WAT
a. F
b
capab
distrib
metho
tortuo
coeffic
results
Keywo
I. INTRMembr membra applied reported MEA’s multi n transpo permea approac Based o flux is and deh research electrod flux in a
2.THEO
MEA c membra adopted characte (Midlem
Where turtocity
study is post pro sprayer sprayin The pro
TER PERM
Fuel Cell Inst
b. Teknik Ki
The fabric
le of adjust
butions pore
dology. The
city parame
cient param
s were then c
ords: perme
RODUCTIONrane Electrode ane, anode and d to the anode d, such as rol structure. One ozzle (Chun, 2 rt phenomeno ability coefficie ched the water on the mechan pressure depen hydration that her by achievin de. In this rese a certain value
ORY
consists of thr ane. The fabr d the Chun’s
erized. We a man, 1997, Mu
K is the memb y factor, effect
s an in-house r ocessor conve r in X-Y direc ng the GDL wi oduced MEA i
MEABILITY
R
titute, Unive
mia, FTI, UP
cation of ME
ting its X-Y
e and water
e results of
eter which i
meter of wat
compared to
eability coeff
NAssemblies (M d cathode elec
and cathode s lling, screen-pr e of the recent 2001). The mo on. The wate
ent, and proto r transport phe nism of hydrog ndent. The ba
will cause an ng various com earch, we obse e.
ree componen rication proces method (200 are assuming t uider, 1991, Ba
brane permeabi tive pressure d
robotic sprayer rts the spray c ction. Such sp ith a similar pr is subjected to
Y OF MEA
ROBOT
Ramli Sitang
ersiti Kebang
M
PN ”Veteran
Indon
A
EA is condu
Y motions. T
flux using B
f the MEA
is greater th
ter is 9.10
-5o the ones av
fficient, memb
MEA) is the c trodes. The ele sides of the M
rinting, casting researches in s st important pa er flux itself on movement enomenon in gen bridge wit alancing of hum
n ohmic lost. mposition of m erved the perm
nt Gas Diffusi ss of GDL and 01). The pe the water mas aker,200, Frank
N
=
κ
.
ility coefficient difference (
∆
P
r was in house coating carbon praying system
rocess as ment hot pressing i
FUEL CEL
TIC SPRAY
ggang, Dana
gsaan Malay
Malaysia
n”. Jl. SWK
nesia, 55283
Abstract
cted using a
The MEA p
BET and SE
shown that
han the MEA
5gcm
-1men
–1vailable from
brane electr
core componen ectrochemical MEA. There are
g, and sprayin sprayer as wha arameter in ME
depends on (Eikerling, 19 one, two and thin membrane midity has to b The minimiz materials and rec meability coeffi
ion Layer (GD d GDE was m ermeability co s transfer repr k,2004):
eff
P
∆
.
t that dependseff
P
) and N per fabricates. Dat n ink path-line m will producetioned above b in a sandwich
LL FABRI
YER
ang Jaya
ysia, 43600 U
104 Condon
3
an in-house
roduced wa
EM based o
the pore g
A’s thicknes
1psia
-1or th
m the comme
rode assembl
nt of fuel cell reactions occu e several fabri ng. Each of t at we interested EA is the wate electro – osm 998, Hu, 2004 three dimensi e (Bansal,1998 be insured with zing of ohmic
construction of ficient of MEA
DL), Gas Dif made using in-h
efficient of th resents by the
(1)
on the porosity rmeate flux. Th
ta of work piec to the robot c e an even GD but with differ form of GDE
CATION U
UKM, Bangi
ngcatur, Yog
robotic spr
as analyzed
on the water
geometry of
ss while the
he tortuocity
ercial MEA.
ly
l. It consists o ur when a fuel ication method these types pr d in our laborat er flux, usually motic behavior 4). Some of r onal (Hu, 200 8), we observe h avoiding the lost was sug f pore size of d A by setting th
ffusion Electro house robotic
he fabricated e simplest equ
y, pore radius, he System con
ce is computer control comma DL. The GDE
rence formula with membran
USING X-Y
i, Selangor,
gyakarta,
rayer machin
for porosity
r permeabili
f MEA has
e permeabili
y of 2. Thes
of the electroly l and oxidant a ds of MEA we roduces differe tory, used one y named as wat r, diffusion an researchers ha 04, Chen, 2003 ed that the wat e floods of wat ggested by man
diffusion layer he slope of wat
ode (GDE), an sprayer machi
electrodes w ation as follow
viscosity and nfiguration in o
r controlled. T and to move t E is produced b
of ink-platinum ne inside in hi
Y
ne
ty;
ity
a
ity
se
yte are ere ent or ter nd ave 3). ter ter ny of ter
nd ine was ws
our
2000), a pore of The ana water fl and ME The rob
The spr number designe specific
p.
