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

Abstract

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 312.8 mA 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.