Synthesis of Homogeneous Hollow Co ₃ O ₄ Microspheres for Enhanced Cycle Life and Electrochemical Energy Storage Performance

Abstract

Abstract How to achieve a balance between excellent pseudocapacitive performance and simplicity of the synthetic pathway of Co 3 O 4 is still a challenge. Herein, hollow Co 3 O 4 microspheres were synthesized through a facile template‐free solvothermal approach with a following calcination treatment. The synthetic Co 3 O 4 exhibited remarkable electrochemical properties in terms of high specific capacity 922.7 F g −1 at 1 A g −1 , superior rate capability with 67.7 % capacitance retention (1–20 A g −1 ), as well as excellent cycling stability (105.6 % retention after 10000 cycles). A hybrid supercapacitor device is also successfully assembled consisting of a Co 3 O 4 cathode and a reduced graphene oxide anode with a wide potential window of 0–1.65 V, which delivers a high energy density and an outstanding cycle lifetime. These superior electrochemical properties will render the hollow Co 3 O 4 microsphere material as an attractive material for promising application in high‐performance electrochemical energy storage systems.