A review on hybrid supercapacitors supported by manganese oxide-based nanomaterials

Hybrid supercapacitors have emerged as promising devices for energy storage because they effectively bridge the gap between conventional capacitors and rechargeable batteries. They offer high power, improved energy density, rapid charge/discharge capabilities, and a long cycle life. Among the various materials used for energy storage in hybrid supercapacitors, manganese-based materials have gained significant attention due to their abundant availability, environmental friendliness, and high theoretical capacitance. This review explores the recent advancements in developing manganese-based supercapacitor materials, including manganese oxides, hydroxides, and composites that incorporate conductive materials such as graphene and carbon nanotubes. It covers synthesis methods, energy storage mechanisms, and electrochemical properties such as capacitance, energy and power density, and cycle life, along with strategies for enhancing performance. Additionally, it highlights the challenges and limitations facing commercial applications and outlines future research directions. Finally, the potential role of manganese-based supercapacitors in next-generation energy storage systems is discussed.