Ultrahigh Electrochemical Performance Co₄Sb_11.2Sn_0.02Te_0.78 for Supercapacitor Cathode

Abstract

Due to the high theoretical specific capacitance, the skutterudite CoSb3 alloy is a promising supercapacitor electrode material. However, the lack of oxidative active sites and intrinsic poor electrical conductivity greatly hinder its application prospects. Here, we constructed a CoSb3 alloy compound co-doped with Sn and Te (Co4Sb11.2Sn0.02Te0.78) by a melting and annealing method. As the electrode material of the supercapacitor, Co4Sb11.2Sn0.02Te0.78 cathode shows an ultrahigh specific capacity of 1357 mAh g-1 (at 1 A g-1). Even when the current density is increased to 20 A g-1, 42% of the initial capacity is maintained. The advantageous performance of the supercapacitor cathode based on Co4Sb11.2Sn0.02Te0.78 is attributed to the more redox active sites and the improved electrical conductivity. Furthermore, this work provides a promising strategy for developing high-performance next-generation supercapacitor electrode materials.