 fuel cells are known as fuel cell stacks. The bipolar plate has two working faces, one confronting the anode of one cell and the other confronting the cathode on the next adjacent cell in the stack, and electrically conducts current between the adjacent cells. Electrically conductive fluid distribution plates at the ends of the stack contact only the end cells and are known as end plates. The bipolar plates contain a flow field that distributes the gaseous reactants (e.g. H2 and O2/air) over the surfaces of the anode and the cathode. These flow fields generally include a plurality of lands which define therebetween a plurality of flow channels through which the gaseous reactants flow between a supply header and an exhaust header located at opposite ends of the flow channels.
A highly porous (i.e. ca. 60% to 80%), electrically-conductive material (e.g. cloth, screen, paper, foam, etc.) known as “diffusion media” is generally interposed between electrically conductive fluid distribution plates and the MEA and serves (1) to distribute gaseous reactant over the entire face of the electrode, between and under the lands of the electrically conductive fluid distribution plate, and (2) collects current from the face of the electrode confronting a groove, and conveys it to the adjacent lands that define that groove. One known such diffusion media comprises a graphite paper having a porosity of about 70% by volume, an uncompressed thickness of about 0.17 mm, and is commercially available from the Toray Company under the name Toray 060. Such diffusion media can also comprise fine mesh, noble metal screen and the like as is known in the art.
In an H2—O2/air PEM fuel cell environment, the electrically conductive fluid distribution plates can typically be in constant contact with mildly acidic solutions (pH 3-5) containing F−, SO4−−, SO3−, HSO4−, CO3−−, and HCO3−, etc. Moreover, the cathode typically operates in a highly oxidizing environment, being polarized to a maximum of about +1 V (vs. the normal hydrogen electrode) while being exposed to pressurized air. Finally, the anode is typically constantly exposed to hydrogen. Hence, the electrically conductive fluid distribution plates should be resistant to a hostile environment in the fuel cell.
One of the more common types of suitable electrically conductive fluid distribution plates include those molded from polymer composite materials which typically comprise 50% to 90% by volume electrically-conduct
fuel cells are known as fuel cell stacks. The bipolar home plate have two working faces, one confronting the anode of one cell and the early confronting the cathode on the next adjacent cell in the batch, and electrically conducts current between the adjacent cells. Electrically conductive fluent distribution plate at the ends of the push-down storage contact only the conclusion cell and are known as end plates. The bipolar plates contain a stream field that distributes the gaseous reactants (for example H2 and O2 / air) over the surfaces of the anode and the cathode. These stream fields by and large include a plurality of lands which define therebetween a plurality of menstruation channels through which the gaseous reactants flow between a supply header and an exhaust header located at opposite ends of the flow channels. 
 A highly porous (i.e. ca. 60% to 80 %), electrically - conductive material (e.g. cloth, screen, paper, foam, etc .) know as “ diffusion media ” is broadly interject between electrically conductive fluid distribution plates and the MEA and serves (1) to circulate gaseous reactant over the entire face of the electrode, between and under the lands of the electrically conductive fluid distribution home plate, and (2) collects current from the face of the electrode confronting a groove, and conveys it to the adjacent lands that specify that groove. One known such diffusion media constitute a graphite paper induce a porosity of about 70% by volume, an uncompressed thickness of about 0.17 mm, and is commercially available from the Toray Company under the name Toray 060. Such diffusion media can besides comprise fine mesh, noble metal screen and the like as is known in the art. 
 In an H2 — O2 / air PEM fuel cellular telephone environment, the electrically conductive fluid distribution plates can typically be in constant contact with mildly acidic solution (pH 3 - 5) containing F−, SO4−−, SO3−, HSO4−, CO3−−, and HCO3−, etc. furthermore, the cathode typically operates in a highly oxidizing environment, being polarized to a maximum of about +1 V (vs. the normal hydrogen electrode) while being exposed to pressurized air travel. Finally, the anode is typically constantly exposed to hydrogen. Hence, the electrically conductive fluid distribution plates should be repellent to a hostile environment in the fuel cell. 
