Exploring GeC/V2CS2 Ohmic heterostructure as anode for alkali metal-ion batteries: Insights and origins

Abstract

2D heterostructures have garnered significant attention in alkali metal-ion batteries due to their rapid charge transfer characteristics, which can dramatically enhance rate performance. However, the challenge of achieving heterostructure materials with both superior electrochemical properties and favorable interfacial contact properties remains a key technical issue currently faced. Herein, we propose a novel 2D Ohmic heterostructure GeC/V₂CS₂ as an anode material for alkali metal-ion batteries. The results reveal that GeC/V₂CS₂ heterostructure forms an excellent p-type Ohmic contact with low interfacial resistance and outstanding electrical conductivity, facilitating rapid electron transport. Analysis of the adsorption and diffusion behaviors of Li, Na, and Mg ions demonstrates that the heterostructure exhibits low diffusion energy barriers and remarkable theoretical specific capacities, particularly for magnesium-ion batteries (1428.57 mA h/g). Furthermore, the built-in electric field within the heterostructure enhances ion adsorption stability and migration rates while maintaining robust thermal and electrochemical stability. This work provides theoretical insights and design principles for developing high-performance 2D heterostructure anode materials, advancing the development of next-generation metal-ion batteries.