Rational Regulation of Cu−Co Thiospinel Hierarchical Microsphere to Enhance the Supercapacitive Properties

Abstract

Micro‐structure of the electrodes play significant role in regulating the supercapacitive properties. Herein, three‐dimensional hierarchical heterostructures (3DHHs) CuCo2S4 microspheres with regulated micro‐structure is constructed via a simple one‐step method. The 3DHHs CuCo2S4 microspheres experience two‐dimensional (2D) lamellar interpenetration structure → two‐dimensional (2D) lamellar interpenetration structure with nanoparticles embedded on the 2D lamellar → nanoparticles assembled lamellar interpenetration structure by simply tuning the reaction time. Typically, the transition state exhibits much higher specific surface area, which is conducive to electrochemical reaction by providing adequate electrochemical interfaces. As supercapacitor electrode, the 3DHHs CuCo2S4‐10 exhibits an excellent capacitance of 1060 F g‐1 at 1 A g‐1, and even superior capacity retention of 86.7% at 5 A g‐1 after 13000 cycles. Noteworthy, asymmetric supercapacitor assembles by 3DHHs CuCo2S4‐10 and active carbon can achieve high energy density of 56.3 Wh kg‐1 at 750 W kg‐1, which holds more than 150% capacitance retention over 5000 cycles. This work provides simply micro‐structure regulation in materials synthesis, which has significant potential in renewable energy applications.