Multifunctional catalytic porous transport layer integrated with NiSe₂ chalcogen compound for high-performance electrochemical energy devices

The porous transport layer (PTL) is an essential component for electrochemical energy devices using gaseous fuels such as polymer electrolyte membrane water electrolyzers (PEMWEs) and lithium air batteries (LABs). Generally, PTL serves to transfer the chemical species required for chemical reactions to the active site. In this study, we prepare a bifunctional catalytic metal-foam porous transport layer (CMPTL) that can serve as an electrochemical catalyst as well as mass transfer. A CMPTL consists of nanostructured NiSe₂ directly synthesized on Ni foam with a porous 3D structure by hydrothermal synthesis, and NiSe₂ provides catalytic activity for the OER and HER. As a result of evaluating the linear sweep voltammetry (LSV) of the CMPTL using three electrode systems, the total overpotential of CMPTL is reduced by about 30.8% compared to commercial PTL (Ni foam). In addition, the energy density of LABs with CMPTL increases by 16.7% at a current density of 200 μA cm⁻², and the current density of PEMWE with CMPTL increases by 23.5 times at 1.9 V.