LBM studies at pore scale for graded anodic porous transport layer (PTL) of PEM water electrolyzer

Tailored Porous Transport Layers for Optimal Oxygen Transport in Water Electrolyzers: Combined Stochastic Reconstruction and Lattice Boltzmann Method

“…The contact angle of Ti fibers was set to 45° (i. e., hydrophilic character) and the surface tension was set to 0.0625 $${N/{\rm { m}}}$$ . Assuming a temperature of 298.15 $${{\rm K}}$$ , [51] the density of water and oxygen was set to 997.05 $${{\rm { kg/}}{{\rm { m}}}^{{\rm { 3}}}}$$ and 1.14 $${{\rm { kg/}}{{\rm { m}}}^{{\rm { 3}}}}$$ , respectively.…”

“…The contact angle of Ti fibers was set to 45°(i. e., hydrophilic character) and the surface tension was set to 0.0625 N=m. Assuming a temperature of 298.15 K, [51] the density of water and oxygen was set to 997.05 kg=m 3 and 1.14 kg=m 3 , respectively.…”

“…In previous studies, [20,29,44,51] spatially gradient-porosity PTLs were proposed to trade off ohmic losses and mass transport losses, which further enhanced the performance of PEM electrolyzers. Although the low-to-high porosity PTL configuration from CL to BPP has been reported to enhance the performance of PEM electrolyzers, the mass transport behavior within the PTL has not been investigated in detail.…”

“…The much more complex 3-D temporal and spatial two-phase distributions inside PTLs cannot be obtained with the latter. Most of the current work considered the direct relationship between PTL structural properties and PEMEC performance, [12,29,[48][49][50] but the necessary and important correlations between the pore-scale structure and mass transport are still missing, as concluded in the latest work of Bhaskaran et al [51] In their work, they numerically investigated the oxygen propagation inside graded PTLs in relation to the structural properties, indicating a strong dependence of the two-phase flow behaviors on the graded structure. The porosity and pore structural properties of PTLs are critical to the mass transport losses and ohmic losses of PEMECs.…”

“…[16,21] Therefore, the selection of PTL structures is a very contradictory and intractable problem, and this work will focus on the impact of PTL structural properties on the distribution of gas/water within this layer, aiming to provide more perspectives for the design and application of PTLs. Inspired by the work of Bhaskaran et al, [51] an optimal graded PTL structure is targeted in our work while other structural details of the PTL, such as the porosity, fiber radius, and fiber orientation are fully considered.…”