Research ArticleMATERIALS SCIENCE

Design of flexible polyphenylene proton-conducting membrane for next-generation fuel cells

See allHide authors and affiliations

Science Advances  25 Oct 2017:
Vol. 3, no. 10, eaao0476
DOI: 10.1126/sciadv.aao0476
  • Fig. 1 Novel design principle for flexible polyphenylene membranes.

    (A) Estimated persistence length (lp) of polyphenylenes. (B) Specific design of a novel monomer based on this principle.

  • Fig. 2 Novel polyphenylene-based PEM.

    Synthesis (A) and membrane (B) of the SPP-QP.

  • Fig. 3 Water uptake and proton conductivity.

    Humidity dependence at 80°C of (A) water uptake and (B) proton conductivity of PEMs. The IEC values (mmol g−1) in parentheses were determined by acid base titration. Fenton’s test was conducted by immersing the membrane in Fenton’s solution (aqueous solution containing 3% H2O2 and 2 ppm Fe2+) at 80°C for 1 hour. The solid lines are guides for the eye.

  • Fig. 4 DMA analysis.

    Humidity dependence at 80°C of (A) storage modulus (E′), (B) loss modulus (E″), and (C) tan δ (= E″/E′) of PEMs. Fenton’s test was conducted by immersing the membrane in Fenton’s solution (aqueous solution containing 3% H2O2 and 2 ppm Fe2+) at 80°C for 1 hour.

  • Fig. 5 Oxidative stability test (Fenton’s test).

    Remaining weight (W), molecular weight (Mw), and IEC of the reference SPP-bl-1 (3.0 mmol g−1) and SPP-QP (2.4 mmol g−1) membranes after the Fenton’s test (aqueous solution containing 3% H2O2 and 2 ppm Fe2+, 80°C, 1 hour). The second Fenton’s test of the first tested SPP-QP membrane was conducted, and the results are depicted as SPP-QP (twice). All IECs were determined by acid base titration. The chemical structure of the reference SPP-bl-1 copolymer is shown in fig. S9 (27).

  • Fig. 6 Fuel cell performance and durability (OCV hold test).

    IR-included H2/O2 polarization curves (solid symbols) and ohmic resistances (open symbols) of the SPP-QP cell (IEC = 2.6 mmol g−1) at 80°C under humidity conditions of (A) 100% RH and (B) 30% RH. (C) Changes in the cell voltage (solid symbols) and ohmic resistance (open symbols) of the SPP-QP cell (IEC = 2.6 mmol g−1) at 80°C and 30% RH (H2/air).

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/3/10/eaao0476/DC1

    fig. S1. Synthesis of QP monomer.

    fig. S2. NMR assignment of 3,3″-dibromo-para-terphenyl.

    fig. S3. NMR assignment of QP monomer.

    fig. S4. 1H NMR assignment of SPP-QP (titrated IEC = 2.4 mmol g−1) copolymer.

    fig. S5. Morphology of SPP-QP (titrated IEC = 2.4 mmol g−1) membrane.

    fig. S6. SAXS profile.

    fig. S7. Number of absorbed water molecules per sulfonic acid group (λ).

    fig. S8. Stress versus strain curves.

    fig. S9. Chemical structure of the SPP-bl-1 copolymer.

    fig. S10. Hydrogen and oxygen permeability.

    fig. S11. Membrane durability and flexibility.

    fig. S12. The effect of the OCV hold test on the molecular structure of the SPP-QP membrane (IEC = 2.6 mmol g−1).

    Mathematica Notebook

  • Supplementary Materials

    This PDF file includes:

    • fig. S1. Synthesis of QP monomer.
    • fig. S2. NMR assignment of 3,3″-dibromo-para-terphenyl.
    • fig. S3. NMR assignment of QP monomer.
    • fig. S4. 1H NMR assignment of SPP-QP (titrated IEC = 2.4 mmol g−1) copolymer.
    • fig. S5. Morphology of SPP-QP (titrated IEC = 2.4 mmol g−1) membrane.
    • fig. S6. SAXS profile.
    • fig. S7. Number of absorbed water molecules per sulfonic acid group (λ).
    • fig. S8. Stress versus strain curves.
    • fig. S9. Chemical structure of the SPP-bl-1 copolymer.
    • fig. S10. Hydrogen and oxygen permeability.
    • fig. S11. Membrane durability and flexibility.
    • fig. S12. The effect of the OCV hold test on the molecular structure of the SPPQP
      membrane (IEC = 2.6 mmol g−1).
    • Mathematica Notebook

    Download PDF

    Files in this Data Supplement:

Stay Connected to Science Advances

Navigate This Article