Electrodeposited MnO2 films for energy storage and catalysis: a review

Abstract

Manganese dioxide (MnO₂) has demonstrated significant potential in electrochemical energy storage and catalytic applications due to its low cost, environmental friendliness, and polymorphic structures. Electrodeposition is an efficient and controllable technique that enables direct deposition of uniform MnO₂ thin films on conductive substrates; their morphology and performance can be tuned by adjusting parameters such as electrolyte composition and current density. This review systematically summarizes the principles of anodic and cathodic deposition of MnO₂, compares the advantages and limitations of potentiostatic, galvanostatic, pulsed, and cyclic voltammetric electrodeposition methods, and explores its applications in batteries, supercapacitors, metal electrowinning anodes, and electrocatalysis. MnO₂ film electrodes exhibit outstanding performance in enhancing battery capacity and stability, improving supercapacitor-specific capacitance, reducing anode overpotential, and boosting catalytic activity. However, challenges such as low conductivity, insufficient structural stability, and the need for scalable fabrication optimization remain. Further advancements in process engineering are essential to accelerate industrial applications.