Source: https://brevets-patents.ic.gc.ca/opic-cipo/cpd/eng/patent/2292146/summary.html
Timestamp: 2020-05-30 16:07:43+00:00
Document Index: 99890468

Matched Legal Cases: ['art.\n11', 'art 254', 'arts 152', 'arts\n154', 'arts 152', 'art 154', 'art 154', 'art 154', 'art 152', 'art 154', 'art 162', 'arts 154', 'arts 152', 'arts 154', 'art 152', 'art 154', 'art 152', 'art 154', 'art 152', 'art 154', 'arts 152', 'arts 154', 'art 154', 'arts 152', 'art 154', 'arts 152', 'arts 252', 'arts\n254', 'arts 252', 'arts 152', 'arts 254', 'arts 154', 'art 254', 'art 257', 'art 257', 'art 254', 'art 254', 'art 264', 'art 257', 'art 264', 'art 252', 'art 262', 'arts 254', 'art 254', 'art 252', 'art 254', 'arts 252', 'arts 252', 'arts 254', 'art 252', 'art 252', 'art 154']

Patent 2292146 Summary - Canadian Patents Database
Canadian Patents Database / Patent 2292146 Summary
(11) CA 2292146
JOINT D'ETANCHEITE ET PILE A COMBUSTIBLE AVEC JOINT D'ETANCHEITE
HEI 10-357649 Japan 1998-12-16
Joint dans une pile à combustible électrochimique, empêchant la fuite de fluide présent dans un espace. Le joint inclut une première couche et une deuxième couche ayant des coefficients d'élasticité différents. Le joint est constitué de caoutchouc. Une pile à combustible électrochimique inclut une membrane à électrolyte, une première électrode sur un côté de la membrane à électrolyte et une deuxième électrode sur un autre côté de la membrane à électrolyte, un premier séparateur et un deuxième séparateur, ainsi que le joint. Les premier et deuxième séparateurs prennent en sandwich les première et deuxième électrodes. Le joint est non seulement disposé entre la membrane à électrolyte et l'un des premier et deuxième séparateurs pour obturer un trajet d'un gaz combustible ou d'un gaz oxydant, mais se trouve également entre les premier et deuxième séparateurs pour obturer un trajet de fluide frigorigène. Puisque la couche souple dans le joint se déforme élastiquement et absorbe une rugosité de surface de la membrane à électrolyte ou de l'électrode, la capacité d'obturation du joint est élevée. Le joint peut répondre ou s'adapter à un changement de longueur de la membrane à électrolyte ou du séparateur dû à une variation de température. En outre, puisque la couche plus dure supporte la membrane à électrolyte ou l'électrode, une rigidité élevée de l'assemblage de pile à combustible peut être obtenue.
1. A seal for stacks of polymer electrolyte fuel cells and for preventing
space of said fuel cells from leaking, said seal comprising:
a first layer, said first layer having a coefficient of elasticity; and
a second layer, said second layer having a coefficient of elasticity so that
coefficient of elasticity of said second layer is higher than the coefficient
of said first layer.
2. The seal according to claim 1, further comprising a third layer, said third
having a coefficient of elasticity, said first, second, third layers being
arranged from a
higher to a lower coefficient of elasticity.
3. The seal according to claim 1, further comprising a third layer, said third
having a coefficient of elasticity, said first, second and third layers being
such that said first layer is between said second layer and said third layer.
4. The seal according to claim 1, 2 or 3, wherein said layers are made of
5. The seal according to claim 4, wherein a rubber hardness of a higher
coefficient of elasticity layer is equal to or higher than 60 degrees and a
hardness of a lower coefficient of elasticity layer is lower than 60 degrees.
6. A seal in an electrochemical fuel cell for preventing fluid in a space from
leaking, wherein a coefficient of elasticity consecutively increases from one
said seal to another side of said seal.
a first electrode on one side of said electrolyte membrane and a second
electrode on another side of said electrolyte membrane;
a first separator and a second separator sandwiching the first and second
a seal as claimed in one of claims 1, 2, 3 and 6 between said electrolyte
membrane and one of said first and second separators.
8. The electrochemical fuel cell according to claim 7, wherein a coefficient
elasticity of a layer of said seal facing said electrolyte membrane is higher
coefficient of elasticity of a layer of said seal facing said separator.
a coolant path between said first and second separators, coolant flowing in
said coolant path; and
a seal as claimed in one of claims 1, 2, 3 and 6 between said first and second
10. A seal in an electrochemical fuel cell for preventing fluid provided in a
from leaking, said seal comprising:
a base part having a first surface, a second surface, and a third surface, the
second and third surfaces being opposite to the first surface, the third
closer to the first surface than the second surface, the base part having a
a seal part on the third surface of the base part and extending beyond a plane
defined by the second surface of the base part, the seal part having a
wherein the coefficient of elasticity of the base part is higher than the
coefficient of elasticity of the seal part.