e
t
, dp,ε
Assume toward equatio
e
t
, dp,ε
The vis surface
e
t
, dp,ε
Equatio
(Nspray).
with the model f
Current
coth
x
K
i
=
K
4=
5
K
=
and Vo
and then boile f MEA, GDL a
alyzed permeat flux by linear fi EA performanc bot used in the
ray variable is r of spray coati ed perpendicul c surface (as). T
ε
,a
s = f(K,e p is constant all variables n 4
ε
, as.= f(Nsprayscosity effect . Based on equ
ε
, as.= f(Nsprayons 4 to 5, the
Assumed the e current densi for MEA fabric
t density (i):
5 2 4
exp(
h(
(
1
(
OK
K
K
C
K
−
−
p e
d
F
t
5
.
0
)
1
(
12
−
ε
2 2 1 , 0
4
5
.
0
(
O ref o
p s c
D
FC
d
a
i
ltage (V):
ed it to avoid w and GDE using te was done us fitting curve ag ce was investig system employ
expressed by ing line on sub ar to substrate The variable of
µ
, v,σ
, p) …t, surface tensi and the robot
y,,Re,W)………
and surface t uation 3, the
t
ey) ………
e
t
, dp,ε
andlayers results f ity of PEM fu cation is as foll
2 / 1 6
6 5
)))
(
(
exp(
s
K
K
K
ϕ
−
O
FD
2=f(Nspray)
2 2
)
= f(Nspray)…
Z
water and gases g BET and SE sing continuou gainst pressure gated using FCT
ys a specific at
Fig 1. The
frequency (
ω
bstrate (n) and e. If thick size f ink drop distr………3
ion (
σ
) const ic movement……….………4
tension are co
, dp,
ε
, as are…………..….. 5
as of an electr
from robotic sp el cell can be lows:
2 / 1
)
))
(
φ
s……
y)…………..…7
………8
Y W
s inside the po EM by analyzin us membrane sy difference as p TS.
ttitude expressi
e x-y configura
ω
), nozzle heig nozzle velocit e (t
e), pore diribution of the
tant, thus theo as well as the
4
onstant and ne e given by the d
rode can be det
prayer is set to formulated usi
………
7
8
S
2
W
Subs
ore. MEA was ng the permea ystem method presented in E
ion of the x-y c
ation
ght (W1), distri
ty (S). The spr iameter (dp,),p
nozzle will af
oretically the c e drop variabl
eglecting the s dimensionless
termined by the
o be the MEA, ing Grujicic (2
………
stra
s characterize t ate and the slop
and the analyz q.(1). Permea
configuration s
ibution distanc ray direction co porosity (
ε
), tffect the layer s
correlation of le are given b
solidifying eff equation 4 to 5
e robotic chara
therefore the r 2004) . The spr
……….
the dimension pe of water flu zing of the slo ability coefficie
shown in Fig 1
ce (W2), divisi
oating process typical activat size are
µ
, v ane
t
, dp,ε
,andby dimensionle
fect on substra 5, as follows :
acteristic numb
relationship of raying techniq
.6
of ux.
pe ent
.
on is ted nd
as
ess
ate
ber
ref o
c
f C
i R E V
2 , 0
coth( ex
. 0 − =
Based o the mai
General M-E-GD activate membra
3.EXPE
Nafion medium DuPont activati carbon, about 1 sprayin position be dried and per In case Pt, wate carbon above. The thi impurit using h dryer in FCTS.
4.RESU Charac
Surface GDE su and in roughne characte
ref o
c s
C i dp f
F RT
dp f F RT
2 , 0 1
1
e ) , (
( 5 . 0 xp(
, ( ln{ 5
ε
φ
−
on equations, t in control for m
lly, the MEA d DL-G. In this p ed specific sur
ane (novel).
