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Protonated phosphonic acid electrodes for high power heavy-duty vehicle fuel cells

Abstract

State-of-the-art automotive fuel cells that operate at about 80 °C require large radiators and air intakes to avoid overheating. High-temperature fuel cells that operate above 100 °C under anhydrous conditions provide an ideal solution for heat rejection in heavy-duty vehicle applications. Here we report protonated phosphonic acid electrodes that remarkably improve the performance of high-temperature polymer electrolyte membrane fuel cells. The protonated phosphonic acids comprise tetrafluorostyrene-phosphonic acid and perfluorosulfonic acid polymers, where a perfluorosulfonic acid proton is transferred to the phosphonic acid to enhance the anhydrous proton conduction of fuel cell electrodes. By using this material in fuel cell electrodes, we obtained a fuel cell exhibiting a rated power density of 780 mW cm2 at 160 °C, with minimal degradation during 2,500 h of operation and 700 thermal cycles from 40 to 160 °C under load.

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Fig. 1: Protonation of phosphonic acid.
Fig. 2: Anhydride formation from phosphonic acids.
Fig. 3: Impact of protonation of phosphonic acid on fuel cell performance.
Fig. 4: H2/air fuel cell performance comparison.
Fig. 5: Performance comparison among different fuel cell technologies.
Fig. 6: Durability of the protonated HT-PEMFC under H2/air conditions.

Data availability

The data supporting the findings of this study are available within the paper, Extended Data and Supplementary Information. Source data are provided with this paper.

References

  1. Cano, Z. P. et al. Batteries and fuel cells for emerging electric vehicle markets. Nat. Energy 3, 279–289 (2018).

    Google Scholar 

  2. Cullen, D. A. et al. New roads and challenges for fuel cells in heavy-duty transportation. Nat. Energy 6, 462–474 (2021).

    Google Scholar 

  3. Forrest, K., Kinnon, M. M., Tarroja, B. & Samuelsen, S. Estimating the technical feasibility of fuel cell and battery electric vehicles for the medium and heavy duty sectors in California. Appl. Energy 276, 115439 (2020).

    Google Scholar 

  4. Hong, B. K., Kim, S. H. & Kim, C. M. Powering the future through hydrogen and polymer electrolyte membrane fuel cells. Current commercialisation and key challenges with focus on work at Hyundai. Johnson Matthey Technol. Rev. 64, 236–251 (2020).

    Google Scholar 

  5. Gittleman, C. S., Jia, H., De Castro, E. S., Chisholm, C. & Kim, Y. S. Proton conductors for heavy-duty vehicle fuel cells. Joule 5, 1660–1677 (2021).

    Google Scholar 

  6. US Drive Partnership Fuel Cell Technical Team Roadmap (US Department of Energy, 2017); https://www.energy.gov/sites/default/files/2017/11/f46/FCTT_Roadmap_Nov_2017_FINAL.pdf

  7. Dicks, A. L. & Rand, D. A. J. Proton-Exchange Membrane Fuel Cells in Fuel Cell Systems Explained 3rd edn, 69–133 (John Wiley, 2018).

  8. Valdés-López, V. F., Mason, T., Shearing, P. R. & Brett, D. J. L. Carbon monoxide poisoning and mitigation strategies for polymer electrolyte membrane fuel cells—a review. Prog. Energy Combust. Sci. 79, 100942 (2020).

  9. Chan T. Methanol Fuel Cells: Powering the Future (Methanol Institute, 2020); https://www.methanol.org/wp-content/uploads/2020/04/Methanol-Fuel-Cell-Powering-the-Future-webinar-presentation.pdf

  10. Park, C. H. et al. Nanocrack-regulated self-humidifying membranes. Nature 532, 480–483 (2016).

    Google Scholar 

  11. Yang, J. S. et al. High molecular weight polybenzimidazole membranes for high temperature PEMFC. Fuel Cells 14, 7–15 (2014).

    Google Scholar 

  12. Pingitore, A. T., Huang, F., Qian, G. Q. & Benicewicz, B. C. Durable high polymer content m/p-polybenzimidazole membranes for extended lifetime electrochemical devices. ACS Appl. Energy Mater. 2, 1720–1726 (2019).

