A silicon-based micro direct methanol fuel cell (μDMFC) for portable applications has been fabricated and its electrochemical characterization carried out. A membrane-electrode assembly (MEA) was specially fabricated to mitigate methanol crossover. The cell with active area of 1.625cm2 demonstrated a maximum power density of 50mWcm2 at 60°C. Since the silicon wafer is too fragile to compress for sealing, and a thicker layer of gold has to be coated on the silicon wafer to reduce contact resistance, further development of micro DMFCs for high power application was carried out using stainless steel as bipolar plate in which flow channels were fabricated by photochemical etching technology. The maximum power density of the micro DMFC reaches 62.5mWcm2 at 40°C and 100mWcm2 at 60°C with atmospheric pressure. An 8-cell air-breathing DMFC stack has been developed. Mass transport phenomena such as water transport and oxygen transport were investigated. By using a water management technique, cathode flooding was avoided in our air-breathing DMFC stack. Furthermore, it was found that oxygen transport in the air-breathing cathode is still very efficient. The DMFC stack produced a maximum output power of 1.33W at 2.21V at room temperature, corresponding to a power density of 33.3mWcm2. A passive DMFC using pure methanol was demonstrated with steady-state output power of 20-25mWcm2 over more than 10h without heat management.

1.
Narayanan
,
S. R.
, and
Valdez
,
T. I.
, 2003, “
Portable Direct Methanol Systems
,”
Handbook of Fuel Cells—Fundamentals, Technology and Application
,
Vielstich
,
W.
,
Gasteiger
,
H. A.
, and
Lamm
,
A.
, eds.,
Wiley
New York
, Vol.
4
, p.
1133
.
2.
Ren
,
X.
,
Springer
,
T. E.
, and
Gottesfeld
,
S.
, 2000, “
Water and Methanol Uptakes in Nafion Membranes and Membrane Effects on Direct Methanol Cell Performance
,”
J. Electrochem. Soc.
0013-4651,
147
, p.
92
.
3.
Weber
,
A.
,
Darling
,
R.
,
Meyers
,
J.
, and
Newman
,
J.
, 2003, “
Mass Transfer at Two-Phase and Three-Phase Interfaces
,”
Handbook of Fuel Cells—Fundamentals, Technology and Application
,
Vielstich
,
W.
,
Gasteiger
,
H. A.
, and
Lamm
,
A.
, eds.,
Wiley
,
New York
, Vol.
1
, p.
47
.
4.
Arico
,
A. S.
,
Srinivasan
,
S.
, and
Antonucci
,
V.
, 2001, “
DMFCs: From Fundamental Aspects to Technology Development
,”
Fuel Cells
1615-6846,
1
, p.
133
.
5.
Lu
,
G. Q.
,
Wang
,
C. Y.
,
Yen
,
T. J.
, and
Zhang
,
X.
, 2004, “
Development and Characterization of a Silicon-Based Micro Direct Methanol Fuel Cell
,”
Electrochim. Acta
0013-4686,
49
, p.
821
.
6.
Lu
,
G.
, and
Wang
,
C.-Y.
, 2005, “
Two-Phase Microfluidics, Heat and Mass Transport in Direct Methanol Fuel Cells
,”
Transport Phenomena in Fuel Cells (Series of Developments in Heat Transfer)
,
Sunden
,
B.
, and
Fahgri
,
M.
, eds.,
WIT Press
, Vol.
19
, pp.
317
358
.
7.
Lim
,
C.
, and
Wang
,
C. Y.
, 2003, “
Development of High Power Electrodes for a Liquid-Feed Direct Methanol Fuel Cell
,”
J. Power Sources
0378-7753,
113
, pp.
145
150
.
8.
Lu
,
G. Q.
, and
Wang
,
C. Y.
, 2004, “
Electrochemical and Flow Characterization of a Direct Methanol Fuel Cell
,”
J. Power Sources
0378-7753,
134
, pp.
33
40
.
9.
Blum
,
A.
,
Duvdevani
,
T.
