Fast Ion Transport in Li-Rich Alloy Anode for High-Energy-Density All Solid-State Lithium Metal Batteries

All-solid-state Li batteries (ASSLBs) with solid-polymer electrolytes are considered promising battery systems to achieve improved safety and high energy density. However, Li dendrite formation at the Li anode under high charging current density/capacity has limited their development. To tackle the issue, Li-metal alloying has been proposed as an alternative strategy to suppress Li dendrite growth in ASSLBs. One drawback of alloying is the relatively lower operating cell voltages, which will inevitably lower energy density compared to cells with pure Li anode. Herein, a Li-rich Li13In3 alloy electrode (LiRLIA) is proposed, where the Li13In3 alloy scaffold guides Li nucleation and hinders Li dendrite formation. Meanwhile, the free Li can recover Li's potential and facilitate fast charge transfer kinetics to realize high-energy-density ASSLBs. Benefitting from the stronger adsorption energy and lower diffusion energy barrier of Li on a Li13In3 substrate, Li prefers to deposit in the 3D Li13In3 scaffold selectively. Therefore, the Li-Li symmetric cell constructed with LiRLIA can operate at a high current density/capacity of 5 mA cm(-2)/5 mAh cm(-2) for almost 1000 h.

Automated summary

All-solid-state Li batteries with solid-polymer electrolytes have potential for improved safety and high energy density. However, Li dendrite formation at the Li anode limits their development. This study proposes a Li-rich Li13In3 alloy electrode as a solution to suppress Li dendrite growth and achieve high-energy-density ASSLBs.