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Highlights: A fluorinated zincophilic covalent organic framework (COF-S-F) with sulfonic acid group (-SO3H) is prepared on the surface of Zn anode, which promotes the desolvation of hydrated Zn ions and inhibits the side reactions. The highly electronegative -F group in COF-S-F promotes fast and uniform transport of Zn ions along the interconnected channels, which contributes to the uniform electrodeposition process of Zn metal. Zn@COF-S-F symmetric cell achieves a superior stability of 1,000 h and Zn@COF-S-F|MnO2 cell delivers high specific capacity of 206.8 mAh g−1 at current density of 1.2 A g−1. Achieving a highly robust zinc (Zn) metal anode is extremely important for improving the performance of aqueous Zn-ion batteries (AZIBs) for advancing "carbon neutrality" society, which is hampered by the uncontrollable growth of Zn dendrite and severe side reactions including hydrogen evolution reaction, corrosion, and passivation, etc. Herein, an interlayer containing fluorinated zincophilic covalent organic framework with sulfonic acid groups (COF-S-F) is developed on Zn metal (Zn@COF-S-F) as the artificial solid electrolyte interface (SEI). Sulfonic acid group (− SO3H) in COF-S-F can effectively ameliorate the desolvation process of hydrated Zn ions, and the three-dimensional channel with fluoride group (-F) can provide interconnected channels for the favorable transport of Zn ions with ion-confinement effects, endowing Zn@COF-S-F with dendrite-free morphology and suppressed side reactions. Consequently, Zn@COF-S-F symmetric cell can stably cycle for 1,000 h with low average hysteresis voltage (50.5 mV) at the current density of 1.5 mA cm−2. Zn@COF-S-F|MnO2 cell delivers the discharge specific capacity of 206.8 mAh g−1 at the current density of 1.2 A g−1 after 800 cycles with high-capacity retention (87.9%). Enlightening, building artificial SEI on metallic Zn surface with targeted design has been proved as the effective strategy to foster the practical application of high-performance AZIBs. [ABSTRACT FROM AUTHOR]

Lithium metal is considered to be a promising anode material for high‐energy‐density rechargeable batteries because of its high theoretical capacity and low reduction potential. Nevertheless, the practical application of Li anodes is challenged by poor cyclic performance and potential safety hazards, which are attributed to non‐uniform electrodeposition of Li metal during charging. Herein, diffusion limited current density (DLCD), one of the critical fundamental parameters that govern the electrochemical reaction process, is investigated as the threshold of current density for electrodeposition of Li. The visualization of the concentration field and distribution of Faradic current density reveal how uniform electrodeposition of Li metal anodes can be obtained when the applied current density is below the DLCD of the related electrochemical system. Moreover, the electrodeposition of Li metal within broken solid electrolyte interphases preferentially occurs at the crack spots that are caused by the non‐uniform electrodeposition of Li metal. This post‐electrodeposition leads to more consumption of active Li when the applied current density is greater than the DLCD. Therefore, lowering the applied current density or increasing the DLCD are proposed as directions for developing advanced strategies to realize uniform electrodeposition of Li metal and stable interfaces, aiming to accelerate the practical application of state‐of‐the‐art Li metal batteries. [ABSTRACT FROM AUTHOR]

Lithium metal has been considered as the most promising anode material due to its distinguished specific capacity of 3860 mAh g–1 and the lowest reduction potential of ‐3.04 V versus the Standard Hydrogen Electrode. However, the practicalization of Li‐metal batteries (LMBs) is still challenged by the dendritic growth of Li during cycling, which is governed by the surface properties of the electrodepositing substrate. Herein, a surface modification with indium oxide on the copper current collector via magnetron sputtering, which can be spontaneously lithiated to form a composite of lithium indium oxide and Li‐In alloy, is proposed. Thus, the growth of Li dendrites is effectively suppressed via regulating the inner Helmholtz plane modified with LiInO2 to foster the desolvation of Li‐ion and induce the nucleation of Li‐metal in two‐dimensions through electro‐crystallization with Li‐In alloy. Using the In2O3 modification, the Li‐metal anode exhibits outstanding cyclic stability, and LMBs with lithium cobalt oxide cathode present excellent capacity retention (above 80% over 600 cycles). Enlightening, the scalable magnetron sputtering method reported here paves a novel way to accelerate the practical application of the Li anode in LMBs to pursue higher energy density. [ABSTRACT FROM AUTHOR]

