Barrel effect in an air-cooled proton exchange membrane fuel cell stack

The performance of a single cell affects the proton exchange membrane fuel cell (PEMFC) stack's overall output performance, and the barrel effect occurs in PEMFC stacks. This research presents strategies to alleviate single-cell performance degradation in an air-cooled PEMFC stack. Results show that the poorest cell performance is caused by location-related issues. By embedding a copper plate in the position of cell-1, a hollow chamber replaces the cell-1 flow field. The stack equipped with an embedded copper plate achieved its peak power at 2151.22 W under a current of 40 A, signifying an 8.6 % enhancement in performance compared to the original stack. The incorporation of carbon paper and copper plates contributes to the establishment of a uniform stress distribution within the stack, consequently resulting in enhanced voltage consistency, characterized by a minimal variance value of approximately 0.033. Furthermore, the output performance of cell-1 increased by 0.101 V in the stack with copper plate compared to the original stack under 30 A current loading. By introducing a copper plate, the hollow gas chamber replaces the low pressure-drop cells position, effectively resolving the barrel effect in the PEMFC stack, and alleviating the single-cell degradation problem.