High-performance alkali metal ion battery anodes: A graphene-like ZnO/Ti2CS2 heterostructure study via first-principles

Abstract

Two-dimensional transition metal oxides and MXenes stand out as potential anode materials for alkali metal ion batteries, yet their performance is hindered by semiconductor conductivity and layer re-stacking issues. To circumvent these limitations, we explored the use of van der Waals heterostructures, specifically assembling a graphene-like ZnO/Ti₂CS₂ heterostructure (g-ZnO/Ti₂CS₂), and evaluated its efficacy as an anode material for Li/Na/K ion batteries (LIBs/NIBs/KIBs) through first-principles calculations. Our findings reveal that g-ZnO/Ti₂CS₂ maintains thermal stability at room temperature and demonstrates metallic conductivity. It also supports stable adsorption of single Li/Na/K atoms and facilitates their diffusion with a barrier under 0.5 eV, indicating superior rate performance. Furthermore, g-ZnO/Ti₂CS₂ exhibits an average open circuit voltage (OCV) between 0–1 V and delivers specific capacities of 529/317/317 mAh/g for LIBs/NIBs/KIBs, surpassing traditional graphite anodes. These characteristics indicate that g-ZnO/Ti₂CS₂ is a promising anode material, particularly for LIBs, offering a theoretical foundation for future anode material research for alkali metal ion batteries.