One-pot synthesis of nanocrystalline SnS@tremella-like porous carbon by supercritical CO2 method for excellent sodium storage performance

Abstract

Sodium-ion batteries (SIBs) have been regarded as latent complementary energy storage devices of lithium-ion batteries (LIBs). How to construct and manufacture advanced materials is a great challenge for the development of SIBs. In this work, we design a simple supercritical CO2 method to fabricate an interesting composite of nanocrystalline SnS@tremella-like porous carbon (SnS@TPC). The composite retains porous structure of TPC and reveals a uniform dispersion of SnS nanocrystals. The SnS@TPC performs an impressive cycling stability (457 mA h g − 1 after 100 cycles with capacity retention of 90.5% at 0.2 A g − 1, 397 mA h g − 1 after 100 cycles with capacity retention of 93% at 1 A g − 1) and great rate performance. The results of subsequent tests show that the outstanding electrochemical performance derives from the double surface capacitive characteristics and good composite effect between TPC and nanocrystalline SnS. This work provides an innovative synthesis of sulphides and carbonaceous materials, thus addressing some of the disadvantages of sulphides as an anode electrode for SIBs.