Title of Invention

AN END PLATE FOR A FUEL CELL STACK

Abstract The present invention relates to an end plate for a fuel cell stack, containing at least one channel (7) for the supply and/or removal of at least one reactant and/or a reaction product and/or a coolant, wherein at least a part at least of one pump (8) for delivering the reactants and/or reaction products and/or coolant and which is arranged in the course of the respective channel (7) is integrated into the end plate. The invention further relates to a fuel cell stack which contains such an end-plate.
Full Text WO 2006/037661 PCT/EP2O05/010898
1
An end plate for a fuel cell stack
The invention relates to an end plate for a fuel
cell stack, according to the preamble of the main
5 claim, as well as to a fuel cell stack which contains
at least one such end plate.
Usually end plates assume the function of holding
together a fuel cell stack which comprises several
10 fuel cells connected in series, for example by way of
clamping with a second end plate, as well as for
collecting current at a first or last fuel cell of the
respective fuel cell stack. According to the state of
the art, it is furthermore known to lay channels for
15 the supply and/or removal of reactants, reaction
products and/or coolants through an end plate, so that
the respective end plate contains a section at least
of one such channel. Typically, with an end plate
according to the state of the art, such channels are
20 arranged in an end region of the end plate, in order


WO 2006/037661 PCT/EP2005/010898
from there to accordingly lead into edge regions of
the adjacent fuel cells.
Typically, pumps are required for the operation
5 of fuel cell stacks, which in each case may serve for
conveying a reactant, a reaction product or a coolant.
At the same time, with conventional fuel cell stacks,
the pumps form auxiliary units which are arranged
separately from the actual fuel cell stack. This
10 demands an expensive tube/piping system which is
disadvantageously costly, and simultaneously leads to
relatively long transport paths, which in turn leads
to undesired, uncontrollable flow dynamics with
disadvantageously high energy losses.
15
It is then the object of the present invention to
overcome the mentioned disadvantages and
simultaneously to permit a construction of fuel cell
systems which is more compact compared to the state of
20 the art.
According to the invention, this object is
achieved by an end plate with the characterising
features of the main claim in combination with the
25 features of the preamble of the main claim, and by way
of a fuel cell stack with the features of claim 19, as
well as a method according to claim 20. Advantageous
further developments of the invention are to be
deduced by the features of the dependent claims.
30
By way of the fact that with such an end plate
which contains at least one channel for the supply
and/or removal of at least one reactant and/or a
reaction product and/or a coolant, at least one part
35 of at least one pump arranged in a course of the
respective channel for conveying the reactants and/or


WO 2006/037661 PCT/EP2005/010898
3
reaction products and/or coolant, is integrated into
the end plate, then with the use of this end plate one
may realise a fuel cell system which as a whole has an
extremely compact construction. Further advantages
5 result by way of being able to realise extremely short
transport paths for a medium delivered by the
respective pump, between the pump and the location of
application of the respective medium by way of this.
With regard to the mentioned application location, it
10 may be the case of a reaction space of a fuel cell or
Of a coolant layer of a bipolar plate of a respective
fuel cell stack. Thereby, the type of fuel cell
considered is of no significance. With typical
arrangements, hydrogen and oxygen or air are used as
15 reactants, and/or water as a coolant.
A part of a pump is to be deemed as being
integrated into the end plate when it takes its place
within the external dimensions of the end plate,
20 preferably within a convex envelope of a base body of
the end plate. With this, the convex envelope is
defined as the smallest convex quantity which contains
the mentioned base body, wherein the pump or parts of
the pump, inasmuch as they are not incorporated into
25 the base body as one piece, are not themselves
considered as being a constituent of the base body.
The base body itself is preferably plate-like.
With regard to a construction manner which is as
30 compact as possible, it is particularly advantageous
if the respective pump is completely integrated into
the end plate within this context, or with the
exception of a drive motor or a part of a drive motor
of the pump.
35

