Tuning the Li-Sn alloy dispersity to improve the lithiophilicity of lithium metal anode towards stable lithium metal batteries

Abstract

The pursuit of high-energy-density batteries has generated significant interest in lithium metal anodes due to their high specific capacity and low redox potential. However, challenges such as the formation of lithium dendrites and the subsequent generation of "dead lithium" during the plating/stripping processes seriously hinder their practical application. In this study, we present a novel composite lithium anode, Li/Li13Sn5, which is fabricated using a straightforward "roll and fold" technique that incorporates metallic lithium and tin powder. This method ensures a uniform distribution of Li13Sn5 particles within the lithium matrix, thereby enhancing the lithiophilicity of the composite electrode. The unique structural characteristics of the Li/Li13Sn5 anode lead to significantly improved. Compared to bare Li anode, the Li/Li13Sn5 anode exhibits a stable voltage response and reduced interfacial impedance in symmetric cells over 400 hours cycling. When paired with a high capacity sulfurized polyacrylonitrile (SPAN) cathode (5.6 mAh cm−2), the Li/Li13Sn5 cell displayed superior cycling stability, achieving 91.5% capacity retention over 100 cycles. This innovative approach, which leverages lithiophilic metal powders to build highly dispersed lithium alloy networks present a promising strategy for the advancement of lithium metal batteries. Our findings contribute to the development of composite lithium alloy anodes with high lithium alloy utilization, paving the way for next-generation lithium battery technologies.