Modified organic-template synthesis of Co3O4 as high-performance electrode with superior capacitive storage

Abstract

Electrochemical supercapacitors (ESCs) have great potential in many energy storage technologies because of their outstanding performance. Transition metal oxides with high theoretical specific capacity are promising for ESC electrodes, but their low utilization of capacitive active components and poor cycle stability limit their practical usage. Herein, we have prepared a novel cobalt metal cyanometallic framework (Co-CMF) and further thermally modified it to easily produce a Co₃O₄ positive electrode with excellent capacitive storage performance. As a result, the electrode exhibits fast, stable and reversible electrochemical performance with a high specific capacity of 241.9 C g⁻¹ and long-term stability with as low as 0.004 % decline per cycle in the 5 M KOH aqueous electrolyte, which are confirmed by in-situ Raman investigation and electrochemical tests, further demonstrating that this modified approach provides a new idea for the development of promising high-capacity electrode materials for large-scale energy storage.