Effect of Silicotungstic acid on Cathode Performance in Proton Exchange Membrane Fuel Cells

摘要

Silicotungstic acid, a heteropolyacid, was added to the cathode of polymer electrolyte membrane fuel cells and evaluated for increased performance at high temperature and low relative humidity (RHs). Electrodes showed significant flaking and cracking with addition of silicotungstic acid at 15%. Adjustment of catalyst ink pH and addition of silicotungstic acid to a known ionomer morphology showed increased activity at 120℃/35%RH by as much as 36% for cells dipped in STA compared to cells dipped in deionized water. Additionally, membrane resistance was improved by 28%. The performance impact of STA was extended out to higher current densities showing a significant improvement in cell performance.