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It has been well recognized that introducing secondary porous networks (SPNs) into the electrodes can effectively improve the electrochemical performance of lithium-ion batteries (LIBs), especially under fast-charging operations. However, the process complexity and high cost limit the commercial success of advanced electrodes with SPNs. To address this issue, we developed a facile screen-printing process to produce structured graphite electrodes with SPNs. The experimental results demonstrated that, by tuning the diameter and center-to-center (C2C) distance of emulsion dots on the stencil screen, the pore diameters and C2C pore distances of SPNs in screen-printed electrodes can be precisely controlled in the range of 100 μm to 1 mm and 100 μm to 3 mm respectively. In addition, the SPNs with hexagonal and square-shape pore alignments have also been imprinted onto the electrode coatings through adjusting the patterns of screen stencils. Used as anodes, the printed graphite electrodes demonstrated significantly reduced overpotential and voltage fluctuation under fast-charging operations from 2C to 6C. Coupled with LiNi 0.6 Mn 0.2 Co 0.2 O 2 (NMC622) cathodes, the full cells with printed graphite anodes exhibited an unprecedently stable performance with almost no capacity decay up to 170 cycles when charged to 80 % SOC at 2C. Observations from electron microscopy showed plated lithium undetectable at the surface of printed graphite electrodes after numerous cycles. The electrochemical analysis on the voltage evolution during the cell rest period indicated the significantly delayed onset of lithium plating in the presence of printed graphite electrodes. All these results suggest that the significantly improved cell performance is associated with the shortened Li-ion diffusion distance, reduced polarization and suppressed Li plating in the printed electrodes with patterned SPNs. [ABSTRACT FROM AUTHOR]

Physics-based electrochemical battery models are highly valuable tools in understanding the internal state of batteries and simulating their behaviour. These models elucidate the fundamental electrochemical processes involved, such as ion diffusion, and provide information about the parameters affected by electrode kinetics and electrolyte dynamics. This information is crucial for improving battery efficiency and reliability, as well as for computing voltage and state of charge profiles without the need for experimentation. Furthermore, these models assist in optimizing battery design and management, thereby accelerating the development of Sodium-ion batteries (SIBs). A range of models exists for different types of batteries, from lithium-ion batteries (LIBs) to SIBs. These models vary in terms of complexity, accuracy, and computational time. This study investigates various modelling methods, encompassing detailed Doyle–Fuller–Newman Model (DFN) models that offer extensive insights, as well as simplified reduced-order models such as the Single Particle Model (SPM). These reduced-order models strike a balance between computational efficiency and precision, which is essential for real-time control of SIB behaviour under various operating conditions. Furthermore, we examine the applicability of these models in practical applications, considering their advantages and limitations. • Comprehensive evaluation of DFN, SPMe, and SPM models for sodium-ion batteries. • Insights into ion diffusion and electrode kinetics from physics-based battery models. • Analysis of model trade-offs between computational efficiency and accuracy. [ABSTRACT FROM AUTHOR]

• First-principles calculations are conducted to uncover the molecular mechanisms of CPA additives. • EMPA oxidizes before the solvent in the electrolyte while also scavenging HF and H 2 O. • Dimerization of asymmetric EMPA is thermodynamically very favorable. • Calculated close packing distances show that asymmetric EMPA forms close dimers. • Polymer dimer analysis is useful for understanding the mechanisms involved in developing robust and thin CEI-forming additives. High-voltage lithium-ion batteries (LIBs) have attracted increasing attention for their high energy density. However, at high voltages, cathode degradation and electrolyte decomposition trigger parasitic side reactions that deteriorate battery cycle performance. These issues have been addressed through various studies on cathode‒electrolyte interphase (CEI)-forming additives. In particular, 2-ethylmethylamino-1,3,2-dioxaphospholane 2-oxide (EMPA), a cyclophosphamide (CPA) CEI-forming additive, has shown excellent capacity retention and battery cycle performance at high voltages when added at only 0.5 vol % in LIB systems. However, the molecular-level understanding of CPA additives remains limited. Here, our first-principles calculations reveal that EMPA oxidizes before the solvent in the electrolyte while also scavenging HF and H 2 O. Specifically, calculations of the dimerization of asymmetric EMPA trimers, represented by two identical [(EMPA) 3 OH] species forming a [(EMPA) 3 OH] 2 dimer, imply that after oxidation these two identical EMPA polymers bind very strongly and in very close proximity. This was due to the favorable electrostatic interactions with the more widely distributed polar surface in EMPA, in addition to the small number of carbons in the alkyl groups of the amine moiety in CPA. We suggest that the asymmetry in the alkyl groups of the amine moiety in CPA is closely related to the excellent CEI formation observed in the experimental results. [Display omitted] [ABSTRACT FROM AUTHOR]

