质子交换膜燃料电池膜电极组件研究进展综述
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摘要
燃料电池具有能量密度高、利用率高和清洁安静等优点,质子交换膜燃料电池因能够在近常温条件下工作而备受关注,其中膜电极是燃料电池的核心部件。综述了质子交换膜燃料电池膜电极组件的研究进展,从质子交换膜、催化层和气体扩散层3方面阐述各部件在膜电极中的作用,及其对膜电极性能的影响,并讨论通过调控膜电极中不同部件的结构提高膜电极性能的方法,提高贵金属催化剂的利用率,降低膜电极组件中贵金属用量。
Fuel cells have the advantages of high energy density, high utilization efficiency of fuel,cleanness and noiselessness during working. Among all kinds of fuel cells, proton exchange membrane fuel cells(PEMFCs) are most popular since they function at near ambient temperatures. Membrane electrode assembly(MEA) is the key component of PEMFCs where the electrochemical reactions take place. In this paper, research progress of MEA in PEMFCs is reviewed. The role and influencing factors of each component in MEA, including the proton exchange membrane(PEM), catalytic layer(CL) and gas diffusion layer(GDL), are discussed. Meanwhile, the methods of improving the performance of MEA by tuning the structure of different components in order to enhance the efficiency of Pt-based catalyst and lower the loading of precious metal in MEA are presented.
Fuel cells have the advantages of high energy density, high utilization efficiency of fuel,cleanness and noiselessness during working. Among all kinds of fuel cells, proton exchange membrane fuel cells(PEMFCs) are most popular since they function at near ambient temperatures. Membrane electrode assembly(MEA) is the key component of PEMFCs where the electrochemical reactions take place. In this paper, research progress of MEA in PEMFCs is reviewed. The role and influencing factors of each component in MEA, including the proton exchange membrane(PEM), catalytic layer(CL) and gas diffusion layer(GDL), are discussed. Meanwhile, the methods of improving the performance of MEA by tuning the structure of different components in order to enhance the efficiency of Pt-based catalyst and lower the loading of precious metal in MEA are presented.
引文
[1]ZHANG J.PEM fuel cell electrocatalysts and catalyst layers:fundamentals and applications[M].London:Springer,2008.
[2]STOLTEN D,SAMSUN R C,GARLAND N.Fuel cells:Data,facts,and figures[M].Germany:John Wiley&Sons,2016,
[3]US Department of Energy Hydrogen and Fuel Cells Program.Record 15015:Fuel cell system cost-2015[R/OL].(2015-10-22)[2019-04-20].https://www.hydrogen.energy.gov/pdfs/15015_fuel_cell_s ystem_cost_2015.pdf.
[4]DEBE M K.Electrocatalyst approaches and challenges for automotive fuel cells[J].Nature,2012,486:43.
[5]MAURITZ K A,MOORE R B.State of understanding of nafion[J].Chemical reviews,2004,104(10):4535-4586.
[6]KUSOGLU A,WEBER A Z.New insights into perfluorinated sulfonic-acid ionomers[J].Chemical reviews,2017,117(3):987-1104.
[7]MEHTA V,COOPER J S.Review and analysis of PEMfuel cell design and manufacturing[J].Journal of Power Sources,2003,114(1):32-53.
[8]GOTTESFELD S,ZAWODZINSKI T A.Polymer electrolyte fuel cells[J].Advances in electrochemical science and engineering,1997(5):195-301.
[9]DE ALMEIDA S H,KAWANO Y,Thermal behavior of nafion membranes[J].Journal of thermal analysis and calorimetry,1999,58(3):569-577.
[10]SCHIRALDI D A.Perfluorinated polymer electrolyte membrane durability[J].Journal of macromolecular science C,2006,46(3):315-327.
[11]TAKATA H,MIZUNO N,NISHIKAWA M,et al.Adsorption properties of water vapor on sulfonated perfluoropolymer membranes[J].International journal of hydrogen energy,2007,32(3):371-379.
[12]RIKUKAWA M,SANUI K.Proton-conducting polymer electrolyte membranes based on hydrocarbon polymers[J].Progress in polymer science,2000,25(10):1463-1502.
[13]LIU W,SUZUKI T,MAO H,et al.Development of thin,reinforced PEMFC membranes through understanding of structure-property-performance relationships[J].ECStransactions,2013,50(2):51-64.
