Synthesis and Properties of Segmented Block Copolymers of Functionalised Polybenzimidazoles for High‐Temperature PEM Fuel Cells

A series of novel segmented block copolymers of sulphonated polybenzimidazole (PBI) (s-PBI) and p-PBI were prepared with various polymer ratios (10–90 mol% s-PBI; 90-10 mol% p-PBI). A two-step synthesis of oligomeric species, followed by combination and further polymerisation was used via the polyphosphoric acid (PPA) process. The membranes showed improved high-temperature proton conductivities and fuel cell performance over previous literature reports, with moderate incorporation of s-PBI into the copolymer showing the best results. The non-humidified fuel cell performance was extensively studied with various fuels and oxidants and showed excellent properties. Block copolymers that incorporated 40, 50 or 60 mol% s-PBI and the corresponding 60, 50 or 40 mol% p-PBI, at 0.2 A cm–2 and 160 °C, had hydrogen–air performances of 0.661–0.666 V, depending on composition. The performance was improved using hydrogen–oxygen, with voltages between 0.734 and 0.742 V at 0.2 A cm–2 and 160 °C. Fuel cells operating on a reformed hydrocarbon gas showed decreased performance (0.622–0.627 V, same conditions), especially at lower temperatures, but was significantly improved over previous literature reports of sulphonated PBI membranes operating at high temperatures.

[1]  E. Tsuchida,et al.  Synthesis of Poly(phenylene sulfide sulfonic acid) via Poly(sulfonium cation) as a Thermostable Proton-Conducting Polymer , 1996 .

[2]  J. R. Stevens,et al.  Proton conducting gel/H3PO4 electrolytes , 1997 .

[3]  Deborah J. Jones,et al.  Recent advances in the functionalisation of polybenzimidazole and polyetherketone for fuel cell applications , 2001 .

[4]  B. Benicewicz,et al.  Synthesis and Properties of Random Copolymers of Functionalised Polybenzimidazoles for High Temperature Fuel Cells , 2011 .

[5]  Brian C. Benicewicz,et al.  Synthesis and Characterization of Pyridine‐Based Polybenzimidazoles for High Temperature Polymer Electrolyte Membrane Fuel Cell Applications , 2005 .

[6]  V. Antonucci,et al.  Sulfonated polybenzimidazole membranes — preparation and physico-chemical characterization , 2001 .

[7]  Xianfeng Li,et al.  Direct synthesis of sulfonated aromatic poly(ether ether ketone) proton exchange membranes for fuel cell applications , 2004 .

[8]  N. Ogata,et al.  Properties of selected sulfonated polymers as proton-conducting electrolytes for polymer electrolyte fuel cells , 2002 .

[9]  J. R. Stevens,et al.  Proton transport in polyacrylamide based hydrogels doped with H3PO4 or H2SO4 , 1997 .

[10]  G. Wegner,et al.  Proton mobility in oligomer-bound proton solvents: imidazole immobilization via flexible spacers , 2001 .

[11]  H. Kita,et al.  Synthesis, water stability and proton conductivity of novel sulfonated polyimides from 4,4′-bis(4-aminophenoxy)biphenyl-3,3′-disulfonic acid , 2004 .

[12]  Brian C. Benicewicz,et al.  Sulfonated Polybenzimidazoles for High Temperature PEM Fuel Cells , 2010 .

[13]  Dennis W. Smith,et al.  Synthesis and characterization of high molecular weight perfluorocyclobutyl-containing polybenzimidazoles (PFCB–PBI) for high temperature polymer electrolyte membrane fuel cells , 2009 .

[14]  Ronghuan He,et al.  PBI‐Based Polymer Membranes for High Temperature Fuel Cells – Preparation, Characterization and Fuel Cell Demonstration , 2004 .

[15]  Michael A. Hickner,et al.  Direct polymerization of sulfonated poly(arylene ether sulfone) random (statistical) copolymers: candidates for new proton exchange membranes , 2002 .

[16]  M. Hickner,et al.  Alternative polymer systems for proton exchange membranes (PEMs). , 2004, Chemical reviews.

[17]  Qingfeng Li,et al.  Approaches and Recent Development of Polymer Electrolyte Membranes for Fuel Cells Operating above 100 °C , 2003 .

[18]  B. Benicewicz,et al.  Synthesis of Poly (2,2′‐(1,4‐phenylene) 5,5′‐bibenzimidazole) (para‐PBI) and Phosphoric Acid Doped Membrane for Fuel Cells , 2009 .

[19]  Deborah J. Jones,et al.  Solution sulfonation of a novel polybenzimidazole: a proton electrolyte for fuel cell application , 2008 .

[20]  James Larminie,et al.  Fuel Cell Systems Explained , 2000 .

[21]  R. Savinell,et al.  Thermal Stability of Proton Conducting Acid Doped Polybenzimidazole in Simulated Fuel Cell Environments , 1996 .

[22]  C. Jegat,et al.  Proton conduction in poly (acrylamide)-acid blends , 1993 .

[23]  P. Jannasch.  Recent developments in high-temperature proton conducting polymer electrolyte membranes , 2003 .

[24]  Harry R. Allcock,et al.  Polyphosphazene solid electrolytes , 1984 .

[25]  P. Donoso.  NMR, conductivity and neutron scattering investigation of ionic dynamics in the anhydrous polymer protonic conductor PEO(H3PO4)x) , 1988 .

[26]  J. Zupancic,et al.  Proton conducting interpenetrating polymer networks , 1988 .

