Interface-engineered graphene oxide membranes for high-performance fluorine-free fuel cells

Abstract

Hydrogen fuel cells have emerged as promising clean energy devices, with polymer electrolyte fuel cells (PEFCs) already implemented in transportation and residential power systems in the past. Benchmark perfluorosulfonic acid membranes exhibit excellent proton conductivity but face drawbacks, including prohibitively high cost, reliance on fluorine-based chemistry, and increasing regulatory restrictions on PFAS. Therefore, the development of fluorine-free, low-cost, scalable, and high-performance electrolytes is critical for next-generation fuel cells. Graphene oxide (GO), with its two-dimensional structure and high dispersibility arising from abundant oxygen functional groups, has attracted significant attention as a potential electrolyte. However, its overall performance remains insufficient for practical applications. Here, we demonstrate a high-performance GO electrolyte achieved through the combined use of defect-rich GO to enhance proton transport, protonic interfacial modification to reduce electrode–electrolyte resistance, and ultrathin membrane engineering to maintain gas-barrier integrity. The GO fuel cell achieved a power density of 0.7 W cm−2 at 40 °C, surpassing the performance of state-of-the-art PFSA membranes under identical conditions. This work establishes an interfacial engineering concept that unites resistance reduction, protonic modification, and thin-film processing, providing a broadly applicable pathway for nanosheet-based electrolytes in next-generation fuel cells.