Synthesis of phosphonated graphene oxide by electrochemical exfoliation to enhance the performance and durability of high- temperature proton exchange membrane fuel cells

The doping of functionalized graphene oxide (GO) in the membranes becomes a promising method for improving the performance of high-temperature proton exchange membrane fuel cells (HT-PEMFC). Phosphonated graphene oxide (PGO) with a P/O ratio of 8.5% was quickly synthesised by one-step elec-trochemical exfoliation based on a three-dimensiaonal (3D) printed reactor and natural graphite flakes. Compared with the GO prepared by the two-step electrochemical exfoliation method, the PGO synthe-sized by the one-step electrochemical exfoliation can better improve the performance of the membrane-electrode-assembly (MEA) based on the polybenzimidazole (PBI) membrane in the HT-PEMFC. The doping of 1.5 wt% GO synthesised by electrochemical exfoliation with the 2-step method or reactor method in PBI increased the peak power density by 17.4% or 35.4% compared to MEA based on pure PBI membrane at 150 degrees C, respectively. In addition, the doping of PGO in PBI improves its dura-bility under accelerated stress test (AST).(c) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. This is an open access article under the CC BY license (http://creati-vecommons.org/licenses/by/4.0/).