    Google Scholar 

  13. Søndergaard, T. et al. Long-term durability of PBI-based HT-PEM fuel cells: effect of operating parameters. J. Electrochem. Soc. 165, F3053–F3062 (2018).

    Google Scholar 

  14. Jakobsen, M. T. D., Jensen, J. O., Cleemann, L. N. & Li, Q. in High Temperature Polymer Electrolyte Membrane Fuel Cells: Approaches, Status, and Perspectives (eds Li, Q. et al.) 487–509 (Springer, 2016).

  15. Lee, K. S., Spendelow, J. S., Choe, Y. K., Fujimoto, C. & Kim, Y. S. An operationally flexible fuel cell based on quaternary ammonium-biphosphate ion pairs. Nat. Energy 1, 16120 (2016).

    Google Scholar 

  16. Lee, A. S., Choe, Y. K., Matanovic, I. & Kim, Y. S. The energetics of phosphoric acid interactions reveals a new acid loss mechanism. J. Mater. Chem. A 7, 9867–9876 (2019).

    Google Scholar 

  17. Atanasov, V. et al. Synergistically integrated phosphonated poly(pentafluorostyrene)s for fuel cells. Nat. Mater. 20, 370–377 (2021).

    Google Scholar 

  18. Kongkanand, A. & Mathias, M. F. The priority and challenge of high-power performance of low-platinum proton-exchange membrane fuel cells. J. Phys. Chem. Lett. 7, 1127–1137 (2016).

    Google Scholar 

  19. Kotz, R., Clouser, S., Sarangapani, S. & Yeager, E. Ionization of trifluoromethane sulfonic acid in phosphoric acid: Raman studies. J. Electrochem. Soc. 131, 1097–1100 (1984).

    Google Scholar 

  20. Parvole, J. & Jannasch, P. Polysulfones grafted with poly(vinylphosphonic acid) for highly proton conducting fuel cell membranes in the hydrated and nominally dry state. Macromolecules 41, 3893–3903 (2008).

    Google Scholar 

  21. Aili, D. et al. Phosphoric acid dynamics in high temperature polymer electrolyte membranes. J. Electrochem. Soc. 167, 134507 (2020).

  22. Haouas, M., Taulelle, F., Prudhomme, N. & Cambon, O. NMR analysis of GaPO4 crystal growth in mixtures of phosphoric and sulfuric acids. J. Cryst. Growth 296, 197–206 (2006).

    Google Scholar 

  23. Melchior, J.-P., Majer, G. & Kreuer, K.-D. Why do proton conducting benzimidazole phosphoric acid membranes perform well in high-temperature PEM fuel cells? Phys. Chem. Chem. Phys. 19, 601–612 (2017).

  24. Frisch, M. J., Head-Gordon, M. & Pople, J. A. Direct MP2 gradient method. Chem. Phys. Lett. 166, 275–280 (1990).

    Google Scholar 

  25. Zhang, S. M., Baker, J. & Pulay, P. A reliable and efficient first principles-based method for predicting pKa values. 1. Methodology. J. Phys. Chem. A 114, 425–431 (2010).

    Google Scholar 

  26. Matanovic, I., Chung, H. T. & Kim, Y. S. Benzene adsorption: a significant inhibitor for the hydrogen oxidation reaction in alkaline conditions. J. Phys. Chem. Lett. 8, 4918–4924 (2017).

    Google Scholar 

  27. Li, D., Chung, H. T., Maurya, S., Matanovic, I. & Kim, Y. S. Impact of ionomer adsorption on alkaline hydrogen oxidation activity and fuel cell performance. Curr. Opin. Electrochem. 12, 189–195 (2018).

    Google Scholar 

  28. He, Q. G., Shyam, B., Nishijima, M. & Ramaker, D. Mitigating phosphate anion poisoning of cathodic Pt/C catalysts in phosphoric acid fuel cells. J. Phys. Chem. C. 117, 4877–4887 (2013).

