Highly Conductive and Dendrite‐Free Li–Ga Compound Anodes for High‐Performance Lithium All‐Solid‐State Batteries

ABSTRACT Lithium all‐solid‐state batteries (LASSBs) with sulfide‐type solid electrolytes (SEs) offer enhanced safety and higher energy densities compared to conventional Li‐ion batteries. However, Li‐metal anodes are incompatible with sulfide‐type SEs and prone to dendrite formation, which severely limits their practical applicability. Although various strategies, including the use of Li‐free, carbon‐based, alloy‐based, or oxide‐based anodes, as well as interfacial protection layers, have been explored, they typically deliver poor rate performance and suffer from dendrite growth. Herein, we introduce a Li–Ga compound anode, specifically the LiGa phase, predicted through density functional theory simulations, which exhibits dendrite‐free behavior, high ionic/electronic conductivities, stable operation at low stack pressures, room temperature stability, and excellent interfacial compatibility with SEs. Benefiting from these properties, a full cell comprising a LiGa anode and the LiNi 0.6 Co 0.2 Mn 0.2 O 2 (NCM622) cathode (LiGa|NCM622) delivers a high areal capacity of 14.47 mAh cm −2 at a high cathode loading of 100 mg cm −2 , along with fast rate capability and stable cycling at a low stack pressure of 3 MPa at room temperature. Furthermore, a LiGa|NCM622 pouch cell demonstrates outstanding electrochemical performance, highlighting the potential of LiGa as a high‐performance anode for next‐generation LASSBs, with the concept broadly applicable to diverse Li‐based compounds.