Potential of MnO2-based composite and numerous morphological for enhancing supercapacitors performance

The development of materials and electrochemical energy storage (EES) technologies are currently taking the lead and showing excellent performance in the global effort to tackle the issues of sustainable energy supply. Supercapacitors have been widely studied among the EES technologies as they exhibit quick charging rates under high-power conditions. Manganese dioxide (MnO₂) has attracted renewed interest as a promising material due to its high theoretical capacitance and high energy density. However, the widespread application is immediately impacted by low conductivity. Hence, combining nanomaterials and various morphologies of MnO₂ can improve the electrochemical performance of supercapacitors. This paper presents a review based on the composites of nanomaterials/MnO₂ with various morphologies. Their mechanism and practical applications in supercapacitors are introduced in detail. Finally, the challenges and next steps in developing MnO₂ electrode materials are proposed.