    Google Scholar 

  29. Li, Q. et al. Phosphate-tolerant oxygen reduction catalysts. ACS Catal. 4, 3193–3200 (2014).

    Google Scholar 

  30. Lee, K.-S. et al. Intermediate temperature fuel cells via an ion-pair coordinated polymer electrolyte. Energy Environ. Sci. 11, 979–987 (2018).

    Google Scholar 

  31. Eberhardt, S. H. et al. Dynamic operation of HT-PEFC: in-operando imaging of phosphoric acid profiles and (re)distribution. J. Electrochem. Soc. 162, F310–F316 (2015).

    Google Scholar 

  32. Matanovic, I., Lee, A. S. & Kim, Y. S. Energetics of base–acid pairs for the design of high-temperature fuel cell polymer electrolytes. J. Phys. Chem. B 124, 7725–7734 (2020).

    Google Scholar 

  33. Maurya, S. et al. Rational design of polyaromatic ionomers for alkaline membrane fuel cells with >1 W cm–2 power density. Energy Environ. Sci. 11, 3283–3291 (2018).

    Google Scholar 

  34. Ott, S. et al. Ionomer distribution control in porous carbon-supported catalyst layers for high-power and low Pt-loaded proton exchange membrane fuel cells. Nat. Energy 19, 77–85 (2020).

    Google Scholar 

  35. Cleve, T. V. et al. Tailoring electrode microstructure via ink content to enable improved rated power performance for platinum cobalt/high surface area carbon based polymer electrolyte fuel cells. J. Power Sources 482, 228889 (2021).

    Google Scholar 

  36. Lai, Y.-H. et al. Accelerated stress testing of fuel cell membranes subjected to combined mechanical/chemical stressors and cerium migration. J. Electrochem. Soc. 165, F3100–F3103 (2018).

    Google Scholar 

  37. Noh, S., Jeon, J. Y., Adhikari, S., Kim, Y. S. & Bae, C. Molecular engineering of hydroxide conducting polymers for anion exchange membranes in electrochemical energy conversion technology. Acc. Chem. Res. 52, 2745–2755 (2019).

    Google Scholar 

  38. Wang, J. et al. Poly(aryl piperidinium) membranes and ionomers for hydroxide exchange membrane fuel cells. Nat. Energy 4, 392–398 (2019).

    Google Scholar 

  39. Mader, J., Xiao, L., Schmidt, T. J. & Benicewicz, B. C. Polybenzimidazole/acid complexes as high-temperature membranes. Adv. Polym. Sci. 216, 63–124 (2008).

    Google Scholar 

  40. Li, X. et al. Highly conductive and mechanically stable imidazole-rich cross-linked networks for high-temperature proton exchange membrane fuel cells. Chem. Mater. 32, 1182–1191 (2020).

    Google Scholar 

  41. Krishnan, N. N. et al. Phosphoric acid doped crosslinked polybenzimidazole (PBI-OO) blend membranes for high temperature polymer electrolyte fuel cells. J. Membr. Sci. 544, 416–424 (2017).

    Google Scholar 

  42. Wang, L., Liu, Z., Liu, Y. & Wang, L. Crosslinked polybenzimidazole containing branching structure with no sacrifice of effective N-H sites: Towards high-performance high-temperature proton exchange membranes for fuel cells. J. Membr. Sci. 583, 110–117 (2019).

    Google Scholar 

  43. Ghosh, P. et al. Enhanced power generation, faster transient response and longer durability of HT-PEMFC using composite benzimidazole electrolyte membrane with optimum rGO loading. Int. J. Hydrogen Energy 45, 16708–16723 (2020).

    Google Scholar 

  44. Xie, J., Wood, D. L., More, K. L., Atanassov, P. & Borup, R. L. Microstructural changes of membrane electrode assemblies during PEFC durability testing at high humidity conditions. J. Electrochem. Soc. 152, A1011–A1020 (2005).

    Google Scholar 

  45. Yu, J. R., Matsuura, T., Yoshikawa, Y., Islam, M. N. & Hori, M. In situ analysis of performance degradation of a PEMFC under nonsaturated humidification. Electrochem. Solid State Lett. 8, A156–A158 (2005).