[14]VERBRUGGE M W,HILL R F,SCHNEIDER E W.Composite membranes for fuel-cell applications[J].AIChE journal 1992,38(1):93-100.
[15]CURTIN D E,LOUSENBERG R D,HENRY T J,et al.Advanced materials for improved PEMFC performance and life[J].Journal of power sources,2004,131(1):41-48.
[16]GUBLER L,KOPPENOL W H.Kinetic simulation of the chemical stabilization mechanism in fuel cell membranes using cerium and manganese redox couples[J].Journal of the Electrochemical Society,2011,159(2):B211-B218.
[17]DANILCZUK M,SCHLICK S,COMS F D.Cerium(III)as a stabilizer of perfluorinated membranes used in fuel cells:in situ detection of early events in the ESRresonator[J].Macromolecules,2009,42(22):8943-8949.
[18]ALKIRE R C,KOLB D M,GERISCHER H,et al.Advances in electrochemical science and engineering[M].New York:Wiley VCH,2002.
[19]LARMINIE J,DICKS A,MCDONALD M S.Fuel cell systems explained[M].2nd ed.England:John Wiley and Sons,2003.
[20]HOLDCROFT S.Fuel cell catalyst layers:A polymer science perspective[J].Chemistry of materials,2014,26(1):381-393.
[21]KREUER K D.On the development of proton conducting polymer membranes for hydrogen and methanol fuel cells[J].Journal of membrane science,2001,185(1):29-39.
[22]KOPITZKE R W,LINKOUS C A,ANDERSON H R,et al.Conductivity and water uptake of aromatic‐based proton exchange membrane electrolytes[J].Journal of the Electrochemical Society,2000,147(5):1677-1681.
[23]XU F,ZHANG H,ILAVSKY J,et al.,Investigation of a catalyst ink dispersion using both ultra-small-angle X-ray scattering and cryogenic TEM[J].Langmuir,2010,26(24):19199-19208.
[24]LEE S J,YU T L,LIN H L,et al.Solution properties of nafion in methanol/water mixture solvent[J].Polymer,2004,45(8):2853-2862.
[25]UCHIDA M,AOYAMA Y,EDA N,et al.New preparation method for polymer-electrolyte fuel cells[J].Journal of the Electrochemical Society,1995,142(2):463-468.
[26]SHIN S J,LEE J K,HA H Y,et al.Effect of the catalytic ink preparation method on the performance of polymer electrolyte membrane fuel cells[J].Journal of power sources,2002,106(1):146-152.
[27]SUZUKI T,TSUSHIMA S,HIRAI S.Effects of Nafion?ionomer and carbon particles on structure formation in a proton-exchange membrane fuel cell catalyst layer fabricated by the decal-transfer method[J].International journal of hydrogen rnergy,2011,36(19):12361-12369.
[28]KIM K H,LEE K Y,KIM H J,et al.The effects of Nafion?ionomer content in PEMFC MEAs prepared by a catalyst-coated membrane(CCM)spraying method[J].International journal of hydrogen energy,2010,35(5):2119-2126.
[29]SONG J M,CHA S Y,LEE W M.Optimal composition of polymer electrolyte fuel cell electrodes determined by the AC impedance method[J].Journal of power sources,2001,94(1):78-84.
[30]ZHAO J,HE X,WANG L,et al.Addition of NH4HCO3 as pore-former in membrane electrode assembly for PEMFC[J].International journal of hydrogen energy,2007,32(3):380-384.
[31]PRASANNA M,CHO E A,LIM T H,et al.Effects of MEA fabrication method on durability of polymer electrolyte membrane fuel cells[J].Electrochimica acta,2008,53(16):5434-5441.
[32]MIDDELMAN E.Improved PEM fuel cell electrodes by controlled self-assembly[J].Fuel cells bulletin,2002(11):9-12.
[33]VAN DER VLIET D F,WANG C,TRIPKOVIC D,et al.Mesostructured thin films as electrocatalysts with tunable composition and surface morphology[J].Nature materials,2012,11(12):1051-1058.
[34]CHEON J Y,AHN C,YOU D J,et al.Ordered mesoporous carbon-carbon nanotube nanocomposites as highly conductive and durable cathode catalyst supports for polymer electrolyte fuel cells[J].Journal of materials chemistry A,2013,1(4):1270-1283.
