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Lithium-ion batteries (LIBs) has extensively utilized in electric vehicles and portable electronics due to their high energy density and prolonged lifespan. However, the current commercial LIBs are plagued by relatively low energy density. High-entropy materials with multiple components have emerged as an efficient strategic approach for developing novel materials that effectively improve the overall performance of LIBs. This article provides a comprehensive review the recent advancements in rational design of innovative high-entropy materials for LIBs, as well as the exceptional lithium ion storage mechanism for high-entropy electrodes and considerable ionic conductivity for high-entropy electrolytes. This review also analyses the prominent effects of individual components on the high-entropy materials' exceptional capacity, considerable structural stability, rapid lithium ion diffusion, and excellent ionic conductivity. Furthermore, this review presents the synthesis methods and their influence on the morphology and properties of high-entropy materials. Ultimately, the remaining challenges and future research directions are outlined, aimed at developing more effective high-entropy materials and improving the overall electrochemical performance of LIBs. [ABSTRACT FROM AUTHOR]

• Pyrolysis combined with ball milling is proposed to upcycle SG from retired LIBs. • Pyrolysis at 500 °C leads to about 82.2 % PVDF dissociation in TG. • Ball milling assisted by urea produces abundant graphite flakes at the edge of MG. • High purity and unique edge structural features of MG result in exceptional capacity. Vast quantities of anode graphite from waste lithium ion batteries (LIBs), as a type of underrated urban mine, has enormous potential to be exploited for resource recovery. Herein, we propose a benign process integrating low-temperature pyrolysis and mechanochemical techniques to upcycle spent graphite (SG) from end-of-life LIBs. Pyrolysis at 500 °C leads to about 82.2 % PVDF dissociation in thermal treated graphite (TG). Solid-phase exfoliation via ball milling assisted by urea successfully produces abundant graphite flakes and a small amount of monolayer graphene nanosheet at the edge of mechanochemically processed graphite (MG). Subsequent rinsing removes the residual LiF salts. High purity and unique edge structural features of the as-prepared MG offer more active sites and storage reservoir for intercalation and de-intercalation of lithium ions, resulting in enhanced lithium-ion diffusion kinetics, excellent reversible specific capacity and desirable rate capability. Inspiringly, MG exhibits a remarkably enhanced initial specific charge capacity of 521.3 mAh g−1 during the first charge–discharge, and only declines from 569.9 mAh g−1 to 538 mAh g−1 with slight attenuation after 50 consecutive cycles at 0.1 A/g, indicating satisfactory cycle stability. Additionally, the purification and reconstruction mechanism for MG have been illustrated in detail. This study offers a green strategy to reconstruct and upgrade anode graphite from LIBs, which can realize sustainable waste management. [ABSTRACT FROM AUTHOR]

Lithium‐ion batteries have found extensive applications due to their high energy density and low self‐discharge rates, spanning from compact consumer electronics to large‐scale energy storage facilities. Despite their widespread use, challenges such as inherent capacity degradation and the potential for thermal runaway hinder sustainable development. In this study, we introduce a unique approach to synthesize anode materials for lithium‐ion batteries, specifically imidazole‐intercalated cobalt hydroxide. This innovative material significantly enhances the Li+ desolvation/diffusion reaction and flame‐retardant dynamics through complexing and catalytic synergetic effects. The lithium‐ion batteries incorporating these materials demonstrate exceptional performance, boasting an impressive capacity retention of 997.91 mAh g−1 after 500 cycles. This achievement can be attributed to the optimization of the solid electrolyte interphase (SEI) interface engineering, effectively mitigating anode degradation and minimizing electrolyte consumption. Experimental and theoretical calculations validate these improvements. Importantly, imidazole intercalated Co(OH)2 (MI−Co(OH)2) exhibits a remarkable catalytic effect on electrolyte carbonization and the conversion of CO to CO2. This dual action suppresses smoke and reduces toxicity significantly. The presented work introduces a novel approach to realizing high‐performance and safe lithium‐ion batteries, addressing key challenges in the pursuit of sustainable energy solutions. [ABSTRACT FROM AUTHOR]

Lithium‐ion batteries have found extensive applications due to their high energy density and low self‐discharge rates, spanning from compact consumer electronics to large‐scale energy storage facilities. Despite their widespread use, challenges such as inherent capacity degradation and the potential for thermal runaway hinder sustainable development. In this study, we introduce a unique approach to synthesize anode materials for lithium‐ion batteries, specifically imidazole‐intercalated cobalt hydroxide. This innovative material significantly enhances the Li+ desolvation/diffusion reaction and flame‐retardant dynamics through complexing and catalytic synergetic effects. The lithium‐ion batteries incorporating these materials demonstrate exceptional performance, boasting an impressive capacity retention of 997.91 mAh g−1 after 500 cycles. This achievement can be attributed to the optimization of the solid electrolyte interphase (SEI) interface engineering, effectively mitigating anode degradation and minimizing electrolyte consumption. Experimental and theoretical calculations validate these improvements. Importantly, imidazole intercalated Co(OH)2 (MI−Co(OH)2) exhibits a remarkable catalytic effect on electrolyte carbonization and the conversion of CO to CO2. This dual action suppresses smoke and reduces toxicity significantly. The presented work introduces a novel approach to realizing high‐performance and safe lithium‐ion batteries, addressing key challenges in the pursuit of sustainable energy solutions. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) are greatly limited in their practical application because of their poor cycle performance, low conductivity and volume expansion. Herein, molten salts (MSs) FeCl3·6H2O-NMP with low temperature via simple preparation are used as the anode material of LIBs for the first time to break through the bottleneck of LIBs. The good fluidity and high self-healing of FeCl3·6H2O-NMP effectively avoid the collapse and breakage of the structure. Based on this feature, the initial discharge specific capacity reached 770.28 mA h g-1, which was more than twice that of the commercial graphite anode. After 200 cycles at a current density of 100 mA g-1, the specific capacity did not decrease rather it was found to be higher than the initial discharge specific capacity, reaching 867.24 mA h g-1. Besides, the good conductivity of MSs provides convenience for the removal and intercalation of Li+. The active H sites that can combine with lithium ions form LiH and provide capacity for LIBs. Density functional theory (DFT) calculation also provided theoretical proof for the mechanism of LIBs. [ABSTRACT FROM AUTHOR]

