抄録
To improve the rate performance of the manganese dioxide positive electrode of the fuel cell/battery systems, we fabricated electrodes by adding small amount (5 and 10 wt%) of nickel hydroxide to the manganese dioxide. Electrochemical characterizations such as galvanostatic measurements and electrochemical impedance spectroscopy were carried out to determine the discharge rate performance and electrical resistance. Scanning electron microscope and X-ray diffraction were also used to observe the crystal structure and morphology of the electrode before and after the electrochemical test. The electrochemical results indicated that the positive electrode with nickel hydroxide has better rate performance than the pure manganese dioxide electrode. It is considered that the electrical path in the electrode was improved owing to the low electrical resistance of the nickel hydroxide and the bimodal effects between the nickel hydroxide and manganese dioxide particles. Additionally, X-ray diffraction confirmed that the formation of δ-MnO_2, which results in electrochemically unreactive Mn_3O_4 after electrochemical discharging, is inhibited in the presence of nickel hydroxide.