[35]LI M,XIONG Y,LIU X,et al.Iron and nitrogen co-doped carbon nanotube@hollow carbon fibers derived from plant biomass as efficient catalysts for the oxygen reduction reaction[J].Journal of materials chemistry A,2015,3(18):9658-9667.
[36]JIANG S,YI B,CAO L,et al.Development of advanced catalytic layer based on vertically aligned conductive polymer arrays for thin-film fuel cell electrodes[J].Journal of power sources,2016,329:347-354.
[37]SUN R,XIA Z,SHANG L,et al.Hierarchically ordered arrays with platinum coated PANI nanowires for highly efficient fuel cell electrodes[J].Journal of materials chemistry A,2017,5(29):15260-15265.
[38]PARK S,LEE J-W,POPOV B N.Effect of carbon loading in microporous layer on PEM fuel cell performance[J].Journal of power sources,2006,163(1):357-363.
[39]MATHIAS M,ROTH J,FLEMING J,et al.Handbook of fuel cells-Fundamentals,technology and applications:Vol4[M].London:John Wiley&Sons Ltd,2003.
[40]RALPH T R,HARDS G A,KEATING J E,et al.Low cost electrodes for proton exchange membrane fuel cells:Performance in single cells and ballard stacks[J].Journal of the Electrochemical Society,1997,144(11):3845-3857.
[41]WANG Y,WANG C Y,CHEN K S.Elucidating differences between carbon paper and carbon cloth in polymer electrolyte fuel cells[J].Electrochimica acta,2007,52(12):3965-3975.
[42]MATHIAS M,ROTH J,LEHNERT W.Diffusion media materials and characterization[M].New York:John Wiley&Sons Ltd,2003.
[43]OEDEGAARD A,HEBLING C,SCHMITZ A,et al.Influence of diffusion layer properties on low temperature DMFC[J].Journal of power sources,2004,127(1/2):187-196.
[44]IOROI T,OKU T,YASUDA K,et al.Influence of PTFEcoating on gas diffusion backing for unitized regenerative polymer electrolyte fuel cells[J].Journal of power sources,2003,124(2):385-389.
[45]AHN J,HOLZE R.Bifunctional electrodes for an integrated water-electrolysis and hydrogen-oxygen fuel cell with a solid polymer electrolyte[J].Journal of applied electrochemistry,1992,22(12):1167-1174.
[46]CABASSO I,YUAN Y,XU X.Gas diffusion electrodes based on poly(vinylidene fluoride)carbon blends:US5783325[P].1998-07-21.
[47]LIM C,WANG C Y.Effects of hydrophobic polymer content in GDL on power performance of a PEM fuel cell[J].Electrochimica acta,2004,49(24):4149-4156.
[48]BEVERS D,ROGERS R,VON BRADKE M.Examination of the influence of PTFE coating on the properties of carbon paper in polymer electrolyte fuel cells[J].Journal of power sources,1996,63(2):193-201.
[49]PARK G G,SOHN Y J,YANG T H,et al.Effect of PTFEcontents in the gas diffusion media on the performance of PEMFC[J].Journal of power sources,2004,131(1):182-187.
[50]NAM J H,KAVIANY M.Effective diffusivity and water-saturation distribution in single-and two-layer PEMFC diffusion medium[J].International journal of heat and mass transfer,2003,46(24):4595-4611.
[51]WEBER A Z,NEWMAN J.Effects of microporous layers in polymer electrolyte fuel cells[J].Journal of the Electrochemical Society,2005.152(4):A677-A688.
[52]JORDAN L,SHUKLA A,BEHRSING T,et al.Effect of diffusion-layer morphology on the performance of polymer electrolyte fuel cells operating at atmospheric pressure[J].Journal of applied electrochemistry,2000,30(6):641-646.
[53]PASSALACQUA E,SQUADRITO G,LUFRANO F,et al.Effects of the diffusion layer characteristics on the performance of polymer electrolyte fuel cell electrodes[J].Journal of applied electrochemistry,2001,31(4):449-454.
[54]GIORGI L,ANTOLINI E,POZIO A,et al.Influence of the PTFE content in the diffusion layer of low-Pt loading electrodes for polymer electrolyte fuel cells[J].Electrochimica acta,1998,43(24):3675-3680.
[55]PARK S,LEE J-W,POPOV B N.Effect of PTFE content in microporous layer on water management in PEM fuel cells[J].Journal of power sources,2008,177(2):457-463.