• A new cyano-functional lithium salt (Li-FBCSI) was synthesized and integrated into poly(ethylene oxide) (PEO)-based solid-state polymer electrolytes (SPEs). • Defective UiO-66 modified SPEs exhibit high ionic conductivity, a wide electrochemical stabilization window, and an improved Li+ transference number. • The assembled all-solid-state LiFePO 4 battery delivered an initial discharge capacity of 130 mA·h·g-1 at 60 °C, and maintained a discharge capacity of 114.2 mA·h·g-1 after 100 cycles. • The excellent electrochemical performance of all-solid-state LiFePO 4 battery is attributed to defective UiO-66, which offers open metal sites for anchoring FBCSI anions, thereby facilitating a rapid Li+ transport. Solid polymer electrolytes (SPEs) can effectively reduce the safety hazards associated with traditional liquid electrolytes due to their excellent thermal and mechanical stability. However, the low ionic conductivity of SPEs at room temperature and their poor interfacial stability have hindered their broader applications. Herein, we have designed and synthesized of a cyano-functional lithium salt, named Li-FBCSI, and further prepared poly(ethylene oxide) (PEO)-based polymer electrolytes composited with defective UiO-66 nanoparticles using a solution casting approach. The as-prepared defective UiO-66 nanoparticles decorated SPEs exhibit high ionic conductivity (2.19 × 10–4 S·cm-1 at 60 °C), a wide electrochemical stabilization window (5.39 V, vs Li+/Li), and an improved Li+ transference number (0.44). On the contrary, SPEs without the use of defective UiO-66 nanoparticles as fillers exhibit an ionic conductivity of 1.03 × 10–4 S·cm-1 at 60 °C, and the electrochemical stabilization window decreased to 5.16 V. The assembled all-solid-state LiFePO 4 battery delivered an initial discharge capacity of 130 mA·h·g-1 at 60 °C, and maintained a discharge capacity of 114.2 mA·h·g-1 after 100 cycles. The excellent electrochemical performance of all-solid-state LiFePO 4 battery is mainly attributed to the Li-FBCSI/ PEO/UiO-66 composites, where the defective UiO-66 offers a significant number open metal sites for anchoring FBCSI anions, thereby facilitating a rapid Li+ transport. Our work presents a simple and effective route for preparing MOF-decorated SPEs for high-performance all-solid-state lithium-ion batteries. [Display omitted] [ABSTRACT FROM AUTHOR]

• Square wave electrophoretic deposition enables coatings from aqueous suspensions. • 40KHz frequency results in higher deposition rate and higher content of carbon. • Specific capacity of the LTO/Li cells are close to commercial. Electrophoretic deposition (EPD), while being a scientifically interesting technique due to its inherent versatility, has only limited success in industrial applications. This is partly due to the need to employ expensive and potentially hazardous organic solvents in traditional suspensions. Recently, a significant effort has been focused on the use of aqueous systems and AC-EPD approaches. In this article we present a study and characterization of square-wave electrophoretic deposition at different frequencies of the lithium titanate water-based suspension for application in lithium-ion batteries. We have found that the mass of the deposit linearly increases with time. This reveals that depletion zones are less prone to form in an alternating field, hence enabling formation of homogeneous films and diminishing a growth in bath resistance as compared to DC mode. The EPD performed at critical frequency of 40 kHz results in higher content of carbon co-deposited with LTO, improved capacity and power capability and of Li/LTO cells. [Display omitted] [ABSTRACT FROM AUTHOR]