Nonuniform electrodeposition of lithium during charging processes is the key issue hindering development of rechargeable Li metal batteries. This deposition process is largely controlled by the solid electrolyte interphase (SEI) on the metal surface and the design of artificial SEIs is an essential pathway to regulate electrodeposition of Li. In this work, an electro‐chemo‐mechanical model is built and implemented in a phase‐field modelling to understand the correlation between the physical properties of artificial SEIs and deposition of Li. The results show that improving ionic conductivity of the SEI above a critical level can mitigate stress concentration and preferred deposition of Li. In addition, the mechanical strength of the SEI is found to also mitigate non‐uniform deposition and influence electrochemical kinetics, with a Young's modulus around 4.0 GPa being a threshold value for even deposition of Li. By comparison of the results to experimental results for artificial SEIs it is clear that the most important direction for future work is to improve the ionic conductivity without compromising mechanical strength. In addition, the findings and methodology presented here not only provide detailed guidelines for design of artificial SEI on Li‐metal anodes but also pave the way to explore strategies for regulating deposition of other metal anodes. [ABSTRACT FROM AUTHOR]

A double‐wrapped binder has been rationally designed with high Young's modulus polyacrylic acid (PAA) inside and low Young's modulus bifunctional polyurethane (BFPU) outside to address the large inner stress of silicon anode with drastic volume changes during cycling. Harnessing the "hard to soft" gradient distribution strategy, the rigid PAA acts as a protective layer to dissipate the inner stress first during lithiation, while the elastic binder BFPU serves as a buffer layer to disperse residual stress, and thus avoids structural damage of rigid PAA. Moreover, the introduction of BFPU with fast self‐healing ability can dynamically recover the microcracks arising from large stress, further ensuring the integrity of silicon anode. This multifunctional binder with smart design of double‐wrapped structure provides enlightenment on enlarging the cycling life of high‐energy‐density lithium‐ion batteries that suffer enormous volume change during the cycling process. [ABSTRACT FROM AUTHOR]

The application of lithium metal as an anode material for next generation high energy‐density batteries has to overcome the major bottleneck that is the seemingly unavoidable growth of Li dendrites caused by non‐uniform electrodeposition on the electrode surface. This problem must be addressed by clarifying the detailed mechanism. In this work the mass‐transfer of Li‐ions is investigated, a key process controlling the electrochemical reaction. By a phase field modeling approach, the Li‐ion concentration and the electric fields are visualized to reveal the role of three key experimental parameters, operating temperature, Li‐salt concentration in electrolyte, and applied current density, on the microstructure of deposited Li. It is shown that a rapid depletion of Li‐ions on electrode surface, induced by, e.g., low operating temperature, diluted electrolyte and a high applied current density, is the underlying driving force for non‐uniform electrodeposition of Li. Thus, a viable route to realize a dendrite‐free Li plating process would be to mitigate the depletion of Li‐ions on the electrode surface. The methodology and results in this work may boost the practical applicability of Li anodes in Li metal batteries and other battery systems using metal anodes. [ABSTRACT FROM AUTHOR]

• Ionic conductive Ge@PAA/PVA layer is fabricated on Li electrode. • Li x Ge after lithiation enables controlled Li-flux. • PAA-PVA organic matrix works as a soft base for weakening side reactions. • Electrochemical plating/striping process of Li anode is dramatically stabilized. • Ge@PAA/PVA modified Li anode realizes ultralong lifespan of full cells. Lithium metal is regarded as a promising anode material for high energy density battery systems owing to its ultrahigh theoretical capacity (3860 mAh g−1). Unfortunately, problematic dendrite is the key obstacle for practical utilization. In general, it is taken for grant that the growth of lithium dendrites is accelerated at high current densities. Here, we built an ion-conductive skin, containing germanium (Ge), polyacrylic acid (PAA) and polyvinyl alcohol (PVA), named Ge@PAA-PVA, to tackle the dendrite issues. In the hybrid skin, Ge particles work as boosted ionic migrating channels to manage the Li-ion flux for realizing the stable and dendrite-free morphology, while PAA-PVA organic matrix as a soft base for weakening side reactions. Taking advantages of this hybrid skin layer, Li|LiCoO 2 full cells with Ge@PAA-PVA grafted anode deliver an excellent cycle performance with 81.5% capacity retention at 2C and 74% capacity retention at 5C over 500 cycles. This work may open a new avenue for commercial utilization of Li metal with high retention of capacity and ultra-long lifespan in rechargeable high-energy-density lithium metal batteries. [ABSTRACT FROM AUTHOR]

