithium-transference number of 0.35 for the sample with 99 wt.% LATP and 1 wt.% polymeric binder. Additionally, a room temperature discharge capacity of 141 mAh.g-1 at C/10 rate was attained after 50 cycles, validating this three-component structure as a promising platform for high-performance CSEs in solid-state batteries. [ABSTRACT FROM AUTHOR]

• In-situ prepared γ-LiV 2 O 5 /carbon composite was synthesized via two-step solid state reaction at elevated temperatures. • Electrochemical performances of the obtained γ-LiV 2 O 5 /C composite were investigated in organic and aqueous electrolyte and compared to the ones of the pristine γ-LiV 2 O 5 material. • The composite γ-LiV 2 O 5 /C exhibits up to two times higher charge-storage capabilities than pristine γ-LiV 2 O 5. • Replacing the organic electrolyte with the aqueous one has negligible effects on mechanism and efficacy of lithium storage in γ-LiV 2 O 5 /C. • Electrochemical exchange of lithium with sodium in aqueous environment leads to a decrease of cathode performances of γ-LiV 2 O 5 /C, as a result of γ-Li x V 2 O 5 to β-Na x V 2 O 5 phase transformation. Preparation of in-situ composites with carbon by pyrolysis of an organic precursor is an effective strategy to improve performances of insulating and semiconducting cathode materials. However, due to the property of organic precursor to act as a strong reductive agent during carbonization process, the in-situ synthesis of LiV 2 O 5 /C composite cathode material is delicate and presents a challenge for researchers, since vanadium in LiV 2 O 5 coexists in two oxidation states, V4+ and V5+. In our research, we utilized an adopted conventional solid state method for the in-situ preparation of Li x V 2 O 5 /C composite (x ≈ 0.86). By using methylcellulose polymer as a carbon source, Li x V 2 O 5 /C was synthesized via two-step solid state reaction at elevated temperatures. Li x V 2 O 5 crystallized as gamma polymorph phase, and the amount of in-situ formed carbon does not exceed 3wt%. The electrochemical characteristics of the as-prepared Li x V 2 O 5 /C were investigated in aqueous and non-aqueous electrolyte via cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) tests and electrochemical impedance spectroscopy (EIS). On lithium insertion/removal, the Li x V 2 O 5 /C composite exhibits stable cycling performance and achieves significant storage capacity enhancement when compared to pristine Li x V 2 O 5 obtained under similar conditions. Under current densities of 0.1, 0.2, 0.3 and 1 A/g, the specific capacity enhancement is around 112, 91, 80 and 62 %, respectively. Replacing the organic electrolyte with the aqueous one has a negligible effect on the mechanism and efficiency of lithium intercalation within the Li x V 2 O 5 /C, which opens up the possibility of using this material in aqueous as well as in organic-electrolyte batteries. The decay of cathode's activity evidenced during electrochemical exchange of lithium with sodium in aqueous environment comes as a result of the formation of electrochemically inactive β-Na x V 2 O 5. [Display omitted] [ABSTRACT FROM AUTHOR]

• First application of core-shell battery materials for lithium production applications. • Demonstration that the material properties requirements of LiFePO 4 for non-aqueous battery applications and for lithium production from brines are markedly different. • Demonstration of the improved performance of core-shell carbon-coated LiFePO 4 materials over commercial materials for lithium production applications. The development of affordable and environmentally friendly methods to produce lithium is urgently required to cope with the accelerating growth of the lithium battery market. Battery materials such as LiFePO 4 can be used to selectively sequestrate lithium from brine natural resources, thus producing a high-purity lithium salt for battery manufacture, but the long-term stability of the material is currently not sufficient for practical applications. Here, we report, for the first time, the development of a nanosized core-shell structured LiFePO 4 /C material for applications in lithium production from brines. This LiFePO 4 /C with a LiFePO 4 -core (∼123 nm size) covered by a pinhole-free carbon shell (∼5 nm thickness) was prepared via solvothermal synthesis, and the carbon content was optimised to 5 wt%. The optimal core-shell structured LiFePO 4 /C material exhibits a lithium extraction capacity of ca. 160 mA h g-1 at C/10 and ca. 130 mA h g-1 at 1C, and >87 % capacity retention after 50 cycles of lithium sequestration and release at C/10 in synthetic brines. This excellent electrochemical performance is attributed to the homogenous nanosizing of the LiFePO 4 particles as well as the full coverage of the carbon coating, which provides effective protection by preventing the direct contact of LiFePO 4 with the brines, thus stopping the surface degradation reactions that compromise the long-term stability. A direct comparison with three commercial LiFePO 4 materials demonstrates that, while similar performance is obtained in non-aqueous lithium-ion batteries, for lithium production applications, core-shell nanostructuring is crucial to achieve high capacity and preserve the material's longevity. [Display omitted] [ABSTRACT FROM AUTHOR]

