Considering the application of the polymer electrolyte membrane fuel cell (PEMFC), the separator thickness plays a significant role in determining the weight, volume, and costs of the PEMFC. In addition, thermal management, i.e., temperature distribution is also important for the PEMFC system to obtain higher performance. However, there were few reports investigating the relation between the temperature profile and the power generation characteristics e.g., the current density distribution of PEMFC operated at higher temperatures (HT-PEMFC). This paper aims to study the impact of separator thickness on the temperature profile and the current density profile of HT-PEMFC. The impact of separator thickness on the gases i.e., H₂, O₂ profile of HT-PEMFC numerically was also studied using CFD software COMSOL Multiphysics in the paper. In the study, the operating temperature and the relative humidity (RH) of the supply gas were varied with the separator thickness of 2.0 mm, 1.5 mm, and 1.0 mm, respectively. The study revealed that the optimum thickness was 2.0 mm to realize higher power generation of HT-PEMFC. The heat capacity of the separator thickness of 2.0 mm was the biggest among the separators investigated in this study, resulting in the dry-up of PEM and catalyst layer was lower compared to the thinner separator thickness. It also clarified the effects of separator thickness of profile gases, e.g., O₂, H₂O, and current density profile became larger under the higher temperature and the lower RH conditions.

1. New Energy and Industrial Technology Development Organization (NEDO). Available online: http://www.nedo.go.jp/cotent/100871973 (accessed on 16 August 2023).

2. Zhang G, Kandlikar SG. A critical review of cooling techniques in proton exchange membrane fuel cell stacks. International Journal of Hydrogen Energy 2012; 37(3): 2412–2429. doi: 10.1016/j.ijhydene.2011.11.010

3. Agbossou K, Kolhe M, Hamelin J, et al. Performance of a stand-alone renewable energy system based on energy storage as hydrogen. IEEE Transactions on Energy Conversion 2004; 19(3): 633–640. doi: 10.1109/tec.2004.827719

4. Zhang J, Zhang C, Hao D, et al. 3D non-isothermal dynamic simulation of high temperature proton exchange membrane fuel cell in the start-up process. International Journal of Hydrogen Energy 2021; 46(2): 2577–2593. doi: 10.1016/j.ijhydene.2020.10.116

5. Li Q, He R, Jensen JO, et al. Approaches and recent development of polymer electrolyte membranes for fuel cells operating above 100 °C. Chemistry of Materials 2003; 15(26): 4896–4915. doi: 10.1021/cm0310519

6. Lee CY, Weng FB, Kuo YW, et al. In-situ measurement of high-temperature proton exchange membrane fuel cell stack using flexible five-in-one micro-sensor. Sensors 2016; 16(10): 1731. doi: 10.3390/s16101731

7. Budak Y, Devrim Y. Micro-cogeneration application of a high-temperature PEM fuel cell stack operated with polybenzimidazole based membranes. International Journal of Hydrogen Energy 2020; 45(60): 35198–35207. doi: 10.1016/j.ijhydene.2019.11.173

8. Nanadegani FS, Lay EN, Sunden B. Computational anlysis of the impact of a micro porous layer (MPL) on the characteristics of a high temperature of PEMFC. Electrochimica Acta 2020; 333. doi: 10.1016/j.electacta.2019.133552

9. Nishimura A, Okado T, Kojima Y, et al. Impact of MPL on temperature distribution in single polymer electrolyte fuel cell with various thicknesses of polymer electrolyte membrane. Energies 2020; 13(10): 2499. doi: 10.3390/en13102499

10. Nishimura A, Yamamoto K, Okado T, et al. Impact analysis of MPL and PEM thickness on temperature distribution within PEFC operating at relatively higher temperature. Energy 2020; 205: 117875. doi: 10.1016/j.energy.2020.117875

11. Nishimura A, Toyoda K, Kojima Y, et al. Numerical simulation on impacts of thickness of nafion series membranes and relative humidity on PEMFC operated at 363 K and 373 K. Energies 2021; 14(24): 8256. doi: 10.3390/en14248256

12. Nishimura A, Mishima D, Toyoda K, et al. Numerical simulation on effect of separator thickness on coupling phenomena in single cell of PEFC under higher temperature operation condition at 363 K and 373 K. Energies 2023; 16(2): 606. doi: 10.3390/en16020606

13. Nishimura A, Kojima Y, Ito S, et al. Impacts of separator thickness on temperature distribution and power generation characteristics of a single PEMFC operated at higher temperature of 363 and 373 K. Energies 2022; 15(4): 1558. doi: 10.3390/en15041558