  46. Schmidt, T. J. & Baurmeister, J. Properties of high-temperature PEFC Celtec®-P 1000 MEAs in start/stop operation mode. J. Power Sources 176, 428–434 (2008).

    Google Scholar 

  47. Borup, R. et al. Scientific aspects of polymer electrolyte fuel cell durability and degradation. Chem. Rev. 107, 3904–3951 (2007).

    Google Scholar 

  48. Marcinkoski, J. et al. Hydrogen Class 8 Long Haul Truck Targets (US DOE, 2019); https://www.hydrogen.energy.gov/pdfs/19006_hydrogen_class8_long_haul_truck_targets.pdf

  49. Hibbs, M. R. Alkaline stability of poly(phenylene)-based anion exchange membranes with various cations. J. Polym. Sci. B 51, 1736–1742 (2013).

    Google Scholar 

  50. Maurya, S., Fujimoto, C., Hibbs, M. R., Villarrubia, C. N. & Kim, Y. S. Toward improved alkaline membrane fuel cell performance using quaternized aryl-ether free polyaromatics. Chem. Mater. 30, 2188–2192 (2018).

    Google Scholar 

  51. Atanasov, V. & Kerres, J. Highly phosphonated polypentafluorostyrene. Macromolecules 44, 6416–6423 (2011).

    Google Scholar 

  52. Marenich, A. V., Cramer, C. J. & Truhlar, D. G. Universal solvation model based on solute electron density and on a continuum model of the solvent defined by the bulk dielectric constant and atomic surface tensions. J. Phys. Chem. B 113, 6378–6396 (2009).

    Google Scholar 

  53. Zhao, Y. & Truhlar, D. G. The M06 suite of density functionals for main group thermochemistry, thermochemical kinetics, noncovalent interactions, excited states, and transition elements: two new functionals and systematic testing of four M06-class functionals and 12 other functionals. Theor. Chem. Acc. 120, 215–241 (2008).

    Google Scholar 

  54. Frisch, M. J. et al. Gaussian 09 Revision C.01 (Gaussian, 2010).

  55. Zhao, Y. & Truhlar, D. G. A new local density functional for main-group thermochemistry, transition metal bonding, thermochemical kinetics, and noncovalent interactions. J. Chem. Phys. 125, 194101 (2006).

  56. Kim, Y. S. et al. Origin of toughness in dispersion-cast Nafion membranes. Macromolecules 48, 2161–2172 (2015).

    Google Scholar 

  57. Asghari, S., Mokmeli, A. & Samavati, M. Study of PEM fuel cell performance by electrochemical impedance spectroscopy. Int. J. Hydrogen Energy 35, 9283–9290 (2010).

    Google Scholar 

  58. Stampino, P. G. et al. Investigation of hydrophobic treatments with perfluoropolyether derivatives of gas diffusion layers by electrochemical impedance spectroscopy in PEM-FC. Solid State Ion. 216, 100–104 (2012).

    Google Scholar 

  59. Liang, H., Su, H., Pollet, B. G., Linkov, V. & Pasupathi, S. Membrane electrode assembly with enhanced platinum utilization for high temperature proton exchange membrane fuel cell prepared by catalyst coating membrane method. J. Power Sources 266, 107–113 (2014).

    Google Scholar 

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Acknowledgements

PA-PBI samples were provided by E. S. De Castro (Advent Technologies). We thank A. Muenchinger (MPI) and K. D. Kreuer (MPI) for the conductivity data on PWN. This work was supported by the US Department of Energy, Energy Efficiency and Renewable Energy, Fuel Cell Technology Office (L’Innovator program) and Advanced Research Projects Agency-Energy (award number DE-AR0001003). The synthesis of the PWN polymer was developed and supported by the following German National Projects: DFG KE 673/10-1 no. 576968, BMBF 03SF0432B and 03SF0531C. A.S.L. acknowledges support from the KIST internal research program and the National R&D Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (2020M3H4A3106354 and 2020M3H4A3106403). Los Alamos National Laboratory is operated by Triad National Security under US Department of Energy Contract Number 89233218CNA000001. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, a wholly owned subsidiary of Honeywell International, for the US Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. I.M. acknowledges access to the computational resources of LANL Institutional Computing Program, which is supported by the US Department of Energy National Nuclear Security Administration under contract 89233218CNA000001, NERSC, a DOE Office of Science User Facility supported by the Office of Science of the US Department of Energy under contract DE-AC02-05CH11231, and CARC, UNM Center for Advanced Research Computing.