The combination of two-dimensional layered heterostructures with transition metal oxide electrodes has attracted considerable attention. In this work, the hydrothermal method is adopted to produce graphitic carbon nitride-embedded Nickel oxide (g-CN/NiO) nanocomposites and tested their electrochemical performance against Li/Li+ half cells. The formation of g-CN/NiO nanocomposite is confirmed through structural analysis techniques, such as XRD and XPS. The scanning electron microscopy image reveals the existence of spherical g-CN/NiO nanocomposite. The g-CN embedded NiO anodes exhibited excellent electrochemical performance and cyclability, and the g-CN/NiO versus Li/Li+ half-cell delivered an initial discharge capacity of 906.4 mAh g-1 at a 0.1C rate. At 500 cycles, the anode delivered 195 mAh g-1 capacity with a columbic efficiency of 99.5 %. Interestingly, the g-CN/NiO anode exhibits two distinct trends in its cycling performance. Until 300 cycles, the capacity fade was perceived, and after 300 cycles, due to the overhang mechanism, an increasing trend was observed. The electrochemical result reveals that the introduction of g-CN improves the structural stability and electron transport properties of g-CN/NiO anodes. [ABSTRACT FROM AUTHOR]

To enhance the thermal stability, electrochemical compatibility, and overshoot protection of separators, it is common practice to incorporate inorganic particles for separator modification. In this work, we discussed a polypropylene (PP) separator that was coated with a combination of hydrothermal boehmite (AlOOH) and ammonium polyphosphate (APP). The coating layer can greatly reduce the thermal shrinkage rate of the separator, enabling the modified separator to retain its original size at 180 °C. In addition, part of the material formed by the decomposition of the coating material at high temperatures can be well-diluted oxygen, thus reducing the risk of combustion. Furthermore, the presence of the coating layer increases the ionic conductivity and electrolyte wettability, thereby improving the cycle stability of the battery. This study utilizes inexpensive, lightweight, and eco-friendly materials to enhance a commercially available polypropylene separator. This modification not only increases the efficiency of material usage but also enhances the economic and environmental advantages of the improved separator. [Display omitted] [ABSTRACT FROM AUTHOR]

• An unsupervised feature extraction method of Li-ion batteries' EIS is proposed. • The latent variables are extracted automatically without prior knowledge. • The extracted latent variables are related to battery aging. • The capacity of batteries for uneven usage during degradation is estimated. • The proposed method generates reliable EIS data. In this paper, we propose an unsupervised feature extraction technique using a variational autoencoder and generative adversarial network (VAEGAN) that automatically extracts meaningful latent variables from the electrochemical impedance spectra (EIS) of lithium-ion (Li-ion) batteries. These variables accurately reflect the degree of Li-ion battery degradation and are closely related to its capacity. By analyzing the latent variables, it was found that the network can learn the effect of Li-ion battery capacity degradation on the EIS. The extracted latent variables are then used as input features for Gaussian Process Regression (GPR) to estimate the capacity of Li-ion batteries under uneven usage and with unknown historical data. The results show that the capacity prediction method proposed in this paper can significantly reduce prediction errors compared to the current state-of-the-art methods. The method not only provides a more reliable capacity estimation but is also robust to highly noisy EIS data, making it more suitable for practical application scenarios. [Display omitted] [ABSTRACT FROM AUTHOR]