LiFePO 4 /Very-few-layer-graphene (LFP/VFLG) composites have been prepared using the sol-gel method for lithium-ion battery cathode. VFLG dominated by 1∼3 layers was obtained from an economical and environmentally benign process. Structural properties of LFP/VFLG composites were studied using Fourier-transform infrared spectra (FTIR) spectroscopy, X-ray diffractometry (XRD), high-resolution transmission electron microscopy (HRTEM) and Raman spectroscopy, while the electrochemical performance was measured using galvanostatic discharge, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) tests. The FTIR analysis confirmed that incorporating VFLG neither affected the chemical structure of LiFePO 4 nor initiated any side reactions during the LiFePO 4 formation reaction. The XRD results showed that LFP/VFLG composites had better lattice parameters, crystallinity, and phase purity than LiFePO 4 without VFLG addition. The Raman spectroscopy analysis indicated that LFP/VFLG composites had a lower disorder in the carbon arrangement. HRTEM results indicated that a VFLG was successfully wrapped around the LFP particle offers a versatile way to enhanced electrochemical performance of LFP/VFLG composites. The galvanostatic discharge profiles showed an enhancing specific discharge capacity of up to 58.3% after incorporating VFLG. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) tests revealed that LFP/VFLG delivered small polarization, low inner resistance, high electrochemical reaction reversibility, and high lithium-ion diffusion coefficient. VFLG is a promising additive to improve the structural and electrochemical properties of the LiFePO 4 cathode of lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Silicon-based material is one of the most promising substitutes for commercial graphite anodes for the next generation lithium-ion batteries due to its extremely high theoretical capacity. However, the huge volume changes during the charging and discharging processes will cause rapid capacity decay and a short cycle life. Developing novel silicon-based materials requires a fundamental understanding of their properties. However, in many cases, the present experiments are incapable of completely mimicking real battery-operation conditions, and detailed information about the electrochemical mechanisms and ion and electron kinetic transport at the electrode/electrolyte interface is still ambiguous due to their complexity. First-principles calculations have become an effective method for predicting and interpreting the characteristics of electrode materials, understanding the electrochemical mechanisms at the atomic scale and delivering rational design strategies for electrode materials. In this review, the first-principles calculations of silicon-based anode materials in recent years, based on different modification strategies, are summarized. First, we introduce the diffusion kinetics of lithium ions in silicon and the mechanism of structure changes during the lithiation process. Then, typical examples of novel Si-based anodes, including 2D nanomaterials, silicide materials and coating materials based on theoretical predictions, are presented. Finally, we provide perspectives and future directions of first-principles calculations on Si-based anodes. [ABSTRACT FROM AUTHOR]

Graphite has been serving as the key anode material of rechargeable Li‐ion batteries, yet is difficultly charged within a quarter hour while maintaining stable electrochemistry. In addition to a defective edge structure that prevents fast Li‐ion entry, the high‐rate performance of graphite could be hampered by co‐intercalation and parasitic reduction of solvent molecules at anode/electrolyte interface. Conventional surface modification by pitch‐derived carbon barely isolates the solvent and electrons, and usually lead to inadequate rate capability to meet practical fast‐charge requirements. Here we show that, by applying a MoOx−MoNx layer onto graphite surface, the interface allows fast Li‐ion diffusion yet blocks solvent access and electron leakage. By regulating interfacial mass and charge transfer, the modified graphite anode delivers a reversible capacity of 340.3 mAh g−1 after 4000 cycles at 6 C, showing promises in building 10‐min‐rechargeable batteries with a long operation life. [ABSTRACT FROM AUTHOR]

Graphite has been serving as the key anode material of rechargeable Li‐ion batteries, yet is difficultly charged within a quarter hour while maintaining stable electrochemistry. In addition to a defective edge structure that prevents fast Li‐ion entry, the high‐rate performance of graphite could be hampered by co‐intercalation and parasitic reduction of solvent molecules at anode/electrolyte interface. Conventional surface modification by pitch‐derived carbon barely isolates the solvent and electrons, and usually lead to inadequate rate capability to meet practical fast‐charge requirements. Here we show that, by applying a MoOx−MoNx layer onto graphite surface, the interface allows fast Li‐ion diffusion yet blocks solvent access and electron leakage. By regulating interfacial mass and charge transfer, the modified graphite anode delivers a reversible capacity of 340.3 mAh g−1 after 4000 cycles at 6 C, showing promises in building 10‐min‐rechargeable batteries with a long operation life. [ABSTRACT FROM AUTHOR]

Three‐dimensional (3D) self‐supported Ge anode is one of the promising candidates to replace the traditional graphite anode material for high‐performance binder‐free lithium‐ion batteries (LIBs). The enlarged surface area and the shortened ions/electrons transporting distance of the 3D electrode would greatly facilitate the rapid transfer of abundant lithium ions during cycling, thus achieve enhanced energy and power density during cycling. Cycle stability of the 3D self‐supported Ge electrode would be improved due to the obtained enough space could effectively accommodate the large volume expansion of the Ge anode. In this review, we first describe the electrochemical properties and Li ions storage mechanism of Ge anode. Moreover, the recent advances in the 3D self‐supported Ge anode architectures design are majorly illustrated and discussed. Challenges and prospects of the 3D self‐supported Ge electrode are finally provided, which shed light on ways to design more reliable 3D Ge‐based electrodes in energy storage systems. [ABSTRACT FROM AUTHOR]

Multiplex sampling, so far mainly used as a tool for S/N ratio improvement in spectroscopic applications and separation techniques, has been investigated here for its potential suitability for time-resolved monitoring where chromatograms of transient signals are recorded at intervals much shorter than the chromatographic runtime. Different designs of multiplex sample introduction were developed and utilized to analyze lithium-ion battery degradation products under normal or abuse conditions to achieve fast and efficient sample introduction. After comprehensive optimization, measurements were performed on two different GC systems, with either barrier discharge ionization detection (BID) or mass spectrometric detection (MS). Three different injector designs were examined, and modifications in the pertinent hardware components and operational conditions used. The shortest achievable sample introduction time was 50 ms with an interval of 6 s. Relative standard deviations were lower than 4% and 10% for the intra- and inter-day repeatability, respectively. The sample introduction system and column head pressure had to be carefully controlled, as this parameter most critically affects the amount of sample introduced and, thus, detector response. The newly developed sample introduction system was successfully used to monitor volatile degradation products of lithium-ion batteries and demonstrated concentration changes over the course of time of the degradation products (e.g., fluoroethane, acetaldehyde and ethane), as well as for solvents from the battery electrolyte like ethyl carbonate. [ABSTRACT FROM AUTHOR]

Electrolyte is critical for transporting lithium‐ion (Li+) in lithium‐ion batteries (LIBs). However, there is no universally applicable principle for designing an optimal electrolyte. In most cases, the design process relies on empirical experiences and is often treated as highly confidential proprietary information. Herein, a solvation structure‐related model for the quantitative design of electrolytes is introduced, focusing on the principles of coordination chemistry. As a paradigmatic example, a high‐voltage electrolyte (i.e., 4.5 V vs anode) aimed at achieving a high energy density and fast charging LIB, which is specifically composed of an emerging, well‐constructed hybrid hard carbon‐silicon/carbon‐based anode, and lithium cobalt oxide cathode, is developed. Not only the functions of each electrolyte component at the molecular scale within the Li+ solvation structure are analyzed but also an interfacial model is introduced to elucidate their relationship with the battery performance. This study represents a pioneering effort in developing a methodology to guide electrolyte design, in which the mutual effects of the Li+ de‐solvation process and solid electrolyte interface (SEI) on the electrode surface are explored concurrently to understand the root cause of superior performance. This innovative approach establishes a new paradigm in electrolyte design, providing valuable insights at the molecular level. [ABSTRACT FROM AUTHOR]