[56]CHEN S,YANG Q,WANG H,et al.Initial reaction mechanism of platinum nanoparticle in methanol-water system and the anomalous catalytic effect of water[J].Nano letters,2015,15(9):5961-5968.
[57]CINDRELLA L,KANNAN A M,AHMAD R,et al.Surface modification of gas diffusion layers by inorganic nanomaterials for performance enhancement of proton exchange membrane fuel cells at low RH conditions[J].International journal of hydrogen energy,2009,34(15):6377-6383.
[58]PAGANIN V,TICIANELLI E,GONZALEZ E.Development and electrochemical studies of gas diffusion electrodes for polymer electrolyte fuel cells[J].Journal of applied electrochemistry,1996,26(3):297-304.
[59]KONG C S,KIM D Y,LEE H K,et al.Influence of pore-size distribution of diffusion layer on mass-transport problems of proton exchange membrane fuel cells[J].Journal of power pources,2002,108(1/2):185-191.
[60]TANG H,WANG S,PAN M,et al.Porosity-graded micro-porous layers for polymer electrolyte membrane fuel cells[J].Journal of power sources,2007,166(1):41-46.
[2]STOLTEN D,SAMSUN R C,GARLAND N.Fuel cells:Data,facts,and figures[M].Germany:John Wiley&Sons,2016,
[3]US Department of Energy Hydrogen and Fuel Cells Program.Record 15015:Fuel cell system cost-2015[R/OL].(2015-10-22)[2019-04-20].https://www.hydrogen.energy.gov/pdfs/15015_fuel_cell_s ystem_cost_2015.pdf.
[4]DEBE M K.Electrocatalyst approaches and challenges for automotive fuel cells[J].Nature,2012,486:43.
[5]MAURITZ K A,MOORE R B.State of understanding of nafion[J].Chemical reviews,2004,104(10):4535-4586.
[6]KUSOGLU A,WEBER A Z.New insights into perfluorinated sulfonic-acid ionomers[J].Chemical reviews,2017,117(3):987-1104.
[7]MEHTA V,COOPER J S.Review and analysis of PEMfuel cell design and manufacturing[J].Journal of Power Sources,2003,114(1):32-53.
[8]GOTTESFELD S,ZAWODZINSKI T A.Polymer electrolyte fuel cells[J].Advances in electrochemical science and engineering,1997(5):195-301.
[9]DE ALMEIDA S H,KAWANO Y,Thermal behavior of nafion membranes[J].Journal of thermal analysis and calorimetry,1999,58(3):569-577.
[10]SCHIRALDI D A.Perfluorinated polymer electrolyte membrane durability[J].Journal of macromolecular science C,2006,46(3):315-327.
[11]TAKATA H,MIZUNO N,NISHIKAWA M,et al.Adsorption properties of water vapor on sulfonated perfluoropolymer membranes[J].International journal of hydrogen energy,2007,32(3):371-379.
[12]RIKUKAWA M,SANUI K.Proton-conducting polymer electrolyte membranes based on hydrocarbon polymers[J].Progress in polymer science,2000,25(10):1463-1502.
[13]LIU W,SUZUKI T,MAO H,et al.Development of thin,reinforced PEMFC membranes through understanding of structure-property-performance relationships[J].ECStransactions,2013,50(2):51-64.
[14]VERBRUGGE M W,HILL R F,SCHNEIDER E W.Composite membranes for fuel-cell applications[J].AIChE journal 1992,38(1):93-100.
[15]CURTIN D E,LOUSENBERG R D,HENRY T J,et al.Advanced materials for improved PEMFC performance and life[J].Journal of power sources,2004,131(1):41-48.
[16]GUBLER L,KOPPENOL W H.Kinetic simulation of the chemical stabilization mechanism in fuel cell membranes using cerium and manganese redox couples[J].Journal of the Electrochemical Society,2011,159(2):B211-B218.
[17]DANILCZUK M,SCHLICK S,COMS F D.Cerium(III)as a stabilizer of perfluorinated membranes used in fuel cells:in situ detection of early events in the ESRresonator[J].Macromolecules,2009,42(22):8943-8949.
[18]ALKIRE R C,KOLB D M,GERISCHER H,et al.Advances in electrochemical science and engineering[M].New York:Wiley VCH,2002.
[19]LARMINIE J,DICKS A,MCDONALD M S.Fuel cell systems explained[M].2nd ed.England:John Wiley and Sons,2003.
