Hydrogen as a clean energy carrier is of great potential to store energy coming from renewable and intermittent power sources and proton exchange membrane mater electrolysis (PEMWE) is one of the most desired technology for high purity hydrogen production. However, the electrolytic performance of PEMWE is limited by several factors and more efforts should be paid to improve the performance. In this paper, a nonpressurized PEMWE was constructed and the effects of key influencing factors (inlet water temperature, water flow rate, assembly pressure, porous transport layer type and proton exchange membrane type) on electrolytic performance were experimentally investigated. The results show that a good pressure distribution was found inside the electrolyzer. The optimal inlet water temperature of 80 oC and flowrate of 90 sccm can meet the requirement of mass transfer at rated current density. At 1 atm, the assembly torque of 2 Nm can achieve effective sealing while extra torque is needed for high-pressure working conditions. Durability test over 60 h indicated that a good durability of the nonpressurized PEMWE under the above conditions. In addition, the electrolytic performance could be also improved by using titanium felt as anode/cathode PTL and decreasing the thickness of PEM in a certain range.
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