In the field of lithium-ion batteries, the challenges posed by the low melting point and inadequate wettability of conventional polyolefin separators have increased the focus on ceramic-coated separators. This study introduces a highly efficient and stable boehmite/polydopamine/polyethylene (AlOOH-PDA-PE) separator. It is crafted by covalently attaching functionalized nanosized boehmite (γ-AlOOH) whiskers onto polyethylene (PE) surfaces. The presence of a covalent bond increases the stability at the interface, while amino groups on the surface of the separator enhance the infiltration of the electrolyte and facilitate the diffusion of lithium ions. The PE-PDA-AlOOH separator, when used in lithium-ion batteries, achieves a discharge capacity of 126 mAh g−1 at 5 C and retains 97.1% capacity after 400 cycles, indicating superior cycling stability due to its covalently bonded ceramic surface. Thus, covalent interface modification is a promising strategy to prevent delamination of ceramic coatings in separators. [ABSTRACT FROM AUTHOR]

[Display omitted] Lithium cobalt phosphate (LiCoPO 4) has great potential to be developed as a cathode material for lithium-ion batteries (LIBs) due to its structural stability and higher voltage platform with a high theoretical energy density. However, the relatively low diffusion of lithium ions still needs to be improved. In this work, Fe and Zn co-doped LiCoPO 4 : LiCo 0.9-x Fe 0.1 Zn x PO 4 /C is utilized to enhance the battery performance of LiCoPO 4. The electrochemical properties of LiCo 0.85 Fe 0.1 Zn 0.05 PO 4 /C demonstrated an initial capacity of 118 mAh/g, with 93.4 % capacity retention at 1C after 100 cycles, and a good capacity of 87 mAh/g remained under a high current density of 10C. In addition, the diffusion rate of Li ions was investigated, proving the improvement of the materials with doping. The impedance results also showed a smaller resistance of the doped materials. Furthermore, operando X-ray diffraction displayed a good reversibility of the structural transformation, corresponding to cycling stability. This work provided studies of both the electrochemical properties and structural transformation of Fe and Zn co-doped LiCoPO 4 , which showed that 10 % Fe and 5 % Zn co-doping enhanced the electrochemical performance of LiCoPO 4 as a cathode material in LIBs. [ABSTRACT FROM AUTHOR]

The massive volume dilation, unsteady solid electrolyte interphase, and weak conductivity about Si have failed to bring it to practical applications, although its potential capacity is up to 4200 mAh g−1. For solving these problems, novel binary regulated silicon–carbon materials (Si/BPC) were done by a sol–gel procedure combined with single carbonization. Analytical techniques were systematically utilized to examine the effects of element doping at several gradients on morphology, structure and electrochemical properties of composites, thus the optimal content was identified. Si/BPC preserves a discharge specific capacity of 1021.6 mAh g−1 with a coulomb efficiency of 99.27% after 180 cycles at 1000 mA g−1, within the upgrade than single-doped and undoped. In rate test, it has a specific capacity of 1003.2 mAh g−1 at a high current density of 5000 mA g−1, quickly back towards 2838.6 mAh g−1 at 200 mA g−1. The inclusion of B and P elements is linked to the electrochemical characteristics. In the co-doped carbon layers, the synergistic impact of doping B and P accelerates the diffusion kinetics of lithium ions, boosts diffusion rate of Li+, offers low electrochemical impedance (45.75 Ω). This brings more defects to provide transport carriers and induces a substantial amount of electrochemically active sites, which fosters the storage of Li+, thus making silicon material electrochemically more active and potential. [ABSTRACT FROM AUTHOR]

Ru-doping introduces abundant oxygen defects and enlarges interlayer spacing, accelerating the ion and electron transmission of tetragonal phase Nb 2 O 5. [Display omitted] Breaking through the limitations of lithium-ion transmission is imperative for high-power rechargeable batteries. As a promising anode material for fast-charging lithium-ion batteries (LIBs), niobium pentoxide (Nb 2 O 5) has garnered considerable research attention due to its exceptional rate performance, stable lithium storage performance and high safety attributes. Nevertheless, the limited intrinsic conductivity of Nb 2 O 5 , coupled with its structural degradation during the cycling process, imposes constraints on its viability as a commercially viable electrode material. Herein, a ruthenium (Ru) doping method is employed to regulate the oxygen defects and the interlayer spacing of the tetragonal Nb 2 O 5 (M−Nb 2 O 5), offering superior reaction kinetics, higher stability for lithium storage sites and more unobstructed lithium-ion transport channels. Ru-doped Nb 2 O 5 (RNO) manifests excellent electrochemical properties, including remarkable rate capacity (166 mAh/g at 80C), reversible capacity (246.98 mAh/g at 0.5C), improved initial Coulombic efficiency (95.77 % compared to 81.44 % of the pure sample) and cycling stability (maintaining a capacity of 113.5 mAh/g at 10C for 2,000 cycles). The enhancement mechanism of Ru doping on the structural stability and ion transport kinetics in tetragonal Nb 2 O 5 is comprehensively elucidated through diverse electrochemical analyses and in-situ techniques. [ABSTRACT FROM AUTHOR]

High-entropy oxides (HEOs), as a new type of single-phase solid solution with a multi-component design, have shown great potential when they are used as anodes in lithium-ion batteries due to four kinds of effects (thermodynamic high-entropy effect, the structural lattice distortion effect, the kinetic slow diffusion effect, and the electrochemical "cocktail effect"), leading to excellent cycling stability. Although the number of articles on the study of HEO materials has increased significantly, the latest research progress in porous HEO materials in the lithium-ion battery field has not been systematically summarized. This review outlines the progress made in recent years in the design, synthesis, and characterization of porous HEOs and focuses on phase transitions during the cycling process, the role of individual elements, and the lithium storage mechanisms disclosed through some advanced characterization techniques. Finally, the future outlook of HEOs in the energy storage field is presented, providing some guidance for researchers to further improve the design of porous HEOs. [ABSTRACT FROM AUTHOR]

A series of cathode materials, Li[Ni0.6Co0.12Mn0.2Fe0.08]1‐xCrxO2 (x=0, 0.02, 0.04, 0.06), are synthesized via the co‐precipitation method. Structural characterization shows that Cr3+ ions are successfully incorporated into the material structure and evenly dispersed on the surface of crystal particles with other metal elements. The Cr‐doped material shows a well‐defined hexagonal layered structure with less cation mixing, and the increase in interionic and interlayer distances is beneficial for the transport of lithium ions. Compared to the pure NCMFe phase, the cyclic and rate performances of the Cr‐doped quaternary materials have been significantly improved. Among them, the 4Cr material exhibits the best electrochemical performance. The capacity retention rate after 50 charge‐discharge cycles at 0.1 C was increased from 74.83 % to 87.32 %. The rate performance has also increased from 87.6 % to 92.69 %. The Cr‐doped cathode can reduce the charge transfer resistance and enhance the stability of the layered structure, which results in outstanding electrochemical performance of the Cr‐doped cathode. CV and EIS tests were conducted on materials with various Cr doping levels, further confirming that Cr doping can reduce the degree of polarization in electrode materials, enhance charge and discharge reversibility, and reduce the charge transfer resistance of materials. [ABSTRACT FROM AUTHOR]

