Carbon material/MnO2 as conductive skeleton for supercapacitor electrode material: A review

In the current background of energy and the environment, as a new type of energy storage device between secondary batteries and capacitors, supercapacitors have received widespread attention, and electrode materials are the core of preparing high-performance supercapacitors. The composites based on carbon material/MnO2 have become a hotspot in the field of electrode materials for supercapacitors. In addition, the properties of the composites can be further enhanced by introducing a third material such as transition metal oxides, conductive polymers, and carbon materials. This paper presents a review based on the binary and ternary composites of carbon materials/MnO2 and their applications, the mechanism of various materials and their practical applications in supercapacitors are introduced in detail. On this basis, the characteristics of each composite are analyzed deeply and it is pointed out that a superposition of different dimensions and an optimum capacitive balance index are required for excellent performance. It also predicts that biomass activated carbon/low-dimensional carbon material (1D, 2D)/MnO2 will be one of the most promising materials, as well as graft oxidation, 3D printing and other new technologies are the future trend of the process. Finally, the challenges and development trends of multi-composite based on carbon material/MnO2 are summarized and predicted. [Display omitted] •Carbon material/MnO2 multi-composites applied to supercapacitors were reviewed.•Different strategies to achieve high performance of composites were discussed.•The properties of carbon materials with different dimensions were and compared.•The challenges were summarized, and the future development trend was forecasted.