First principles unveiling the metallic TaS2/GeC heterostructure as an anode material in sodium-ion batteries

Abstract

In this work, we designed the metal/semiconductor TaS₂/GeC heterostructure and explored its structural, electronic properties and adsorption performance using first-principles prediction. The potential application of the TaS₂/GeC MSH as an anode material for Na-ion batteries is also evaluated. Our findings show that the metal/semiconductor TaS₂/GeC heterostructure is energetically, thermally and mechanically stable at room temperature. Notably, the heterostructure exhibits metallic behavior and forms a p-type Schottky contact with an ultra-low Schottky barrier, enabling efficient charge carrier transport across the interface. This property is particularly advantageous for high-performance electronic and optoelectronic devices, as it minimizes energy loss during carrier injection and extraction. Furthermore, the TaS₂/GeC heterostructure achieves a low Na-ion diffusion barrier of 0.34 eV and delivers a high theoretical capacity of 406.4 mA h g⁻¹. The open-circuit voltage (OCV) of the system remains within the optimal range for anode materials, further supporting its suitability for sodium-ion batteries. These findings highlight the TaS₂/GeC heterostructure as a promising anode candidate for next-generation sodium-ion batteries with high capacity, structural stability and efficient charge transport.