• A simple, safe, solvent-free dry method is proposed to prepare Si@PC. • Moderately developed pores enhance Si expansion tolerance and electrode stability. • Excessive porosity weakens mechanical strength, leading to electrode failure. • Optimized Si@PC anode achieves 847 mAh g-1 after 500 cycles with 74.4% retention. Silicon-porous carbon composites (Si@PC) are considered promising candidates for next-generation anodes in lithium-ion batteries (LIBs). However, the intrinsic relationship between the pore structure of Si@PC and its electrochemical performance remains largely unexplored. Additionally, fabricating high-performance Si@PC typically involves complex processes, significant risks, and extensive solvent use. This study proposes a simple, safe, solvent-free dry method to prepare Si@PC, using Si nanoparticles as the Si source, (NH 4) 2 SO 4 as the pore-forming agent, and pitch as the porous carbon precursor, through a one-step carbonization process. Through the results of mechanical performance, the relationship between the degree of pore development and electrochemical performance of Si@PC is investigated. We find that pore development is not positively correlated with electrochemical stability. Moderately developed pores effectively alleviate Si's volume expansion, maintaining structural integrity and electrochemical stability of the electrode. However, excessively developed pores significantly reduce mechanical strength, leading to electrode pulverization and rapid performance decay during cycling, even underperforming non-porous electrodes. The optimized Si@PC anode retains a high specific capacity of 847 mAh g-1 after 500 cycles at 1.0 C, with a retention of 74.4%. This study offers guidance on optimizing Si@PC electrode structures by balancing pore development and mechanical strength. [Display omitted] [ABSTRACT FROM AUTHOR]

• Distinct electro-thermal characteristics of semi-solid-state batteries compared to liquid batteries. • Introduction of a new electro-thermal model for better thermal response predictions. • Higher internal resistance in semi-solid-state batteries, especially at extreme SOC levels. • Irreversible heat generation is the dominant factor in semi-solid-state batteries. Solid-state batteries are increasingly seen as the future of battery development due to their higher energy density and improved thermal stability. While all-solid-state batteries are gaining attention, semi-solid-state batteries, serving as a bridge between liquid batteries and all-solid-state ones, have not been extensively studied. This article delves into the electro-thermal characteristics of a commercial semi-solid-state battery through various experiments like HPPC, adiabatic calorimetry, and entropy heat coefficient analysis. It compares the internal resistance traits with those of a similar liquid lithium-ion pouch battery. By integrating a second-order RC equivalent circuit model with the Bernardi heat generation model, a comprehensive electro-thermal coupled model for semi-solid-state lithium-ion batteries is established. This model considers parameters such as temperature, state of charge, and charge/discharge rates to accurately predict terminal voltage, reversible and irreversible heat generation power, and temperature variations. The study demonstrates a high prediction accuracy with the maximum root mean square error of 0.043 V for terminal voltage, 0.67 W for heat generation power, and 0.56 °C for temperature. Following the validation of the model, an analysis is conducted to dissect the different components contributing to battery heat generation. The insights gained from the characteristics analysis and electro-thermal model of semi-solid-state batteries can be valuable for enhancing the control strategies of battery management systems in the future. [ABSTRACT FROM AUTHOR]