[20]HOLDCROFT S.Fuel cell catalyst layers:A polymer science perspective[J].Chemistry of materials,2014,26(1):381-393.
[21]KREUER K D.On the development of proton conducting polymer membranes for hydrogen and methanol fuel cells[J].Journal of membrane science,2001,185(1):29-39.
[22]KOPITZKE R W,LINKOUS C A,ANDERSON H R,et al.Conductivity and water uptake of aromatic‐based proton exchange membrane electrolytes[J].Journal of the Electrochemical Society,2000,147(5):1677-1681.
[23]XU F,ZHANG H,ILAVSKY J,et al.,Investigation of a catalyst ink dispersion using both ultra-small-angle X-ray scattering and cryogenic TEM[J].Langmuir,2010,26(24):19199-19208.
[24]LEE S J,YU T L,LIN H L,et al.Solution properties of nafion in methanol/water mixture solvent[J].Polymer,2004,45(8):2853-2862.
[25]UCHIDA M,AOYAMA Y,EDA N,et al.New preparation method for polymer-electrolyte fuel cells[J].Journal of the Electrochemical Society,1995,142(2):463-468.
[26]SHIN S J,LEE J K,HA H Y,et al.Effect of the catalytic ink preparation method on the performance of polymer electrolyte membrane fuel cells[J].Journal of power sources,2002,106(1):146-152.
[27]SUZUKI T,TSUSHIMA S,HIRAI S.Effects of Nafion?ionomer and carbon particles on structure formation in a proton-exchange membrane fuel cell catalyst layer fabricated by the decal-transfer method[J].International journal of hydrogen rnergy,2011,36(19):12361-12369.
[28]KIM K H,LEE K Y,KIM H J,et al.The effects of Nafion?ionomer content in PEMFC MEAs prepared by a catalyst-coated membrane(CCM)spraying method[J].International journal of hydrogen energy,2010,35(5):2119-2126.
[29]SONG J M,CHA S Y,LEE W M.Optimal composition of polymer electrolyte fuel cell electrodes determined by the AC impedance method[J].Journal of power sources,2001,94(1):78-84.
[30]ZHAO J,HE X,WANG L,et al.Addition of NH4HCO3 as pore-former in membrane electrode assembly for PEMFC[J].International journal of hydrogen energy,2007,32(3):380-384.
[31]PRASANNA M,CHO E A,LIM T H,et al.Effects of MEA fabrication method on durability of polymer electrolyte membrane fuel cells[J].Electrochimica acta,2008,53(16):5434-5441.
[32]MIDDELMAN E.Improved PEM fuel cell electrodes by controlled self-assembly[J].Fuel cells bulletin,2002(11):9-12.
[33]VAN DER VLIET D F,WANG C,TRIPKOVIC D,et al.Mesostructured thin films as electrocatalysts with tunable composition and surface morphology[J].Nature materials,2012,11(12):1051-1058.
[34]CHEON J Y,AHN C,YOU D J,et al.Ordered mesoporous carbon-carbon nanotube nanocomposites as highly conductive and durable cathode catalyst supports for polymer electrolyte fuel cells[J].Journal of materials chemistry A,2013,1(4):1270-1283.
[35]LI M,XIONG Y,LIU X,et al.Iron and nitrogen co-doped carbon nanotube@hollow carbon fibers derived from plant biomass as efficient catalysts for the oxygen reduction reaction[J].Journal of materials chemistry A,2015,3(18):9658-9667.
[36]JIANG S,YI B,CAO L,et al.Development of advanced catalytic layer based on vertically aligned conductive polymer arrays for thin-film fuel cell electrodes[J].Journal of power sources,2016,329:347-354.
[37]SUN R,XIA Z,SHANG L,et al.Hierarchically ordered arrays with platinum coated PANI nanowires for highly efficient fuel cell electrodes[J].Journal of materials chemistry A,2017,5(29):15260-15265.
[38]PARK S,LEE J-W,POPOV B N.Effect of carbon loading in microporous layer on PEM fuel cell performance[J].Journal of power sources,2006,163(1):357-363.
[39]MATHIAS M,ROTH J,FLEMING J,et al.Handbook of fuel cells-Fundamentals,technology and applications:Vol4[M].London:John Wiley&Sons Ltd,2003.
