Synthesis of cobalt phosphate nanoflakes for high-performance flexible symmetric supercapacitors

Abstract

Herein, leaf-like Co-3(PO4)(2) was synthesized via a simple and low-cost approach without adding any additional surfactant. Such leaf-like Co-3(PO4)(2) showed the high crystallinity as proved by spectra analysis. The electrochemical performance of as-synthesized Co-3(PO4)(2) was firstly characterized in a three-electrode system, which shows the specific capacitance of 410 F g(- 1) at the current density of 1.0 A g(- 1). Furthermore, flexible symmetric supercapacitor was fabricated with PVA-KOH gel electrolyte, exhibiting the specific capacitance of 165 F g(- 1) at a current density of 0.5 A g(- 1) with a high energy density of 52.8 Wh kg(- 1) at a power density of 756 W kg(- 1). This superior performance is attributed to the unique morphology and fast surface redox reaction. These excellent results suggested that Co-3(PO4)(2) nanoflakes are promising materials for potential application in high-performance flexible energy storage devices.