Imaging and Modeling of Passive Water Management in a Miniature Fuel Cell

Date Published
07/2019
Publication Type
Journal Article
Authors
DOI
10.1149/09208.0395ecst
Abstract

A small microwatt fuel cell stack with 8 cells was designed, fabricated, and tested for passive operation with pure H2 and O2 to provide continuous power for multiple decades with uncontrolled fluctuating ambient conditions. The stack was designed to operate with dead ended gas flows with water removal via passive membrane diffusion to notches in the bipolar plates. Two stacks with active areas of 0.2 cm2 , one with 200 µm of membrane and the other with 400 µm, were assembled and tested at varying temperatures and current conditions. Temperatures ranged –55 ºC to 70 ºC, with focus on the lower temperatures. Factors affecting water production and removal included temperature, gas crossover, and membrane thickness. Currents were applied from 16 µA to 10 mA after the cells were stabilized at temperature, followed by a period of drying to observe water transport to the external peripheries of the cell. A two-dimensional multiphysics model was developed to further explore the water management system in varying conditions.

Journal
ECS Transactions
Volume
92
Year of Publication
2019
Issue
8
Pagination
395 - 409
ISSN Number
1938-6737
URL
Short Title
ECS Trans.
Refereed Designation
Refereed
Organizations
Research Areas
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