Transition metal nitride negative electrode materials with a high capacity and electronic conduction are still troubled by the large volume change in the discharging procedure and the low lithium ion diffusion rate. Synthesizing the composite material of F-doped Fe3N and an N-doped porous carbon framework will overcome the foregoing troubles and effectuate a preeminent electrochemical performance. In this study, we created a simple route to obtain the composite of F-doped Fe3N nanoellipsoids and a 3D N-doped porous carbon framework under non-ammonia atmosphere conditions. Integrating the F-doped Fe3N nanoellipsoids with an N-doped porous carbon framework can immensely repress the problem of volume expansion but also substantially elevate the lithium ion diffusion rate. When utilized as a negative electrode for lithium-ion batteries, this composite bespeaks a stellar operational life and rate capability, releasing a tempting capacity of 574 mAh g–1 after 550 cycles at 1.0 A g–1. The results of this study will profoundly promote the evolution and application of transition metal nitrides in batteries. [ABSTRACT FROM AUTHOR]

The development of low‐cost, high‐power lithium‐ion batteries requires durable anode materials that can store and release lithium quickly. Here a mixed phase of H‐Nb2O5 and M‐Nb2O5 (denoted as d‐H,M‐Nb2O5) that demonstrates excellent performance as an anode material for lithium storage is reported. Experimental and computational analyses reveal several salient features of d‐H,M‐Nb2O5. First, the edge‐sharing arrangement between the mixed niobium oxygen polyhedral block structures helps alleviate volume expansion during cycling, thereby enhancing stability and reversibility. Second, the mixed‐phase structure facilitates a continuous pathway for lithium ion adsorption These characteristics allow for sequential transport of lithium ions, enabling fast charging. As a result, the d‐H,M‐Nb2O5 electrode material exhibits a high capacity of 142 mAh g−1 at an ultra‐fast charging rate of 100 C, while maintaining 85% of its initial capacity after 5000 cycles. Moreover, its practical feasibility is established by demonstrating full‐cell performance at a 5 C discharge/charge rate (13 mA cm−2), maintaining 79% of its capacity over 1000 cycles. [ABSTRACT FROM AUTHOR]

Lithium Iron Phosphate (LiFePO4) microstructures have been synthesized using the sol-gel process. One-dimensional (1D) LiFePO4 microstructures were fabricated using tissue paper as a template under different temperatures to form pure phase microstructures. XRD analysis confirmed the single phase nature of orthorhombic olivine-structured LiFePO4 with Pnma space group. SEM analysis authenticated the formation of 1D LiFePO4 microstructures along with some clusters of particles. LiFePO4-multi-walled carbon nanotubes (MWCNT) freestanding sheets were prepared using a tape-casting process. Further, the electrochemical properties of LiFePO4-MWCNT freestanding sheet were analyzed through electrochemical impedance spectroscopy, cyclic voltammetry, and galvanostatic charge-discharge analysis. [ABSTRACT FROM AUTHOR]

Solid polymer electrolytes (SPEs) possessing attractive electrochemical performance are essentially required for lithium-ion batteries (LIBs). Herein, a poly(imidazolium ionic liquid-co-ethylene oxide) (PILEO) is synthesized via a facile one-pot poly-Radziszewski reaction. The incorporated PILEO can reduce the crystallinity of the obtained SPEs, and hence facilitates lithium ion migration. It is demonstrated that the developed PILEO-60 SPE, without adding any plasticizers or inorganic fillers, exhibits a high ionic conductivity of 1.78 × 10−4 S cm−1 at 25 ℃ and a wide electrochemical stability window of 4.9 V (vs. Li/Li+). The assembled LFP/PILEO-60/Li cell possesses a high discharge capacity (140 mAh g−1 at 25 ℃), good cycling performance (90.3% of capacity retention after 100 cycles), and stable coulombic efficiency (99.7%). In combination with the industrially feasible synthetic procedure of PILEO, this work provides a facile and effective strategy for the fabrication of high-performance LIBs. [ABSTRACT FROM AUTHOR]

Silicon (Si) with high specific capacity, abundant reserve, and low cost is a promising replacement for graphite in anodes of next‐generation lithium‐ion batteries (LIBs). However, practical implementation is still hampered by the poor rate performance and short lifespan due to the unstable electrode/electrolyte interface and low ion/electron conductivity. Therefore, design of a stable and high‐conductivity interface for Si anodes is desirable albeit challenging. Herein, a mixed ion/electron conducting interlayer (MIECI) consisting of LiF and Li−Mg alloy is formed in situ from an intermediate MgF2 layer on the surface of the porous Si electrode in the first lithiation step to produce a robust solid electrolyte interface (SEI). The MIECI formation mechanism is investigated by operando Raman scattering, X‐ray diffraction, and Fourier transform infrared spectroscopy. LiF in the MIECI provides high ion conductivity, while the Li−Mg alloy produces fast electron conductivity and high mechanical strength. As a result, the p‐Si@MgF2 anode shows excellent cycling stability with 90% capacity retention after 200 cycles and a superior rate capacity of 70% when the current density is increased from 0.5 to 5.0 A g−1. The novel interfacial modification and engineering strategy has large potential in the design and fabrication of Si anodes for LIBs. [ABSTRACT FROM AUTHOR]

The rationally designed reaction between the GO sheets, Sn2+ ions and GA molecules in mild hydrothermal condition contributes to the formation of an intermediate SnO 2 @GA@RGO sample with a MOF on graphene configuration, which is converted to the final SnO 2 /C/RGO composite with optimized microstructures after thermal treatment. [Display omitted] Tin dioxide (SnO 2) is being investigated as a promising anode material for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). Effectively dispersing small sized SnO 2 crystals in well-designed carbonaceous matrices using eco-friendly materials and simplified methods is an urgent task. Herein, gallic acid (GA) molecules, abundant in plant kingdom, are firstly selected to react with few-layered graphene oxide (GO) in mild hydrothermal condition, and the GA modulated reduced graphene oxide (GA@RGO) supporting skeleton can be obtained. Then Sn-GA metal–organic framework (MOF) domains can be directly engineered on the surface of the GA@RGO sheets with controlled size and improved dispersion. Finally, the well-designed Sn-GA@RGO precursor is converted to the SnO 2 /C/RGO nanocomposite with significantly optimized microstructure. The SnO 2 /C/RGO sample delivers an excellent specific capacity of 823.6 mAh·g−1 after 700 cycles at 1000 mA·g−1 in half-cells and 741.3 mAh·g−1 after 50 cycles at 200 mA·g−1 in full-cells for LIBs, a specific capacity of 370.3 mAh·g−1 after 600 cycles at 200 mA·g−1 in half-cells for SIBs. The sample preparation strategy is rationally established by comprehensively understanding the interactions between GO sheets, Sn2+ ions and GA molecules, and the engineered SnO 2 /C/RGO nanocomposite has good prospects in wider fields. [ABSTRACT FROM AUTHOR]