WO 2006/037661 PCT/EP2005/010898
4
In this manner, one may arrange a pump for the
supply of a reactant, typically a reactant gas such as
hydrogen for example, as well as a pump for conveying
a coolant such as water for example or for
5 transporting away a reaction product, e.g. in the form
of water vapour. It is also possible to arrange two or
more pumps in the described manner completely or
partly integrated into the end plate.
10 A fuel cell stack which contains at least one end
plate of the described type has been shown to be
advantageous. A fuel cell stack may also be provided
with two such end plates in an advantageous manner,
wherein for example one pump for a reactant may be
15 integrated into a first end plate and a pump for a
coolant into the second end plate of the fuel cell
stack. Of course any other combination of arrangements
of two or more pumps in two end plates of a fuel cell
stack is possible.
20
An integration of pumps of the described type,
which are designed as peripheral assemblies with
conventional fuel cell systems, into the end plate or
into the end plates permits a very compact
25 construction manner of the fuel cell system.
Connection elements such as fittings, pipes and/or
flexible tubes may be largely done away with. This
leads to a reduced variant of parts and to a
minimisation of connection locations which in turn
30 renders the fuel cell system less prone to failures.
Extremely short transport paths result on account of
the integration, wherein particularly with a suitable
design of a coolant pump it is also possible to
realise relatively small fluid volumes. Heat losses
35 may also be kept low by way of this, which has a
positive effect of the thermal economics of the fuel

WO 2006/037661 PCT/EP2005/010898
5
cell. Thereby one is to take into account the fact
that although heat needs to be transported away in
larger quantities on operation of the fuel cell, a
discharge of heat should however be advantageously
5 effected only in a controlled manner and therefore
should be effected where possible only or mainly via a
coolant, whilst a thermal loss only due to long
transport paths may render a controlled temperature
control of a fuel cell more difficult, which is
10 undesirable. Good and easily controllable flow
dynamics and thus good control ability or regulating
ability of system parameters such as temperature and
humidity result on account of the short transport
paths and small fluid volumes. Finally, a material
15 saving may also result due to the integration of at
least one pump into the end plate.
The at least one channel contained in the end
plate may usefully be incorporated into the end plate
20 such that it is formed by recesses in the end plate.
End plates of the described type which are relatively
effortless to manufacture and therefore particularly
advantageous, may comprise a base body formed of an
insulator, for which a manufacture with the injection
25 moulding method lends itself. This base body is
preferably to be manufactured of plastic. For
injection moulding manufacture, one may particularly
use filled and/or fibre-reinforced or unfilled
thermoplastic plastics such as PA (polyamide), PI
30 (polyimide), PTFE (polytetrafluorethylene), PET
(polyethylene terephthalate) , PC (polycarbonate) PEEK
(polyetheretherketone), PPS (polyphenylene sulphide) ,
LCP (liquid crystal polymers), POM (polyoxymethylene),
PPO (polypropylene oxide).
35

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6
One advantageous simple construction results with
a single-piece design of the base body. One may
however also envisage the mentioned base body being
joined together of two or more than two parts, which
5 for example may in turn be designed in a plate-like
manner. A multi-part design of the base body may lend
itself, depending on the geometry of the channel
integrated into the end plate or the channels
integrated into the end plates, and depending on the
10 arrangement and shape of recesses provided for the
pump or pumps, in order to permit its inexpensive
manufacture with an injection moulding method. In this
case, the parts forming the base body should be
mutually sealed in order to prevent an undesirable
15 exit of reactants, reaction products or a coolant. For
this, the parts may be bonded, welded and/or mutually
braced to one another. One may also envisage arranging
one seal or several seals between the individual parts
for the same purpose.
20
For producing only a low number of units, a
material-removing manufacture of the base body or
parts of the base body may be more meaningful for
reasons of cost. One may then also apply fibre-
25 reinforced layer press materials with binders of epoxy
resins, silicone resins, phenol resins or melamine
resins. A manufacture of the base body or parts of the
base body amid the use of duroplastic, fibre-
reinforced plastics based on e.g. PF-phenol resin, MF-
30 raelamine resin or UP-unsaturated polyesters is also
conceivable.
With typical embodiments of the invention, the
pump which is completely or partly integrated into the
35 end plate is designed as a rotatory pump which permits
a uniform transport of the medium concerned

