Green Synthesis and Electrochemical Properties of A3(Po4)2 (a = Mn, Zn, Co) Hydrates for Supercapacitors with Long-Term Cycling Stability

Abstract

Energy storage materials are currently considered to promote the development of life and economy in a society with high energy consumption. Particularly, supercapacitors play a significant role in providing a sustainable human society as a kind of green energy storage system. Currently, most researchers are mainly focusing on improving the electrochemical properties of electrode materials. In light of cost-effective and discharged pollutants, eco-friendly and simple-operated synthesis would be an advanced option to fabricate high-energy storage electrode materials. Herein, an advanced and green strategy was introduced to prepare a series of A3(PO4)2 (A = Mn, Zn, Co) hydrates for the high-performance supercapacitor electrodes. A one-step method was utilized to synthesis these electrodes at room temperature along with the characterization in terms of their phase structure, morphology, and electrochemical performances. Interestingly, Co3(PO4)2∙8H2O electrode showed a good specific capacity value of 210.67 mAh g-1 (specific capacitance of 1516.8 F g-1) with a large voltage of 0.5 V under the current density of 1 A g-1. Moreover, the constructed pouch-type device still exhibited an outstanding cycling stability of ~ 90.53% after the following 24000 cycles. In addition, the energy density of the fabricated device was estimated to be 33.44 Wh kg-1 while the maximum power density was found to be about 3750 W kg-1. This work suggests that researchers prepare excellent electrodes for supercapacitors with ultra-long cycling stability through a simple and green strategy.

Keywords: room-temperature, Green synthesis, supercapacitors, capacity, Cycling stability