In this study, 1T phase MoS2 nanosheets were synthesized on the surface of a carbon cloth via a hydrothermal reaction. After heat treatment, the 1T phase MoS2 was transformed into the 2H phase with a better capacity retention performance. As an anode material for lithium-ion batteries, 2H phase MoS2 on the carbon cloth surface delivers a capacity of 1075 mAh g−1 at a current density of 0.1 A g−1 after 50 cycles; while the capacity of the 1T phase MoS2 on the surface of the carbon cloth without heat treatment fades to 528 mAh g−1. The good conductivity of a carbon cloth substrate and the separated MoS2 nanosheets help to increase the capacity of MoS2 and decrease its charge transfer resistance and promote the diffusion of lithium ions in the electrode. [ABSTRACT FROM AUTHOR]

Recently, coordination polymers (CPs) have been frequently reported in the field of energy storage as electrode materials for lithium-ion batteries (LIBs) due to their highly adjustable architectures, which have a variety of active sites and obviously defined lithium transport routes. A well-designed redox-active organic linker with potential active sites for storing lithium ions, pyrazine-2,3-dicarboxylate (H2PDA), was applied for generating CPs by a simple hydrothermal method. When employed as anode materials in LIBs, those two one-dimensional (1D) CPs with an isomorphic composition, [M(PDA)(H2O)2]n (M = Co for Co-PDA and Ni for Ni-PDA), produced outstanding reversible capacities and stable cycling performance. The Co-PDA displays a substantial reversible capacity of 936 mAh g−1 at 200 mA g−1 after 200 cycles, as well as an excellent cycling life at high currents. According to the ex situ characterizations, the high reversible specific capacity of the post-cycled electrodes was found to be a result of both the transition metal ions and the organic ligands, and Co-PDA and Ni-PDA electrode materials show reversible insertion/extraction processes that are accompanied by crystallization to an amorphous state. [ABSTRACT FROM AUTHOR]

To simultaneously reduce the cost of environmental treatment of discarded food waste and the cost of energy storage materials, research on biowaste conversion into energy materials is ongoing. This work employs a solid-state thermally assisted synthesis method, transforming natural eggshell membranes (NEM) into nitrogen-doped carbon. The resulting NEM-coated LFP (NEM@LFP) exhibits enhanced electrical and ionic conductivity that can promote the mobility of electrons and Li-ions on the surface of LFP. To identify the optimal synthesis temperature, the synthesis temperature is set to 600, 700, and 800 °C. The NEM@LFP synthesized at 700 °C (NEM 700@LFP) contains the most pyrrolic nitrogen and has the highest ionic and electrical conductivity. When compared to bare LFP, the specific discharge capacity of the material is increased by approximately 16.6% at a current rate of 0.1 C for 50 cycles. In addition, we introduce innovative data-driven experiments to observe trends and estimate the discharge capacity under various temperatures and cycles. These data-driven results corroborate and support our experimental analysis, highlighting the accuracy of our approach. Our work not only contributes to reducing environmental waste but also advances the development of efficient and eco-friendly energy storage materials. [ABSTRACT FROM AUTHOR]

In this study, a multiphysics model that reproduces the cracking of Si nanoparticle for a battery application was demonstrated. Two types of cracks appear on Si nanoparticle during lithiation. An essential condition for surface crack (SC) nucleation and propagation is a fast charging rate to form a high concentration gradient of lithium ions near the surface. A slower charging rate induces internal cracks (ICs) radiating from the center of the particle. The critical charging rates, at which SC or IC occurs, decrease rapidly with increasing particle radius. This indicates the difficulty of cracking of small nanoparticles, which is in a good agreement with the previous experimental results. Multiple cracks can appear in the particle, especially when the diffusivity is high. These cracks can be combined during the charging process, leading to the fracture or isolation of the particles. Additionally, two different peak stresses and Young's moduli from the literature were used considering their effects on the cracking of Si nanoparticle films. We believe our results provide a guideline for the fabrication and operation of Si nanoparticle-based anodes for lithium ion batteries. [ABSTRACT FROM AUTHOR]

In this investigation, a lithium-free cathode material, Na0.7MnO2.05–Na0.91MnO2, was synthesized by the solid phase method. The intercalation mechanism and partial phase transformation mechanism of NMO600 were clarified by in situ X-ray diffraction and impedance. The design of the heterostructure is favourable for improving the lithium ion storage of NMO600, which can deliver a discharge capacity of 83.12 mA h g−1 at 1 A g−1 and keep 61.71 mA h g−1 after 700 cycles. [ABSTRACT FROM AUTHOR]

2D layered FePS3 is an anode material with high energy density for lithium‐ion batteries. Here, a simple and effective vacuum filtration method is used to successfully synthesize nanocellulose (NC) and FePS3 into a FePS3‐NC electrode with a 3D network structure. Based on the detailed structural characterization, electrochemical testing, and density functional theory, the relationship between NC and FePS3 materials in the lithium storage process is established from the perspective of lithium ions dynamics. The results display that NC can effectively decrease the adsorption energy of FePS3 materials, promote the construction of a 3D network structure, and form flexible FePS3‐NC electrodes. In addition, the migration path of lithium ions in the FePS3‐NC system is more inclined to the Y‐axis, and the migration barrier is also significantly reduced from 0.7714 to 0.4245 eV, which significantly improves the migration speed of lithium ions and the battery capacity. Therefore, the results of this study are conducive to further understand the dynamic mechanism of NC promoting rapid lithium storage in FePS3 materials and can provide good guidance for the study of flexible electrodes. [ABSTRACT FROM AUTHOR]

Graphene encapsulation is an attractive surface‐coating technology that can simultaneously improve the rate capability and cycle stability of nickel‐rich LiNixCoyMn1−x−yO2 (NCM). Here, carbon encapsulation with the addition of polyethylenimine (PEI) and polyhedral oligomeric silsesquioxane (POSS), which can effectively suppress access to and generation of harmful factors in the electrolyte to maximize the rate performance and cycle stability of nickel‐rich NCM, is described. The PEI‐POSS/carbon layer not only facilitates electron and lithium‐ion transport on the NCM surface but also inhibits side reactions with the electrolyte during repeated electrochemical reactions. In addition, it provides mechanical support that suppresses the formation of microcracks related to anisotropic volume change of nickel‐rich NCM secondary particles and inhibits irreversible phase transitions on surface structures by mitigating electrolyte wettability. As a result, PEI‐POSS/carbon‐encapsulated NCM exhibits a higher rate capability (84 mAh g−1 at 5 C) and cycle stability (93.5% for 100 cycles at 1 C) compared with bare NCM (0 mAh g−1 at 5 C and 78.4% for 100 cycles at 1 C). In a cycle test at 45 °C, it achieves a capacity retention of 72.6% for 100 cycles at 1 C, which is a 323% improvement in performance over that of bare NCM (22.5%). [ABSTRACT FROM AUTHOR]