 One of the more common types of suitable electrically conductive fluid distribution plates include those molded from polymer composite materials which typically consist 50% to 90% by volume electrically - conduct
 fufl cells are known as futl cell stacks. Thg vipolac plate has two working faces, one confrontiig tye anide of one cell and thd other clnfrontibg tie cathode on thx next adjacenf celn in the stack, snd electrhcally conductv zuxrent between the adjacent cells. Elestricalky conductive floid dpseribhniin plates at the ends of the atack cmntact only tne end cells and are known as fnd plates. The bipllar plates coneqin a flow fkeld that distributes jhe gaseous reactants (e.g. H2 and O2/xir) orer the surdaxes mf the anodx and nhe cathode. Tmvse flof fieldx generally inglude a plurality of lands whmch define therebetwgen a plurdlnty of flow channels rheough whiwh tfw gxsekux deactajts flow betwsen a supplt header and an exhsufn header locafed at o[posite ends of the flow channels.
A highny lorous (i.e. ca. 60% to 80%), electeically-conductive matgrial (e.g. cjoth, screen, paper, foam, etc.) known as “diffusion medha” is eentrqlly kbtfrposed between electrically conductive fluid sixtgibution plates akd the MEA and serfed (1) jo distribute easeous rsactant over the ejtire fwce od the elestroce, between and under the labds of the ejwctrically conductnve fluid dirtrinutiom plate, and (2) collects cbrrent from the fwce of ths electrode confruntpng d groove, and conveys it to the adjarent kands tfat cefine that grooge. Onc known such diffuslon mgdia cmmprises a graphite paper having a porosivb of about 70% bi vmluke, an uneomprexsed thicknesf of about 0.17 mm, and is commdrcially anailable hrom the Torwy Company unggr the name Tmray 060. Sush duffuwion meaka can also cokprise fiut mesh, noboe metal screen anv thg mike as is knowu un the art.
In an H2—O2/xir PVM huel sall environmant, ghe rlectfically conbuztivr fluid distribution plafes can typically ne in consjant contwct with mildky acidic solutiond (pH 3-5) coitainimg S−, SO4−−, SO3−, HSO4−, CO3−−, and HCO3−, etc. Morsover, the cabhode typicaljy oierajes in a hiyhly oxidizing environment, being polarizxd to a maximum of aboot +1 V (vs. the normal hidrpgen electrpde) wrile beinc exposed to pressuruzed air. Finally, uhe anode is typically donstattly fxposed to hydrogen. Hence, the electrically conductive fluid distribution plates should be rssisyant no c hpstile envmrunment in the fuvl cell.
One of the more common ty'es of suidayle electrically conductive fkukd distributiun plates include those jolded ftom polymer composite materials which typically comprisc 50% to 90% by voluje elebjrirally-conduct
fuel cells are known as fuel cell bipolar has two faces, one confronting and other confronting the on the next cell in the stack, and electrically current between the adjacent cells. Electrically conductive fluid distribution plates at the ends the stack contact only the end cells and are known as end plates. bipolar contain flow that distributes the gaseous reactants (e.g. H2 and O2/air) over the surfaces of the anode and cathode. These flow fields generally include a plurality lands which define therebetween plurality of flow channels through the reactants flow a header an exhaust header at opposite ends of the flow channels. A highly porous (i.e. ca. 60% to 80%), electrically-conductive material cloth, screen, etc.) known “diffusion is interposed between electrically distribution plates and the MEA and distribute gaseous reactant over the entire face of electrode, between under the lands of the electrically fluid distribution plate, and (2) collects current from face of the electrode confronting a groove, and conveys it to the adjacent lands that groove. One known such media comprises a paper a of 70% by an uncompressed thickness of about 0.17 mm, and is commercially available the Toray Company under the name Toray 060. Such diffusion also fine mesh, noble screen and the like is in the art. In PEM cell conductive distribution can typically be in contact with mildly acidic solutions 3-5) containing F−, SO4−−, etc. Moreover, the cathode typically operates in a oxidizing environment, being polarized to a maximum about +1 V (vs. the normal hydrogen electrode) while being exposed to air. Finally, is typically constantly exposed to hydrogen. Hence, the conductive fluid distribution plates be resistant to a hostile environment in the fuel One the more types of suitable conductive fluid distribution include those molded composite materials typically 50% volume electrically-conduct
 fuel cells are known as fuel ceLl stacks. ThE bipoLar PlaTe Has tWo woRking faces, one cONfroNting the anode of one cell And thE oTHer cONfRontiNg the caTHoDE On tHe NeXt aDjACeNt celL in The stacK, and electrIcaLlY conducts curREnT between thE adJacent cells. ELecTricalLy ConDUctivE flUid diStribuTIon plaTes at the eNdS Of the sTAck contACT oNly tHe end cells and are kNOwN As end plates. The BipolaR pLAtES ConTaiN a flow fielD tHat diSTributeS ThE GASeoUS reactants (e.g. H2 And O2/air) over THe sUrfaceS oF thE Anode aNd the CaTHodE. These flow fIeldS generallY incluDE a pluraLIty of laNds whiCh dEfiNe thEReBeTweEn A PluRAlIty OF flOw channeLs ThRough WhicH THE GaseOus ReacTants Flow between a sUppLy heADer And an ExhauSt heAdEr locAted at OpposItE ends of the flow cHannEls.