• Phenyl boronic acid was first introduced to NCM/Si-C full cell system. • PBA could be preferentially oxidized and reduced on cathode and anode. • The electrode interfacial property was improved by the robust and B-rich SEI/CEI film. Electrolyte additive engineering is one of the most useful approaches to improve the interfacial property of electrode material in Li-ion batteries (LIBs), which plays a vital role in the mass transport during the electrochemical process. Boron-based electrolyte additives have a good application prospect, however exploring new additives with lower-cost and higher efficiency is still needed. In this study, Phenyl boric acid (PBA), acting as a two-sided interface modifier, is introduced to LiNi 0.5 Co 0.2 Mn 0.3 O 2 /SiC batteries. Through both theoretical calculations and experimental measurements, it is found that PBA could be preferentially reduced on the SiC anode and induce the formation of B-rich solid electrolyte interphase (SEI), which efficiently protects the anode material from the parasitic reaction. Besides, PBA can be sacrificially oxidized before other salt/solvent decomposition, achieving a highly-reversible lithiation/delithiation process at the cathode. Benefiting from these synergistic effects, the target Si-C/Li half-cells achieve a 2.5 % improvement in average coulomb efficiency of 100 cycles, while the capacity retention rate of NCM/Li half-cells and NCM/Si-C full cells increase by 21.4 % and 15.8 %, respectively. This work provides an effective approach to ameliorating the electrode interface chemistry of LIBs employing Si-based anodes Ni-rich cathodes and another analogous battery systems. [ABSTRACT FROM AUTHOR]

• Binder effects on high-entropy (CrMnFeNiCu) 3 O 4 anode performance are examined. • PVDF, PNVF, NaCMC, Na alginate, and NaPAA binders are systematically compared. • NaPAA increases electrode coulombic efficiency, rate capability, and cyclability. • A capacity of 800 mAh g–1 and a 99 % capacity retention after 300 cycles are found. • NaPAA reduces heat generation during thermal runaway and increases safety. High entropy oxide (HEO) materials have recently emerged as promising anodes for lithium-ion batteries (LIBs). In this study, we conduct the first comparative analysis to investigate the influence of various electrode binders on electrochemical properties of (CrMnFeNiCu) 3 O 4 HEO anodes. The organic-solvent-soluble polyvinylidene fluoride and water-soluble polyvinyl formamide, sodium carboxymethyl cellulose, sodium alginate, and sodium polyacrylate (NaPAA) binders are examined. Notably, the NaPAA binder leads to a significant enhancement in the HEO performance. The NaPAA coating on (CrMnFeNiCu) 3 O 4 effectively improves the electrode charge-discharge Coulombic efficiency and mitigates the electrode deterioration. Binder adhesion strength and stability toward electrolyte are assessed. The charge-transfer resistance and apparent Li+ diffusion of the HEO electrodes with various binders, accompanied by the post-cycling analyses, are examined. By employing the NaPAA binder, exceptional electrode capacities of 800 and 495 mAh g–1 are attained at charge-discharge rates of 50 and 2000 mA g–1, respectively, without noticeable capacity degradation after 300 cycles. The thermal reactivity of the lithiated electrodes is investigated using differential scanning calorimetry, and the impact of binders on the electrode exothermic onset temperature and total heat released is studied. Our findings provide valuable insights for enhancing the performance and safety of HEO anodes for LIBs. [Display omitted] [ABSTRACT FROM AUTHOR]

High-temperature Li-ion batteries capable of operating up to 100 ℃ can replace lithium thionyl chloride primary batteries in specialized industrial applications. Room-temperature ionic liquids (RTIL) offer high thermal stability and can be a promising choice of electrolyte for high-temperature batteries. This work elucidates that high thermal stability alone does not guarantee effective battery operation due to the electrochemical instability observed in RTIL-LiTFSI mixtures at elevated temperatures. Here, we investigate the impact of varying electrochemical stability in RTILs on half-cell, full-cell, and calendar aging. Electrochemical instability of the electrolyte at the cathode interface injects additional electrons and Li-ions into the electrochemical cell, triggering a cascade of detrimental chain reactions that hinder efficient battery performance. We demonstrate that electrochemical information gathered from a full-cell configuration can frequently obscure the presence of electrochemical instability at the cathode surface. To accurately evaluate this instability, it is essential to perform in-depth half-cell studies and other characterizations. Our results indicate that cathode electrolyte interphase (CEI) can reach a thickness of up to 100 nm, with a depth-dependent composition showing higher concentration of inorganic species like LiF and LiNSO near the cathode surface. Further, accelerated calendar aging measurements of such cells at high temperature revealed complete irreversible self-discharge within as little as 14 days. These findings shed light on the critical factors influencing the stability and performance of cells under challenging operating conditions. [ABSTRACT FROM AUTHOR]

