Mn₃P₂O₈/TiN on Titanium Substrate for Superapacitor Electrode with Long Cycle Stability in KOH and Na₂SO₄ Aqueous Eletrolytes

Abstract

The limitation of low-cost and high-safety aqueous manganese-based materials for electrochemical energy storage is largely hampered by their poor cyclic stability, which is usually caused by the manganese dissolution and interfacial kinetics. Here we synthesize a composite electrode which possesses unique structural properties for aqueous supercapacitor application and exhibits higher area specific capacitance. The remarkable long cycle stability of Mn3P2O8/TiN on titanium (Mn3P2O8/TiN@Ti) outperforms that most manganese-based pseudocapacitive electrode materials. The designed unique structure is attractive for quick charge migration, which confirms that the appropriate anodizing of substrate, electrodeposition of active substances and their in-situ loading, is an efficient strategy to improve kinetics for high power density pseudocapacitive supercapacitor energy storage application.