11. The seal according to claim 10, wherein said base part and said seal part
12. The seal according to claim 11, wherein a rubber hardness of said base
equal to or higher than 60 degrees and a rubber hardness of said seal part is
a seal as claimed in claim 10 between said electrolyte membrane and one of
said first and second separators.
said first and second separators,
wherein said first surface of said base part faces at least one of said
and said seal part extending beyond the plane defined by the second surface of
base part faces said electrolyte membrane.
a seal as claimed in claim 10 between said first and second separators.
16. A seal in an electrochemical fuel cell for preventing fluid in a space
leaking, said seal comprising:
a base part having a first surface, a second surface, a third surface, and a
surface, the first surface being opposite to the second surface, the third
opposite to the fourth surface, and the distance between the first and second
being greater than the distance between the third and forth surfaces, the base
having a coefficient of elasticity; and
a seal part on the third and fourth surfaces and extending beyond a plane
defined by the first surface and/or the second surface, the seal part having a
a seal as claimed in claim 16 between said electrolyte membrane and one of
a seal as claimed in claim 16 between said first and second separators.
19. A seal in an electrochemical fuel cell for preventing fluid in a space
leaking, said seal comprising a first side having a substantially plane
second side having a first sealing member and a second distinct sealing
cross-sectional area of the second sealing member being less than the cross-
area of the first sealing member.
20. The seal according to claim 19, wherein the second sealing member is
substantially half elliptical or half circular in cross-section.
21. The seal according to claim 19, wherein the second sealing member is
substantially trapezoidal or rectangular in cross-section.
22. The seal according to claim 19, wherein the second sealing member extends
above a plane defined by the first sealing member.
a seal as claimed in claim 19 between said electrolyte membrane and one of
a seal as claimed in claim 22 between said electrolyte membrane and one of
a seal as claimed in claim 19 between said first and second separators.
a seal as claimed in claim 22 between said first and second separators.
CA 02292146 1999-12-08
The present invention relates to a seal and an electrochemical fuel cell
the seal. Especially, the seal in the electrochemical fuel cell prevents fluid
provided in a space from leaking. Furthermore, the seal is provided in the
electrochemical fuel cell for sealing a space between an electrolyte membrane
separator or for sealing a coolant path between two separators.
In an electrochemical fuel cell, uniting a generator part and a frame part as
body by a hot-press method is proposed, as a sealing method which seals a path
shaped by an electrolyte membrane and a separator for a fuel gas containing
or an oxidative gas containing oxygen. Two electrodes sandwich the electrolyte
membrane in the generator part, and an opening area of the frame is marginally
smaller than one of the generator parts made of plastic. One of these examples
disclosed in Japanese Laid-Open Patent Application No. 10-199551. Moreover, in
above-mentioned method, the path shaped by the electrolyte membrane and the
separator for the fuel gas or the oxidative gas is sealed by providing a seal
O-ring between the frame part and the separator.
As another method, a method in which the generator part and the separator are
connected by using adhesives is also proposed. In this method, the adhesives
as a comparatively soft seal after the connection, and the adhesives seal the
the fuel gas or the oxidative gas.
In the aforementioned methods, which unite the generator part and the frame
part as one body and furthermore puts the seal between the frame and the
sealing ability on the sealing surface could not be secured, because a
between the frame and the separator varies by a thermal expansion caused by
the electrolyte membrane in the generator part.
Furthermore, in the above-mentioned method which uses the adhesives, when
a fuel cell stack is assembled by stacking a plurality of the generators and
separators, a stiffness of the fuel cell stack is weakened by laminating,
using adhesives. Consequently, the fuel cell stack can not have sufficient
It is thus one object of the present invention to solve the aforementioned
problems. Another object of the invention is to provide a seal which can seal
by following and responding to a varying length of an electrolyte membrane or
separator. Furthermore, an object of the invention is to provide a fuel cell
stack which
has a sufficient stiffness, when a plurality of electrolyte membranes,
According to one aspect of the invention, a seal has at least two layers with
different coefficients of elasticity. As the first embodiment of a seal in an
electrochemical fuel cell, a seal includes a first layer and a second layer
different coefficients of elasticity, and the seal prevents fluid in a space
For example, the seal is made of rubber, and the rubber hardness of the harder
60 degrees or higher and the softer layer is 60 degrees or lower.
Since the coefficients of elasticity of the layers in the seal are different,
can appropriately respond to two members which sandwich the seal, and the seal
seal sufficiently even if one of the two members or two members change its
both lengths. Providing the layers with , different coefficients of elasticity
between the two members indicates that a softer layer and a harder layer are
in the seal. Since the softer layer is provided in the seal, this softer layer
can elastically
deform by resp6nding to the changing length of the one or two members. On the
contrary, since the harder layer is provided in the seal, the other layer
harder one changes the shape by elastic defon!nation, and the other layer can
the changing length. The harder layer contributes to obtain a higher stiffness
the two members, because the harder layer has a higher resilience of elastic
deformation. Consequently, the stiffness of the parts which uses the seal
higher, and an upper limit of the compression rate of the two members with the
can be improved. At the same time, a high sealing performance of the seal can
Incidentally, a seal containing three or more layers is also available,
above-mentioned results can be obtained by having at least two layers with
When the softer layer is connected to one of the two members after the harder
layer is connected to another member, the softer layer (that is, the lower
elasticity) absorbs a surface roughness of the one of the two members.
the higher sealing ability can be achieved.