• Reaction distribution of electrodes for lithium-ion batteries was investigated. • Operando Raman observations were conducted for graphite composite electrodes. • Structural changes on the outer and inner sides of electrodes were compared. • The results were correlated with the thicknesses and densities of the electrodes. Understanding the mechanisms of inhomogeneous charging and discharging reactions in an electrode is critical to improving the rate capability of lithium-ion batteries. Various methods have been developed to observe the distribution of electrode structure or lithium ions within an electrode; however, most of these methods require large-scale equipment or entail complex procedures. To simplify reaction distribution measurements within electrodes, this study developed specially designed cells and conducted operando observations of reaction distribution in graphite composite electrodes using Raman spectroscopy. Behaviors on both the electrolyte and current collector sides of the electrodes were compared, and electrodes of various densities and thicknesses were examined. For electrodes with low density, the changes in graphite structure were almost simultaneous on the electrolyte and current collector sides and were hardly dependent on the electrode thickness. In contrast, the changes in electrode structure with increased density were dependent on their thickness. This implies that the ion transportation length is responsible for the reaction distribution in the electrodes when ion channels connecting the current collector and electrolyte sides decrease owing to the increased electrode density. The simple method developed in this study is expected to further contribute to the understanding of the distribution of reactions within graphite composite electrodes. [ABSTRACT FROM AUTHOR]

Li-sulfur batteries represent a promising class of next-generation batteries with high theoretical gravimetric capacity. Moreover, the absence of scarce elements such as nickel or cobalt makes them a sustainable alternative to Li-ion batteries. However, it is well known that the main problem of Li-sulfur batteries is the so-called polysulfide shuttle, which leads to self-discharge, capacity fading and low coulombic efficiency. In recent years, several mitigation strategies have been developed for Li-sulfur batteries to reduce the polysulfide shuttle effect. One promising approach is to covalently bond the sulfur to a polymer backbone. A well-known class of materials is sulfurized poly(acrylonitrile) (SPAN), for which long cycle life and high specific capacities have been reported. In this work, we present a novel continuum model for SPAN electrodes and demonstrate its application in Li-SPAN batteries. Within our simulation framework we include both red/ox reactions of covalently sulfur on PAN as well as transport and reactions of polysulfides in the solution. By combining simulations and experimental data we analyze the discharge mechanism and provide guidelines for electrode design. [Display omitted] • Continuum model of a Li-SPAN battery is presented for the first time. • Simulation results are compared to and in agreement with experimental data. • The model is able to describe the discharge mechanism of the SPAN material. • Transport in the electrolyte is limiting cell performance for thicker electrode with higher cell energy density. [ABSTRACT FROM AUTHOR]

Understanding Li-ion transport at the solid | solid interface is crucial to improving the performance of all-solid-state Li-ion batteries. Electrochemical four-electrode cells have been widely used for electrochemical measurements of ion transports at liquid | liquid and solid | liquid interfaces. However, there is no report of the application to the Li-ion transport at the solid | solid interface, and the electrochemistry of Li-ion transport at the solid | solid interface has not been understood well. In this study, we develop an all-solid-state electrochemical four-electrode cell and investigate the Li-ion transports at the interfaces between two sulfide solid electrolytes. The Li-ion transport resistances at the solid | solid interfaces are successfully evaluated by AC impedance measurement. The activation energy of the Li-ion transports at the solid | solid interfaces is similar to that of the Li-ion transports in the solid electrolytes with lower ionic conductivities. [ABSTRACT FROM AUTHOR]

