High Fire‐Safety, Thinning Lithium Metal Anode for High‐Energy‐Density Lithium Metal Batteries

Abstract Lithium (Li) metal batteries have garnered significant attention due to their high energy density. However, the safety concerns associated with Li‐metal batteries need to be addressed for their commercial viability. Most research has focused on the safety of separators and electrolytes, yet little emphasis is placed on the heat safety of lithium metal. In an out‐of‐control scenario, the combustion of lithium metal can release significantly more heat compared to other components. In this study, a highly safe composite Li metal anode is introduced fabricated by repeatedly rolling copper (Cu) powder and lithium metal. Electrochemical tests show that the Cu/Li anode can withstand up to 200 cycles, far surpassing the 50‐cycle lifespan of conventional Li metal anodes. Safety test results indicate that the Li/Cu composite anode possesses self‐extinguishing properties, significantly mitigating the safety risks associated with lithium metal batteries. Thermal runaway tests on the 1.0 Ah pouch cell demonstrate that the Li/Cu composite anode exhibits excellent safety characteristics, effectively inhibiting thermal runaway phenomena. The proposed straightforward, and high‐safety Li/Cu composite anode can enhance the safety profile of lithium metal batteries and provide crucial technical support for their industrial application.