Influence of La-dopant on the Material Characteristics and Supercapacitive Performance of MnO2 Electrodes

Manganese dioxide was synthesized by electrodeposition method with Mn (CH3COO)(2) center dot 4H(2)O as a raw material. La(NO3)(3) center dot 6H(2)O was doped in electroyte during the preparing process to improve the performance of MnO2 electrodes. The micrographs, crystal structure and element content of electrodes were analyzed by SEM, XRD and atomic absorption spectroscopy, respectively. It is found that the La content ratio in the dioxide can be easily controlled by adjusting the composition of the plating solution. Appropriate amount of doped La can increase the surface area of Mn/La materials, resulting in the supercapacitive behavior enhancement. Electrochemical tests show that the specific capacitance is significantely increased from 198.72 F . g(-1) to 276.60 F . g(-1) by La-doping.