PROTON EXCHANGE MEMBRANE FUEL CELLS FOR FROM BASIC RESEARCH TO TEiCJ3NOLOGY DEVELOPMENT SPACE AND ELECTRIC VEHICLE APPLICATIONS -

The proton exchange membrane fuel cell (PEMFC) is one of the most promising electrochemical power sources for space and electric vehicle applications. The wide spectrum of R&D activities on PEMFCs, carried out in our Center from 1988 to date, is as follows (1) Electrode Kinetic and Electrocatalysis of Oxygen Reduction; (2) Optimization of Structures of Electrodes and of Membrane and Electrode Assemblies; (3) Selection and Evaluation of Advanced Proton Conducting Membranes and of Operating Conditions to Attain High Energy Efficiency; (4) Modeling Analysis of Fuel Cell Performance and of Thermal and Water Management; and (5 ) Engineering Design and Development of Multicell Stacks. The accomplishments on these tasks may be summarized as follows: 1. A microelectrode technique was developed to determine the electrode kinetic parameters for the fuel cell reactions and mass transport parameters for the H2 and reactants in the proton conducting membrane. High energy efficiencies and high power densities were demonstrated in PEMFCs with low platinum loading electrodes (0.4 mg/cm2 or less), advanced membranes and optimized structures of membrane and electrode assemblies, as well as operating conditions. 2.