Designing SiC/MoN2 heterostructure as Na/K host material for Na/K-ion batteries

The limited electrical conductivity of silicon carbide (SiC) hinders its large-scale application as an anode material in Na-ion and K-ion batteries (SIBs/KIBs), despite its excellent chemical stability. Inspired by recent advances in heterostructure design, we propose a novel SiC/MoN₂ heterostructure to address this challenge. First-principles calculations reveal that integrating MoN₂ transforms SiC from an insulator into a metallic conductor, enhancing electronic properties essential for battery performance. This heterostructure maintains structural integrity after sodiation/potassiation, with a low ionic migration barrier and favorable open-circuit voltage (Na = 0.62 V, K = 0.80 V). Notably, SiC/MoN₂ exhibits a high theoretical capacity of 490 m Ah/g, outperforming traditional graphite anode. Its low diffusion barriers (Na = 0.38 eV, K = 0.21 eV) and robust stability suggest that SiC/MoN₂ is a promising and efficient anode material for SIBs/KIBs. This study demonstrates that heterostructure engineering can effectively enhance the electrochemical performance of limited materials, paving the way for advanced, high-capacity energy storage devices.