Phosphonium cation-based ionic liquids (phosphonium ILs) have several advantages for electrochemical device applications compared with ammonium cation-based ionic liquids because of their unique features, such as higher ionic conductivity and a larger electrochemical potential window. In this study, we prepared various phosphonium ILs with different substituents (alkyl, alkyl ether, or allyl) on the cation, and bis(fluorosulfonyl)amide (FSA) or bis(trifluoromethanesulfonyl)amide (TFSA) as the anion. This study describes these phosphonium ILs used as electrolytes for lithium-ion batteries and investigates their performance as typical Li/LiCoO 2 cells. We demonstrate that discharge capacity increases with increasing lithium-ion conductivity determined by electrochemical impedance and pulsed-field gradient nuclear magnetic resonance. A discharging rate test conducted in constant current (CC) mode also displays good high conductivity phosphonium IL electrolyte performance. Furthermore, the difference in cycle performance between FSA-based and TFSA-based phosphonium IL electrolytes is explained in terms of solid electrolyte interphase formation, similar to the performance of other cation-based ILs. [Display omitted] [ABSTRACT FROM AUTHOR]

• The Cu-Sn/nano-SiO 2 composite is fabricated by electrodeposition for the first time. • The Cu-Sn/nano-SiO 2 composite exhibits excellent long cycle performance. • The integrated structure of the composite electrode remains intact after 100 cycles. • The mechanism of electrodeposited Cu-Sn/nano-SiO 2 composite is firstly proposed. Cu-Sn/nano-SiO 2 composite materials are fabricated through electrodeposition process coupled with precise thermal treatment, which employs hexadecyl trimethyl ammonium bromide to guarantee the even distribution of nano-SiO 2 particles within the Cu-Sn alloy framework. The characterization results indicate that integrating nano-SiO 2 into the Cu-Sn matrix effectively prevents active particles from detaching from the copper foil current collector. By adjusting the current density, the electrochemical performance of the Cu-Sn/nano-SiO 2 composite electrode is significantly enhanced. Specifically, the initial charge and discharge specific capacities of the composite electrolyte are approximately 746.6 and 1470.8 mAh/g at 100 mA/g, respectively. Moreover, the cell can still maintain a discharge specific capacity of 358.6 mAh/g after 100 cycles. Furthermore, the cell demonstrates an improved lithium-ion diffusion coefficient of approximately 9.639 × 10–15 cm²/s and a lower transfer resistance of 54.65 Ω. Therefore, a direct approach of fabricating the Cu-Sn/nano-SiO 2 composite electrode with enhanced electrochemical properties may provide valuable guidance for alloy anodes in the energy storage field. Preparation schematic of the Cu-Sn/nano-SiO 2 composite electrodes and the corresponding cycling performance of the assembled coin cells [Display omitted] [ABSTRACT FROM AUTHOR]

• The proposed method can detect lithium plating earlier in the charging process. • Compared with other methods, this method is more sensitive and simple. • Combined with the model, the source of lithium plating signal is analyzed. • The universality of the method is verified by model simulation. Lithium plating is one of the most severe problems threatening the durability and safety of lithium-ion batteries. Therefore, accurate detection of lithium plating is crucial for the health management and charging control of lithium-ion batteries. In this paper, an impedance-based method is proposed to detect lithium plating of lithium-ion battery by comparing the normalized charing internal resistance profiles. After verifying that the model-based method is effective and feasible, it was used to analyze the reason and internal mechanism of the detection signal compared with the more frequently used lithium plating detection procedures today. The proposed detection method is more sensitive and accurate and expected to detect lithium plating in real-time during the charging process. Finally, the model showed that the method remained effective and reliable for lithium plating detection when the charging conditions changed. This paper, through the analysis, simulation, and experimental verification of online lithium plating detection method based on charging internal resistance, provides innovative ideas for the subsequent development of lithium plating detection and stimulates potential technologies for future development. [ABSTRACT FROM AUTHOR]

We use a facile high-temperature solid-phase method to coat a layer of Ni-rich ternary material (LiNi 0.8 Co 0.1 Mn 0.1 O 2) on the surface of lithium iron phosphate. This active coating greatly improves the intrinsic conductivity of LiFePO 4. Compared to the conventional carbon material cladding, since this cladding layer is electrochemically active, the problem of decreasing the proportion of active material due to the addition of a cladding layer can be avoided to a certain extent. Compared with the samples capped with conventional organic carbon source (151.2 mAh g−1) and inorganic carbon source (155.9 mAh g−1) at 0.2 C, the discharge specific capacity was as high as 165.7 mAh g−1. Capacity retention after 200 cycles is up to 98 %, which is much higher than that of glucose and graphene oxide (GO)-coated samples (95.9 %, 96.6 %). Even when charging and discharging cycles are performed at different multipliers (2C and 10C), the retention rate remains higher than the latter. [ABSTRACT FROM AUTHOR]

