| The proton exchanged membrane fuel cell (PEMFC) adopts platinum as catalyst, which restricts its commertialization due to high price. In this paper, membrane electrode assembly (MEA), a key component of fuel cell, was investigated on fabrication of electrode and operation. Farther research has been done on MEA, including membrane, gas diffusion layer and catalyst layer. Based on work above, a noval structure of dual-bonded catalyst layer electrode was introduced to enhance the cell performance with low Pt loading.Polarization curve was introduced to characterize the cell performance and data was used to fit by non-linear least square. AC impedance was also used to study the effect of opertation conditions on performance of cell. Scanning electron microscope graphs were adapted to investigate MEA, including substrate, gas diffusion layer and catalyst layer.Preparation and operation condition of MEA were studied. Resistance of MEA reduced to 40??cm-2 when it was hot-pressed at 130℃under 8MPa for 120 seconds. Torque of fixture was matained 3N?m for cell assemblage. Utilization of reactant gas was increased with temperature and decreased with increasing flow rate under 1atm when temperature was less than 65℃. Utilization of oxygen was reduced when temperature was more than 65℃.Operation temperature of cell should be chosed as 65℃with lowest resistance. Investigating MEA's activation at ambient pressure, cell showed stable performance when actived with varied current at 50℃after 10h.Three part of MEA were investigated and found that high protonic conductivity was conrresponding to thinner membrane. Protonic conductivity of different membrane was increased with high temperature. Gas diffusion layer was comprised of substrate and micro-pouose layer. Thinner substrate was favorable for gas transport. Micro-porous layer of electrode with 2mg·cm-2 cabon black XC-72 containing 20wt.% PTFE provided 0.35W·cm-2. Micro-porous laye formed by XC-72 was favorable for gas transport and showed a better performance in active rigion, whilst it formed by BP2000 was advantage in water drainage and showed a better performance in concertration polarization. Cell performance was poor when two types of carbon mixed to make micro-porous laye because incrased of mass transport resistance. Spray was a better choice to make catalyst layer than print. Hydrophobic catalyst layer containing 35wt.% PTFE and 1.5mg·cm-2 Nafion showed high performance. Hydrophilic catalyst layer containing 30wt.% Nafion and 0.2mg·cm-2 Pt loading showed performance of 0.5W·cm-2. There exsit active layer and inactive layer when PTFE or Nafion was chosed as bonded material for catalyst layer. Electrochemical reaction was decreased from active layer to inactive layer.The dual-bonded catalyst layer with inner and outer catalsty layer was designed. Inner catalyst layer was hydrophilic and bonded with Nafion. Outer catalyst layer was hydrophilic and bonded with PTFE. A transition layer formed when two catalyst layers was hot-pressed that main reaction occurs. PTFE of out layer and Nafion of inner layer were distributing in grads for reaction. When electrode with 0.3mg·cm-2 Pt loadings at 1A·cm-2, it was calculated that performance of cathode with dual-bonded catalyst layer offers 37.2% higher than that of hydrophobic cathode and 20.4% higher than that of hydrophilic catalyst layer. Two groups of dual-bonded electrode with 0.3mg·cm-2 Pt loadings were fabricated to investigate Nafion effect on cell performance. Peak power density of electrodes increased from 0.64W·cm-2 to 0.77W·cm-2 at ambient pressure as recast film decrase. The prtonic conductivity affected more on reaction than that of mass transfer when adjust ratio of catalyst layer.Catalyst layer was decreased to below 0.2mg·cm-2 Pt loading and the cell performance was increased to above 0.7W·cm-2 when operated in hydrogen and oxygen. Cell performance was increased whilst cost of MEA was reduced.
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