Novel mesh-based porous transport layer structures for low-cost, high-performance and durable proton exchange membrane water electrolyzers

Proton exchange membrane water electrolysis (PEMWE) is promising for hydrogen production and renewable energy utilization. However, the high cost of titanium porous transport layers (PTLs) has hindered their large-scale commercialization. Woven titanium mesh is considered a cost-effective PTL material, but it leads to suboptimal PEMWE cell performance. This study presents a low-cost, high-performance, and durable PEMWE cell utilizing a woven titanium mesh PTL filled with titanium powders (Ti mesh/powder-PTL), which is comprehensively investigated for the first time. When woven titanium meshes were used as PTLs, the cell voltage reached 1.988 V at 2 A/cm2 and 60 °C. Upon the introduction of titanium powders to the titanium mesh, the cell achieved an unprecedented performance of 1.901 V under the same conditions, outperforming previous studies using titanium woven meshes as PTLs. The PEMWE cell with Ti mesh/powder-PTL was evaluated in an accelerated stress test (AST) for 800 h and compared with the cell with Ti mesh-PTL. The results showed a 39.3 % reduction in the irreversible voltage decay rate, corresponding to a decrease of 120.97 μV/h. The Ti mesh/powder-PTL significantly reduced ohmic losses before the AST, while considerably reducing activation and mass transfer losses post-test. Extensive physical and electrochemical analysis indicates that the filled titanium powders optimize the interface between the PTL and catalyst layer, gradient the titanium mesh, and provide extra pathways for interfacial electron transport and additional bubble nucleation. Furthermore, the use of woven Ti mesh filled with Ti powder as a PTL reduces the cost by over 90 % compared with traditional porous materials like Ti felt and sintered Ti. Therefore, we demonstrate the potential of a Ti-powder-filled titanium mesh as a PTL from the perspectives of cost reduction, performance, and durability, thereby advancing the development of green hydrogen production technology.