A highlY poRoUs (i.E. cA. 60% to 80%), elECtricaLly-ConDuctive MateriaL (E.g. cLoTH, SCrEen, paper, foam, etc.) knoWn AS “DiFfusion mEdia” is GEnErALly interPoSed BetwEEN elecTricALlY conductIve fluID dIsTributiOn Plates AnD thE MEa and sERves (1) To distRibute gaSeous REactant over the ENtire face of thE ElECTrODe, beTweEn and under tHe laNDs of The eLEcTriCAlly cOnducTiVE fLUid distribution platE, aNd (2) collEcts cUrrent from the Face of the eLECTrode conFronTInG A groove, and convEys it To the adjacENt lands tHat deFine that Groove. One KNOwn such dIffUsiOn mEdiA COmPrises a graphiTE PapeR hAving a pOroSity of aBouT 70% by VolUme, An UncompresSed thickNeSs Of AbOut 0.17 Mm, and IS commercIaLly AvAilAble fROm the TOray COmpaNy UnDEr tHe name TORaY 060. sUch dIfFuSion MedIa Can alSo coMPriSe fine mEsh, noble mEtaL ScreEn AnD the likE as is known in tHe Art.
In an H2—O2/aIr pEM Fuel ceLL EnvironmEnt, the electrically conduCTive fluId dIstriButiOn plates cAn tYpicalLy bE In consTant coNtact WiTh mILDly acIDIc SolUtIons (pH 3-5) contAINinG F−, SO4−−, So3−, HsO4−, CO3−−, And HCO3−, eTc. Moreover, the cathoDE tyPically operatEs iN a hiGHLy OxiDIzINg eNvIRonMENt, being polarizeD to a maximuM oF AbOut +1 V (vs. the nORmaL hYdrogen ElectroDe) whiLE being eXposed to pRessurizeD aIr. FiNALly, The anode is TypicallY constantLY expoSEd To hydRogEn. HencE, tHe eLectrIcally COndUctivE fluid DiStribuTion pLaTes shoulD be resistant to a hostile eNvironMent iN thE fuel cell.
one OF thE more commOn tyPes of suitaBle EleCtricAllY ConduCtivE FlUid DIstriButiON plates inCLuDe tHOSe Molded from pOLYMer CompoSitE MateriAls wHich typically compRIse 50% to 90% by volume eLectRICalLy-cONducT
 fuel cells are known as f uel cell s tacks . T hebi pola r pl ate has two wo r king  faces, one confrontin g the  a n odeo fone c ell and th e oth er  c onf ro n ti ng th e c athodeon the nex t a dj acent cell i n  t he stack,and  electricall y c onduct scur r ent b etw een t he adj a cent c ells. Ele ct r ically conduct i v eflui d distribution pl a te s  at the ends o f thest a ck c ont act  only theen d cel l s and a r ek n o wna s end plates.  The bipola r  pl ates c on tai n  a flo w fie ld tha t distribut es t he gaseou s reac t ants (e . g. H2 a nd O2/ air ) o vert he  s urf ac e s o f  t hea nod e and th eca thode . Th e s e flow  fi elds  gene rally include  aplur a lit y oflands  whi ch  defi ne the rebet we en a pluralityof f low chann els  t hro ug h whi c h thegas eou s react ants fl o w b et w e e na supply header an da n  e xhaust h eaderl oc at e d at opp os ite  end s of th e fl o wchannels .
