Electrochemical properties of Ml(NiCoMnCu)(5) used as an alkaline fuel cell anode

The electrochemical properties of AB(5)-type rare earth-nickel multicompone nt compounds Ml(NiCoMnCu)(5) (Ml: La-rich mischmetal) used as an alkaline f uel cell anode were investigated at 30 degrees C. A double-layer porous fil m structure with foamed nickel as current collector was adopted for the ano de. A catalyst layer made of Ml(NiCoMnCu)(5) alloy powder and a 60% aqueous suspension of polytetrafluoroethylene (PTFE) was on the electrolyte side, and a waterproof layer made of a Teflon aqueous suspension and Na2SO4 powde r was on the gas side. The experimental results revealed that the anode per formance strongly depends on the PTFE content of the catalyst layer, the th ickness of the catalyst layer and the waterproof layer, and the cold compre ssion pressure for electrode formation. When these four parameters were 12 wt.%, 0.25 mm, 0.2 mm and 12 MPa, respectively, the anode had a life-time o f approximatly 550 h at a current density of 20 mA/cm(2). (C) 1999 Elsevier Science S.A. All nights reserved.