Self-templating growth of Sb 2 Se 3 @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 Sb 2 Se 3 @C microtube prepared via a self-templated route by employing Sb 2 O 3 microrods as the self-sacrificial templates. In situ Raman spectra investigation confirmed that the potassium storage mechanism of the Sb 2 Se 3 @C microtubes is the convention-alloying-type with the formation of K 2 Se in the first convention reaction process and K 3 Sb phase in the following alloying reaction stage. As an anode material for PIBs, the Sb 2 Se 3 @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.