Author information

Authors and Affiliations

Authors

Contributions

A.S.L. and Y.S.K. developed the intellectual concept and designed all the experiments of this research. V.A., J.K., S.A. and C.F. prepared the polymeric materials. E.J.P., S.M., L.D.M., J. Jung, Z.H. and H.J. synthesized the model compounds and performed the electrochemical experiments. J. Jankovic performed the TEM and image analyses. K.H.L., S.M. and A.S.L. tested the fuel cells. I.M. performed the DFT calculations. K.H.L., A.S.L. and Y.S.K. analysed all the experimental data and wrote the paper.

Corresponding author

Correspondence to Yu Seung Kim.

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Competing interests

A.S.L. and Y.S.K. filed a US patent application (application no. 17/196283) on 9 March 2021 related to the ionomer composition described in this article. Z.H. and H.J. are employed by Toyota Research Institute of North America. The remaining authors declare no competing interests.

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Extended data

Extended Data Fig. 1 DFT calculations on protonation of PFPA.

(a) Linear regression fit to deprotonation energies using the difference in DFT calculated electronic energy (ΔE) of A−and HA. The ΔE values are calculated using SMD solvation model with water as solvent at the M062X/6-311 + +G(d,p) level. Equation of line is determined as \(pK_a = 0.108 \ast {\Delta}E - 28.2\) with R2 of 0.90 and rms error of 0.2 pKa units. (b) DFT structures that correspond to calculated 31P NMR shifts; M06L/6-311 + G(2d,p) level of theory and (c) Optimized structure of one perfluoroethanesulfonic acid in interaction with three PFPAs.

Source data

Extended Data Fig. 2 EIS characterization of MEA using the Nafion/PWN composite ionomer as a function of IEC of PWN at 0.6 V.

Composite ionomers: Nafion/PWN-0.9, Nafion/PWN-1.8 and Nafion/PWN-3.0 (Nafion content = 0.5). The impedance with frequency range from 1 MHz to 0.1 Hz was measured under H2/O2 conditions at 160 °C and 170 kPa backpressure.

Source data

Extended Data Fig. 3 Proton conductivity of Nafion, PWN, and Nafion/PWN mixture in DMSO (solid content: 5 wt%).

PWN-0, 0.9, 1.3, 1.8 and 3.0. The Nafion content of the ionomer = 0.5. Mean ± s.d. (n = 3) are shown. Compared to the conductivity in NMP, the conductivity of Nafion, PWN, and Nafion/PWN increased in DMSO.

Source data

Extended Data Fig. 4 H2/O2 fuel cell performance of MEAs employing Nafion/PWN-1.8 as a function of Nafion content.

MEA component: QAPOH-PA ion-pair membrane, anode (Pt-Ru/C, 0.5 mgPt cm-2), and cathode (Pt/C, 0.7 mgPt cm-2).

Source data

Extended Data Fig. 5 EIS characterization of MEA using the Nafion, (1:0), protonated phosphonic acid and non-protonated phosphonic acid ionomers.

(a) 0.8 V (b) 0.6 V and (c) 2 A cm-2. Ionomers: Nafion (Nafion content = 1), protonated phosphonic acid ionomer (Nafion content = 0.4), non-protonated phosphonic acid ionomer (Nafion content = 0). The impedance was measured with frequency range from 1 MHz to 0.1 Hz under H2/O2 condition at 160 °C and 170 kPa backpressure.

Source data

Extended Data Fig. 6 Impact of phosphoric acid and phenyl adsorption on ECSA and HOR, ORR activity.