ERIMENT
Active carbo liquid was us m for carbon m
t. The fabricat on and assemb alcohol, wate 1.17 cp and us ng as 0.5 ccs, n of nozzle is p d using vacuum rmeate test char
of the fabricat er, and alcohol ink C-Pt and h
ird material tha ties and stored hot press. The n room temper
ULT AND DIS cterization. Th
e scanning was urface. From t experimental ess with com erization BET
(a
s O
F RT x
f C
2 / 1
1 2
( 5 . 0 exp(
) ))
( 1 ( )
ϕ
ε
− −
the value of co manufacturing l
design form co paper the catal rface area. In
on with 400 m sed also. Mod mobilition, an tion process o bly of membra er, Nafion and sually called a 6 bar air pres perpendicular w m dryer in room racterization. T tion of GDE, t l. Nafion, PTPE
has 1.16 cp vi
at we used is m in deionized w produces elect rature for 2 ho
SCUSSION
he fabrication s done using S the SEM chara
(see Fig. 2b) mmercial GDE studies was pe
)
c o
s i
dp
, 2 / 1
/ ) )))
) , (
ϕ
ε
…
oeffisient mode layer size of M
onfiguration em lyst layer empl
Fig.3c the cat
meshes was lam derately polar nd the membra
of MEA consi ane electrodes d PTPE are sti as carbon ink.
ssure through with the object m temperature The profile and the GDL must E. The materia iscosity. The p
membrane Na water further u trode will be r ours. The resu
process of G SEM have pro acterization of the result is f E (see Fig. 2 erformed and r
………
el of current d MEA design for
mployed by res loyed the confi talyst utilised a
minated on car of mix solven ane used in th ists of three s
(MEA). In the rred for 10 m
The carbon in spraying nozz t, with 10 time
for about 2 ho d permeability be sprayed wi als must be mix procedures of
afion 117. Mem use. The MEA,
rinsed with 0.5 ult then has to
GDE was repea duced to chara experimental 1 free of crack. 2c). Matrix m
eveal
………
density depend rm
searches as sho figuration as sh a support to c
rbon cloth. Po nt from water his observatio steps; the layin
e GDL fabrica inutes. The slu nk is sprayed zle, with patte es moving peri ours, and then w
coefficient of t ith another mix xed for 5 minu spraying after
mbrane were c GDE and mem 5 M H2SO4 an
be characteriz
ated seven tim acterized the c 1 to 6 (see Fig. Experimenta morphology w
………
on Nspray. Th
own in Fig.3a i hown in Fig.3b composite the
olytetrafluoroe and isopropan on is nafion 1
ng of GDL, G ation layer mix
urry produce h on carbon clo ern of 4 cm, a iod. The fabri will be subject the material wa xed material th utes, and the re r mixing proce
cleaned to rem mbrane will sa nd have to be zed using perm
mes in insure crack and the r . 2a), the result al (b) also has was investigate
……..9
e Nspray becom
is the G-GDL-b to oG-GDL-btain high
catalyst into t
ethylene (PTFE nol was used
17 produced b GDE, membra xture of activat has viscosity f oth with flow and the standin icated GDL mu ed to BET, SE as test also. hat consists of esult is namely ess are similar
ove any trace andwich togeth dried in vacuu meability test an
reproductabilit roughness of t ts still has crac s similar surfa
ed for particl mes
E-hly the
E), as by ane ted for of ng ust EM
C-as as
of her um nd
F
For the g cm-2
point o 1997). than the (b), the that the
Permea
evacuat for trigg hydroge then the
ig. 2 Surface m
next observati PTFE, 0.51 g of view within Another advan e other experim pore dimensio e experimental
ability Coeffic
te water from e gering the reac en and sweepin e water flux ins (b
(
microscope sca
Prop
Diame pore (A Surfac area (m Volum pore (c
ion, we will fo cm-2 C-Pt and
n micropore sc ntage of exper mental in our o on of MEA rem
(b) is appropri
cient. Within M
electrode part, ction between P
ng out the elec side each layer b)
c)
anning of (a). F
Table 1 perty GDE
(a)
eter A o
) 34.3 1 ce m2/g)
472
me cc/g)
0.09 7
cus on experim d the scale cha cale, experime rimental (b) is observation. Af mains similar w iate as a materi
MEA fuel cell, meanwhile the Pt and CO. Th tron (Mikko, 2 r will depend o
First trial (b). A
1. BET analys GDE (b)
ME A (a)
41.15 34.4 1 451 410
0.157 0.06 0
mental (b) that aracteristic as m ental (a) and (
that it has gre fter assembly t with GDE expe ial for fabricati
the GDL has a e electrode is u he membrane al 2003). If we flo on the channel
After modified
sis MEA (b)
ME A (c
39.41 68.2
450 220
0.102 0.08 1
has activated c mentioned in T (b) have meso eater adsorptio the membrane erimental (b) st ing fuel cell.
