3D hierarchical architectures of CoSe2 nanoparticles embedded in rice‐derived hard carbon for advanced sodium storage

Abstract

AbstractA low‐cost and feasible method to fabricate three‐dimensional (3D) hierarchical composites composed of CoSe2 nanoparticles embedded in rice‐derived hard carbon (HC) interconnected with carbon nanotubes (CNTs) is devised in this study. The deployment of CoSe2 in the elecrode has provided a very high rate capacity, which is crucial for sodium‐ion commercialization. The deployment of HC with CNTs further provides a 3D hierarchical structure effective in shortening the diffusion paths of both electrons and Na+ ions, offering abundance of active sodium storage sites. Consequently, the CoSe2 acted as an active material with the carbonaceous template, a commonly utilized sodium‐ion battery anode material, which exhibited a superior reversible capacity of 550 mAh g−1 at 0.5 A g−1, outstanding rate performance (451 mAh g−1 at 20 A g−1) and excellent cycling performance (~100% capacity retention over 2500 cycles at 20 A g−1 after electrochemical stabilization).