Conversion‐alloying anodes have garnered escalating attention with high theoretical capacity, however, they are seriously hindered by large volume distortion and capacity fading. To counter, structural modification needs more exploration. Herein, advantageous structure and high‐performance are realized in new amorphous PbSb2O6 (PSO‐a) nanosphere via facile instantaneous precipitation induced amorphization; conversion‐alloying mechanism endows it with prominent lithium‐storage capability; nanostructure can shorten ion‐transfer distance and accommodate volume change outside the bulk of PSO‐a; and loosely‐stacked isotropic amorphous structure can enhance kinetics both at electrode/electrolyte interfaces and in the bulk. Volume change is synergistically stabilized from within to outside the bulk, leading to accelerated capacity and cycling. As expected, when employed in half‐cells with 1 m LiPF6 in ethylene carbonate/diethyl carbonate/dimethyl carbonate/fluoroethylene carbonate (3:3:3:1 by mass) as electrolyte, glass microfiber filter as separator, and pure lithium foil as counter electrode, it realizes eminent performance with high specific capacity of 1512.6 mA h g−1 at 0.1 A g−1 and 755.1 mA h g−1 after 1000 cycles at 3 A g−1. To the best of the authors' knowledge, this is the first time PbSb2O6 is utilized as high‐performance anode for lithium‐ion batteries. Furthermore, this facile strategy provides a promising direction for high‐performance amorphous anode material. [ABSTRACT FROM AUTHOR]

Polyelectrolyte solutions have been proposed as a method to improve the efficiency of lithium-ion batteries by increasing the cation transference number because the polymer self-diffusion coefficient is much lower than that of the counterion. However, this is not necessarily true for the polymer mobility. In some cases, negative transference numbers have been reported, which implies that the lithium ions are transporting to the same electrode as the anion, behavior that is often attributed to a binding of counterions to the polyion. We use a simple model where we bind some counterions to the polymer via harmonic springs to investigate this phenomenon. We find that both the number of bound counterions and the strength of their binding alter the transference number, and, in some cases, the transference number is negative. We also investigate how the transference number depends on the Manning parameter, the ratio of the Bjerrum length to charge separation along the chain. By altering the Manning parameter, the transference number can almost be doubled, which suggests that charge spacing could be a way to increase the transference number of polyelectrolyte solutions. [ABSTRACT FROM AUTHOR]

Optimizing the structure of materials has proven to be an efficient solution for improving the electrochemical performance of lithium-ion batteries. In this work, SnO 2 -WS 2 -CNTS (SWC) ternary composites were prepared by hydrothermal and ball milling methods to first obtain SnO 2 -WS 2 mixture, which was then embedded on CNTS to form a special multi-level structure. Due to the special 2D structure of transition metal sulfide WS 2 and CNTS, the de-intercalation speed of lithium ions is greatly increased and the inherent particle aggregation phenomenon of SnO 2 is weakened. The three materials show their advantages while compensating for each other's disadvantages, forming an interesting synergistic effect which results in extremely stable anode materials. At 0.2Ag-1, the capacity of SWC reaches 930.71 mAhg-1 after 100 cycles, and reaches 1043 mAhg-1 after 1000 cycles at 1.0Ag-1. It is worth noting that after multiple cycles, SWC still exhibits an extremely stable state in the SEM image. The above results confirm that the special structure of SWC leads to excellent electrochemical performance, and its simple preparation method makes it a potential leading battery anode material in the future. [ABSTRACT FROM AUTHOR]

Transition metal oxide (TMO) anode materials in lithium‐ion batteries (LIBs) usually suffer from serious volume expansion leading to the pulverization of structures, further giving rise to lower specific capacity and worse cycling stability. Herein, by introducing polyoxometalate (POM) clusters into TMOs and precisely controlling the amount of POMs, the MnZnCuOx‐phosphomolybdic acid hybrid sub‐1 nm nanosheets (MZC‐PMA HSNSs) anode is successfully fabricated, where the special electron rich structure of POMs is conducive to accelerating the migration of lithium ions on the anode to obtain higher specific capacity, and the non‐covalent interactions between POMs and TMOs make the HSNSs possess excellent structural and chemical stability, thus exhibiting outstanding electrochemical performance in LIBs, achieving a high reversible capacity (1157 mAh g−1 at 100 mA g−1) and an admirable long‐term cycling stability at low and high current densities. [ABSTRACT FROM AUTHOR]

Transition metal oxide (TMO) anode materials in lithium‐ion batteries (LIBs) usually suffer from serious volume expansion leading to the pulverization of structures, further giving rise to lower specific capacity and worse cycling stability. Herein, by introducing polyoxometalate (POM) clusters into TMOs and precisely controlling the amount of POMs, the MnZnCuOx‐phosphomolybdic acid hybrid sub‐1 nm nanosheets (MZC‐PMA HSNSs) anode is successfully fabricated, where the special electron rich structure of POMs is conducive to accelerating the migration of lithium ions on the anode to obtain higher specific capacity, and the non‐covalent interactions between POMs and TMOs make the HSNSs possess excellent structural and chemical stability, thus exhibiting outstanding electrochemical performance in LIBs, achieving a high reversible capacity (1157 mAh g−1 at 100 mA g−1) and an admirable long‐term cycling stability at low and high current densities. [ABSTRACT FROM AUTHOR]

Currently, the safety of lithium-ion batteries has attracted much attention. All-solid-state batteries (ASSBs) are promising replacements for liquid-electrolyte lithium-ion batteries due to their high energy density and excellent safety. The choice of electrolyte is the most critical part of ASSBs. Li 7 La 3 Zr 2 O 12 (LLZO)-based solid-state electrolytes (SSEs) render high energy density, wide electrochemical window and high lithium-ion mobility. However, their low lithium-ion conductivity compared with liquid organic electrolytes and rigid interfacial contact at electrode/electrolyte interface mainly hinder the development of LLZO-based ASSBs. Herein, we review recent progress in the area of LLZO-based SSEs by discussing the structure and transport mechanism of lithium (Li)-ions of LLZO. Also, we summarize bottleneck problems and corresponding solutions, providing theoretical basis and technical support for the development of LLZO-based ASSBs. Finally, future prospects of LLZO-based ASSBs are discussed in next-generation energy storage systems. [ABSTRACT FROM AUTHOR]

Coordination polymers (CPs) have attracted greater scientific attention as promising electrode materials for lithium–ion batteries (LIBs) due to their diverse and versatile structural chemistry. This study introduces a croconate-based one-dimensional CP, namely [Fe(C5O5)(H2O)3]n) (referred to as Fe-CP), as an efficient anode material with high-performance characteristics for rechargeable LIBs. The ligand with abundant redox sites coordinating to the transition metal ion endowed the anode material with a remarkable stability in the electrolyte, in addition to high capacity, high-rate capability, and high cycling performance during charging/discharging process. The Fe-CP has a unique chain-based supramolecular structure, setting it apart from other porous three-dimensional molecular materials. The presence of unrestricted channels between the chains facilitates the diffusion of lithium ions in this unique structure. When tested at 100 mA g−1 over a range of voltages between 0.01 and 2.4 V, the Fe-CP anode demonstrated a noteworthy specific capacity of 521 mA h g−1 over 140 cycles. Moreover, the Fe-CP anode material exhibited excellent rate performance and demonstrated favorable cyclability. Following exposure to high charging and discharging rates of 2 A g−1, the anode ultimately regained its initial capability when the current rate was back at 100 mA g−1. [ABSTRACT FROM AUTHOR]

