Green synthesis and electrochemical properties of A3(PO4)2 (A = Mn, Zn, and Co) hydrates for supercapacitors with long-term cycling stability

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. Recently, most researchers mainly focus on improving the electrochemical properties of electrode materials. In light of cost-effective and discharged pollutants, eco-friendly and simple-operated synthesis is an advanced option to fabricate high-energy storage electrode mate-rials. Herein, a green one-step strategy is introduced to prepare a series of A(3)(PO4)(2) (A = Mn, Zn, and Co) hydrates at room temperature along with the characterization in terms of their phase structure, morphology, and electrochemical properties for potential high-performance supercapacitor electrodes. Interestingly, the Co-3(PO4)(2)center dot 8H(2)O electrode delivers a good specific capacity value of 210.67 mAh g(-1) (specific capacitance value of 1516.8 F g(-1)) with a high voltage of 0.5 V under the current density of 1 A g(-1). Moreover, the constructed pouch-type device exhibits an outstanding cycling stability of similar to 90.53% after the following 24000 cycles. In addition, the energy density of the fabricated device is estimated to be 33.44 Wh kg(-1) while the maximum power density is found to be about 3750 W kg(-1). This work suggests that the A(3)(PO4)(2) hydrates are very promising as excellent electrodes for supercapacitors with ultra-long cycling stability through a simple and green strategy.

Automated summary

Energy storage materials, particularly supercapacitors, are essential for promoting sustainable development in high energy consumption societies. This study presents a green and simple synthesis strategy to fabricate A(3)(PO4)(2) hydrates as high-performance supercapacitor electrodes, demonstrating excellent electrochemical properties and cycling stability.