,
Philosoph
,
M.
,
Rudoy
,
N.
, and
Peled
,
E.
, 2003, “
Water-Neutral Micro Direct-methanol Fuel Cell (DMFC) for Portable Applications
,”
J. Power Sources
0378-7753,
117
, p.
22
.
10.
Peled
,
E.
,
Blum
,
A.
,
Aharon
,
A.
,
Philosoph
,
M.
, and
Lavi
,
Y.
, 2003, “
Novel Approach to Recycling Water and Reducing Water Loss in DMFCs
,”
Electrochem. Solid-State Lett.
1099-0062,
6
, p.
A268
.
11.
Lu
,
G. Q.
,
Liu
,
F. Q.
, and
Wang
,
C. Y.
, 2005, “
Water Transport Through Nafion 112 Membrane in Direct Methanol Fuel Cells
,”
Electrochem. Solid-State Lett.
1099-0062,
8
(
1
), pp.
A1
A4
.
12.
Kelley
,
S. C.
,
Deluga
,
G. A.
, and
Smyrl
,
W. H.
, 2000, “
A Miniature Methanol/Air Polymer Electrolyte Fuel Cell
,”
Electrochem. Solid-State Lett.
1099-0062,
3
, pp.
407
409
.
13.
Yen
,
T. J.
,
Fang
,
N.
,
Zhang
,
X.
,
Lu
,
G. Q.
, and
Wang
,
C. Y.
, 2003, “
A Micro Methanol Fuel Cell Operating at Near Room Temperature
,”
Appl. Phys. Lett.
0003-6951,
83
, pp.
4056
4058
.
14.
Shimizu
,
T.
,
Momma
,
T.
,
Mohamedi
,
M.
et al.
, 2004, “
Design and Fabrication of Pumpless Small Direct Methanol Fuel Cells for Portable Applications
,”
J. Power Sources
0378-7753,
137
, p.
277
.
15.
Gold
,
S.
,
Chu
,
K. L.
,
Lu
,
C.
et al.
, 2004, “
Acid Loaded Porous Silicon as a Proton Exchange Membrane for Micro-Fuel Cells
,”
J. Power Sources
0378-7753,
135
, pp.
198
203
.
16.
Yang
,
H.
,
Zhao
,
T. S.
, and
Ye
,
Q.
, 2005, “
In Situ Visualization Study of CO2 Gas Bubble Behavior in DMFC Anode Flow Fields
,”
J. Power Sources
0378-7753,
139
, pp.
79
90
.
17.
Pavio
,
J.
,
Bostaph
,
J.
,
Fisher
,
A.
,
Hallmark
,
J.
,
Mylan
,
B. J.
, and
Xie
,
C. G.
, 2002, “
LTCC Fuel Cell System for Portable Wireless Electronics
,”
Adv. Microelectron.
,
29
, pp.
8
11
.
18.
Lu
,
G. Q.
, and
Wang
,
C. Y.
, 2005, “
Development of Micro Direct Methanol Fuel Cells for High Power Applications
,”
J. Power Sources
0378-7753,
144
, pp.
141
145
.
19.
Lu
,
G. Q.
,
Lim
,
P. C.
,
Liu
,
F. Q.
, and
Wang
,
C. Y.
, 2005, “
On Mass Transport in an Air-Breathing DMFC Stack
,”
Int. J. Energy Res.
0363-907X,
29
, pp.
1041
1051
.
20.
Ren
,
X.
, and
Gottesfeld
,
S.
, 2001, “
Electro-Osmotic Drag of Water in Poly(Perfluorosulfonic Acid) Membranes
,”
J. Electrochem. Soc.
0013-4651,
148
, p.
A87
.
21.
Liu
,
F. Q.
,
Lu
,
G. Q.
, and
Wang
,
C. Y.
, 2005, “
Low Crossover of Methanol and Water through Thin Membranes of Direct Methanol Fuel Cells
,”
J. Electrochem. Soc.
0013-4651, in press.
You do not currently have access to this content.