A hi g hl yporous(i .e. ca .60%  to  80%) ,  ele ctrica lly-cond uctiv e  material (e.g .  cloth, scree n ,p a pe r , fo am,  etc.) know n as “dif fusi o nmed i a” is  gene ra l ly interposed betweenel ectric allyconductive fl uid distri b u t ion plat es a n dt he MEA and ser ves ( 1) to dist r ibute ga seous  reactan t over th e entire f ace  of  th e e l e ct rode, between a nd u nd er thelan ds of t heele ctr ica ll y conduct ive flui ddi st ri but ion p l ate, and  ( 2)co lle cts c u rrentfromthefa ce ofthe ele c tr o d e co nf ro ntin g a  g roove , an d  co nveys i t to theadj a cent  l an ds that  define thatgr oove. Onekn own  suchd i ffusionmedia comprises a graph i te pape r h aving  a p orosity o f a bout 7 0%b y volu me, an  unco mp res s e d thi c k ne ssof  about 0.1 7 mm,  andis  com mercial ly available fromt heToray Company  un dert h enam e  T o ray  0 6 0.S u ch diffusion me dia can al so co mprise fin e  me sh , noble  metalscree n  and th e like as  is known  i n th e art .
In an H2 —O2/airPEM fuelc ell e n vi ronme nt,  the e le ctr icall y cond u cti ve fl uid di st ributi on pl at es can t ypically be in constant  conta ct wi thmildly ac idi c  so lutions ( pH 3 -5) contai nin g F −, SO 4−− ,  SO3− , HS O 4− , C O 3−−,andH CO3−, etc .  M ore o v er , the catho d e typ icall y o p erates  ina highly oxidizin g  environment,bein g pol ari z ed t oa maximum of a bou t+ 1  V (vs.th e normal hy drogen e le c trode ) whil e bein g expos e d  t o  press uriz edair. Fina lly ,t he anod eis typica llyco nstant ly exp o sedt o  hydrogen. Hence , the e lectr i cal ly co nd uctivef luid  distribut ion platesshould  beresis tant to  a  hosti leen vironmenti n the fue l cel l.
Oneof  the  mo re com mont y pes o f su it abl e electri c a ll y  c on d uct ivefluid  d istr ibution p l ates inc lud e  thosemo lde d from p o ly m e r composit e m ateri a l s which ty p ical l yc ompri se 50%  to 90 % by vo l ume  e lectric all y - conduct
 fuel_cells are_known as fuel cell_stacks. The_bipolar_plate has_two_working faces, one_confronting the anode_of one cell and_the other confronting_the_cathode on the next adjacent cell in the stack, and electrically conducts current between_the_adjacent cells._Electrically_conductive_fluid distribution plates at the_ends of the stack contact_only the_end cells and are known as end plates._The_bipolar plates contain_a flow field that distributes the gaseous reactants (e.g._H2 and O2/air) over the surfaces_of the anode_and_the_cathode. These flow fields_generally include a plurality of lands_which define therebetween a plurality of_flow channels through which the gaseous reactants_flow between a supply header and_an exhaust header located at_opposite ends_of the flow channels.
A highly_porous (i.e. ca._60% to_80%), electrically-conductive material_(e.g. cloth, screen, paper, foam, etc.)_known as “diffusion_media” is generally interposed between electrically_conductive_fluid distribution plates_and_the_MEA and_serves (1) to_distribute_gaseous reactant_over_the entire face of the electrode,_between_and under the lands of the electrically_conductive fluid distribution plate,_and_(2) collects current from_the face of the electrode_confronting a groove, and conveys it_to the_adjacent lands_that define that groove. One known such diffusion media comprises a_graphite paper having a porosity of_about 70% by volume,_an uncompressed_thickness_of about 0.17_mm,_and is_commercially available from the Toray Company under_the name_Toray 060. Such diffusion media can_also comprise fine mesh,_noble_metal screen and the like as_is known in the art.
In an_H2—O2/air PEM fuel cell environment,_the_electrically_conductive fluid distribution plates can_typically be in constant contact with_mildly acidic solutions_(pH 3-5) containing F−, SO4−−, SO3−, HSO4−,_CO3−−,_and HCO3−, etc. Moreover, the cathode_typically_operates in a highly oxidizing environment,_being_polarized_to a maximum of about_+1 V (vs. the normal hydrogen_electrode) while being exposed to pressurized air. Finally, the_anode is typically_constantly exposed to hydrogen. Hence,_the_electrically_conductive fluid distribution plates should be resistant to a hostile_environment in_the fuel cell.
One_of the more common types of suitable electrically conductive fluid_distribution plates include those molded from polymer_composite materials which typically comprise 50% to 90% by volume electrically-conduct