Impact of clamping pressure and stress relaxation on the performance of different polymer electrolyte membrane water electrolysis cell designs

In situ investigation of ion exchange membranes reveals that ion transfer in hybrid liquid/gas electrolyzers is mediated by diffusion, not electromigration

“…Borgardt and co-workers reported in fact that mass transport and ohmic losses rise drastically in polymer electrolyte membrane (PEM) fuel cells when clamping pressures are above the critical value of 2.5 MPa. 48 To the best of our knowledge, no similar type of information could be retrieved in the literature for H-type (photo)electrolyzers. The cap is provided with a circular opening ( Ø = 12.0 mm), allowing the X-ray beam to reach the membrane and the analyzer nozzle to approach the membrane for the photoelectron collection (Fig.…”

“…Properties such as conductivity and permeability of membranes, mechanical stability, as well as current/potential characteristics of polymer electrolyte membrane (PEM) fuel cells, are strongly inuenced by the clamping pressure. 48,49 The reproducibility of the applied clamping pressure was ensured by using ISO M3 HELICOIL® threaded inserts (Böllhoff, stainless steel 304) in the PEEK cell body, calibrated for torques up to 0.10 N m. The use of metallic bolts and threaded inserts also ensures a higher resistance against wearing compared to polymer-based materials, which is also an important source of non-reproducibility over time of the clamping pressure. The calibration of the torque was performed using a torque wrench (Wiha, ESD Tor-queVario®-S, 0.04-0.46 N m), setting the applied torque (M) to 0.04 N m. It is possible to determine the total force (and therefore pressure) applied to the membrane as follows.…”

A Review of Accelerated Stress Tests for Enhancing MEA Durability in PEM Water Electrolysis Cells

“…Other AST strategies than the experiments presented in Table 5 exist focus on the mechanical degradation of the membrane. For instance, Borgardt et al [70] tested the influence of the clamping pressure on the performance of different PEMWE cell designs. To minimize the negative impact of membrane degradation on the cell performance, novel approaches like the reinforcement or modification of membranes exist.…”

Constructing a Multifunctional Interface between Membrane and Porous Transport Layer for Water Electrolyzers

“…Such conditions demand the use of highly corrosion-resistant PTLs and bipolar plates on the anode side. To circumvent this, PEM water electrolyzer components are typically made of titanium due to its excellent chemical stability, good conductivity, and high corrosion resistivity. , A variety of titanium-based PTL architectures including titanium felt, − mesh, , foam, , as well as sintered titanium powders − can be used in PEM electrolyzers. In recent decades, several research groups have investigated the effects of different parameters, such as thickness, particle size, pore diameter, and porosity in PTLs. − However, the passivation of titanium-based PTLs that occurs under real cell conditions is one of the essential factors that restricts their application in the absence of any surface modifications.…”

“…To circumvent this, PEM water electrolyzer components are typically made of titanium due to its excellent chemical stability, good conductivity, and high corrosion resistivity. 7,8 A variety of titanium-based PTL architectures including titanium felt, 9−12 mesh, 13,14 foam, 14,15 as well as sintered titanium powders 16−18 can be used in PEM electrolyzers. In recent decades, several research groups have investigated the effects of different parameters, such as thickness, particle size, pore diameter, and porosity in PTLs.…”