The first embodiment of an electrochemical fuel cell is an electrochemical
fuel cell including an electrolyte membrane, a first electrode on one side of
electrolyte membrane and a second electrode on another side of the electrolyte
membrane, a first separator and a second separator sandwiching the first and
electrodes, and the above-mentioned seal between the electrolyte membrane and
of the first and second separators. The electrolyte membrane, two electrodes
separators are stacked in the lamination condition. This electrochemical fuel
good performance of a sealing ability, and a high stiffness of the fuel cell
obtained, because it provides the first embodiment seal for the seal. The
performance and reliability of the fuel cell, then, can be improved.
In this first embodiment of the fuel cell, it is also available that the layer
higher coefficient of elasticity is positioned to face the electrolyte
membrane and the
layer with a lower coefficient of elasticity is positioned to face the
separator. Since the
layer having a lower coefficient of elasticity absorbs the surface roughness
separator in this case, a higher sealing performance can be secured.
In the first embodiment of the fuel cell, the above-mentioned seal of the
embodiment of the seal can be provided for sealing a coolant path between the
separator and the second separator.
As the same reason of the first above-mentioned embodiment of the fuel cell
including the seal, the first embodiment of the fuel cell including the seal
the coolant path has a high sealing ability and a high stiffness of the fuel
cell stack in
the lamination direction. The performance and the reliability of the fuel cell
As the second embodiment of a seal in an electrochemical fuel cell, a seal
includes a base part and a seal part. The base part has a first surface, a
and a third surface. The second and third surfaces are opposite to the first
the third surface is closer to the first surface than the second surface. The
seal part on
the third surface of the base part extends beyond a plane defined by the
of the base part. The coefficient of elasticity of the base part is higher
coefficient of elasticity of the seal part. For example, the seal is made of
the rubber hardness of the base part is 60 degrees or higher and the rubber
the seal part is 60 degrees or lower.
In this second embodiment of the seal, since the seal part is comparatively
by the elastic deformation the seal part can follow the length of the members
sandwiches the seal, though the length changes due to a heat expansion. When
part is connected to one of the members after the base part is connected to
member, the seal part having the lower coefficient of elasticity absorbs a
roughness of the one of the members. Consequently, the higher sealing ability
attained. Moreover, since the base part has a high resilience against
deformation, the
stiffness in the pressure direction can be improved. Especially, if the base
parts are made up so that the base part receives a pressure from the members
seal receives an excessive pressure than a predetermined value, the higher
the pressure direction can be obtained.
The second embodiment of an electrochemical fuel cell is attained by
providing the above-mentioned second embodiment of the seal as a seal to the
type of the fuel cell as the first embodiment. A high sealing ability and high
of the fuel cell stack are obtained as the same as the first embodiment of the
In the second embodiment of the electrochemical fuel cell, the fuel cell can
also be designed so that the base part receives a pressure from the separator
seal part receives a pressure from the electrolyte membrane and the base part.
high stiffness of the fuel cell stack and high sealing ability can be achieved
by this fuel
In the second embodiment of the fuel cell, the above-mentioned seal of the
second embodiment of the seal can not only be provided to a seal between an
electrolyte membrane and a separator, but can also be provided as a seal
,which seals a
coolant path between the separators.
As the third embodiment of a seal in an electrochemical fuel cell, a seal
includes a base part and a seal part . The base part has a first surface, a
a third surface, and a fourth surface. The first surface is opposite to the
and the third surface is opposite to the fourth surface. The distance between
and second surfaces is greater than the distance between the third and fourth
The seal part on the third and fourth surfaces extends beyond a plane defined
first and/or the second surface. Furthermore, the coefficient of elasticity of
part is higher than the coefficient of elasticity of the seal part.
In this seal, since the seal part has a comparatively soft seal part, by the
deformation the seal part can follow the length of the members which
seal, though the length changes due to a heat expansion. Accordingly, the
sealing ability can be attained. Moreover, since the base part has a high
against deformation, the stiffness in the pressure direction can be obtained,
same way as the second embodiment of the seal.
The third embodiment of an electrochemical fuel cell is attained by providing
the above-mentioned third embodiment of the seal to the same type fuel cell of
first or second embodiment. By assembling the fuel cell high sealing ability
stiffness of the fuel cell stack are obtained as the same as the first or
embodiment. Accordingly, the performance and reliability of the fuel cell can
In the third embodiment of the fuel cell, the above-mentioned seal of the
embodiment of ythe seal can not only be provided as a seal between an
membrane and a separator, but can also be provided as a seal which seals a
path between the separators.
As the fourth embodiment of a seal in an electrochemical fuel cell, a seal has
first side with a substantially plane surface and a second side with a first
member and a second distinct sealing member. The cross-sectional area of the
sealing member is less than the cross-sectional area of the first sealing
second sealing member is substantially half elliptical in cross-section. It is
available that a cross-sectional shape of the second sealing member is
half circular, trapezoidal or rectangular. It is also available that the
member is substantially extends above the plane defined by the first sealing.
