Electrochemical performance in alkaline and neutral electrolytes of a manganese phosphate material possessing a broad potential window

Abstract

An underlying electrode material of manganese phosphate has been designed and synthesized, possessing wide potential windows (−0.9–0.7 V in neutral and −0.5–0.6 V in alkaline electrolyte), satisfying specific capacitances (203 F g⁻¹ in neutral and 194 F g⁻¹ in alkaline electrolyte), outstanding rate capabilities and excellent cycling stabilities. The morphological characteristics and electrochemical analyses indicate that the layered crystal structure offers many nano-paths and improves the diffusion of electrolyte ions, which can noticeably promote electrochemical performance. Furthermore, a Mn₃(PO₄)₂//AC asymmetric supercapacitor and a Mn₃(PO₄)₂//Mn₃(PO₄)₂ symmetric supercapacitor have been assembled at a cell voltage between 0 and 1.6 V, and exhibit excellent electrochemical stabilities and stable energy and power characteristics, which reveal that this manganese phosphate material is promising for electrochemical energy storage applications.