Degradation of gas diffusion layers through repetitive freezing

A review of the gas diffusion layer in proton exchange membrane fuel cells: Durability and degradation

“…The highly stiff felt GDL showed the best freeze/thaw durability, while cloth and paper GDLs had the medium and the worst durability, respectively [65] Freeze/thaw cycle Repetitive cycle from À10°C to 1°C 1000 cycles Felt The GDL aligned perpendicular to the major flow field direction showed a higher durability than the GDL parallel to the flow field [66] Freeze/thaw cycle Repetitive cycle from À40°C to 80°C 100 cycles Cloth/paper Deteriorated cell performance in carbon paper due to the breakage of fibers, decreased MPL contact angle, and detachment of catalyst was observed [67] Freeze/thaw cycle Repetitive cycle from À15°C to 70°C 50 cycles Felt/paper The existence of MPL caused more damage to the catalyst layer due to more water remaining in the membrane [70] Freeze/thaw cycle Repetitive cycle from À20°C to 10°C 10 times Felt/paper The reduction in the contact angle may be due to the separation of PTFE from the carbon fiber rather than the deformation of the planar pore structure [71] Cold start Cold start test at À5°C and À10°C -Paper…”

“…Lee et al [71] investigated the effect of PTFE content on GDL, regarding its various properties such as porosity, bulk density, pore distribution, surface image, gas permeability, and contact angle. Because the PTFE physically covers the carbon fibers and binders, it suppresses the carbon fiber detachment and eases the structural changes, such as the formation of cracks on the MPL, at a cost of a decrease in porosity.…”

Variation of Porosity and Gas Permeability of Gas Diffusion Layers Under Compression

“…여기서 d g 는 particle 의 직경이며 GDL 에서는 carbon fiber 의 직경으로 대체할 수 있다. 본 연구에서 사용한 GDL 과 동일 제조사의 GDL 의 SEM 이미지 (6) 로부터 측정한 결과 대략 10 µm 의 직경을 갖고 있는 것으로 판단된다.…”

Effects of Freeze–Thaw Thermal Cycles on the Mechanical Degradation of the Gas Diffusion Layer in Polymer Electrolyte Membrane Fuel Cells

“…Mostly, the degradation of GDLs can be classified into mechanical degradation (including compression force effect, freeze–thaw thermal cycle effect, dissolution, and erosion effect) and physicochemical degradation (including chemical dissolution effect, carbon corrosion effect, and electrochemical degradation) [1,3]. Han et al [9], Lee et al [10], and Yan et al [11] only investigated the freezing effects on the physical properties of GDLs, such as polarization curves, voltage and current performance, high-frequency resistance, thickness, surface morphology, pore size distribution, gas permeability, and contact angle of the surface. Although the effects of freeze–thaw thermal cycles on GDL degradation have been studied [3,12,13,14], the majority merely focused on the GDLs’ physical degradation performance.…”