(417b) Ni-Doped Porous Manganese Dioxide as Positive Electrode Material for Fuel Cell/Battery (FCB)System

For a Fuel Cell/Battery (FCB) system, manganese dioxide (MnO2) could serve not only as active positive electrode materials of secondary battery but also as a catalyst for oxygen reduction (ORR) in fuel cells. In the present study, porous MnO2 materials with huge surface areas were prepared using a template method in order to provide enough space for the electrochemical redox reaction and ORR. In addition, the Ni ion was doped on the prepared porous MnO2 to enhance the proton transportation. The obtained materials were characterized by BET, XRD, and SEM. It is found that the porous Ni-MnO2 had the crystal structure like the gamma MnO2. The performance of the positive electrode composed of the porous Ni-MnO2 in FCB system was also investigated via Electrochemical Impedance Spectroscopy (EIS) and galvanostatic discharge curves. The results showed that the electrochemical impedance of this positive electrode obviously decreased while the output voltage increased both in the secondary battery and in the fuel cell, suggesting that the Ni doped MnO2 with porous structure could improve the power density of the FCB system and be suitable for high power output energy generation/storage applications.