YANG Xuguang¹, CHEN Pan², GUO Yuhang², DONG Songtao²

(1.Department of Medicine and Chemical Engineering, Lianyungang Technical College, Lianyungang 222000, Jiangsu, China; 2. Department of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, Jiangsu, China)

Abstract: Al-doped MnO₂ hollow nanospheres were prepared by hydrothermal method to enhance electrochemical properties. The morphology, crystal structures, and element content of the samples were characterized by using field emission scanning electron microscopy (FESEM), powder X-ray diffraction (XRD), and the rmogravimetric analysis (TG), respectively. The electrochemical performances were characterized by cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) testing and electrochemical impedance spectroscopy (EIS). The results show that the MnO₂ gains the highest Al³⁺ doping content when adding 3 mmol Al₂(SO₄)₃∙18H₂O to the precursor solution. At the same time,the MnO₂ sample with the highest Al³⁺ doping content shows the best electrochemical performance. At a current density of 0.5 A/g, a specific capacitance of 242.47 F/g was achieved.
Key words: hollow nanospheres; MnO₂; doping; specific capacitance; supercapacitor