The commercial lithium-ion batteries (LIBs) cannot satisfy the drastically increased demand for energy for the limited theoretical capacity density of graphite anode. It is urgent to develop high capacity anode material for high-energy-density batteries. Here, we report a novel phosphorus-carbon nanotube (P-CNT) hybrid as a high-capacity anode for LIBs. This hybrid is obtained via a ball-milling with red P and CNT, in which bulk P and CNT are simultaneous grounded into an overview of nanoscale particles and uniformly distributed in the hybrid. Moreover, the P-O-C chemical bond is formed between P and CNT upon ball-milling, which enables an intimate and robust contact between P and CNT, and thus enhances the overall electrical conductivity and the endurance capability of the P-CNT hybrid employed to heighten the performance during cycling of LIBs. Benefiting from this unique nanostructure with a chemical bond, P-CNT hybrid anode with the high initial Coulombic efficiency of 86.67% and good capacity (2252 mAh/g for first cycle and 1844 mAh/g for 300 cycles) is achieved. This facile and scalable synthesis simple approach and unique nanostructure can be potentially applied to other P-based high-performance anode materials for LIBs. Image 1 [ABSTRACT FROM AUTHOR]

• Soft carbon-combined Li 2 TiSiO 5 is prepared by one-pot sol-gel method. • Conductivity of Li 2 TiSiO 5 anode is effectively improved. • Superior cycling performance is achieved for Li 2 TiSiO 5 /C composite anode. Li 2 TiSiO 5 has been proposed as a practical anode material for lithium-ion batteries with an ideal operational potential of 0.28 V vs. Li/Li+ which can fill the voltage region between graphite and Li 4 Ti 5 O 12. Herein, soft carbon-combined Li 2 TiSiO 5 composite with extra oxygen vacancies is successfully prepared through a one-pot process. When employed as an anode material for lithium-ion batteries, the novel Li 2 TiSiO 5 /C composite delivers a high initial discharge capacity of 443 mA h g−1 at a current density of 100 mA g−1, and presents a reversible capacity of 165 mA h g−1 even at 1600 mA g−1. The long-life cycling is achieved with a capacity retention of 273 mA h g−1 after 1500 cycles under 500 mA g−1 between 0.1 V and 3.0 V. The enhanced cycling stability and prominent rate capability are largely ascribed to the improved conductivities, faster electrochemical reaction kinetics and strong pseudocapacitance effect. This superior lithium-storage performance provides a new opportunity for the further practical applications of novel titanium-based carbon composites as electrode materials in high-power storage devices. [Display omitted] [ABSTRACT FROM AUTHOR]

• Supercritical water-methanol mixture was used as reaction media. • Li 4 Ti 5 O 12 /TiO 2 dual-phase composite showed superior electrochemical properties. • Oxygen vacancy: an important role in enhancing electrochemical performance. • Pseudocapacitive effect in Li 4 Ti 5 O 12 /TiO 2 was pivotal. Li 4 Ti 5 O 12 /TiO 2 dual-phase composite compound is prepared through a supercritical fluid process with the mixture of water and methanol as solvothermal reaction media (380 °C and 31.5 MPa). When employed as anode material for lithium-ion batteries, the newly synthesized Li 4 Ti 5 O 12 /TiO 2 composite exhibits a high initial discharge capacity of 191 mA h g−1 at a current density of 100 mA g−1, and delivers a capacity retention of 90.7% even after 500 cycles at 1000 mA g−1 with the voltage window of (1.0–2.5)V. The enhanced electrochemical performance is attributed to the oxygen vacancies, the phase grain boundaries and reduced size of the Li 4 Ti 5 O 12 /TiO 2 composite particles. In addition, pseudocapacitive effect for the superior electrochemical performance of Li 4 Ti 5 O 12 /TiO 2 dual-phase composite is investigated in detail. The carbon-free Li 4 Ti 5 O 12 /TiO 2 dual-phase composite with high safety would be a promising candidate for applications in high-power lithium ion batteries. [ABSTRACT FROM AUTHOR]