Additives play a pivotal role in enhancing lithium-ion battery performance, safety, and lifespan by mitigating electrolyte degradation, improving ion transport, and stabilizing the SEI layer to address issues of thermal instability and dendritic growth. This study evaluates Ethyl-4-toluene sulfonate (ETS) as a promising cyclic additive for improving lithium-ion battery efficiency and longevity. Through a combination of theoretical and experimental analyses, we assessed the stability and electrochemical properties of SEI layers with ETS integration. Our results show that ETS strongly interacts with electrode surfaces, fostering stable SEI formation and substantially reducing electrolyte oxidation. Highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy analyses indicate that ETS oxidizes prior to carbonate solvents, contributing to enhanced structural integrity. Adsorption energy calculations further reveal that ETS adheres to electrode surfaces more effectively than traditional electrolytes, reinforcing SEI stability. Experimental evaluations using FT-IR, XRD, and Rietveld refinement characterized electrode structure changes pre- and post-cycling. Testing electrolytes composed of ethylene carbonate (EC), dimethyl carbonate (DMC), and LiPF 6 with varied ETS concentrations, we found that the sample with 0.7 % ETS exhibited optimal stability, achieving a high capacity of 1609.559 mAh.g⁻¹ over 400 cycles. SEM and impedance measurements confirmed substantial improvements in electrode structure and reduced resistance. The ETS-free electrolyte retained only 74.08 % capacity after 400 cycles and failed after 610 cycles, whereas the 0.7 % ETS sample maintained 90.55 % capacity and lasted approximately 920 cycles. These findings underscore the potential of ETS to enhance SEI formation, prevent electrolyte degradation, and improve battery performance, positioning ETS as a valuable additive for advanced lithium-ion batteries. [Display omitted] [ABSTRACT FROM AUTHOR]

• An electrochemical thermal aging coupling model closer to the actual operating conditions of cell is developed. • The fast charging performance of the cell is comprehensively evaluated by charging capability and anti-aging capability. • The growth rate of SEI film varies at different stages of a single cycle. • The sensibility of heat generation sources to operating temperature and charging rate varies. Increasing the operational temperature and charging rate can expedite the fast charging process of lithium-ion batteries, but these enhancements also accelerate the formation of solid-electrolyte interfaces (SEI) and heighten the risk of lithium plating, thereby accelerating cell aging. To explore the influence mechanisms of operating temperature and charging rate on fast charging performance, this paper develops and validates an electrochemical-thermal coupling model that incorporates polarization, heat generation, and side reactions. This model is based on extensive cell charging rate testing and is employed to numerically investigate the impacts of operating temperature and charging rate on fast charging performance and heat generation under both isothermal and non-isothermal conditions. Metrics such as charging capability and anti-aging capacity are utilized in this analysis. Our findings indicate that an increase in operating temperature significantly enhances the cell's charging capacity, with the primary factor of capacity loss shifting from lithium plating to SEI growth. We identify an optimal charging temperature that minimizes capacity loss due to SEI formation. As the charging rate increases, while the cell's charging capacity improves, the risk of lithium plating rises and the SEI growth rate accelerates, although the reduced charging duration mitigates the overall capacity loss. Under consistent operating conditions, the SEI growth rate varies across charging, resting, and discharging phases. Furthermore, operating temperature and charging rate differentially impact the heat sources of various internal reactions within the cell, leading to an increase in cell temperature and thus affecting fast charging performance. Notably, a higher charging rate not only shortens the charging time but also leverages the generated heat to enhance charging capability while reducing capacity loss associated with side reactions. The results of this study will contribute to the development of more efficient and safer fast charging strategies. [ABSTRACT FROM AUTHOR]

Graphene as conductive additives for enhancing the electrochemical performance of commercial cathode materials (e.g., LiFePO 4 , LiCoO 2 , and LiMn 2 O 4) in advanced Li-ion batteries (LIBs) has attracted great attention in recent years. However, the LiFePO 4 and LiCoO 2 electrodes usually show a poor rate capability when using graphene as the conductive additive, since its planar structure hinders ion transmission. Herein, a variety of reduced graphene oxides (rGO-x) have been successfully prepared using the modified Hummer's method followed by calcination. The results show that due to a large specific area and moderate defect density, rGO-5 can ensure good enough interfacial contact between active material particles and collector, thus maintaining fast electron/ion transportation. It has been found that LiFePO 4 and LiCoO 2 electrodes exhibit good lithium storage properties of 160.95 and 139.41 mA h g-1 at a rate of 0.1 C when rGO-5 is utilized as a conductivity additive. Meanwhile, combined with the electrochemical impedance and kinetic exploration, it can be seen that the LiFePO 4 and LiCoO 2 electrodes demonstrate a high Li+ diffusion coefficient (D Li+) of 6.7 × 10–14 cm2 s-1 and 4.3 × 10–13 cm2 s-1, respectively. Therefore, this research sheds new light on the practical utilization of rGO additives in high-performance lithium-ion batteries. [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]

