Contribution of different charge storage mechanisms in cobalt pyrophosphate-based supercapattery

Research on supercapattery has been rising as the state of the art of modern energy storage devices because of its excellent efficiency in terms of power and energy density. In this aspect, layered materials supply better electrochemical attributes, but inadequacy in rate performance, which is the key factor of energy storage devices, forbids its wide application. Herein, we report a simple method of alpha phase Co2P2O7 synthesis and evaluated its performance by varying the calcination temperature. The electrochemical performance of C550, C650 and C750 was examined in a three-electrode cell configuration utilizing 1 M KOH electrolyte. Since the sample C750 demonstrated the high electrochemical performance, it was further examined in a two-electrode system for the hybrid device. The assembled hybrid device renders a high specific capacity (126.5 C/g) and energy density (23.8 Wh kg(-1) @ a power density of 575.3 W kg(-1)) with good cycling stability (specific capacitance retention of 79% over 5000 cycles). The improved electrochemical performance is attributed to the augmented redox sites with short diffusion pathways of nanoparticles.

Automated summary

Research on supercapattery is on the rise due to its excellent efficiency in power and energy density. A simple method of alpha phase Co2P2O7 synthesis was reported, with improved electrochemical performance attributed to the augmented redox sites and short diffusion pathways of nanoparticles.