A 3D multifunctional host anode from commercial carbon cloth for lithium metal batteries

Lithium metal batteries (LMBs) represent next-generation high-energy rechargeable batteries. However, practical applications of LMBs are hindered by their Li anode-related shortcomings including continuous electrolyte decomposition, uncontrollable Li dendrite growth, and infinite Li volume change. Various single-functional approaches have been extensively studied to solve these problems but with unsatisfactory results. This strongly indicates the need, although challenging, to have a versatile strategy to simultaneously (hence more effectively) address all of the issues of LMBs. Herein, we propose and demonstrate for the first time a new concept of multifunctional LMB host anodes. Specifically, we develop a facile strategy to simultaneously KOH-etch and nitrogen-dope commercial carbon cloth into a 3D multifunctional host anode (KNCC) for LMBs. The KNCC possesses abundant mesoporous defects and nitrogen-doped sites with superior surface area/porosity and lithiophilicity. It is also highly catalytic, catalyzing the electrolyte reduction to preferentially form a Li3N/LiF/N-O rich solid electrolyte interphase with homogeneous Li nucleation sites. These multiple functionalities of KNCC enable its dendrite-free Li plating/stripping and the simultaneous suppression of electrolyte decomposition, Li dendrite growth, and Li volume change, leading to excellent performance for LMBs. Pairing with a commercial high-loading LiFePO4 cathode (14 mg cm(-2)), the resultant LFP||KNCC full battery shows a remarkable rate capability (10C/0.1C capacity retention: 65.5%) and cycle life (capacity retention: 86.0%, average coulombic efficiency: 96.2%, after 1C cycling for 500 cycles). Broadly, our simultaneous KOH-etching/nitrogen-doping approach can be extended to fabricate host anodes for other metal batteries, and beyond batteries, to produce electrocatalysts for other electrochemical technologies such as fuel cells and water-splitting systems.