Concentrated electrolytes based on dual salts of LiFSI and LiODFB for lithium-metal battery

Li-metal battery (LiMB) has received considerable attention as an alternative energy storage device to Li-ion battery in recent years. However, uncontrolled Li dendrite growth prevents the practical applications of LiMB. Herein, we report the use of concentrated electrolytes based on dual salts of lithium bis(fluorosulfonyl) imide (LiFSI) and lithium difluoro(oxalato) borate (LiODFB) to suppress Li dendrite growth. The compatibility of electrolyte and LiFePO4 cathode was further verified by the long capacity retention and high rate performance of Li/LiFePO4 battery. The superior electrochemical performance was attributed to the concentrated electrolyte, which could simultaneously suppress Li dendrite growth at the anode side and Aluminum (Al) current collector corrosion at the cathode side. This work provides new insights to develop high-performance LiMBs by carefully tailoring the multivariate composition of concentrated electrolyte.