WO 2006/037661 PCT/EP2005/010898
(reactants, reaction products or coolant) and a good
controllability of the transport. With this, a
ventilator, for example a suitable fan serving for
conveying a gaseous medium is to be indicated as a
5 rotatory pump. Other types of pumps too may be
integrated into the end plate in the described manner.
With regard to the pump, it may for example be the
case of a jet pump. An arrangement of several pumps or
parts of several pumps of a different type in the end
10 plate is also possible.
One may design the pump in an advantageous manner
such that it comprises a first connection for the
supply of fresh reactant gas to the pump, a suction
15 connection for re-supplying reactant gas coming from a
reaction space, thus which has already been supplied
once to a fuel cell, and a further connection as a
common exit for the fresh and the re-supplied reactant
gas, wherein the mentioned common exit with a directed
20 use of the end plate in a fuel cell stack again leads
to the reaction space of one or more fuel cells. With
such a design of the pump, one may not only drive a
flow of reactants, but also (additionally or instead
of this) , by way of the re-supply of reactant gas
25 which has already flowed through the reaction space
which is given by a channel system, one ensures a
uniformly humid climate in the reaction space. This is
related to the fact that a reactant as which has
already flowed through the reaction space is usually
30 enriched with diffused water. The described effect is
of great advantage since an undesirable drop in the
humidity between the supply and removal in the
reaction space of a fuel cell may thus be avoided. At
the same time one should take into account the fact
35 that a humid climate is desired in the reaction space,
in order to prevent a drying-out in particular of an


WO 2006/037661 PCT/EP2005/010898
electrolyte membrane of a fuel cell. One in turn is
forced to rely on a humidity which is as uniform as
possible since a climate having a water content which
is too high may in turn act in a reaction-inhibiting
5 manner in a reaction space.
It is conceivable with a pump of the described
type with three connections, of which one forms a
suction connection for re-supply of already used
10 reactant gas, for the mentioned first connection for
the supply of fresh reactant gas to also be designed
as a suction connection. With regard to a construction
which is as simple as possible, it is however
advantageous if the pump is designed as a passive
15 component with which a vacuum at the suction
connection for the re-supply of the used reactant gas
is caused by a flow of the fresh reactant gas from the
first connection to the further connection serving as
a common exit. This may be achieved in a particularly
20 simple manner by way of the design of the pump as a
Venturi nozzle, wherein the suction connection for the
re-supply is advantageously to be arranged in a region
of minimal flow cross section. Moving parts may thus
be advantageously done away with. Other types of jet
25 pumps may be used in a similar manner as a passive
component for recirculating reactant gas.
Pumps of the type described in the previous
paragraphs may then be used in a useful manner in
30 combination with fuel cell systems also when they are
not integrated into an end plate. Thus for example it
would be conceivable to apply such a pump onto an end
plate or to design it as an externally arranged
peripheral apparatus for a fuel cell stack or another
35 fuel cell system.

WO 2006/037661 PCT/EP2005/010898
A further development of the invention,
additionally to the at least one pump also envisages
integrating at least one valve at least partly,
preferably completely into the end plate, with which a
5 flow of reactant, reaction product or coolant is
controlled, regulated and/or blocked when required.
Such valves could be powered and/or may be slide
damper, rotary slide valves, magnetic valves, throttle
flaps or the like. Such a valve in the simplest case
10 may serve as a safety valve in order to prevent a
discharge of medium, for example given an interruption
of operation of the respective fuel cell system. If
such a valve, whose integration into the end plate
serves for an advantageously compact construction and
15 leads to an arrangement of the valve in close
proximity with regard to the fuel cells, is designed
such that a flow of a reactant, reaction product or
coolant may be continuously controlled and/or
regulated with the help of the valve, then there
20 results the possibility of advantageously controlling
a fuel cell temperature and/or an optimal power
exploitation. At the same time, the valve may be
controlled with respect to events or also with respect
to time. The valve too, may be designed as a flush
25 valve for the occasional blowing-free of a channel
system or reaction space, wherein a blowing-out, for
example by way of a brief increase in the reactant
flow may again be effected in a time-controlled
manner, thus in defined time intervals, or in an.
30 event-controlled manner, for example when a water
constituent in a reaction space or in a reaction gas
exiting from the reaction space which is too high is
determined.
35 Typically, the end plate on an active surface
which in the assembled condition bears on a first fuel

