Construction of MoS2/MoO3 Heterostructure with Ultrafast-Charged and Superior Low-Temperature Sodium Storage Properties

The electrochemical reaction kinetics of sodium-ion batteries (SIBs) become sluggish at low temperatures, resulting in significant reductions in energy density and power density. Rational design of anode materials with excellent low-temperature performance is of great significance for promoting the application of SIBs under extreme conditions. Here, the spontaneous hydrolysis and oxidation reactions of MoS₂ in aqueous solution are used to successfully construct the MoS₂/MoO₃ heterostructure. The formation of built-in electric fields at the MoS₂/MoO₃ heterointerfaces improves the electrochemical reaction kinetics, thereby enhancing the rate performance. In addition, the dual-phase material can effectively buffer the volume strain during the cycle process, thereby improving the cycle stability. Thus, the MoS₂/MoO₃ displays ultrafast charging properties at room temperature (up to 244.6 mAh g^-1 at 40 A g^-1, discharge/charge in 22 s). Even at -40 °C, it also exhibits a high capacity of 303.7 mAh g^-1 and superior cycling performance (capacity retention rate up to 92.9% after 900 cycles at 2 A g^-1).