[40]RALPH T R,HARDS G A,KEATING J E,et al.Low cost electrodes for proton exchange membrane fuel cells:Performance in single cells and ballard stacks[J].Journal of the Electrochemical Society,1997,144(11):3845-3857.
[41]WANG Y,WANG C Y,CHEN K S.Elucidating differences between carbon paper and carbon cloth in polymer electrolyte fuel cells[J].Electrochimica acta,2007,52(12):3965-3975.
[42]MATHIAS M,ROTH J,LEHNERT W.Diffusion media materials and characterization[M].New York:John Wiley&Sons Ltd,2003.
[43]OEDEGAARD A,HEBLING C,SCHMITZ A,et al.Influence of diffusion layer properties on low temperature DMFC[J].Journal of power sources,2004,127(1/2):187-196.
[44]IOROI T,OKU T,YASUDA K,et al.Influence of PTFEcoating on gas diffusion backing for unitized regenerative polymer electrolyte fuel cells[J].Journal of power sources,2003,124(2):385-389.
[45]AHN J,HOLZE R.Bifunctional electrodes for an integrated water-electrolysis and hydrogen-oxygen fuel cell with a solid polymer electrolyte[J].Journal of applied electrochemistry,1992,22(12):1167-1174.
[46]CABASSO I,YUAN Y,XU X.Gas diffusion electrodes based on poly(vinylidene fluoride)carbon blends:US5783325[P].1998-07-21.
[47]LIM C,WANG C Y.Effects of hydrophobic polymer content in GDL on power performance of a PEM fuel cell[J].Electrochimica acta,2004,49(24):4149-4156.
[48]BEVERS D,ROGERS R,VON BRADKE M.Examination of the influence of PTFE coating on the properties of carbon paper in polymer electrolyte fuel cells[J].Journal of power sources,1996,63(2):193-201.
[49]PARK G G,SOHN Y J,YANG T H,et al.Effect of PTFEcontents in the gas diffusion media on the performance of PEMFC[J].Journal of power sources,2004,131(1):182-187.
[50]NAM J H,KAVIANY M.Effective diffusivity and water-saturation distribution in single-and two-layer PEMFC diffusion medium[J].International journal of heat and mass transfer,2003,46(24):4595-4611.
[51]WEBER A Z,NEWMAN J.Effects of microporous layers in polymer electrolyte fuel cells[J].Journal of the Electrochemical Society,2005.152(4):A677-A688.
[52]JORDAN L,SHUKLA A,BEHRSING T,et al.Effect of diffusion-layer morphology on the performance of polymer electrolyte fuel cells operating at atmospheric pressure[J].Journal of applied electrochemistry,2000,30(6):641-646.
[53]PASSALACQUA E,SQUADRITO G,LUFRANO F,et al.Effects of the diffusion layer characteristics on the performance of polymer electrolyte fuel cell electrodes[J].Journal of applied electrochemistry,2001,31(4):449-454.
[54]GIORGI L,ANTOLINI E,POZIO A,et al.Influence of the PTFE content in the diffusion layer of low-Pt loading electrodes for polymer electrolyte fuel cells[J].Electrochimica acta,1998,43(24):3675-3680.
[55]PARK S,LEE J-W,POPOV B N.Effect of PTFE content in microporous layer on water management in PEM fuel cells[J].Journal of power sources,2008,177(2):457-463.
[56]CHEN S,YANG Q,WANG H,et al.Initial reaction mechanism of platinum nanoparticle in methanol-water system and the anomalous catalytic effect of water[J].Nano letters,2015,15(9):5961-5968.
[57]CINDRELLA L,KANNAN A M,AHMAD R,et al.Surface modification of gas diffusion layers by inorganic nanomaterials for performance enhancement of proton exchange membrane fuel cells at low RH conditions[J].International journal of hydrogen energy,2009,34(15):6377-6383.
[58]PAGANIN V,TICIANELLI E,GONZALEZ E.Development and electrochemical studies of gas diffusion electrodes for polymer electrolyte fuel cells[J].Journal of applied electrochemistry,1996,26(3):297-304.
[59]KONG C S,KIM D Y,LEE H K,et al.Influence of pore-size distribution of diffusion layer on mass-transport problems of proton exchange membrane fuel cells[J].Journal of power pources,2002,108(1/2):185-191.
[60]TANG H,WANG S,PAN M,et al.Porosity-graded micro-porous layers for polymer electrolyte membrane fuel cells[J].Journal of power sources,2007,166(1):41-46.