Supercapacitive Performance of Manganese-Iron Oxide Films Prepared by Sol-gel Technique

• Main Authors: Chia-Yu Yang, 楊家瑜
• Other Authors: Tse-Ying Liu, Chien-Yie Tsay , Chung-Kwei Lin
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/81908497361176654019

碩士 === 逢甲大學 === 材料科學所 === 97 === In the present study, both of manganese oxide and iron oxide electrodes possessing pseudocapacitance behaviors were prepared successfully by sol-gel process. The effects of the ratio of manganese acetate and iron acetate that served as the precursors, pH value, and post heat treatment on the material characteristics and electrochemical capacitance of the manganese–iron oxide electrodes were investigated. The experimental results showed that the specific capacitance was 40.7, 101.2, 71.6, and 57.8 F/g for pure manganese oxide films heat-treated at 250, 300, 350, and 400 oC, respectively. The specific capacitance increased to 69.6, 210.8, 232.3, and 165.7 F/g for 1% iron oxide added manganese oxide films, heat-treated at 250, 300, 350 and 400 oC, respectively. This indicated that the specific capacitance was improved by adding iron oxide into the manganese oxide electrodes. The surface morphology observations revealed that the higher was the annealing temperature, the smaller pores can be observed. X-ray diffraction results showed that manganese-iron oxide composed of Mn3O4 and Mn2O3 phase, without iron oxide diffraction peaks. The shift of XRD peaks revealed that the addition of iron oxide induced a distortion of manganese oxide lattice. After 1200 cyclic voltammetry tests, the specific capacitance decreased 26.9 % of its maximum value. Compared to a decrease of 49.3 % for pure manganese oxide, manganese-iron oxide electrode exhibited better electrochemical performance and capacitance efficiency.