Two-dimensional Cu2N–A high-performance anode material for ion batteries with excellent electrical conductivity and electrolyte wettability

Abstract

Determining suitable anode materials is crucial in the advancement of lithium-ion and sodium-ion battery technologies. We propose that the two-dimensional (2D) material Cu₂N holds promise as a viable anode candidate. The Cu₂N monolayer exhibits a stable checkerboard lattice crystal structure, ensuring structural integrity. Its excellent metallic electronic structure facilitates efficient conductivity during battery operation. We have observed that Li/Na ions can chemically bond to Cu₂N substrates via specific charge exchange mechanisms. Moreover, the Cu₂N monolayer demonstrates favorable wettability and compatibility with common electrolytes used in lithium-ion and sodium-ion batteries, including solvent molecules and metal salts. Our findings indicate that the Li/Na storage capacity of the Cu₂N monolayer reaches approximately 760/760 mAh/g, surpassing that of graphite anodes significantly. Notably, the Li/Na diffusion barrier on the Cu₂N monolayer is merely 5/13 meV, lower than that of most other 2D anode materials. Our results underscore the potential of the Cu₂N monolayer as an outstanding electrode material, offering high storage capacity, rapid charge/discharge rates, and favorable wettability with electrolytes.