(a) CV scan of MEAs with protonated or non-protonated ionomer. (b) CV scan of Pt/C as a function of the concentration of phosphoric acid. Each electrode (Pt/C) was conditioned in O2 saturated 0.1 M HClO4 solution before transferred into HClO4-H3PO4 mixture solution for ECSA measurement. (c) Effect of phosphoric acid on ECSA. Total concentration of HClO4-H3PO4 was kept the same as 0.5 M for the tests. (d) Effect of pentafluorophenyl phosphonic acid (PPA) on ECSA. Electrolyte for PPA: 0.1 M HClO4 + PPA. (e) HOR mass activity retention of catalysts in presence of phosphoric acid or PPA. Total used for PPA test. Red square: equivalent phenyl concentration of the protonated PtRu/C anode. Blue diamond: equivalent phenyl concentration of the non-protonated PtRu/C anode. (f) ORR mass activity retention of catalysts in presence of phosphoric acid or FPA. Total concentration of HClO4-H3PO4 was kept the same as 0.5 M for the phosphoric acid tests. 0.1 M HClO4 + FPA was used for FPA test. Red square: equivalent phenyl concentration of the protonated Pt/C cathode. Blue diamond: equivalent phenyl concentration of the non-protonated Pt/C cathode.

Source data

Extended Data Fig. 7 H2/air fuel cell performance of Nafion-based LT-PEMFCs at 100 °C as a function of RH.

i-V curve, power density and HFR of Nafion LT-PEMFC at 100 °C and 148 kPa (absolute) backpressure and high H2/air flows (500/500 sccm). Nafion MEA component: Nafion 211 membrane (25 µm thickness), Nafion ionomer, anode and cathode (TEC10E40E, Pt/C, 0.1 mgPt cm-2).

Source data

Extended Data Fig. 8 Effect of cathode catalyst loading on H2/air fuel cell performance.

Cathode catalyst: (a) HiSPEC 9100: Pt 60% on high surface area carbon (Johnson Matthey). (b) TEC10E40E: Pt 40% on high surface area carbon. (c) TEC10E20E: Pt 20% on high surface area carbon. The other MEA components: QAPOH-PA membrane (35 µm thick), anode catalyst (Pt-Ru/C, 0.5 mgPt cm-2), cathode catalyst (Pt/C, 0.1, 0.3, and 0.6 mgPt cm-2), and Nafion/PWN-1.8 ionomer (Nafion content: 0.5). The performance was measured at 160 °C under anhydrous conditions.

Source data

Extended Data Fig. 9 Comparison of H2/air fuel cell performance of different MEAs at 120 °C.

Protonated ionomer-bonded MEA: QAPOH-PA membrane (35 µm thickness), Nafion/ PWN-1.8 ionomer (Nafion content: 0.5), anode (Pt-Ru/C, 0.5 mgPt cm-2), and cathode (Pt/C, 0.3 mgPt cm-2). Commercial PA−PBI: PA-PBI membrane (50 µm thickness), PTFE binder, anode (Pt/C, 1.0 mgPt cm-2), and cathode (Pt-alloy, 0.75 mgPt cm-2). Nafion MEA: Nafion 211 membrane (25 µm thickness), Nafion ionomer, anode (Pt/C, 0.2 mgPt cm-2) and cathode (Pt/C, 0.3 mgPt cm-2).

Source data

Extended Data Fig. 10 Fuel cell performance of the protonated HT-PEMFC at 80 °C.

MEA components: QAPOH-PA membrane, anode catalyst (Pt-Ru/C, 0.5 mgPt cm2), cathode catalyst (Pt/C, 0.6 mgPt cm2), and Nafion/PWN-1.8 ionomer (Nafion content: 0.5). The performance was measured under anhydrous conditions.

Source data

Supplementary information

Supplementary Information

Supplementary Figs. 1–9 and Table 1.

Supplementary Data 1

Numerical data for Supplementary Figs. 2–8.

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Lim, K.H., Lee, A.S., Atanasov, V. et al. Protonated phosphonic acid electrodes for high power heavy-duty vehicle fuel cells. Nat Energy 7, 248–259 (2022). https://doi.org/10.1038/s41560-021-00971-x

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