In the fourth embodiment of a seal, since the smaller and extending area of
seal receives a greater stress, it elastically deforms more largely and the
seal ability is
secured. Since the larger area of the seal receives a lower stress than the
smaller area,
the elastic deformation of the larger area is smaller and a high stiffness in
of the pressure is secured. The high sealing ability and the stiffness is,
then, obtained.
The fourth embodiment of an electrochemical fuel cell is achieved by
providing the above-mentioned fourth embodiment of the seal as a seal to the
type of the fuel cell as the first, second or third embodiment.
In the fourth embodiment of the fuel cell, the above-mentioned seal of the
fourth embodiment of the seal can be adopted to a seal part which seals a
shaped by the separators.
By this fuel cell a high sealing ability and a high stiffness of the fuel cell
are obtained as the same as the first, second, or third embodiment.
performance and reliability of the fuel cell can be achieved.
The above and other objects, features, advantages and technical and industrial
significance of this invention will be better understood by reading the
detailed description of a presently preferred embodiment of the invention,
considered in connection with the accompanying drawing, in which:
Fig. 1 is a part of a first embodiment of an electrochemical fuel cell stack
which provides a first embodiment of a seal 50, shown in a cross-section;
Fig. 2 is ~a part of a second embodiment of an electrochemical fuel cell stack
120 which includes a second embodiment of a seal 150, shown in a cross-
Fig. 3 shows an electrochemical fuel cell stack 120a in a cross-section, as a
modified example of the second embodiment;
Fig. 4 is a part of a third embodiment of an electrochemical fuel cell stack
which provides a third embodiment of a seal 250, shown in a cross-section;
Fig. 5 is a magnified cross-sectional view of a base part 254 in the third
embodiment of the seal;
Fig. 6 is a part of a fourth embodiment of an electrochemical fuel cell stack
320 which includes a fourth embodiment of a seal 360, shown in a cross-
Fig. 7 is a magnified cross-sectional view of a seal 360 of the fourth
Fig. 8 is a magnified cross-sectional view of a modified seal 360a; and
Fig. 9 is a magnified cross-sectional view of a modified seal 360b.
In the following description and the accompanying drawings, the present
invention will be described in more detail in teens of specific embodiments.
shows a partial cross-sectional view of a first embodiment of an
cell including a first embodiment of a seal. For the convenience of
explanation, an
electrochemical fuel cell stack 20 is first explained, and a seal 50 or a seal
60 which is
deposited in the fuel cell stack 20 is later mentioned in details in relation
cell stack 20.
Fig. 1 shows one unit cell included in the fuel cell stack 20, and the unit
the fuel cell stack 20 is made up by laminating an electrolyte membrane 22,
electrodes 24, 26, and a first and second separators 30, 40, and by sealing a
fuel gas containing hydrogen, a path for an oxidative gas containing oxygen by
seal 50, and a sealing path for coolant by the seal 60. Incidentally, water
as the coolant. The two electrodes which are respectively a fuel electrode 24
oxygen electrode 26 sandwich the electrolyte membrane 22. The first and second
separators 30, 40 shape a coolant path 44 for the coolant. In order to make
the paths for the fuel or oxidative gas, a sealing plate 58 is deposited
separator 30 and the seal 50.
The electrolyte membrane 22 is a proton-conductive membrane which is made
of solid polymer electrolyte material, for example fluorine resin. The two
24, 26 are respectively made of carbon-cloths and are kneaded with catalyst on
one side. The catalyst is made of platinum or platinum-alloy. The surface of
electrode 24 which the catalyst is kneaded with faces and touches the
membrane 22, and in the same way as the fuel electrode 24 the surface of the
electrode 26 which the catalyst is kneaded with faces and touches the
membrane 22. The electrolyte membrane 22 and the two electrodes 24, 26
sandwiching the electrolyte membrane 22 are united as one body by a hot-press
method. It is also available to join them by other methods.
The first and second separators 30, 40 are made of solid and dense carbon
which is gas-impermeable. A plurality of projections and depressions are
both surfaces of each separator 30, 40. Here, such a projection is called a
rib 32 in the
first separator 30 or a rib 42 in the second separator 40. The ribs 32, 42
shape a fuel
gas path 34, an oxidative gas path 36, or the coolant path 44.
