Coralloid Carbon Fiber-Based Composite Lithium Anode for Robust Lithium Metal Batteries

Lithium metal is among the most promising anode materials in next-generation energy-storage systems. However, Li dendrite growth and unstable solid electrolyte interphase have hindered its practical applications. Structured current collectors have been widely proposed to settle these issues, whereas the pre-filling of Li metal into structured anode is challenging. We proposed a coralloid silver-coated carbon fiber-based composite Li anode (CF/Ag-Li) through Ag electroplating and molten Li infusion. The molten Li can be infused into the carbon fiber framework due to the lithiophilic nature of Ag. In addition, a dendrite-free morphology and extraordinary electrochemical performance are achieved in Li-LiFePO4 and Li-sulfur cells. The CF/Ag-Li|Li symmetrical cells can cycle for 160 cycles at 10.0 mA cm−2 and 10.0 mAh cm−2. The CF/Ag-Li|S cells exhibited a high initial discharge capacity of 785 mAh g−1 and a large capacity retention rate after 400 cycles at 0.5C.