Construction of MnO₂-Mn₃O₄ heterostructures to facilitate high-performance aqueous magnesium ion energy storage

MnO2-Mn3O4 heterostructure materials are applied in aqueous magnesium ion energy storage for the first time. The heterostructure yields an exceptionally high pseudocapacitance contribution, resulting in a specific capacitance of 313.5 F g(-1) at 1 A g(-1), which contrasts with that of MnO2 (108.8 F g(-1)) and Mn3O4 (123.5 F g(-1)). Additionally, it shows potential for practical applications as a cathode for magnesium ion hybrid supercapacitors (MHS).