Reactivating Dead Li by Shuttle Effect for High-Performance Anode-Free Li Metal Batteries
Abstract Anode-free Li metal batteries are considered the ultimate configuration for next-generation Li-based batteries due to the nonuse of excess Li metal and high energy density. However, the limited Li source worsens the issues in anode caused by Li dendrites and dead Li. Any Li loss in the formation of SEI and dead Li has a great influence on the full cell. Here, we introduce LiI with shuttle effect to suppress the Li dendrites and reactivate the dead Li in the anode-free LiFePO4 (LFP) |Cu full cells. During cycling, the iodine will transform between I and I3, and a chemical reaction will occur spontaneously between I3 and Li dendrites or dead Li. The generated Li in the electrolyte will be active in the following cycling. The anode-free LFP|Cu cells deliver an initial discharge capacity of 139 mAh g-1 and maintain capacities of 100 mAh g-1 with a capacity retention of 72% after 100 cycles. Both the anode-free LFP|Cu coin cells and pouch cells with LiI additive show much-improved performances. This work provides a new strategy for high-performance anode-free Li metal batteries.