Interlayer expanded VS2 nanosheet for efficient sodium storage

Abstract

An interlayer-expanded vanadium disulfide (VS2) electrode has been developed to enhance the performance of sodium ion batteries. The interlayer expansion of the (001) plane from the standard 5.7 Å to 9.5 Å improves capacity by 2–3 times at various current densities even over long cycles. This advancement is credited to the optimized kinetics of Na+ diffusion, as the intrinsic structure of VS2 with weak van der Waals interlayer interactions leads to minimal resistance along 2D ionic diffusion routes. Our findings highlight the significance of interlayer engineering in designing efficient energy storage electrodes.