CN102017251A

CN102017251A - A flow field plate for use in a stack of fuel cells

Info

Publication number: CN102017251A
Application number: CN2008801262199A
Authority: CN
Inventors: 奥洛夫·达尔伯格; 珀·西德; 汉斯-阿克·奥尔森
Original assignee: MOFICK TECHNOLOGY STOCK Co
Current assignee: MOFICK TECHNOLOGY STOCK Co; Morphic Technologies AB
Priority date: 2007-12-18
Filing date: 2008-12-11
Publication date: 2011-04-13
Also published as: SE0702818L; EP2232618A1; WO2009078792A1; SE532057C2; JP2011507211A

Abstract

The present invention relates to a flow field plate for use in a stack of fuel cells, which comprises at least one flow field plate (1, 9) of electrically conductive material and a meander electric assembly (MEA) (39) at each side of the bipolar electrode, wherein the bipolar electrode consists of a plate (1) mounted in an electrically insulating sealing frame (9), which is provided with channel portions (12, 32), each one connecting an arbitrary valley (4, 24) at an arbitrary side of the plate (1).

Description

The flow-field plate that is used for fuel cell stack

Technical field

The present invention relates to flow-field plate, in fuel cell stack, this flow-field plate comprises the bipolar electrode that at least one electric conducting material is made and is positioned at the amberplex of each side of bipolar electrode.

Background technology

Flow-field plate (for example, bipolar electrode and/or demarcation strip) is the diskware/plate that has open channel, can distribute reactant, gas or the liquid of supply, and can provide mechanical strength for fuel/reaction cell.Described passage is at electrode one side distributed anode reactant, and in opposite side distribution cathode reactant.Proposed metal for example, plastics and pottery as material, and claimed that described passage can also be by eliminating with laser or chip elimination, embossing, compacting or punching press realize by etching.The viewpoint that forms is that the passage of anode one side must intersect the passage of negative electrode one side, and this hints out that plate must be quite thick, so consumed wide variety of materials in manufacture process.Therefore, manufacture the comparison costliness.In general, bipolar electrode can be made of for example graphite, wherein eliminates by molded or chip and realizes channel pattern; Perhaps constitute, wherein eliminate forming pattern by etching or chip by metallic plate.And, brought into use plate with compacting channel pattern, wherein two boards spare is joined together to form bipolar electrode, referring to for example WO00/31815 and US6,051,331, wherein the photoetching plate is bonded together and forms so-called bipolar separator.

Summary of the invention

Target of the present invention is that a kind of flow-field plate/bipolar electrode can be provided, and this flow-field plate/bipolar electrode can utilize same block of plate that multiple difference/variable flow pattern is set easily.

Extra design object for example is:

Be provided at bipolar electrode/flow-field plate both sides and form the ability of different flow pattern, for example a side is a parallel channels and opposite side is single than long-channel, promptly flow channel is arranged to the possibility of whole geometries from the battery to the battery.

In order to eliminate the corrosion in the hole, hole that plate is all and edge can be casted in the main body of framework, for the material that has the bimetallic corrosion risk, do like this and have advantage especially.

The bipolar electrode that realization can provide structure height (perpendicular to electrode direction) to reduce than the bipolar electrode of before having known.

Because framework is made with insulating material, can increase the insulation distance between the bipolar electrode conductive component in the fuel cell stack.

Can make flow-field plate at lower cost.

The such bipolar electrode that utilizes beginning to mention has been realized one or more above-mentioned targets by arrange electrode according to claims.

Description of drawings

Hereinafter with reference to preferred implementation and accompanying drawing the present invention is described in more detail.

Fig. 1 is the plane graph of a side of bipolar electrode first execution mode according to the invention, this bipolar electrode has the plate of the channel pattern of being provided with, described plate is square in this case and has the passage that extends to relative two edges of plate, and described plate is included in the seal frame that is provided with formation channel bends part;

Fig. 2 a is that plate shown in Figure 1 is installed to described framework perspective view before;

Fig. 2 b is the sectional view that meets the plate of alternate embodiments;

Fig. 3 is the sectional view according to the III-III among Fig. 1;

Fig. 4 is the sectional view according to the line IV-IV among Fig. 1;

Fig. 5 is the sectional view according to the line V-V among Fig. 1;

Fig. 6 is the plane graph of a side that is provided with plate second execution mode of channel pattern, described plate is frame area square and that have the described channel pattern of encirclement in this case, described plate will be installed in the seal frame, and described seal frame is provided with the part that forms channel bends according to the invention;

Fig. 7 is the sectional view according to the line VII-VII among Fig. 6;

Fig. 8 is the sectional view according to the line VIII-VIII among Fig. 6;