The seals 50, 60 respectively consist of first layers 52, 62 and second layers
54, 56. The first layers 52, 62 are made of comparatively soft rubber foam.
example, silicon rubber foam or butyl rubber foam, a rubber hardness of which
equal to or lower than 60 degrees, is used for material of the first layers
52, 62. The
second layers 54, 64 are made of harder rubber than the rubber which is
the first layers 52, 62. For instance, silicon rubber or butyl rubber which
hardness is equal to or higher than 60 degrees. It means that coefficients of
of the rubber of the second layers 54, 64 are greater than those of the first
layers 52,
Next, how to assemble the fuel cell stack 20, mainly how to assemble the seal
50 is explained. The second layer 54 is positioned at a place where sealing is
necessary on the each surface of the electrolyte membrane 22, after the
membrane 22 is connected by the two electrodes 24, 26. The second layers 54
electrolyte membrane 22 are united as one body. Places where sealing is
necessary are,
for example, a periphery of the electrolyte membrane 22, the periphery of the
path 34, or the oxidative gas 36 shaped in the direction of the laminating
fuel cell stack 20. A hot-press method or a method of using adhesives is
uniting the second layer 54 and the electrolyte membrane 22. Next, the first
layer 52 is
set on the second layer 54, and furthermore the sealing plate 58 and the first
separator 30, 40 are put thereon.
When the coolant path 44 is shaped by setting the first and second separators
and 40 on together, the second layer 64 is positioned at a place where sealing
necessary on the first separator 30 or the second separator 40. Subsequently,
second layer 64 and the second separator 40 are united as one body. In the
30 as the seal 50 is assembled, the first layer 62 is positioned on the second
layer 64, and
the first separator 30 is put thereon.
The first layer 52 is put on after the second layer 54 connected to the
electrolyte membrane 22 or the second separator 40 as mentioned above, to
the sealing ability by absorbing the surface roughness of the first or second
30, 40 by the first layer 52 with its lower rubber hardness, because the
roughness might cause to decrease the sealing ability. Another purpose is for
layer 52 to elastically respond and follow the length of the electrolyte
changed by the varying temperature. Furthermore, the second layer 54, having
higher rubber hardness, is used to increase the stiffness of the fuel cell
stack 20 in the
direction of the lamination of each unit cell. By providing the seal 50 or 60
two layers with different coefficients of elasticity, the softer layer (that
is, the second
layer 52 or 62) absorbs surface roughness of a sealing member and responds to
changing length of the electrolyte membrane 22 or the separator 30, 40, and
layer (that is, the second layer 54 or 64) restrains an elastic deformation of
stack 20, and the higher stiffness of the fuel cell stack 20 is obtained.
The fuel cell stack 20 which is assembled and made up as mentioned above is
pressed by a predetermined pressure in the direction of lamination of a
unit cells. The pressure reduces a contacting electric resistance between the
24 or 26 and separator 30 or 40 and increases sealing ability of the seal 50
or 60 by
increasing the pressure on the surface of the seal 50 or 60.
As mentioned above, because the fuel cell stack 20 of the first embodiment has
the seal 50 including two layers with different coefficients of elasticity,
roughness of the first separator 30 or the second separator 40 which might
the sealing ability can be absorbed, and the changing length of the
membrane 22 or etc. caused by changing temperature can be followed. The high
sealing performance, thus, can be achieved. Moreover, because the seals 50, 60
provide the harder layers (the second layers 54, 64), the high stiffness of
stack 20 in the laminating direction of the unit cells is attained. The total
of the fuel cell 20 is improved by these advantages of the seals 50, 60.
Incidentally, the seal 50 is not only limited to consist of two layers with
different coefficients of elasticity as mentioned above, but it can also
or more layers. Furthermore, a seal which material's coefficient , of
consecutively changes from one surface to another surface of the seal is also
In the seal consisting of three or more layers, it is not only available that
layer is set to contact the separator 30, 40, etc., but it is also available
that the softer
layer is not set to contact them. For instance, the softer layer is inserted
harder layers. When this type of fuel cell stack is assembled, the softer
positioned and connected, after uniting the electrolyte membrane 22 with one
layer and uniting the separators 30, 40 with another harder layer.
The seal 50 of the first embodiment consists of the first layer 52 and the
second layer 54, each of which is a completely laminated Layer. It is also
the harder layer 52 includes material of a softer layer. From the view point
absorbing the surface roughness of the separator or etc., though it is
softer layer is a completely laminated layer, it is not necessary that the
harder layer is a
completely laminated layer. Furthermore, it is not necessary that the softer
layer is a
completely laminated layer, and it is no problem that one part of the softer
material of further softer, or that small part of the softer Layer is made of
Next, the second embodiments of the seal and the fuel cell are explained using
a seal 150 and a fuel cell stack 120 including the seal 150 in Fig. 2. Fig. 2
cross-sectional view of the fuel cell stack 120 including the seal 150.
As the same as the fuel cell stack 20 of the first embodiment, the fuel cell
stack 120 includes an electrolyte membrane 122, a fuel electrode 124, an
electrode 126, a first separator 130, a second separator ~ 140, and seals 150,
electrolyte membrane 122, and the two electrodes 124, 126 are respectively the
as the above-mentioned electrolyte membrane 22, and electrodes 24, 26. The
separators 130, 140 are walls for one unit cell, and by sandwiching the
electrode 124
or 126, the first or second separator 130, 140 and the electrolyte membrane
122 shapes
a fuel gas path 134 or an oxidative gas path 136. In the same way, the first
separators 130, 140 shape a coolant path 144. The seal 150 seals the fuel gas
path 134
or the oxidative gas path 136, and the seal 160 seals the coolant gas path
explanation of the same parts in this second embodiments as in the first
are, here, omitted.
