A hybrid PEMFC/supercapacitor device with high energy and power densities based on reduced graphene oxide/Nafion/Pt electrode

Proton exchange membrane fuel cells (PEMFCs) possess high energy and low power den-sities, while supercapacitors are characterized by high power and low energy densities. A hybrid PEMFC/supercapacitor device (HPSD) with high energy and power densities was proposed and fabricated for the first time using a reduced graphene oxide/Nafion/Pt elec-trode in this study. The reduced graphene oxide (rGO) was a capacitive material, and Pt was used as the electrocatalyst. Nafion ionomers adsorbed onto the rGO sheets surface and connected the rGO sheets and the electrolyte (Nafion membrane), thus increasing the utilization rate and specific capacitance of rGO. During the half-cell tests, the rGO/Nafion/ Pt electrode exhibited better pulse discharge and galvanostatic discharge performance than the conventional Nafion/Pt electrode. Due to the unique synergy of electrochemical reaction current and capacitance current during the discharge process, the HPSD exhibited a higher power density (26.2 kW kg(-1)) than the PEMFC (23.9 kW kg(-1)). The energy density (12.7 kWh kg(-1)) exhibited by HPSD was close to that of the PEMFC (13.5 kWh kg(-1)). Therefore, the concept of HPSD is to create a new method for developing next-generation electrochemical devices with high energy and power densities.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.