WO 2006/037661 PCT/EP2005/O10898
10
cell of a fuel cell stack would have a current
collector. This is preferably designed in a two-
dimensional manner, for example as a metal plate or
sheet-metal piece, in order to permit the supply of
5 current with as low as possible resistance losses. In
particular, if the end plate comprises a base body
formed of an insulator, the current collector is
preferably to be designed as separate component which
may be applied onto the base body on the mentioned
10 surface or here may be applied into the base body.
One may envisage the base body of the end plate
comprising hollows open towards the current collector,
which possibly may only be separated by way of
15 individual webs on which the current collector may
bear. In this context, all bodies which are closed on
the rear side and comprise peripheral side walls as
well as at least one intermediate wall are to be
understood as being provided with open hollows. An
20 undesired loss of heat at a first fuel cell bearing on
the end plate may be well prevented by way of this.
Thus by way of this, fuel cells lying on the outside
may be thermally insulated particularly, by which
means a uniform temperature control of a complete fuel
25 cell stack is rendered possible. Furthermore, one may
achieve a high stiffness of the end plate in this
manner. In order to fulfil their purpose, the
mentioned hollows may advantageously be designed with
a depth (thus a dimension perpendicular to a current
30 collector plane) of between 0.5 and 50 mm. With
particularly preferred embodiments of the invention,
the hollows form a honeycomb structure which is open
towards the adjacent fuel cell stack and which is
covered only by the current collector, for example a
35 sheet metal piece. The honeycomb structure offers
advantages with regard to the stiffness of the plate

WO 2006/037661 PCT/EP2005/010898
11
and the support of the current collector. Furthermore,
the air cushion arising in the honeycombs acts as a
thermal insulation. As with other designs of the
mentioned hollows, a more uniform temperature level
5 sets in over all cells on account of this. This
contributes to an improved regulating ability or
controlling ability of the fuel cell stack, by way of
which one obtains a higher performance. The at least
one pump integrated into the end plate is usefully to
10 be arranged in a region of one side of the end plate
which is distant to the current collector. The
construction height of one of the units or of the unit
integrated into the end plate in such a manner may
also be used in order to design the end plate thicker
15 and thus stiffer, without increasing the construction
volume for the complete system.
The present invention is generally suitable for
many pump types. It has particular advantages for
20 mechanical pumps which for example comprise a drive
shaft. Thus a pump may comprise a drive shaft which is
mounted on one or two sides, i.e. has one or two
bearings. Here, one embodiment envisages a fan wheel
or the pump/pump impeller being arranged between both
25 bearings. This is particularly advantageous
mechanically. Also the fact that at least one mounting
is arranged within the end plate base body is also
advantageous, and the accommodation of both mountings
in the end plate base body is also possible. It is
30 advantageous that the drive shaft is arranged
essentially perpendicular to the end plate, i.e. in
the stack direction of the fuel cell stack. However an
arrangement which deviates from this with regard to
the angle is of course also possible.
35

WO 2006/037661 PCT/EP2005/010898
12
Various power/output values are possible for the
pump. For fuel cell systems of smaller than 1,000 W,
volume flows of the fluid to be delivered of 0.01 -
0.5 1/s at 0.01 to 1 bar are advantageous.
5
For a corresponding fan with a system power of
smaller than 1,000 W, the volume flow is
advantageously 100 - 2,000 1/min, preferably 250 1/min
to 500 (at maximal 800 Pa) .
10
The above mentioned mechanical pump may for
example advantageously be a rotatory pump. Here there
results the advantage that no uncontrolled pressure
increase occurs given a blockage of this pump.
15
According to the invention, the end-plate assumes
the function of the pump housing. A reduction in the
number of parts is given on account of this, and also
the risk of the selection of components which are not
20 compatible with the media is minimised. The end plate
and the pump form a functional unit and for this
reason this pump without the end plate is as a rule no
longer capable of functioning. The material of the
pump (of the pump impeller) as well as of the end
25 plate may preferably be the same, but however may also
be different. The pump may, as specified above be
mounted on one or both sides. The bearings here may
also be contacted by the media, by which means a
simultaneous lubrication arises, which may increase
30 the life duration. An increased running smoothness is
achieved with a mounting on both sides, and thus a
significantly higher life duration. Those advantages
which have just been mentioned for a "pump" are of
course analogous with regard to a fan. The possibility
35 of mounting the shaft on both sides is absolutely
decisive here, since the fan in a compact

WO 2006/037661 PCT/EP2005/010898
13
constructional shape, as with the present field of
application, must run at very high rotational speeds
(up to approx. 16,000 rev/min).
5 Further advantageous formations of the present
invention are described in the remaining claims.
Embodiments of the invention are hereinafter
explained by way of the Figures 1 to 6. There are
10 shown in:
Fig. 1 a cross section through an end plate
according to the invention, and a part of a
fuel cell stack limited by this end plate,
15
Fig. 2 a second end plate of the same fuel cell
stack, likewise designed according to the
invention, in a corresponding
representation;
20
Fig. 3 a cross section through an end plate in
another embodiment of the invention;
Fig. 4 as a sketch, a cross section through a
25 further embodiment of a pump mounted on both
sides, wherein a special seal is provided
and
Fig. 5 a detailed sketch for bleeding the pump
30 housing as well as
Fig. 6 two opening conditions of a valve which is
designed as a rotary slide valve.