Despite reports of 2D hexagon‐free carbon allotrope anode materials for Li‐ion batteries (LIBs), rate performance enhancement and the practical application of these materials are still major challenges. Here, a novel 2D hexagon‐free carbon allotrope C358X with a unique combination of triangular, pentagonal, octagonal, and decagonal rings is predicted to be a high‐performance anode material in LIBs. The special hexagon‐free configuration enables C358X to introduce many serviceable local strain regions and electron‐deficient regions on the surface. The formation of these regions is very important for enhancing the rate performance of C358X as an anode material for LIBs. C358X has rich adsorption active sites for lithium ions, a lower lithium‐ion diffusion energy barrier of 0.29 eV, a lower average open circuit voltage of 0.31 V, and a high theoretical capacity of 1116.7 mA h g−1. This work may facilitate the utilization of 2D carbon‐based anode materials for cost‐effective LIBs. [ABSTRACT FROM AUTHOR]

Lithium iron silicate (Li 2 FeSiO 4) has high theoretical capacity of 332 mAh∙g-1 upon full extraction of two lithium ions, which is accompanied by high delithiation potential and large volume change. Sulfur modification could be an effective approach for stabilizing Li 2 FeSiO 4 cathodes. A series of carbon-coated Li 2 FeSiO 4 samples were prepared through a hydrothermal and solid-state reaction route at a fixed sucrose content (14 wt% carbon) with varying amounts of sublimed sulfur at 5, 10, 15, 20 and 25 at%. The crystal structures, chemical compositions, microstructures and electrochemical performances of the differently sulfur-modified Li 2 FeSiO 4 /C were systematically investigated. The sulfur-carbon co-modifications and possible existing chemical states of sulfur are discussed in terms of the surface and near-bulk modifications. It was found that all the samples exhibited a monoclinic P 2 1 structural Li 2 FeSiO 4 , while the sulfur contents over 10 at% formed impure phases such as iron sulfides (Fe 1-x S) and lithium metasilicate (Li 2 SiO 3). Furthermore, three types of sulfur states could be found when sulfur and carbon were added simultaneously into Li 2 FeSiO 4. The surfaces were predominated by S–C and S–O–C, indicating the sulfur-carbon co-modification, which would reduce the resistance at the solid/electrode interface (SEI) but increase the charge transfer resistance. Near the bulk, the enhanced interactions between sulfur and iron S–Fe(−S) or sulfur and silicon S–Si(−O) may lead to the formation of possible impurities or oxygen substitution by sulfur. The former is detrimental as the effective sulfur amount is reduced, while the latter is beneficial to improve specific capacity and cycle stability. The overall performance of sulfur-carbon co-modified sample is influenced complicatedly by the sulfur content. The best initial discharge capacity of 152.3 mAh∙g-1 was obtained with 5 at% sulfur modification, while the best overall performance, showing a typical warm-up response and good cycle stability, was observed with 15 at% sulfur modification. [ABSTRACT FROM AUTHOR]

LiNi0.8Co0.1Mn0.1O2 (LNCMO) cathode materials for lithium-ion batteries (LIBs) were prepared by the hydrothermal synthesis of precursors and high-temperature calcination. The effect of precursor hydrothermal synthesis temperature on the microstructures and electrochemical cycling performances of the Ni-rich LNCMO cathode materials were investigated by SEM, XRD, XPS and electrochemical tests. The results showed that the cathode material prepared using the precursor synthesized at a hydrothermal temperature of 220 °C exhibited the best charge/discharge cycle stability, whose specific capacity retention rate reached 81.94% after 50 cycles. Such enhanced cyclic stability of LNCMO was directly related to the small grain size, high crystallinity and structural stability inherited from the precursor obtained at 220 °C. [ABSTRACT FROM AUTHOR]

The nanosized rod‐like LiMnPO4/C cathode materials have successfully in situ synthesized on the surface of flaky structure MnPO4·H2O self‐sacrificing template by the hydrothermal method. The crystal microstructure, micro shape, and electrochemical parameters of LiMnPO4/C are comprehensively studied by XRD, SEM, TEM, and electrochemical measurement methods. The physical and chemical properties analysis confirms that the vinyl acetate solution (VAc‐H2O) with a proper molar ratio is beneficial to generate orthorhombic olivine structure LiMnPO4 with microporous structure and nanorod‐shaped morphology. The electrochemical measurement results indicate that LMP‐X1‐AA sample delivers an initial discharge capacity of 148.1 mAh g−1 at 0.05 C, the capacity retention rate still maintains at 89.2% after 200 cycles. As the discharge rate increases to 1 C, the discharge capacity still remains at 133.4 mAh g−1. The results indicate that the synergistic effect of nanosized rod‐like morphology and conductive carbon coating is beneficial to improving the lithium ions diffusivity and electrochemical properties of LiMnPO4 materials. [ABSTRACT FROM AUTHOR]

In this work, we successfully synthesized porous C/Fe3O4 microspheres by spray pyrolysis at 700ºC with a sodium nitrate (NaNO3) additive in the precursor solution. Furthermore, we studied their electrochemical properties as anode material for Li-ion batteries. The systematic studies by various characterization techniques show that NaNO3 catalyzes the carbonization of sucrose and enhances the crystallization of Fe3O4. Moreover, an aqueous etching can easily remove sodium compounds to produce porous C/Fe3O4 microspheres with large surface areas and pore volumes. The porous C/Fe3O4 microspheres exhibit a reversible capacity of ~780 mAh g–1 in the initial cycles and ~520 mAh g–1 after 30 cycles at a current density of 50 mA g–1. Moreover, a reversible capacity of ~400 mAh g–1 is attainable after 200 cycles, even at a high current density of 500 mA g–1. The wide range of pores produced from the removal of sodium compounds might enable easy electrolyte penetration and facilitate fast Li-ion diffusion, while the N-doping can promote the electronic conductivity of the carbon. These features of porous C/Fe3O4 microspheres led to the improved electrochemical properties of this sample. [ABSTRACT FROM AUTHOR]

[Display omitted] • The yolk-shell NiO/NiSe 2 @C was prepared by carbonization, selenization and oxidation of MOF precursor. • The NiO/NiSe 2 @C exhibits a high specific capacity of 992 mAh g−1 for 600 cycles at 0.2 A g−1. • DFT shows that the heterointerface is formed which enhanced the electrochemical properties. Biphasic or multiphase heterostructures have promising futures in advanced electrode materials for energy-related applications because of their desirable synergistic effects. Here we prepared a rational NiO/NiSe 2 @C heterostructure microsphere through carbonization, selenization, and oxidation using Ni-MOF as a precursor. Electrochemical studies were conducted to examine the Li+ storage characteristics, and density functional theory (DFT) was utilized to comprehend the underlying mechanism. When employed as the anode for LIBs, the NiO/NiSe 2 @C showed a high specific capacity and long-term cyclic stability, with a specific capacity of 992 mAh g−1 for 600 cycles at a current density of 0.2 A g−1. The NiO/NiSe 2 @C exhibits a significantly enhanced lithium-ion diffusion coefficient (D Li + ) value. The DFT results show that an electron-rich area forms at the NiO/NiSe 2 heterointerface, where the metalloid selenium transfers electrons to the oxygen atoms. The lithiation reactions were improved dramatically by redistributing interfacial charges, which can trigger a built-in electric field that dramatically promotes the capacitance contribution of electrode materials, enhances the lithium storage capacity, and accelerates the ion/electron transmission. The rational synthesis of NiO/NiSe 2 @C heterostructure can provide an idea for designing novel heterostructure anode materials. [ABSTRACT FROM AUTHOR]