The separator 130 is made of a metal such as aluminum, stainles$ steel, nickel
alloy, or etc. A plurality of projections and depressions are shaped on the
130, and the projections are called ribs 132. The ribs 132 constitute paths
134 for the
fuel gas or paths 136 for the oxidative gas, and the ribs 132 constitutes
paths 144 for
coolant. On the surface of the separator 130 facing the path 134 or 136, high
conductive seat (ex. resin seat permeated with carbon) is connected by press
to prevent the surface of the separator 130 from rusting (not shown in Fig.
2). In the
second embodiment, as shown in Fig. 2, the first and second separators 130,
put on together contacting each surface with plane symmetry. Soft metal with
electrical conductivity (ex. tin, nickel, or etc.) is stuck to the contacting
first and second separators 130, 140 to reduce electrical resistance between
surfaces of the first and second separators 130, 140.
The seals 150, 160 respectively consist of the seal parts 152, 162 made of
comparatively soft (i.e. lower coefficient of elasticity) rubber foam (ex.
butyl rubber, etc. with rubber hardness 60 or less degrees) and the base parts
154, 164,
made of comparatively hard (i.e. higher coefficient of elasticity) rubber (ex.
rubber, butyl rubber, etc. with rubber hardness 60 or more degrees). It is
the seal parts 152, 162 have shapes half elliptical in cross-section.
A first surface 159 is opposite and parallel to a second surface 156 and a
surface 158. The third surface 158 is closer to the first surface 159 than the
surface 156. A seal groove 155, then, is shaped in the base part 154. The seal
is deposited in the seal groove 155. A part between the second surface 156 and
first surface 159 in the base part 154 secures the stiffness in the laminated
against excess pressure, and an extending member 157 is also provided in the
part 154 for supporting the electrolyte 124 or 126. The depth of the seal
groove 155 is
a little bit less than the thickness of the seal part 152.
In the same way as the seal groove 155, a seal groove 165 is shaped in the
surface of the base part 154 by shaping a third surface 168. However, the same
extending member as the extending member 157 is not provided, because it is
necessary to support the electrode 124 or 126. The depth of the seal groove
165 is
substantially the same as the thickness of the seal part 162 on the condition
First, the base parts 154, 164 are closely contacted at a predetermined
of the separators 130, 140 by adhesives or a like, and the seal parts 152, 162
the seal grooves 155, 165 on the base parts 154, 164. After laminating a
the separators 130, 140 and a plurality of the electrolyte membranes 122
the sets of the two electrodes 124, 126, a predetermined pressure is applied
assembled fuel cell stack 120.
When the predetermined pressure is applied, the seal part 152 or 162 is
elastically deformed and the electrolyte membrane 122 and the base part 154 or
closely contacted. Accordingly, the contacting members are sealed with high
reliability, and the seal part 152 or 162 follows and responds to the changing
the electrolyte membrane 122 subjective to its changing temperature, owing to
elastic deformation. Furthermore, when the predetermined pressure is applied
lamination direction of the fuel cell stack 120, the harder base part 154,
- coefficient of elasticity greater than the coefficient of the seal part 152,
electrolyte membrane 122. Consequently, the stiffness of the fuel cell stack
120 in the
lamination direction is obtained, because the base part 154 receives the
As mentioned above, since the seals 150, 160 respectively consist of the
comparatively soft seal parts 152, 162 and the comparatively hard seal parts
in the fuel cell stack 120 of the second embodiment, the high sealing ability
and the seals 150, 160 can respond to the changing .length of the electrolyte
122 or etc. caused by the varying temperature. Moreover, the high stif&less of
cell stack 120 in the lamination direction is obtained. Therefore, the total
of the fuel cell can be improved by the above-mentioned advantages, owing to
seals 150, 160.
In the fuel cell stack 120, the seals 150, 160 consist of the seals 152, 162
the base parts 154, 164. It is, however, also available that a seal 150a
base part 154a and two seal parts 152a in the modified embodiment (a fuel cell
120a) as illustrated in Fig. 3. In this fuel cell stack 120a, the base part
154a, which is
plane symmetry and wraps the end part of the two separators 130, 140, is put
closely, and two seal grooves 155a are shaped on the opposite members of the
part 154a. The two seal parts 152a are respectively deposited in two seal
155a. Since the end part of the separators 130, 140 is covered as shown in
separators 130, 140 can be prevented from rusting. ,
Next, seals 250, 260 and a fuel cell stack 220 including the seals 250, 260
explained, as the third embodiment of the present invention. Fig. 4 is a
partial cross-
sectional view of the fuel cell stack 220 having the seals 250, 260.
The fuel cell stack 220 of the third embodiment has the same structure as the
fuel cell stack 20 of the first embodiment, except the seals 250 and 260. The
explanation of the same parts as the fuel cell stack 20 is, then, omitted in
this fuel cell
stack 220. Incidentally, the appended number of each part of the fuel cell
stack 220 is
added by 100 to the number of the respective part of the fuel cell stack 20.
