Constructing Hollow Microcubes SnS₂ as Negative Electrode for Sodium-ion and Potassium-ion Batteries

Sodium/potassium-ion batteries (NIBs and KIBs) are considered the most promising candidates for lithium-ion batteries in energy storage fields. Tin sulfide (SnS₂) is regarded as an attractive negative candidate for NIBs and KIBs thanks to its superior power density, high-rate performance and natural richness. Nevertheless, the slow dynamics, the enormous volume change and the decomposition of polysulfide intermediates limit its practical application. Herein, microcubes SnS₂ were prepared through sacrificial MnCO₃ template-assisted and a facile solvothermal reaction strategy and their performance was investigated in Na and K-based cells. The unique hollow cubic structure and well-confined SnS₂ nanosheets play an important role in Na⁺/K⁺ rapid kinetic and alleviating volume change. The effect of the carbon additives (Super P/C65) on the electrochemical properties were investigated thoroughly. The in operando and ex-situ characterization provide a piece of direct evidence to clarify the storage mechanism of such conversion-alloying type negative electrode materials.