rGO deposited in stainless steel fiber felt as mass transfer barrier layer for μ-DMFC

• rGO is deposited into SSFF as anode current collector and backing layer for μDMFC.
• SSFF-rGO can improve the performance by reducing methanol crossover.
• SSFF-rGO has a smaller impedance than conventional DMFC.

In this paper, a novel anode mass transfer barrier layer was developed for μ-DMFC (micro direct methanol fuel cell) to decrease methanol crossover. The novel barrier layer was a composite material of SSFF (stainless steel fiber felt) and rGO (reduced graphene oxide), which was prepared by dipping a piece of SSFF plate into graphene oxide solution and subsequently experiencing a reduction process. Using this composite material as anode barrier layer and current collector at the same time, a passive μ-DMFC was fabricated and tested. The results show that the novel barrier layer can effectively increase the methanol mass transport resistance, which lowers the methanol crossover and thus allows the cell operating at a high methanol concentration. In addition, the cell fabricated with the novel barrier layer shows higher discharging stability and smaller inner resistance at the same time when compared with the conventional cell.