The seals 250, 260 respectively consist of seal parts 252, 262 and base parts
254, 264. The seal parts 252, 262 are made of the same material as the seal
parts 152,
162 shown in the second embodiment, and the base parts 254, 264 are made of
same material as the base parts 154, 164, shown in the second embodiment. The
part 254 including an extending part 257 has a first surface 256 and a second
259. The extending part 257 supports an electrodes 224, 226. The base part 254
has a seal hole 255 in which the seal 152 is provided.
With reference to Fig. 5, the seal hole 255 comprises a first seal space 255a
facing a first separator 230 or a second separator 240, a second seal space
255b facing
the electrolyte membrane 222, and a bottom hole 255c. A distance between a
surface 255d which is the bottom of the first seal space 255a and a fourth
surface 255e
which is also the bottom of the second seal space 255b is shorter than the
between the first and second surfaces 256, 259. A plurality of the bottom
holes 255c
are regularly located and connect between the seal spaces 255a and 255b. In
way as the base part 254, a seal hole 265 is provided in the base part 264,
illustrated in Fig. 4 a first surface 266 and a second surface 269 are
However, since it is not necessary to support the electrodes 224, 226, the
the extending part 257 is not shaped in the base part 264. The distance
first surface 256 and the second surface 259 is substantially the same as the
of the seal part 252 which is pressed by a predetermined pressure. In the same
the distance between the first surface 266 and the second surface 269 is
the same as the thickness of the seal part 262 which is pressed by a
pressure. Accordingly, the first and second surfaces 256. (or 266) and 259 (or
receive most of the pressure, when an excessive pressure higher than the
predetermined value is applied to the seal 250 (or 260). Because the base
parts 254,
264 are made of comparatively high coefficient of elasticity material, the
stack 220 can have a higher stiffiiess in the laminating direction.
In order to assemble the fuel cell stack 220, first the base part 254 is
connected to a predetermined place in a first separator 230 or a second
separator 240
by adhesives or etc. Next, the seal part 252 is inserted into the seal hole
255 in the
base part 254, and the two separators 230, 240 with seals 250 and two
electrodes 224,
225 connected to the electrolyte membrane 222 are put together as a unit cell.
plurality of such unit cells are stacked and assembled to the fuel cell stack
sealing material is inserted by a pressure to the seal spaces 255a and 255b,
seal 250 is sufficiently and closely connected to the separators 230, 240 or
electrolyte membrane 222. The sealing material is inserted to the first seal
space 255a
continuously from the second seal space 255b through the bottom hole 255c.
how to assemble the first and second separators 230, 240 to shape a coolant
path 244
by inserting the seal 260 is the same way as how to insert the seal 250 as
above. Here, the explanation is, then, omitted. After assembling the unit
predetermined pressure is applied in the lamination direction of the units
cells, and the
fuel cell stack 220 is finally completed.
The seal parts 252 and 262 is given the predetermined pressure and closely
connected to the separators 230, 240 and electrolyte membrane 222.
seals 250, 260 seal between the surfaces with high reliability, and respond
due to the elastic deformation to the changing length of the electrolyte
membrane 222
effected by the varying temperature.
In the aforementioned fuel cell stack 220, by providing the seals 250, 260
which comprise the seal parts 252, 262 having lower coefficients of elasticity
base parts 254, 264 having higher coefficients of elasticity, the high sealing
not only obtained, but the seals 250, 260 also respond to and follow the
length of the electrolyte membrane 222 or etc. by the effect of the changing
temperature. Furthermore, the high stiffness of the fuel cell stack is secured
lamination direction. Due to these advantages of the seals 250, 260, the total
performance of the fuel cell can be improved.
In the fuel cell stack 220, the bottom hole 255c is shaped, however, it is
available that there is not a bottom hole between the third and fourth
surfaces 255d,
255e. In this case, it is necessary that the seal part 252 is inserted to both
255a, 255b separately.
In the fuel cell stack 220, the seal holes 255, 265 are shaped in the base
254, 264 and the seal part 252, 262 are inserted into the seal holes 255, 265.
Moreover, it is also available that a base part and a seal part are located in
respectively they receive a pressure by a separator and an electrolyte
membrane or by
two separators. In this case, if the seal part is located in an inner side of
(that is, near the electrode in Fig. 4), the higher sealing ability is
Next, as the fourth embodiment, seals 350, 360 and a fuel cell stack 320
including the seals 350, 360 is explained. Fig. 6 is a partial cross-sectional
fuel cell stack 320 including the seals 350, 360.
Concerning the fuel cell stack 320 as the fourth embodiment, it has the same
structure as the fuel cell stack 120 (the second embodiment). Here, it is,
then, omitted
to explain the same parts in the fuel cell stack 320 as the parts in the fuel
120. Incidentally, appended numbers of parts of the fuel cell stack 320 are
adding 200 to parts numbers of fuel cell stack 120.
