Electrodeposited Manganese Oxide on Carbon Paper for Zinc-Ion Battery Cathodes

Nano-crystalline, flake-like Mn oxide was electrodeposited onto carbon paper (CP) using a pulsed electrodeposition technique. The electrodeposited Mn oxide was identified as Mn3O4 through a combination of X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Raman spectroscopy. The Mn3O4 on CP was used as a cathode for Zn-ion batteries (ZIBs) and showed excellent cyclability at a current density of 1 Ag-1 with a capacity retention of 139% after 200 cycles. Electron microscopy was used to characterize the microstructural changes of the cathode at various stages during discharge/charge cycling. This work in combination with the electrochemical results suggests a two-step reaction mechanism involving both intercalation and conversion reactions. The results demonstrate that electrodeposition of the cathode material is a simple, quick, and potentially scalable electrode synthesis method for producing high performing Zn-ion electrodes without the use of binders or other additives.