Salt-concentrated electrolytes are emerging as promising electrolytes for advanced lithium ion batteries (LIBs) that can offer high energy density and improved cycle life. To further improve these electrolytes, it is essential to understand their inherent behavior at various operating conditions of LIBs. Molecular dynamics (MD) simulations are extensively used to study various properties of electrolytes and explain the associated molecular-level phenomena. In this study, we use classical MD simulations to probe the properties of the concentrated electrolyte solution of 3 mol/kg lithium hexafluorophosphate (LiPF6) salt in the propylene carbonate solvent at various temperatures ranging from 298 to 378 K. Our results reveal that the properties such as ionic diffusivity and molar conductivity of a concentrated electrolyte are more sensitive to temperature compared to that of dilute electrolytes. The residence time analysis shows that temperature affects the Li+ ion solvation shell dynamics significantly. The effect of temperature on the transport and dynamic properties needs to be accounted carefully while designing better thermal management systems for batteries made with concentrated electrolytes to garner the advantages of these electrolytes. [ABSTRACT FROM AUTHOR]

Lithium‐rich layered oxides (LROs) are one class of the most competitive high‐capacity cathode materials due to their anion/cation synergistic redox activity. However, excessive oxidation of the oxygen sublattices can induce serious oxygen loss and structural imbalance. Hence, a near‐surface reconfiguration strategy by fluorinating graphene is proposed to precisely regulate Mn3+/Mn4+ and O2−/(O2)n− redox couples for remarkably stabilizing high‐capacity LROs and realizing the simultaneous reduction of the lattice stress, regulation of the Mn metal at a lower charge state, and construction of 3D Li+ diffusion channels. Combining with a highly conductive graphene‐coating layer, the surface oxygen loss, transition metal dissolution, and electrolyte catalytic decomposition are suppressed. Benefiting from this synergy, the modified LROs disclose higher initial Coulombic efficiency and discharge‐specific capacity and improve cyclability compared with pristine LROs. Further, it is revealed that the F− impact becomes easier for the O sites at the lattice interface of C2/m and R3¯$\bar{3}$m to sufficiently buffer lattice stress. Moreover, lithium ions coupled to the doped F atoms at the lattice interface migrate to the Ni‐rich R3¯$\bar{3}$m lattice sites with lower migration energies. This consolidated understanding will open new avenues to regulate reversible oxygen redox of LROs for high‐energy‐density lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

As a typical transition-metal dichalcogenide (TMD), vanadium disulfide (VS 2) is an excellent candidate for cathode material in lithium-ion batteries due to its metallic properties and large interlayer spacing. But they often suffer from low intercalation capacity and sluggish kinetics processes, significantly limiting their practical application. Herein, the cetyltrimethylammonium bromide (CTAB) is employed in the synthesis process to construct the sulfur (S) vacancy in VS 2. The sulfur vacancy could improve its intercalation capacity and kinetics performance. In this structure, the interlayer vacancy defects could provide extra intercalation sites to improve intercalation capacity. It could induce multiple migration paths for lithium-ion (Li+) and electron (e–), enabling fast Li + migration and rapid charge transfer. It also presents favorable rate performance with a high pseudocapacitance contribution during a typical intercalation reaction. The above positive behaviors significantly promote the kinetics performance of VS 2-x as a cathode material for lithium-ion batteries (smaller charge transfer resistance and high Li+ diffusion rate). Finally, this material could provide a high storage capacity of 140 mAh g−1 after 180th and favorable rate performance (55.5 mAh g−1 at 1A g−1). This work could provide a reference for improving TMD's electrochemical performance and expanding their applications. [ABSTRACT FROM AUTHOR]

In this study, LiNi0.8Co0.15Al0.05O2@x%Al2O3-coated cathode materials were regeneratively compounded by the solid-phase sintering method, and their structural characterization and electrochemical performance were systematically analyzed. The regenerated ternary cathode material precursor synthesized by the co-precipitation method was roasted with lithium carbonate at a molar ratio of 1:1.1, and then completely mixed with different contents of aluminum hydroxide. The combined materials were then sintered at 800 °C for 15 h to obtain the regenerated coated cathode material, LiNi0.8Co0.15Al0.05O2@x%Al2O3. The thermogravimetry analysis, phase composition, morphological characteristics, and other tests show that when the added content of aluminum hydroxide is 3%, the regenerated cathode material, LiNi0.8Co0.15Al0.05O2@1.5%Al2O3, exhibits the highest-order layered structure with Al2O3 coating. This material can better inhibit the production of Ni2+, and improve material structure and electrochemical properties. The first charge–discharge efficiency of the battery assembled with this regenerated cathode material is 97.4%, a 50-cycle capacity retention is 93.4%, and a 100-cycle capacity retention is 87.6%. The first charge–discharge efficiency is far better than that of the uncoated regenerated battery. [ABSTRACT FROM AUTHOR]

Binary metal oxide stannate (M2SnO4; M = Zn, Mn, Co, etc.) structures, with their high theoretical capacity, superior lithium storage mechanism and suitable operating voltage, as well as their dual suitability for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs), are strong candidates for next-generation anode materials. However, the capacity deterioration caused by the severe volume expansion problem during the insertion/extraction of lithium or sodium ions during cycling of M2SnO4-based anode materials is difficult to avoid, which greatly affects their practical applications. Strategies often employed by researchers to address this problem include nanosizing the material size, designing suitable structures, doping with carbon materials and heteroatoms, metal–organic framework (MOF) derivation and constructing heterostructures. In this paper, the advantages and issues of M2SnO4-based materials are analyzed, and the strategies to solve the issues are discussed in order to promote the theoretical work and practical application of M2SnO4-based anode materials. [ABSTRACT FROM AUTHOR]

We report an environment-friendly preparation method of rGO-based flexible self-supporting membrane electrodes, combining Co-MOF with graphene oxide and quickly preparing a hollow CoO@rGO flexible self-supporting membrane composite with a porous structure. This unique hollow porous structure can shorten the ion transport path and provide more active sites for lithium ions. The high conductivity of reduced graphene oxide further facilitates the rapid charge transfer and provides sufficient buffer space for the hollow Co-MOF nanocubes during the charging process. We evaluated its electrochemical performance in a coin cell, which showed good rate capability and cycling stability. The CoO@rGO flexible electrode maintains a high specific capacity of 1103 mAh g−1 after 600 cycles at 1.0 A g−1. The high capacity of prepared material is attributed to the synergistic effect of the hollow porous structure and the 3D reduced graphene oxide network. This would be considered a promising new strategy for synthesizing hollow porous-structured rGO-based self-supported flexible electrodes. [ABSTRACT FROM AUTHOR]