A seal 350 deposited in the fuel cell stack 320 consists of layers 354 and 356
having the same material as the base part 154 of the second embodiment, and a
sealing layer 352 made of rubber adhesives (ex. adhesives by combining silicon
epoxy resin). A coefficient of elasticity of the sealing layer 352 is lower
coefficients of elasticity of the layers 354 and 356 after the fuel cell stack
stacked. The seal 350 consists a sealing layer 352 having a comparatively low
coefficient of elasticity and the layers 354, 356 having a higher coefficient
than the sealing layer 352. Consequently, the seal 350 can be considered to be
modified embodiment, though the arranging of the soft and hard layers is
from the seal 50 of the first embodiment. The same advantages as mentioned in
A seal 360 consists of a comparatively hard rubber (that is, comparatively
coefficient elasticity), for example silicon rubber or butyl rubber which
hardness is equal to 60 degrees or more. A first side of the seal 360 has a
plane surface 366 and a second side of the seal 360 has a first sealing member
a second distinct sealing member 362. The cross-sectional area of the second
member 362 is less than the cross-sectional area of the first sealing member
364, and
the second sealing member 362 is substantially half elliptical in cross-
plane surface 366 and the first sealing member 364 receives a pressure and
to a high stiffness of the fuel cell stack 320 in the stacked direction of the
As illustrated by a magnified cross-sectional view in Fig. 7, the second
member 362 extends by Oh above the plane defined by the first sealing member
Here, the extending value O h is determined by considering the changed value
elastic deformation of the seal 360, and considering an applied pressure to
360, material of the seal 360, the shape of the second sealing member 362,
a predetermined pressure is applied, the second sealing member 362 seals with
reliability. Since the plane surface 366 and the first sealing member 364
receives most
of the extra pressure, when more than the predetermined pressure is applied,
stiffness of the fuel cell stack is secured in the lamination direction.
In the fuel cell stack 320 of the fourth embodiment, by providing a seal
including a sealing member extending above another member, and a plane surface
the sealing member having a smaller area than another sealing member, a high
ability is not only secured, but a high stiffness of the fuel cell stack 320
obtained in the stacked direction.
In the seal 320, the first sealing member 364 is divided to two parts as shown
in Fig. 7, however a.first sealing member 364a which is not divided is also
Furthermore, concerning a shape of the seal 360, the shape of the second
sealing member 362 is half elliptical in the cross-sectional view: Another
second sealing member 362 is, however, also available, for example, half
One example of the seal 360b having the second sealing member 362b of
shape is shown in Fig. 9. A rectangular shape is also available for the shape
Incidentally, in the seal 360 the second sealing member 362 extends above the
first sealing member 364, however it is also available that the second ~
does not extend above the first sealing member 364, that is, both members are
same one plane. In this case advantages are restrained, but it is still
In the fuel cell stack 320, the seal 360 is provided between the separators
for shaping the coolant path 344, however instead of the sealing layer 352 and
layers 354, 356, this type of the seal 320 can also be provided between
separators 330
for sandwiching the electrolyte membrane 322 and the electrode 324 or 326.
(22) Filed 1999-12-08
Lapsed 2015-12-08
Registration of Documents $100.00 1999-12-08
Filing $300.00 1999-12-08
Maintenance Fee - Application - New Act 2 2001-12-10 $100.00 2001-11-23
Maintenance Fee - Application - New Act 3 2002-12-09 $100.00 2002-11-19
Maintenance Fee - Application - New Act 4 2003-12-08 $100.00 2003-11-21
Final Fee $300.00 2004-10-29
Maintenance Fee - Application - New Act 5 2004-12-08 $200.00 2004-11-17
Maintenance Fee - Patent - New Act 6 2005-12-08 $200.00 2005-11-08
Maintenance Fee - Patent - New Act 7 2006-12-08 $200.00 2006-11-08
Maintenance Fee - Patent - New Act 8 2007-12-10 $200.00 2007-11-09
Maintenance Fee - Patent - New Act 10 2009-12-08 $250.00 2009-11-12
Maintenance Fee - Patent - New Act 11 2010-12-08 $250.00 2010-11-19
Maintenance Fee - Patent - New Act 12 2011-12-08 $250.00 2011-11-22
Maintenance Fee - Patent - New Act 13 2012-12-10 $250.00 2012-11-14
Maintenance Fee - Patent - New Act 14 2013-12-09 $250.00 2013-11-13
Representative Drawing 2000-06-07 1 16
Claims 2003-03-24 6 198
Drawings 2003-03-24 6 176
Claims 2003-04-22 6 210
Cover Page 2000-06-07 1 51
Abstract 1999-12-08 1 30
Description 1999-12-08 17 947
Claims 1999-12-08 5 181
Drawings 1999-12-08 6 172
Claims 2004-03-15 5 213
Representative Drawing 2005-01-13 1 28
Cover Page 2005-01-13 1 59
Assignment 1999-12-08 4 148
Prosecution-Amendment 2002-09-25 2 71
Prosecution-Amendment 2003-03-24 7 267
Prosecution-Amendment 2003-04-22 5 188
Prosecution-Amendment 2003-09-25 2 91
Prosecution-Amendment 2004-03-15 7 283
Correspondence 2004-10-29 1 32