35 The end plate illustrated in Fig. 1 comprises a
base body 1 which is joined together of two parts


WO 2006/037661 PCT/EP2005/010898
14
which are each plate-like and manufactured of
polyamide (other thermoplastic plastics could also be
used to the same extent) and bonded to one another.
Alternatively, the two parts of the base body 1 may
5 also be welded to one another or merely mutually
braced. Finally, it would also be conceivable to
design the base body 1 as one piece.
Fuel cells of a corresponding fuel cell stack
10 which are stacked onto one another and are separated
from, one another by bipolar plates 2 connect to one
side of the illustrated end plate, which is on the
right in Fig. 1. The end plate itself on the mentioned
side comprises a two-dimensional current collector 3
15 which is formed by a sheet-metal piece admitted there
into the base body 1, and defines an active surface of
the end plate. The part of the base body 1 bearing on
the current collector 3 is provided with a honeycomb
structure 4 which is open towards the current
20 collector 3 and consists of individual honeycombs
which are separated from one another by webs, or
hollows open towards the current collector 3, which in
turn have a depth of about 30 mm {other shaping and
dimensioning of the hollows with depths of between 0.5
25 mm and 50 mm could also be considered) . The metallic
current collector (e.g. of nickel- (201), copper- or
iron metal or an alloy of the mentioned metals, may
also e.g. have a coating of gold), on the rear side,
is connected to a metallic current collector 5 which
30 is led to the outside through the end plate in the Z-
direction (of the stack, thus perpendicular to a plane
defined by the end plate). The metallic current
collector 5 (e.g. of nickel- (201), copper- or iron
metal or an alloy of the mentioned metals, may also
35 e.g. have a gold coating) is preferably - as in the
present case - designed as a bolt and connected to the


WO 2006/037661 PCT/EP2005/010898
15
current collector 3 preferably by way of welding. By
way of this one may attach the current collector 5 at
a position in the x-y plane of the cell stack which is
advantageous for the design. This entails the
5 advantage that one may do away with a lateral current
down-conductor which would break through a sealing
ring surrounding the current collector 3 and would
thus render a sealing of the end plate towards a first
fuel cell bearing on the end plate more difficult. The
10 represented end plate is braced to a second end plate
which is not shown here, with the help of bracing
screws 6, by which means the complete fuel cell stack
is held together.
15 The illustrated end plate contains a channel 7
incorporated into the base body 1 for the supply of
air serving as a reactant gas to the fuel cell. A pump
8, here designed as a rotatory pump, is arranged in
the course of this channel 7 and with the exception of
20 a drive motor 9 which is seated directly on the end
plate is completely integrated into the end plate and
is seated in a recess in a part of the base body 1.
The channel 7, as other recesses in the base body 1,
is realised by way of a suitable shaping of a casting
25 mould used on manufacture of the mentioned part of the
base body 1. Alternatively a manufacture of the
recesses in a material-removing manner would also be
conceivable, wherein the base body 1 could then be
manufactured of a fibre-reinforced layer press
30 material, for example with a binder of cpoxy resin.
A channel 7 and a pump 8 for a further reactant
gas may also be provided in the same manner, possibly
also using other pump types. Furthermore, it would be
35 possible to also arrange the drive motor 9 integrated

