Performance study of direct borohydride fuel cells employing polyvinyl alcohol hydrogel membrane and nickel-based anode

A direct borohydride fuel cell (DBFC) employing a polyvinyl alcohol (PVA) hydrogel membrane and a nickel-based composite anode is reported. Carbon-supported platinum and sputtered gold have been employed as cathode catalysts. Oxygen, air and acidified hydrogen peroxide have been used as oxidants in the DBFC. Performance of the PVA hydrogel membrane-based DBFC was tested at different temperatures and compared with similar DBFCs employing Nafion® membrane electrolytes under identical conditions. The borohydride-oxygen fuel cell employing PVA hydrogel membrane yielded a maximum peak power density of 242mWcm^-2 at 60°C. The peak power densities of the PVA hydrogel membrane-based DBFCs were comparable or a little higher than those using Nafion® 212 membranes at 60°C. The fuel efficiency of borohydride-oxygen fuel cell based on PVA hydrogel membrane and Ni-based composite anode was found to be between 32 and 41%. The cell was operated for more than 100h and its performance stability was recorded.