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Lithium metal batteries are emerging as the next generation of high-density electrochemical energy storage systems because of the ultra-high specific capacity and ultra-low electrochemical potential of the Li metal anode. However, the uneven Li deposition on commercial Cu current collectors result in low Coulombic efficiencies (CEs) and poor cycle life. In this research, we proposed the modification of ZnFx(OH)y on Cu foils to expand the lifespan. As-generated ZnLi alloy and LiF could promote uniform Li nucleation and deposition, thus resulting in an improved Li plating/stripping CE and extended cycle life. The Li-S battery with sulfurized polyacrylonitrile cathode and Li-ZnFx(OH)y@Cu anode (N/P ratio of 1.5:1) maintains 95% capacity after 60 cycles, proving the feasibility of ZnFx(OH)y@Cu for practical applications. [ABSTRACT FROM AUTHOR]

• An N-doped graphite layer was first as a coating layer of SnO 2. • Graphene coating can provide conductive network and alleviate volume expansion. • Nitrogen doping can provide active centers and improve interface stability. • SnO 2 @NG displays the outstanding electrochemical performances. Tin dioxide (SnO 2) with multiple electron transport is considered as a potential substitute for graphite due to these advantages of natural abundance, environmental friendliness, and high theoretical capacity. However, the ineluctable volume change and structural crushing limit its practical application. Hence, SnO 2 is coated by an N-doped graphite layer to form the flexible composite anode (SnO 2 @NG), which can provide a conductive network, increase the electronic conductivity, and effectively mitigate the irreversible volume expansion/contraction during the circulation process. Furthermore, the SnO 2 @NG anode shows a high specific capacity and stable cycle performance in lithium-ion batteries (677.7 mAh g−1 after 100 cycles) and sodium-ion batteries (169.7 mAh g−1 after 100 cycles). This excellent electrochemical performance illustrates that SnO 2 @NG has broad application prospects for high-performance energy storage systems. [ABSTRACT FROM AUTHOR]

Lithium metal batteries (LMBs) are promising next-generation battery technologies with high energy densities. However, lithium dendrite growth during charge/discharge results in severe safety issues and poor cycling performance, which hinders their wide applications. The rational design and application of functional polymer materials in LMBs are of crucial importance to boost their electrochemical performances, especially the cycling stability. In this review, recent advances of advanced polymer materials are examined for boosting the stability and cycle life of LMBs as different components including artificial solid electrolyte interface (SEI) and functional interlayers between the separator and lithium metal anode. Thereafter, the research progress in the design of advanced polymer electrolytes will be analyzed for LMBs. At last, the major challenges and key perspectives will be discussed for the future development of functional polymers in LMBs. [ABSTRACT FROM AUTHOR]

Lithium-metal batteries have attracted extensive research attention because of their high energy densities. Developing appropriate electrolytes compatible with lithium-metal anodes is of great significance to facilitate their practical application. Currently used electrolytes still face challenges of high production costs and unsatisfactory Coulombic efficiencies of lithium plating/stripping. In this research, we have developed a diluted electrolyte which is compatible with both lithium-metal anode and sulfurized polyacrylonitrile cathode. It presents a very high Li plating/stripping Coulombic efficiency of 99.3% over prolonged cycling, and the as-assembled anode-free Li-S battery maintains 71.5% of the initial specific capacity after 200 cycles at 0.1 A g−1. This work could shed light on designing a low-cost and high-performance liquid electrolyte for next-generation high-energy batteries. [ABSTRACT FROM AUTHOR]