For the commercialization of bipolar plates, several properties must be considered together. Electrical conductivity, corrosion resistance, contact resistance, mechanical strength, and light weight are essential evaluation factors, with corrosion resistance and durability being significant for unitized regenerative fuel cells (URFCs), which must operate in electrolysis and fuel cell mode. However, improving both properties is challenging, since corrosion resistance is largely inversely proportional to conductivity. In this study, to improve both properties together, composites composed of Pb and Zn with excellent conductivity and corrosion resistance were prepared with graphite powder and formed as a coating layer on the surface of 304 stainless steel (SS304) and evaluated for electrical conductivity and corrosion resistance. Among the ZnPb/C composites prepared at various ratios, Zn8Pb2/C exhibited the lowest transmittance resistance of 1.566 Ω, and improved electrical conductivity and durability compared to bare SS304.

ZnPbC composites coating layer on stainless steel for bipolar plate of unitized regenerative fuel cells
    Abstract
    1 Introduction
    2 Experimental
        2.1 Materials
        2.2 Preparation of ZnPbC-coated SS bipolar plate
        2.3 Preparation of stack cell for URFCs
        2.4 Characterizations
    3 Results and discussion
    4 Conclusion
    Acknowledgements 
    References

• Joon Young Kim(Hydrogen Energy Technology Laboratory, Korea Institute of Energy Technology (KENTECH), 200 Hyeoksin‑Ro, Naju, Jeonnam 58330, Republic of Korea)
• Chanmin Jo(Hydrogen Energy Technology Laboratory, Korea Institute of Energy Technology (KENTECH), 200 Hyeoksin‑Ro, Naju, Jeonnam 58330, Republic of Korea)
• Dae Jun Moon(Hydrogen Energy Technology Laboratory, Korea Institute of Energy Technology (KENTECH), 200 Hyeoksin‑Ro, Naju, Jeonnam 58330, Republic of Korea)
• Gyoung Hwa Jeong(Hydrogen Energy Technology Laboratory, Korea Institute of Energy Technology (KENTECH), 200 Hyeoksin‑Ro, Naju, Jeonnam 58330, Republic of Korea)
• Gnanaprakasam Janani(Hydrogen Energy Technology Laboratory, Korea Institute of Energy Technology (KENTECH), 200 Hyeoksin‑Ro, Naju, Jeonnam 58330, Republic of Korea)
• Uk Sim(Hydrogen Energy Technology Laboratory, Korea Institute of Energy Technology (KENTECH), 200 Hyeoksin‑Ro, Naju, Jeonnam 58330, Republic of Korea, Center for Energy Storage System, Chonnam National University, Gwangju 61186, Republic of Korea) Corresponding author
• Ho‑Young Jung(Department of Environment and Energy Engineering, Chonnam National University, 77 Yongbong‑Ro, Buk‑Gu, Gwangju 61186, Republic of Korea, Center for Energy Storage System, Chonnam National University, Gwangju 61186, Republic of Korea)
• Seungryul Yoo(Institute of Plasma Technology, Korea Institute of Fusion Energy (KFE), Gunsan, Jeollabuk‑Do 54004, Republic of Korea)
• Dong Chan Seok(Institute of Plasma Technology, Korea Institute of Fusion Energy (KFE), Gunsan, Jeollabuk‑Do 54004, Republic of Korea)
• Seon Yeop Jung(Department of Chemical Engineering, Dankook University, Yongin‑Si, Gyeonggi‑Do 16890, Republic of Korea)
• Tae‑Hoon Kim(Department of Materials Science and Engineering, Chonnam National University, Gwangju 61186, Republic of Korea)