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. With the rapid development of electric vehicles and portable electronics such as mobile phones and laptops, the widely used lithium (Li)-ion batteries are having many difficulties in meeting the growing demands for high-energy-density energy-storage systems. Li metal, with an ultrahigh theoretical specific capacity of 3,860 mAh g⁻¹ and the lowest negative electrochemical potential (−3.040 V versus standard hydrogen electrode), has become one of the most promising anode materials for next-generation batteries. Unfortunately, the practical application of Li metal anode has been hindered by its low cycling efficiency, short lifespan, and potential safety hazards. Herein we propose a Li-containing composite electrode based on coralloid carbon fibers that exhibited extraordinary electrochemical performance in full cells of Li-S and Li-LiFePO₄ batteries. Such proof of concept on Li-infused structured electrodes sheds fresh light on the dendrite-free plating of Li metal anodes in working rechargeable batteries. Lithium (Li) metal is among the most promising anode materials for next-generation high-energy-density batteries. However, both dendrite growth and unstable solid electrolyte interphases have hindered its practical applications. Herein, we propose a coralloid carbon fiber-based composite lithium anode, which is an initially Li-containing structured anode. Such electrode design renders dendrite-free morphology during repeated stripping/plating cycles and extraordinary electrochemical performance in Li-LiFePO₄ and Li-sulfur cells.