• The amidoxime modified polymer of intrinsic microporosity (AOPIM-1) is designed as a filler. • The AOPIM-1 urges PEO electrolyte to get high mechanical strength. • A stable interface between electrode and electrolyte is obtained. • The LiFePO 4 /Li battery exhibits a long-term cycling stability. • The composite electrolyte can steadily recycle in high-voltage atmosphere. Poly (ethylene oxide) (PEO)-based solid polymer electrolytes (SPEs) have attracted intensive attention in recent years due to the high salt solubility and flexibility in lithium-ion batteries (LIBs). However, the application of such solid electrolytes is severely limited owing to low ionic conductivity and poor mechanical strength. The integration of the amidoxime modified polymer of intrinsic microporosity (AOPIM-1) with PEO electrolyte is designed to attain a novel composite solid electrolyte (CPE). At an optimal doping amount of 1.5 %, the effects of AOPIM-1 on the physicochemical and electrochemical properties of CPE are investigated and discussed. Because of the electrostatic action between Li+ and polar amidoxime groups, more rapid Li+ transport could promote the electrochemical performances of CPE. The liquid-free CPE-1.5 % AOPIM-1 could show a satisfactory ionic conductivity (1.18 × 10−3 S cm−1 at 60 °C). The rigid skeleton of AOPIM-1 endows the high mechanical strength of CPE to inhibit the growth of lithium dendrites for favorable interfacial stability with lithium metal. The LiFePO 4 batteries combined with CPE-1.5% AOPIM-1 can supply 78.4 % capacity retention after 750 cycles at 0.5 C and 88.7 % capacity retention after 200 cycles at 1.0 C (60 °C). The use of AOPIM-1 would raise the oxidation potential of CPE, exhibiting a superior cycling stability (77.8 % capacity retention after 200 cycles at 0.5 C) in high-voltage LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM523)/Li cells. This research can provide novel insights to achieve the much enhanced performance of composite electrolytes. [Display omitted] [ABSTRACT FROM AUTHOR]

• Variations of battery expansion force during charge and discharge are quantified. • Variation patterns of expansion force during thermal runaway are compared. • Time series of expansion force versus T, V during thermal runaway are compared. • Feasibility of expansion force and its growth rate as warning signals are verified. In recent years, lithium-ion batteries have been widely adopted by the automotive industry because of their high energy density and environmentally friendly nature. However, the thermal runaway of lithium-ion batteries poses a significant risk of explosions, fires, and other hazards. Therefore, it is crucial to have effective thermal runaway warning systems to enhance the safety of battery applications. Currently, the main warning signals for thermal runaway include voltage, temperature, internal resistance, gas composition, and smoke. However, these signals suffer from issues such as low accuracy and delayed warnings. During thermal runaway, voltage, temperature, internal resistance, expansion force, and smoke undergo abnormal changes at varying times, with expansion force abnormalities detected notably earlier. To improve the accuracy and timeliness of thermal runaway warnings, it is crucial to quantitatively measure the changes in expansion force and signal progression related to voltage and temperature during thermal runaway through experiments. In this study, the 51 Ah LiNi 0.5 Co 0.2 Mn 0.3 O 2 /Graphite commercialized Li-ion batteries were used to study the characteristics of thermal runaway expansion force at different states of charge (SOCs) (25%, 50%, 100%, 110%). The variation patterns of thermal runaway parameters such as temperature, voltage, internal resistance, expansion force, and flame were analyzed. The test results indicate that the expansion force in lithium-ion batteries is related to the lithium-ion concentration in the negative electrode and remains below 2000 N with a rate of change under 1.8 N/s during normal charging and discharging. However, it surpasses 5000 N for thermal runaway. This paper suggests using a 2000 N expansion force as an early warning signal for thermal runaway, which precedes approximately 11.6 s earlier than the voltage signal and 10 s earlier than the internal resistance and temperature signals. Adopting a 1.8 N/s growth rate can further enhance warning time, issuing alerts 134.2 s before thermal runaway. Research confirms that using expansion force as the main signal significantly improves warning time and alarm accuracy in lithium-ion battery safety. [ABSTRACT FROM AUTHOR]