WO 2006/037661 PCT/EP2005/010898
16
into the end plate, and achieve an even more compact
construction manner on account of this.
Finally in Fig. 1, one may also recognise a cross
5 section of a reactant gas channel 10 which is
integrated into the end pate and which is arranged on
a border surface between the two parts of the base
body 1, as well as two parts of a seal 11 which
mutually seal the mentioned parts to one another and
10 thus also the reactant gas channel 10.
A fan impeller placed in the course of the
channel 7 and indicated in Fig. 1 is to be noted as
being the main component of the pump 8, and this
15 impeller is integrated within a convex envelop of the
base body 1 which defines an outer bordering of the
end plate, and is thus integrated into the end plate.
A second end plate is shown in Fig. 2, which
20 delimits the same fuel cell stack. This end plate, also
comprises a base body 1 which is composed of two
parts, wherein these parts are mutually sealed by way
of an annular seal 12 of an elastomer. Other recurring
features which have already been explained by way of
25 Fig. 1 are again provided with the same reference
numerals.
With the end plate represented in Fig. 2, a part
of a pump 8 is also integrated into the end plate,
30 wherein only the drive motor 9 of this pump 8 is
arranged outside the end plate. The pump 8 is again
designed as a rotatory pump and here is arranged in a
course of a coolant channel 10'. This coolant channel
10 is incorporated into the base body 1 of the end
35 plate and leads to the bipolar plates 2 of the
adjacent fuel cells. In the present case, water is


WO 2006/037661 PCT/EP2005/010898
17
provided as a coolant, which after flowing through the
bipolar plates 2 is led to a cooler and from this
cooler flows into a compensation container 13
integrated into the end plate 12, wherein this
5 container is in connection with a connection of the
pump 8 on the suction side. Finally, one may also
recognise a lid 14 which closes an opening after
refilling the water serving as a coolant, as well as
an examination glass 15 for checking the coolant
10 level.
It is of course possible to design end plates by
way of a combination of the features shown in Figs. 1
and 2 such that several pumps 8 at least partly are
15 integrated in a single end plate, wherein these pumps
in each case serve for conveying a reactant, a
reaction product or a coolant.
Another end plate - likewise an embodiment
20 example of the present invention, is represented in
Fig. 3 as a cross section. There, recurring features
are again provided with the same reference numerals
and to some part are no longer explained in detail.
The end plate represented in Fig. 3 contains a channel
25 7 for leading hydrogen serving as a reactant gas.
Arrows indicate a flow direction as already in Fig. 1.
, In this end plate too a pump 8 is arranged in the
course of the channel 7 and this pump is completely
integrated into a part of the base body 1 of the end
30 plate. The pump 8 in the present case is designed in
the form of a Venturi nozzle as a passive component
and comprises a first connection 16 for the supply of
fresh hydrogen, a suction connection 17 for the re-
supply of hydrogen coming from reaction spaces of
35 adjacent fuel cells, thus hydrogen which has already
once been led to the fuel cells, and a further

WO 2006/037661 PCT/EP2005/010898
18
connection 18 as a common exit for the fresh and re-
supplied hydrogen. With the end plate illustrated in
Fig. 3, the pump 8 serves for suctioning out the
reactant gas from the reaction spaces of the adjacent
5 fuel cells and for the re-supply of a part of this
reactant gas (hydrogen here) into the channel 7
leading to the fuel cells. With this, one achieves a
recirculation, wherein the re-supplied reactant gas is
typically enriched with diffused water, so that a
10 uniformly humid climate is produced in the respective
reaction spaces of the fuel cells on account of the
recirculation. The pump 8 in the present case has no
moving parts, wherein a pump effect arises due to the
fact that the suction connection 17 is arranged at a
15 location of minimal flow cross section of the Venturi
nozzle forming the pump 8. Other types of pumps and in
particular jet pumps could be applied in the described
manner and for this, be integrated into the end plate.
20 Fig. 3 also shows a valve 19 which is integrated
into the end plate and may be controlled by way of a
drive 20 which is applied onto the end plate at the
rear side. A reactant flow prevailing in the channel 7
may be controlled or regulated with this valve 19.
25 Additionally the valve may serve as a safety valve for
completely blocking a supply of hydrogen. It is also
possible to apply the valve 19 or another valve
integrated into the end plate in a similar manner as a
flush valve which when required (controlled with
30 respect to events or to time) may be opened for
blowing out a fuel cell stack limited by the end
plate. Finally, in Fig. 3 one may also recognise a
connection piece 21 integrally formed as one piece on
a part of the base body 1 of the illustrated end
35 plate, for the connection of the end plate to a
hydrogen supply.

