Self-templating growth of Sb2Se3@C microtube: a convention-alloying-type anode material for enhanced K-ion batteries

Potassium-ion batteries (PIBs) have attracted increasing attention in the past two years. However, the lower intercalation-type capacity of the current graphite anode has limited the development of PIBs. Herein, we report a convention-alloying-type hollow Sb2Se3@C microtube prepared via a self-templated route by employing Sb2O3 microrods as the self-sacrificial templates. In situ Raman spectra investigation confirmed that the potassium storage mechanism of the Sb2Se3@C microtubes is the convention-alloying-type with the formation of K2Se in the first convention reaction process and K3Sb phase in the following alloying reaction stage. As an anode material for PIBs, the Sb2Se3@C microtubes exhibit a capacity of 312.8mA h g(-1) at 100 mA g(-1) after 40 cycles, and a rate capability of 223.3 mA h g(-1) at 1 A g(-1). The capacity could be maintained at 191.4 mA h g(-1) at 500 mA g(-1) even after 400 cycles, suggesting that the carbon-supported hollow structure is in favor of enhanced potassium storage.