The positive effect of 3D interpenetrating network porous structure by carbon membranes on alleviating the volume expansion of SnS2 nanosheets for enhancing lithium and sodium storage

Transition-metal sulfide is one of the most promising anode candidates for lithium/sodium-ion batteries, but the extreme volume expansion leads to serious capacity decay during long-term cycling which limits its large-scale application. Herein, we designed a simple hydrothermal synthesis method combined with a membrane technology to fabricate flower-like SnS2 nanosheets uniformly anchored in the pores of the carbon membrane. The unique design demonstrated that an abundant membrane pore space was provided by the membrane technology for uniform growth of SnS2 nanosheet via a C S covalent bond. Meanwhile, the membrane pores and pore walls effectively relieved the volume expansion of SnS2 nanosheets during the charge/discharge process. Further, the even interpenetrating network structure of carbon membrane conductive scaffolds ensured its flexibility and structural integrity as anodes, which can provide plentiful charge transfer channels and large volume reservoirs for ion transmission. When the resulting composites were served as anodes, it achieved prominent electrochemical properties. The maximum reversible capacitance is 808.9 mA h g−1 for LIBs and 570.4 mA h g−1 for SIBs at 50 mA g−1, and outstanding rate capability was still maintained [333.3 mA h g−1 (LIBs) and 257.1 mA h g−1 (SIBs)] even at 2000 mA g−1. Moreover, almost no capacity loss was detected after the first few cycles during long-term cycles, fully suggesting that the membrane pores powerfully alleviated the volume expansion of SnS2 nanosheets and improved the cycle stability. Considering the positive effects of the unique porous structure provided by membrane technology on the electrochemical performance of the hybrid, the study offers an effective, simple, and low-cost strategy for large-scale production of SnS2-based anodes for the battery.