• Conductivity enhancement by co-solvents is strongly correlated to Li coordination. • Interplay of volume fluxes of all constituents is crucial for Li transference. • Bulky co-solvents are less beneficial due to large volume flux. • Size and coordination ability of co-solvents needs to be balanced. In order to improve the ion conducting properties of poly(ethylene oxide) (PEO/PEG)-based electrolytes for application in lithium ion batteries, plasticization of the polymer network with low molecular weight co-solvents can be a viable and easy solution. This study provides guidelines for promising structures by screening a range of co-solvents including 15-crown-5 (15C5), tetra- (G4) and diglyme (G2), sulfolane (SL), dimethyl sulfoxide (DMSO), dimethyl- formamide (DMF) and propylene (PC) and vinylene carbonate (VC), each of them investigated in a mixture of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and PEO ([Li]/[EO] = 0.25). Regarding the generally observed conductivity enhancement, a major contribution arises from reduced Li-anion correlations in case of strongly Li-coordinating solvents. For the four most promising co-solvents in-depth transport studies are performed by electrophoretic NMR, determining not only cation and anion migration, but even chain and co-solvent migrational volume fluxes, which prove to play a crucial role. In contrast to the bulky and strongly coordinating co-solvents 15C5 and G4, the smaller and more weakly coordinating co-solvents DMSO and DMF can better maintain the beneficial effects of a high salt concentration. Overall, co-solvent addition has beneficial effects on salt dissociation and diffusion, but it reduces the Li+ transference number based on a reduction of a chain-supported cation drift. This contrast is rationalized in the picture of an anion-driven volume flux of the chains, which aids the lithium transference, but is reduced upon co-solvent addition. Thus, the nature and amount of co-solvents in PEO-based electrolytes requires careful balancing of these opposing trends. [Display omitted] [ABSTRACT FROM AUTHOR]

• PAA coating enhances flexibility, conductivity, and SEI stabilization for Si anodes. • Lithium diffusion and charge transfer were improved with PAA-modified Si electrodes. • PAA@Si shows potential for scalable, high-performance lithium-ion battery applications. • PAA@Si anodes retain 56 % capacity after 300 cycles, improving cycling stability. The integration of nanomaterials holds great promise for enhancing the performance of lithium-ion batteries (LIBs). Among these, nano-silicon (Si) stands out for its high theoretical capacity, but suffers from significant volume expansion during lithiation/delithiation cycles, leading to rapid capacity fading and electrode degradation. To address this challenge, poly (acrylic acid) (PAA) emerges as a promising candidate for surface modification of nano-silicon due to its ability to form a stable and flexible polymer layer. This manuscript investigates the synthesis and characterization of poly (acrylic acid)-modified nano-silicon (PAA@Si) as an electrode material for LIBs. The PAA modification not only mitigates the volume expansion of Si nanoparticles but also provides additional functionalities such as enhanced electronic conductivity and improved electrolyte compatibility. It is observed that the capacity retention of the PAA@Si anode is 56 % after 300 cycles compared to the silicon anode. Electrochemical performance evaluations demonstrate that PAA@Si electrodes exhibit superior cycling stability and rate capability compared to pristine Si electrodes. Furthermore, insights into the structure-property relationships elucidate the mechanisms underlying the enhanced battery performance. The findings presented herein highlight the potential of PAA-modified nano-silicon as a viable candidate for next-generation LIBs with enhanced energy storage and longevity. [Display omitted] [ABSTRACT FROM AUTHOR]

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]

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]

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]

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]