WO 2006/037661 PCT/EP2005/010898
19
Figure 4 shows a detail for sealing off the drive
motor 9. The magnet coupling here is directly attached
in the air gap of the motor and for this reason there
5 is only one sealing location, and no axial face seal
is required. The bearings LI' and L2' are both within
the sealed region. Here only the bearing location L2'
is accommodated within the end plate base body 1.
Figure 4 shows how the two coils 24 lie outside the
10 sealed region. The sealing is effected at the outer
end-face of the end late base body 1. In this manner
the removal of the pump 8 is particularly simple.
Figure 5 shows a positioning of the pump in a
15 manner such that a targeted bleeding of the pump
housing may be achieved. The cooling water
compensation container 13 may be particularly well
seen in cross section. Furthermore a bleeding bore 22
from the pump space (thus the cavity which is adapted
20 to the pump 8 and essentially is formed following its
course) to the compensation container 13 is to be
seen.
Figure 6 shows the possibility of the design of a
25 valve which is designed as a rotary slide valve and
act like a throttle flap. A stationary housing (a)
with a defined opening (b) is provided. An air flow
may be opened/closed in a defined manner by way of a
rotary slide (c). The flap is opened with a high
30 humidity (moisture content) and simultaneously the
humidity and the air quantity are regulated ([closed-
loop] controlled). The throttle flap here is likewise
integrated into the end plate.

WO 2006/037661 PCT/EP2005/010898
20
Patent claims
1. An end plate for a fuel cell stack, containing at
5 least one channel (7) for the supply and/or removal of
at least one reactant and/or a reaction product and/or
a coolant,
characterised in that at least one part at least of
one pump (8) for delivering the reactant and/or
10 reaction product and/or coolant, which is arranged in
the course of the respective channel (7), is
integrated into the end plate.
2. An end plate according to claim 1, characterised
15 in that the pump (8), completely, or with the
exception of a drive motor (9) or a part of the drive
motor (9), is completely integrated into the end
plate.
20 3. An end plate according to one of the claims 1 or
2, characterised in that the pump (8) is designed as a
rotatory pump.
4. An end plate according to one of the claims 1 or
25 2, characterised in that the pump (8) is designed as a
jet pump.
5. An end plate according to one of the claims 1, 2
or 4, characterised in that the pump (8) is designed
30 as a Venturi nozzle.
6. An end plate according to one of the claims 1 to
5, characterised in that the pump (8) comprises a
first connection (16) for the supply of fresh reactant
35 gas, a suction connection (17) for the resupply of a
reactant gas coming from a reaction space, and a

WO 2006/037661 PCT/EP2005/010898
21
further connection (18) as a common exit for the fresh
and resupplied reactant gas.
7. An end plate according to one of the claims 1 to
5 6, characterised in that it comprises a base body (1)
formed of an insulator.
8. An end plate according to claim 7, characterised
in that the base body (1) is manufactured of exactly
10 one part.
9. An end plate according to claim 7, characterised
in that the base body (1) is joined together of at
least two parts.
15
10. An end plate according to claim 9, characterised
in that the mentioned parts of the base body (1) are
mutually sealed.
20 11. An end plate according to one of the claims 1 to
10, characterised in that at least one valve (19) for
controlling and/or regulating and/or blocking a flow
of reactant, reaction product or coolant, is
integrated into the end plate.
25
12. An end plate according to one of the claims 1 to
11, characterised in that it comprises a current
collector (3) on an active surface.
30 13. An end plate according to the claims 7 and 12,
characterised in that the base body (1) comprises
hollows which are open towards the current collector
(3) .
35 14. An end plate according to claim 13, characterised
in that the hollows form a honeycomb structure (4).

WO 2006/037661 PCT/EP2005/010898
22
15. An end plate according to one of the preceding
claims, characterised in that the pump (0) comprises a
drive shaft which is mounted on one side or two sides.
5
16. An end plate according to claim 15, characterised
in that the drive shaft is mounted on two-sides,
wherein a fan wheel or a pump is arranged between both
bearings.
10
17. An end plate according to claim 16, characterised
in that at least one bearing is arranged within the
end plate base body (1) .
15 18. An end plate according to one of the claims 15-
17, characterised in that the drive shaft is arranged
essentially perpendicularly to the end plate.
19. A fuel cell stack, containing at least one end
20 plate according to one of the claims 1 to 18.
20. A method for manufacturing an end plate according
to one of the claims 1 to 18, characterised in that a
base body or at least a part of a base body, by way of
25 a suitable shaping of a casting mould used for
manufacture of the base body or part of the base body,
or by way of material removal, is provided with at
least one recess for a channel integrated into the end
plate and/or for a pump integrated at least partly
30 into the end plate.

