MnO2 core-shell type materials for high-performance supercapacitors: A short review

Energy storage systems have gotten a lot of attention in recent decades, especially in industries like hybrid electric vehicles and smart portable electronics. MnO2 based materials have been extensively studied for application in pseudocapacitors due to their high theoretical specific capacitance, high power density, fast charge/discharge capability, strong chemical and thermal stability, long cycling life, natural abundance, environmental friendliness, and inexpensive cost. The material's core/shell structure is one of the most effective techniques to create high surface area and high conductivity for providing more Faradaic reaction sites and accelerating charge transfer, respectively, and thus to improve supercapacitors performance. This review paper examines the morphology and synthesis to better comprehend the MnO2 core–shell type materials. The electroactive materials applied in the core/shell structure include metal oxides, metal hydroxides, metal chalcogenides, carbon materials, conducting polymers etc. Finally, the challenges and next steps in developing MnO2 core–shell type materials for high-performance supercapacitors (SCs) are discussed.