a function to di used to distribut lso has task to ow water throu structure.
, (c). Reference
carbon as 1.05 Table 1. Using opore character n capacity and with electrode tand alone. We
istribute humid te humidity wa bond water for ugh the layers w
e electrode
g cm-2 and 0. g pore dimensi ristics (Ruthve d pore capabili e of experiment e could conclu
dity water and ater and will us
r bridging within MEA,
53 on en, ity tal ude
For GD meanwh mesopo Figure 3 kinds o mention
Eq. (2) 4, and
permea the thic (3) as s tortuosi electrod resistan and eva
For calc 2.10-4 g than its follows GDL < After a flux as
DL, the water fl hile the water ore.
3c illustrates g of pore profile ned above, we
is developed f
eff
P
∆
indicateability coefficie ckness of GDL shown in Figu ity. It also me de itself. From nce of water w acuate water ea
culating the w gcm-1men–1psia s thickness. F s
< membrane < ssembly of me in eq. (6).
GDL
0 0,0005 0,001 0,0015 0,002 0,0025 0,003 0,0035
W
a
te
r f
lu
x
(
g
mo
l/
cm2
me
n
)
flux will be affe r flux inside
good profile of are usually cal will explain m
from eq. (1) wi es the pressure
ent. It means itself. Further ure 4b. With eans that the c m the calculati within electrode asier and electr
Fig
water flux withi a-1 or 1.4 tortu From these thr
electrode embrane and e
(3a)
0 2
Membran MEA GDL GDE
Fig 3. S
fected by chann the electrode
f pore within m lled as porosity more detail abou
N
=
3
.
10
N
=
10
−4N
=
2
.
10
ith
κ
for abou e differences othat the length rmore, for calc
10-4 gcm-1men
channel for flo on of water flu e is greater tha rode could flow
g 4. Character
in membrane N uosity, it means ree layers disc
(5)
electrodes on 3
N
=
9
.
10
−5∆
4 6
Pressure difference (p
e
Surface of GD
nel that has bee will be affect
membrane to m y and tortuosit ut the capabilit
eff
P
∆
−4
0
eff
P
∆
4
eff
P
∆
−4
0
ut 3.10-4 gcm-1 of water flux.
h of channel f culating the cap
n–1psia-1 of pe
owing water w ux as mention an within GDL w in or out wate
ristic Permeab
Nafion 177, we s that the chan cussed above,
35 kgfcm-2 pre
eff
P
∆
Electrode (3
8 10
psi) DE
en built within ted by channe
ake possible w ty. To build be ty of MEA to f
(2)
(3)
(4)
men–1psia-1 tha Using tortuos
for flowing wat pability of elec ermeability coe within electrode ned above, we L. It means tha
er faste
bility Water
e use eq. (4) w nnel length wi we could con
essure and 130
(6) b)
12
n the carbon clo el that has be
water flux flow etter understand flow water flux
at has been fou sity table we g
ter within GDL ctrode to flow w efficient it is e greater than could emphas at GDL is capa
with permeabili ithin membran nclude that wa
°C temperatu Mem
oth (see Fig. 3a een built by t
through it. Su d about what w x as follow
und using Figu got 1.1 for 3.10
L is greater th water follows e similar with 1 the thickness ize that the flo able to distribu
ity coefficient ne is also great ater resistance
ure, we get wat mbrane (3c)
a), the
uch we
ure 0-4
han eq. 1.7 of ow ute
of ter as
The cap MEA. restore
1men–1p
GDL < Electrod control
1
men–1p GDL < 4.3. Per In obse oxygen water is 5.
