Improvement of Fuel Cell Durability Performance by Avoiding High Voltage

In order to increase the durability of fuel cell stack, various operating technologies such as voltage cut-off and lean air operation was verified. With an application of upper voltage cut-off, cell performance loss was effectively diminished, which suggests that a formation of surface oxide layer on Pt was suppressed resulting in less irreversible catalyst deterioration such as Pt dissolution. In addition, it was found that voltage sweeping to lower reductive potential with a lean air supply was beneficial in preventing a power loss. With a simulated vehicle driving mode, it was confirmed that performance durability was 3 times improved with an application of both voltage cut-off and lean air supply which might be ascribed to the maintaining the electrochemical acive area of Pt catalyst. The suggested operating conditions based on Pt degradation mechanism will contribute the durability enhancement of fuel cell stack for FCEVs.