14. Agarwal H, Thosar AU, Bhat SD, et al. Interdigitated flow field impact on mass transport and electrochemical reaction in high-temperature polymer electrolyte fuel cell. Journal of Power Sources 2022; 532: 231319. doi: 10.1016/j.jpowsour.2022.231319

15. Cai L, Zhang J, Zhang C, et al. Numerical investigation of enhanced mass transfer flow field on performance improvement of high‐temperature proton exchange membrane fuel cell. Fuel Cells 2023; 23(3): 251–263. doi: 10.1002/fuce.202200131

16. Hazar H, Yilmaz M, Sevinc H. A comparative analysis of a novel flow field pattern with different channel size configurations. Fuel 2022; 319: 123867. doi: 10.1016/j.fuel.2022.123867

17. Zuo Q, Li Q, Chen W, et al. Optimization of blocked flow field performance of proton exchange membrane fuel cell with auxiliary channels. International Journal of Hydrogen Energy 2022; 47(94): 39943–39960. doi: 10.1016/j.ijhydene.2022.09.143

18. Yan F, Pei X, Yao J. Numerical simulation of performance improvement of PEMFC by four-serpentine wave flow field. Ionics 2022; 29(2): 695–709. doi: 10.1007/s11581-022-04849-0

19. Yu D, Yu S. Analysis of flow variation in a straight channel with baffled obstacles on a bipolar plate in a proton-exchange membrane fuel cell. International Journal of Automotive Technology 2023; 24(3): 759–771. doi: 10.1007/s12239-023-0063-0

20. Yu X, Luo X, Tu Z. Development of a compact high-power density air-cooled proton exchange membrane fuel cell stack with ultrathin steel bipolar plates. Energy 2023; 270: 126936. doi: 10.1016/j.energy.2023.126936

21. Tseng CJ, Heush YJ, Chiang CJ, et al. Application of metal foams to high temperature PEM fuel cells. International Journal of Hydrogen Energy 2016; 41(36): 16196–16204. doi: 10.1016/j.ijhydene.2016.06.149

22. Fly A, Meyer Q, Whiteley M, et al. X-ray tomography and modelling study on the mechanical behaviour and performance of metal foam flow-fields for polymer electrolyte fuel cells. International Journal of Hydrogen Energy 2019; 44(14): 7583–7595. doi: 10.1016/j.ijhydene.2019.01.206

23. Kahraman H, Orhan MF. Flow field bipolar plates in a proton exchange membrane fuel cell: Analysis & modeling. Energy Conversion and Management 2017; 133: 363–384. doi: 10.1016/j.enconman.2016.10.053

24. Han Y, Zhuge W, Peng J, et al. A novel heat pipe bipolar plate for proton exchange membrane fuel cells. Energy Conversion and Management 2023; 284: 116945. doi: 10.1016/j.enconman.2023.116945

25. Zhang J, Xie Z, Zhang J, et al. High temperature PEM fuel cells. Journal of Power Sources 2006; 160(2): 872–891. doi: 10.1016/j.jpowsour.2006.05.034

26. Kanchan BK, Randive P, Pati S. Implications of non-uniform porosity distribution in gas diffusion layer on the performance of a high temperature PEM fuel cell. International Journal of Hydrogen Energy 2021; 46(35): 18571–18588. doi: 10.1016/j.ijhydene.2021.03.010

27. Das SK, Gibson HA. Three dimensional multi-physics modeling and simulation for assessment of mass transport impact on the performance of a high temperature polymer electrolyte membrane fuel cell. Journal of Power Sources 2021; 499: 229844. doi: 10.1016/j.jpowsour.2021.229844

28. Panesi ARQ, Silva RP, Cunha EF, et al. Three-dimensional CFD modeling of H2/O2 HT-PEMFC based on H3PO4-doped PBI membranes. Ionics 2021; 27(8): 3461–3475. doi: 10.1007/s11581-021-04107-9

29. Penga Ž, Tolj I, Barbir F. Computational fluid dynamics study of PEM fuel cell performance for isothermal and non-uniform temperature boundary conditions. International Journal of Hydrogen Energy 2016; 41(39): 17585–17594. doi: 10.1016/j.ijhydene.2016.07.092

30. Cooper NJ, Santamaria AD, Becton MK, et al. Neutron radiography measurements of in-situ PEMFC liquid water saturation in 2D & 3D morphology gas diffusion layers. International Journal of Hydrogen Energy 2017; 42(25): 16269–16278. doi: 10.1016/j.ijhydene.2017.05.105

31. The Japan Society of Mechanical Engineers. JSME Heat Transfer Handbook, 1st ed. Maruzen; 1993. p. 387.

32. Freunberger SA, Reum M, Evertz J, et al. Measuring the current distribution in PEFCs with sub-millimeter resolution. Journal of The Electrochemical Society 2006; 153(11): A2158. doi: 10.1149/1.2345591