As can density happene ohmic l rapidly coeffici current transien any dry
5.CON
From th porosity got the membra occur o
ACKN
The aut the fina
0 200 400 600 800 1000 1200
C
u
rre
n
t (m
A
/c
m
2
)
pability of ME With 2.8 psia around 3.6 10 psia-1 or with to
membrane < e de has greatest the water dist psia-1 permeabi membrane < e rmeability expe erving the MEA n. With pressur
s happened wit
be seen in Fi voltage. In th ed through the losses inside th than the comm ient of our ME
will be discha nt current (rise ying process (S
NCLUSION
he discussion a y and tortuosity e permeability ane as 2. 10-4, ohmic losses us
OWLEDGEM
thors would lik ancial support t
0 20
Time (men.)
Cur
Cur
Vo
Vo
EA to distribu a pressure diff
-4
gmol cm-2. ortuosity greate electrode < ME t water resistan tribution and e ility coefficien electrode < ME
eriment related A fuel cell wi re difference o thin membrane
Fig 5.
gure 5, the M his operation, t e membrane. T he MEA fuel c mercial MEA f EA greater than arged very rap e time and fall avadogo, 2003
above, the wate y. The tortuoc coefficient o MEA as 9.10 sing greater per
MENTS
ke to express t through IRPA
0 200 400 600 800 1000 1200
40
Vo
lt
ag
e (m
V)
)
r.MEA exp.
r.MEA com.
lt.MEA exp.
lt MEA com.
ute water is pro ferences, MEA The permeabi er than 2. The
EA (7)
nce, it means th evacuation pro nt), eq. (7) will EA < MEA Com d to performanc ith single stack of 2.8 psi and fl e, then the perf
Characteristi
EA fuel cell w the anode MEA This osmotic e
ell. In such co for 30 minutes n the commerci pidly than the time) is good 3)
er flux within t city of the laye f DGL as 3.1 0-5 gcm-1men–1p rmeability coef
their gratitude grant: IRPA 02
oportional with A could flow w ility coefficient erefore we cou
hat to fabricate operties. Inclu
have to modify m
ce of MEA fue k, pressure at flow rate of H2 formance of M
ic Performanc
with greater pe A fuel cell wil electron or usu ondition, the ch operation time ial MEA. If H
commercial M enough to con
the geometrica er could be def 10-4 gcm-1men psia-1 or tortuo fficient.
to the UKM U
2-02-02-0003-h t2-02-02-0003-he pressure water around
t of water with uld modify eq. (
e MEA, we hav uding the comm fy to
(8) el Cell
anode is set u 2 as 0.3 slpm, o MEA fuel cell c
ce MEA fuel C
ermeability coe l be dehydrate ually called as hanging of curr es. This differ H2 and O2 sudde
MEA. It mean ntrol dehydrati
al structure of M fined as GDL < n–1psia-1, Electr osity greater tha
University and PR0023 11-08
e difference th 3.3 10-5 gmo hin MEA is aro
(5)
ve to modify e mercial MEA
up greater than oxygen 0.4 slpm could be illustr
Cell
efficient will h ed and osmotic s electron diffu
rent within ME rence is due to enly drop out t ns that MEA w
ion in low tem
MEA is influen < membrane < rode as 10-4 g an 2 for MEA
d Environment 8
hat is attached l cm-2 min-1 an ound 9.10-5 gcm
electrode layer (with 2.10-6gcm
n the pressure m and a floodin
ated as in Figu
have less curre c electron will fusion will cau EA tends to dr the permeabili to zero, the ME with very rapid mperature witho
nced strongly b < electrode or w gcm-1men–1psi . The MEA w
t of Malaysia f to nd m
-to m
-of ng ure
ent be use op ity EA dly out
by we a-1 will
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Midlem
Ruthven
Baker W
Chun, W of
Muider Un
Mikkol
Frank M Ce
Besset,
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Eikerlin
Hu M., Fu m
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RENCE
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, Raj K. Organi
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ons. McGraw-H
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ata McGraw-H
ovich, J. Electr
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iley & Sons, In
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omer membran
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Company Lim
45 (1998) 2684
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rane for polym
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ctrolyte memb
ifornia Institut
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don (1987)
ited (1998)
4
model for PEM . Energy an
mer electrolyt
urnal of Electr
rane (PEM) fu te
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el
M d
te
o