[27]  W. Ho,et al.  New sulfonated polybenzimidazole (SPBI) copolymer-based proton-exchange membranes for fuel cells , 2009 .

[28]  Deborah J. Jones,et al.  Synthesis and characterisation of sulfonated polybenzimidazole: a highly conducting proton exchange polymer , 1997 .

[29]  Jesse S. Wainright,et al.  A H2O2 fuel cell using acid doped polybenzimidazole as polymer electrolyte , 1996 .

[30]  G. Robertson,et al.  Sulfonated Poly(aryl ether ketone)s Containing the Hexafluoroisopropylidene Diphenyl Moiety Prepared by Direct Copolymerization, as Proton Exchange Membranes for Fuel Cell Application† , 2004 .

[31]  Jie Yin,et al.  Synthesis of novel sulfonated polybenzimidazole and preparation of cross-linked membranes for fuel cell application , 2007 .

[32]  H. Allcock,et al.  SULFONATION OF (ARYLOXY)- AND (ARYLAMINO)PHOSPHAZENES : SMALL-MOLECULE COMPOUNDS, POLYMERS, AND SURFACES , 1991 .

[33]  K. Sanui,et al.  Proton-conducting polymer electrolyte membranes based on hydrocarbon polymers , 2000 .

[34]  H. Pu,et al.  Methanol permeability and proton conductivity of polybenzimidazole and sulfonated polybenzimidazole , 2004 .

[35]  R. Savinell,et al.  A Polymer Electrolyte for Operation at Temperatures up to 200°C , 1994 .

[36]  G. Robertson,et al.  Synthesis of Poly(arylene ether ether ketone ketone) Copolymers Containing Pendant Sulfonic Acid Groups Bonded to Naphthalene as Proton Exchange Membrane Materials , 2004 .

[37]  T. Springer,et al.  A Comparative Study of Water Uptake By and Transport Through Ionomeric Fuel Cell Membranes , 1993 .

[38]  F. E. Karasz,et al.  A sulphonated poly(aryl ether ketone) , 1985 .

[39]  D. Yan,et al.  Synthesis and characterization of thermally stable sulfonated polybenzimidazoles , 2005 .

[40]  R. Savinell,et al.  Electro‐osmotic Drag Coefficient of Water and Methanol in Polymer Electrolytes at Elevated Temperatures , 1996 .

[41]  J. Maier,et al.  Imidazole and pyrazole-based proton conducting polymers and liquids , 1998 .

[42]  Brian C. Benicewicz,et al.  Synthesis and Properties of Functionalized Polybenzimidazoles for High-Temperature PEMFCs , 2009 .

[43]  M. Durstock,et al.  Proton exchange membranes based on sulfonated polyarylenethioethersulfone and sulfonated polybenzimidazole for fuel cell applications , 2007 .

[44]  H. Allcock,et al.  Synthesis of cyclolinear phosphazene-containing polymers via ADMET polymerization , 2001 .

[45]  K. Kubo,et al.  Proton conducting behavior in non-crosslinked and crosslinked polyethylenimine with excess phosphoric acid , 2000 .

[46]  Brian C. Benicewicz,et al.  High-Temperature Polybenzimidazole Fuel Cell Membranes via a Sol-Gel Process , 2005 .

[47]  V. Antonucci,et al.  Sulfonated polysulfone ionomer membranes for fuel cells , 2001 .

[48]  P. Gómez‐Romero,et al.  Proton‐conducting polymers based on benzimidazoles and sulfonated benzimidazoles , 2002 .

[49]  G. Gebel,et al.  Synthesis of Sulfonated Polybenzimidazoles from Functionalized Monomers: Preparation of Ionic Conducting Membranes , 2007 .

[50]  Michael A. Hickner,et al.  Fabrication and characterization of heteropolyacid (H3PW12O40)/directly polymerized sulfonated poly(arylene ether sulfone) copolymer composite membranes for higher temperature fuel cell applications , 2003 .

[51]  D. Yan,et al.  Synthesis of sulfonated poly(phthalazinone ether sulfone)s by direct polymerization , 2002 .

[52]  J. Maier,et al.  New fully polymeric proton solvents with high proton mobility , 2003 .

[53]  G. Qian,et al.  Synthesis and characterization of high molecular weight hexafluoroisopropylidene‐containing polybenzimidazole for high‐temperature polymer electrolyte membrane fuel cells , 2009 .

[54]  B. Steele,et al.  Materials for fuel-cell technologies , 2001, Nature.

[55]  Ronghuan He,et al.  Proton conductivity of phosphoric acid doped polybenzimidazole and its composites with inorganic proton conductors , 2003 .

[56]  Deborah J. Jones,et al.  Role of post-sulfonation thermal treatment in conducting and thermal properties of sulfuric acid sulfonated poly(benzimidazole) membranes , 2002 .

[57]  Youngkwan Lee,et al.  Aromatic and rigid rod polyelectrolytes based on sulfonated poly(benzobisthiazoles) , 1996 .

[58]  Jesse S. Wainright,et al.  Acid-doped polybenzimidazoles : a new polymer electrolyte , 1995 .

[59]  W. Ho,et al.  New Carbon Dioxide-Selective Membranes Based on Sulfonated Polybenzimidazole (SPBI) Copolymer Matrix for Fuel Cell Applications , 2009 .

[60]  C. Bawn,et al.  Advances in Polymer Science , 1967, Nature.

[61]  K. Sanui,et al.  Relationship between absorbed water and proton conductivity in sulfopropylated poly(benzimidazole) , 2000 .

[62]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.