Copper-doped manganese tetroxide composites with excellent electrochemical performance for aqueous zinc-ion batteries

A copper-doped manganese tetroxide (Cu-Mn3O4) composites were prepared for zinc-ion batteries cathode material through a facile synthesis route. The Cu-Mn3O4 is constructed by numerous irregular nanoparticles with a porous micro/nano structure. The Microscopic observation reveals that the Cu2+ embedded in the lattice of manganese oxide by partly substituting Mn3+. Strikingly, at current densities of 100 mA g?1, the CuMn3O4 electrode delivered a higher discharge capacity of 250 mAh g?1 compared with 150 mAh g?1 for the pure Mn3O4 electrode and the coulombic efficiency is almost 100%. The great enhancement of the electrochemical zinc storage performance can be attributed to the improvement of the electronic/ionic conductivity and zinc diffusivity of electrodes. The present results evidence that metal doping can improve the electronic/ ionic conductivity of Mn3O4, which may also applicable to other metal oxides.