33. Xia L, Ni M, He Q, et al. Optimization of gas diffusion layer in high temperature PEMFC with the focuses on thickness and porosity. Applied Energy 2021; 300: 117357. doi: 10.1016/j.apenergy.2021.117357

34. TORAY. Available online: http://www.torayca.com/en/lineup/composites/com_009_01.html (accessed on 16 August 2023).

35. Kang K, Ju H. Numerical modeling and analysis of micro-porous layer effects in polymer electrolyte fuel cells. Journal of Power Sources 2009; 194(2): 763–773. doi: 10.1016/j.jpowsour.2009.05.046

36. Bit Tech. Product Catalog. Gosyogawara; 2008. p. 1.

37. Reid RC, Prausnitz JM, Poling BE. The Properties of Gases and Liquids, 1st ed. McGraw-Hill; 1987. p. 591.

38. Merck. Available online: http://www.sigmaaldrich.com/japan/materialscience/alternative/nafion.html (accessed on 16 August 2023).

39. Senn SM, Poulikakos D. Polymer electrolyte fuel cells with porous materials as fluid distributors and comparisons with traditional channeled systems. Journal of Heat Transfer 2004; 126(3): 410–418. doi: 10.1115/1.1738424

40. Takayama T. Numerical simulation of transient internal states of PEFC cell and stack considering control of anode system. Research Report of Mizuho Research and Technologies 2018; 9: 1–14.

41. Rostami L, Mohamad Gholy Nejad P, Vatani A. A numerical investigation of serpentine flow channel with different bend sizes in polymer electrolyte membrane fuel cells. Energy 2016; 97: 400–410. doi: 10.1016/j.energy.2015.10.132

42. Huang Y, Xiao X, Kang H, et al. Thermal management of polymer electrolyte membrane fuel cells: A critical review of heat transfer mechanisms, cooling approaches, and advanced cooling techniques analysis. Energy Conversion and Management 2022; 254: 115221. doi.: 10.1016/j.eneconman.2022.115221

43. Nishimura A, Toyoda K, Mishima D, et al. Numerical analysis on impact of thickness of PEM and GDL with and without MPL on coupling phenomena in PEFC operated at higher temperature such as 363 K and 373 K. Energies 2022; 15(16): 5936. doi: 10.3390/en15165936

44. Zhang S, Qu Z, Xu H, et al. A numerical study on the performance of PEMFC with wedge-shaped fins in the cathode channel. International Journal of Hydrogen Energy 2021; 46: 27700–2778.

45. Chen H, Guo H, Ye F, et al. Improving two-phase mass transportation under Non-Darcy flow effect in orientated-type flow channels of proton exchange membrane fuel cells. International Journal of Hydrogen Energy 2021; 46(41): 21600–21618. doi: 10.1016/j.ijhydene.2021.04.004

46. Xing L, Das PK, Song X, et al. Numerical analysis of the optimum membrane/ionomer water content of PEMFCs: The interaction of Nafion® ionomer content and cathode relative humidity. Applied Energy 2015; 138: 242–257. doi: 10.1016/j.apenergy.2014.10.011

47. Nishimura A, Toyoda K, Mishima D, et al. Numerical analysis on temperature distribution in a single cell of PEFC Operated at higher temperature by 1D heat transfer model and 3D multi-physics simulation model. Energy and Power Engineering 2023; 15(05): 205–227. doi: 10.4236/epe.2023.155010

48. Salomov UR, Chiavazzo E, Fasano M, et al. Pore- and macro-scale simulations of high temperature proton exchange fuel cells—HTPEMFC—and possible strategies for enhancing durability. International Journal of Hydrogen Energy 2017; 42(43): 26730–26743. doi: 10.1016/j.ijhydene.2017.09.011

49. Quan P, Lai MC. Numerical study of water management in the air flow channel of a PEM fuel cell cathode. Journal of Power Sources 2007; 164(1): 222–237. doi: 10.1016/j.jpowsour.2006.09.110

50. Jiao K, Park J, Li X. Experimental investigations on liquid water removal from the gas diffusion layer by reactant flow in a PEM fuel cell. Applied Energy 2010; 87(9): 2770–2777. doi: 10.1016/j.apenergy.2009.04.041

51. Zhang Y, He S, Jiang X, et al. 3D multi-phase simulation of metal bipolar plate proton exchange membrane fuel cell stack with cooling flow field. Energy Conversion and Management 2022; 273: 116419. doi: 10.1016/j.enconman.2022.116419