Ex-situ PEM fuel cell testing: towards visualizing gas diffusion
View Patent ↗The invention comprises novel apparatuses and testing methods for evaluating a fluid diffusion component. The apparatus includes a fluid capable of undergoing oxidation or reduction, a half-cell electrode assembly able to receive the fluid, and a change in acidity indicator in communication with the assembly. An inventive method of the invention includes the steps of passing a fluid capable of undergoing oxidation or reduction through a half-cell electrode assembly to form a sample, contacting the sample with an indicator, and detecting a change in acidity in the indicator.
1. A fluid diffusion testing apparatus comprising:
a fluid capable of undergoing oxidation or reduction;
a half-cell electrode assembly capable to receive and chemically modify said fluid,
wherein the half-cell assembly comurises an ion exchange membrane;
a change in acidity indicator in communication with said assembly and the chemically modified fluid; and
a detector for detecting a change in the change in acidity indicator, wherein said detector comprises a fluorescent pH indicator and an UV lamp aligned to illuminate said fluorescent pH indicator.
2. The fluid diffusion testing apparatus according to claim 1 wherein said assembly comprises a catalyst.
3. The fluid diffusion testing apparatus according to claim 2 wherein said apparatus further comprises a fluid permeable element in communication with said catalyst, said fluid permeable element comprises at least one of a gas diffusion layer, a gas diffusion substrate, and combinations thereof.
4. The fluid diffusion testing apparatus according to claim 3 wherein said gas diffusion substrate comprises at least one of a sheet of: flexible graphite, carbon fiber paper, cotton fiber, glass fiber, asbestos, inorganic fiber, cardboard, aluminum oxide membrane, zeolite substrate, polymer material, a composite of flexible graphite and a polymer, a composite of carbon and a polymer, a composite of carbon, flexible graphite, and a polymer, and combinations thereof.
5. The fluid diffusion testing apparatus according to claim 4 wherein said membrane is positioned between said catalyst and said indicator.
6. The fluid diffusion testing apparatus according to claim 2 wherein said assembly further comprises at least one of a flow field plate, a gas diffusion layer, a gas diffusion substrate, and combinations thereof.
7. The fluid diffusion testing apparatus according to claim 1 further comprising an electrical current measuring assembly, said electrical current measuring assembly comprising a pair of electrodes disposed in said indicator and a quantifying element connected to said electrodes.