Highlights • A serious of Li 3 VO 4 /MoS 2 composites were prepared by using a feasible and facile solvothermal method. • Hetero-interface exhibited in the Li 3 VO 4 /MoS 2 composite boosted electronic conductivity and lithium diffusion. • Li 3 VO 4 /MoS 2 composite showed high charge capacity and excellent rate performance. Abstract Novel Li 3 VO 4 /MoS 2 composite was prepared by a facile solvothermal process and used as potential high-performance anode materials for lithium-ion batteries. The synergetic effect between Li 3 VO 4 and MoS 2 as well as the existence of oxygen vacancies in composite were proved, providing high Li-ion storage, electronic and ionic conductivity and structure stability. The Li 3 VO 4 /MoS 2 composite showed superior electrochemical performance with discharge capacity for 789.1 mA h g−1 and charge capacity for 781.2 mA h g−1 after 100 cycles at a specific current of 100 mA g−1. Rate capacity of the Li 3 VO 4 /MoS 2 composite confirmed that high recovery capacity was achieved. Under a current of 500 mA g−1, Li 3 VO 4 /MoS 2 composite compounds exhibited high capacity retention of 632 mA h g−1. Furthermore, mechanism for the synergetic effect in composite compounds as well as its superior electrochemical performance was investigated in detail. [ABSTRACT FROM AUTHOR]

TiNb 2 O 7 compound with extra oxygen vacancies is synthesized through unique supercritical fluid process. When fabricated as anode for lithium ion batteries, such TiNb 2 O 7 anode exhibits high initial discharge capacity of 231 mA h g−1 at a current density of 100 mA g−1, and maintains capacity of 169 mA h g−1 even after 250 cycles in the voltage window of 1.0–3.0 V. The excellent electrochemical performance is mainly attributed to the existence of abundant oxygen vacancies in TiNb 2 O 7 compound, which greatly increases the electronic conductivity and lithium ion diffusion coefficient. Furthermore, the contribution of pseudocapacitive effect to the superior electrochemical performance of as-prepared Ti Nb 2 O 7 is investigated systematically. All in all, it demonstrates that the supercritical fluid is a facile and effective media to create oxygen vacancies in TiNb 2 O 7 , and the TiNb 2 O 7 compound with introduced oxygen vacancies would be a promising candidate for anode materials in high-power lithium ion batteries. This work provides a fresh strategy and route to explore novel multicomponent oxide materials with enhanced electrochemical properties for energy storage. [ABSTRACT FROM AUTHOR]

Multicomponent compounds have been studied as anode materials for lithium-ion batteries since such compounds simultaneously satisfy electrochemical and structural requirements during charge/discharge processes. Herein, LiNbMoO 6 manifests high initial charge/discharge specific capacities and excellent cycle performance when used as anode for lithium battery. Furthermore, after modifying with 1 wt% Li 2 SiO 3 , the LiNbMoO 6 / Li 2 SiO 3 composite delivers increased discharge capacity of 250 mAh g −1 at a current density of 500 mA g −1 even after 1000 cycles. The improved electrochemical performance is attributed to the improved ionic conductivity originating from the unique Li 2 SiO 3 thin film, and the increased electron conductivity due to the introduction of oxygen vacancy in LiNbMoO 6 through the preparation process. In addition, the detailed lithium storage mechanism of the LiNbMoO 6 /Li 2 SiO 3 composite is revealed through ex-situ XPS combined with ex-situ XRD analysis. The unique electrode design strategy in this work would exert significant impact upon constructing other advanced multicomponent electrode materials for high-performance lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Ternary chalcogenides have drawn intense interest as promising alternative anode materials for Li-storage systems benefiting from their high specific capacity. Herein, the electrochemical performance of a new ternary chalcogenide LiInSe 2 used for lithium ion anode has been reported for the first time. Furthermore, in view of carbon-coating treatment, the optimized anode LiInSe 2 @C for Li-ion batteries exhibits enhanced capacitive behavior and high rate capability. LiInSe 2 @C presents a high reversible capacity of 409.1 mA h g−1 at 100 mA g−1 and a reversible capacity of 270 mA h g−1 after 1000 cycles at 1000 mA g−1. Further analyses evidence that the outstanding rate performance stems from fast electrochemical kinetics, enhanced by the pseudocapacitive effect and improved electronic/ionic conductivity. These results elucidate the attractive lithium storage performance of LiInSe 2 compound, and would offer a practical polestar to explore novel ternary chalcogenide for energy storage. [ABSTRACT FROM AUTHOR]