DATE-05/04/2007

The present invention relates to an end plate for a fuel cell stack, containing at least one channel (7) for the supply
and/or removal of at least one reactant and/or a reaction product and/or a coolant, wherein at least a part at least of one pump (8) for
delivering the reactants and/or reaction products and/or coolant and which is arranged in the course of the respective channel (7) is
integrated into the end plate. The invention further relates to a fuel cell stack which contains such an end-plate.

Documents:

01199-kolnp-2007-abstract.pdf

01199-kolnp-2007-claims 1.1.pdf

01199-kolnp-2007-claims.pdf

01199-kolnp-2007-correspondence others 1.1.pdf

01199-kolnp-2007-correspondence others 1.2.pdf

01199-kolnp-2007-correspondence others 1.3.pdf

01199-kolnp-2007-correspondence others 1.4.pdf

01199-kolnp-2007-correspondence others 1.5.pdf

01199-kolnp-2007-correspondence others 1.6.pdf

01199-kolnp-2007-correspondence others.pdf

01199-kolnp-2007-description complete.pdf

01199-kolnp-2007-drawings.pdf

01199-kolnp-2007-form 1.pdf

01199-kolnp-2007-form 13.pdf

01199-kolnp-2007-form 18.pdf

01199-kolnp-2007-form 2.pdf

01199-kolnp-2007-form 3.pdf

01199-kolnp-2007-form 5.pdf

01199-kolnp-2007-gpa.pdf

01199-kolnp-2007-international publication.pdf

01199-kolnp-2007-international search report 1.1.pdf

01199-kolnp-2007-international search report.pdf

01199-kolnp-2007-pct request.pdf

01199-kolnp-2007-priority document 1.1.pdf

01199-kolnp-2007-priority document 1.2..pdf

01199-kolnp-2007-priority document.pdf

1199-KOLNP-2007-ABSTRACT 1.1.pdf

1199-KOLNP-2007-AMANDED PAGES OF SPECIFICATION.pdf

1199-KOLNP-2007-CLAIMS.pdf

1199-kolnp-2007-correspondence.pdf

1199-KOLNP-2007-DESCRIPTION (COMPLETE) 1.1.pdf

1199-KOLNP-2007-DRAWINGS 1.1.pdf

1199-KOLNP-2007-Examination Report Reply Recieved.pdf

1199-kolnp-2007-examination report.pdf

1199-KOLNP-2007-FORM 1 1.1.pdf

1199-kolnp-2007-form 18.pdf

1199-KOLNP-2007-FORM 2 1.1.pdf

1199-kolnp-2007-form 26.pdf

1199-KOLNP-2007-FORM 3 1.1.pdf

1199-kolnp-2007-form 3.pdf

1199-KOLNP-2007-FORM-27.pdf

1199-kolnp-2007-granted-abstract.pdf

1199-kolnp-2007-granted-claims.pdf

1199-kolnp-2007-granted-description (complete).pdf

1199-kolnp-2007-granted-drawings.pdf

1199-kolnp-2007-granted-form 1.pdf

1199-kolnp-2007-granted-form 2.pdf

1199-kolnp-2007-granted-letter patent.pdf

1199-kolnp-2007-granted-specification.pdf

1199-KOLNP-2007-OTHERS 1.1.pdf

1199-kolnp-2007-reply to examination report.pdf

1199-kolnp-2007-translated copy of priority document.pdf

abstract-01199-kolnp-2007.jpg


Patent Number 245809
Indian Patent Application Number 1199/KOLNP/2007
PG Journal Number 05/2011
Publication Date 04-Feb-2011
Grant Date 02-Feb-2011
Date of Filing 05-Apr-2007
Name of Patentee REINZ-DICHTUNGS-GMBH
Applicant Address REINZSTRASSE 3-7, 89233 NEU-ULM
Inventors:
# Inventor's Name Inventor's Address
1 STEFAN SOMMER SCHULINSTRASSE 27, 89073 ULM
2 CHRISTIAN SCHLEIER WASSERBURGER WEG 123, 89312 GUNZBURG
PCT International Classification Number H01M 8/24
PCT International Application Number PCT/EP05/010898
PCT International Filing date 2005-10-06
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 102004049623.4 2004-10-06 Germany