Lithiophilic surface treatment of metal- and metallic compound-based frameworks by gas nitriding for lithium metal batteries

Abstract

Metal-based frameworks are developed for lithium metal batteries due to their effective suppression of the lithium dendritic growth. However, the use of appealing metals such as copper (Cu), the best current collector in batteries, are still limited owing to lithiophobicity. Here, we report a facile lithiophilic surface treatment of metal- and metallic compound-based scaffolds via gas nitriding. Due to nitride anion (N3−) from ammonia (NH3) gas that can bond to almost all elements and form lithiophilic binary nitrides, the gas nitriding on a pristine Cu foam and a Cu(OH)2 nanorods grown Cu foam results in a formation of lithiophilic Cu3N film on the surface without a noticeable structural change. After lithium melt infusion, symmetric cells assembled with two types of lithium hosts show stable structural stability and a smooth Li plating/stripping behavior without a dendritic growth of lithium. Particularly, a full cell test demonstrates that lithiated Cu3N nanorods grown Cu foam exhibits enhanced electrochemical performances including capacity, rate capability, and cycle performance compared to a bare Li foil. Our findings demonstrate the gas nitriding is a powerful tool for lithiophilic surface treatment of metals and metallic compounds with various dimensions and sizes from micro to nanoscale.