V-Doping-Induced Morphology and Electronic Structure Modulation of Cu ₂ O for High Areal Capacity Anodes

High areal capacity anodes are essential for advancing lithium-ion batteries, yet self-supporting electrodes often suffer from limited areal capacity due to low mass loading. Herein, a three-dimensional (3D) Cu2O architecture is directly grown on Cu foam via a hydrothermal process followed by thermal treatment. Vanadium doping is employed to regulate the growth behavior of Cu2O while concurrently modulating its electronic structure. Benefiting from the synergistic effects of optimized morphology and enhanced conductivity, the electrode with a high mass loading of 11 mg cm–2 delivers an areal capacity of 12.6 mAh cm–2, together with an excellent rate capacity of 3.5 mAh cm–2 at 5 mA cm–2. Density functional theory calculations further show that V substitution lowers the Li-ion diffusion barrier from 0.66 to 0.41 eV and introduces V-3d states near the Fermi level, thereby enhancing the conductivity. This work demonstrates an effective dopant regulation strategy for constructing high-performance self-supported Cu2O anodes for lithium-ion batteries.