Synthesis of Homogeneous Hollow Co₃O₄ Microspheres for Enhanced Cycle Life and Electrochemical Energy Storage Performance

Abstract

How to achieve a balance between excellent pseudocapacitive performance and simplicity of the synthetic pathway of Co3O4 is still a challenge. Herein, hollow Co3O4 microspheres were synthesized through a facile template‐free solvothermal approach with a following calcination treatment. The synthetic Co3O4 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 Co3O4 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 Co3O4 microsphere material as an attractive material for promising application in high‐performance electrochemical energy storage systems.