Patterned design of porous carbon materials as microporous layers to enhance fuel cell performance over a wide humidity range

Microporous layers play a crucial role as one of the main components of the membrane electrode assembly (MEA) in facilitating effective water management for proton exchange membrane fuel cells (PEMFCs), which is vital for maintaining optimal performance in a wide humidity range . Herein, Zn-based zeolitic imidazolate framework-8 (ZIF-8)-derived material (ZDM) as a porous carbon material is first developed to construct the microporous layer (MPL). With higher gas permeability , improved water management, and increased electrical conductivity , the MPL equipped with a ZDM layer, denoted as MPL-Z, exhibits superior performance, surpassing commercial MPLs throughout the range of 30–100% relative humidity (RH). The peak power density of an H 2 /air PEMFC at 70% RH utilizing a MPL-Z is 3.3 times that of commercial MPL. Furthermore, a unique patterned dual MPL is designed to boost the performance, ultimately achieving a peak power density of 1.50 W cm −2 (H 2 /air) with a low total Pt loading of 0.3 mg Pt cm −2 at 100 % RH. Even at only 30% RH, the peak power density can reach 0.72 W cm −2 (H 2 /air). The results demonstrate that the material and structural design of the MPL allows for the efficient operation of low Pt loading PEMFCs over a wide humidity range.