MnO2 as a Supercapacitor Electrode via Grinding Redox Reactions

Manganese oxide (MnO2) used for supercapacitors was fabricated via the redox reaction between KMnO4 and CH3CHOHCH3 using a simple grinding method. Amorphous MnO2 products were obtained by grinding the reagents, and their crystal structures and morphologies were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The electrochemical measurements showed that this typical amorphous MnO2 has a specific capacitance of 137 F g(-1) based on the total mass of the products. The relative low capacitance can be attributed to the use of the total mass of the products in the calculation process. delta-MnO2 were obtained after annealing this amorphous MnO2. The effects of different annealing temperatures on the structures and capacitive performances of the products were also investigated. The simple method used in this work is fast and inexpensive, and it can be easily introduced to the industry application.