Fig. 9 is the partial view in Fig. 5 upper left corner, and described plate is provided with seal frame, and the sealing framework has the part that forms channel bends, thereby forms second preferred implementation of bipolar electrode according to the invention;

Figure 10 is the sectional view according to the line X-X among Fig. 9;

Figure 11 is the sectional view according to the line XI-XI among Fig. 9;

Figure 12 is the partial view in the upper left corner among Fig. 5, and described plate is provided with seal frame, and described seal frame has the part that forms channel bends, thereby forms the 3rd preferred implementation of bipolar electrode according to the invention;

Figure 13 is the sectional view according to the line XIII-XIII among Figure 12;

Figure 14,15 and 16; Show some different channel pattern respectively with 14a, 15a and 16a, these channel pattern are that the frame section branch that the channel bends by the channel bends of two-shipper electrode one side of the present invention and opposite side forms is respectively realized; With

Figure 17 shows alternate embodiments of the present invention.

Embodiment

Fig. 1,3 and 4 shows the principle of the bipolar electrode of execution mode according to the invention, and this bipolar electrode comprises the plate shown in Fig. 2 a and 2b respectively, is used for fuel cell stack.In described fuel cell stack, there is at least one conduction bipolar electrode, preferably exist a plurality of; A proton exchange membrane with each side that is positioned at each bipolar electrode.

According to the present invention, the bipolar electrode shown in Fig. 1,3,4 and 5 only is made of a plate 1, and this plate shows that at Fig. 2 a ground is the clearest, and the material thickness scope is 0.1 to 1mm, preferred maximum 0.5mm, more preferably maximum 0.2mm.Open channel 3 patterned arrangement are in this plate one side, and open channel pattern 23 is arranged in this plate opposite side, make that the

recess

4,24 in the pattern of this plate one side forms

spine

25,5 at opposite side.Plate is provided with the part of pattern shown in Fig. 2 a, for example can have sinusoid cross section basically, thereby realizes same widths B1, the B2 of passage 3 in first side, and is the same with the passage 23 of second side.

In other execution modes, shown in Fig. 6 and 7, spine has the parallel trapezoid cross section of isosceles basically with paddy portion.In addition, shown in Fig. 2 b, the width of paddy portion can be different from the width of spine, wherein the paddy portion of the broad of a side and narrower spine are corresponding to the spine of the broad of opposite side and narrower paddy portion, thereby width B 1 bigger passage is formed on first side, and width B 2 narrower passages 23 are formed on second side.This possibility for example is the content that fuel cell is concerned about.

In addition, according to the present invention, plate 1 is installed in the electric insulation seal frame 9, this framework general thickness is H, preferred basically with the identical (see figure 3) of height h of plate 1, so that surperficial 90A and 90B are positioned at equal height with

corresponding spine

5,25 respectively, thereby be that plate 1 and seal 9 form shared sealing plane P1 respectively in each side _SAnd P2 _SAdopt this mode, described electrode can be arranged to see Fig. 4 against opposite planar 39 ' with seal form easily.

It can also be seen that from figure it is

porose

7,28 that plate 1 (coming example to state as adverse current) is provided with here, be used for flowing into reactants to the

passage

3,23 of plate 1 both sides; And

hole

27,8, the product that is used to form flows out from passage 3,23.

First breach

10,31 in the seal frame 9 forms flow path respectively between each introduces the end of

hole

7,28 and adjacent passage 3 and 23.

Second breach

11,30 in the seal frame 9 forms flow path respectively between the end of each

tap

27,8 and adjacent passage 3 and 23.In addition, there are a plurality of extra breach in seal frame 9, form a plurality of

channel parts

12,32, each channel part couples together paddy follow-up, the previous or in parallel portion on any

paddy portion

4,24 and plate 1 the same side, forms at least one

flow channel

3,23 so that introduce

hole

7,28 from each to

corresponding tap

8,27.

In the execution mode shown in Fig. 1, the 2a, 3 to 5, each

channel part

12 and 32 forms U-shaped.Between the shank of each U-shaped

channel part

12 and 32, have the seal member/flow barrier part 9 that lays respectively at spine 5 and place, 25 ends ", surround by channel part 12,32.In addition, between each described U-shaped

channel part

12,32, have sealing tongue piece 9 ', described sealing tongue piece extends to

middle spine

5 and 25 respectively from the outer part of seal frame 9, and against its end seal, also sealing between

channel part

12,32 then.Flow barrier part 9 " and the side 100 of sealing tongue piece 9 ' so extend past plate 1, this side is in the casting process, plate 1 forms when being casted in the material that forms seal 9.

Can be endowed single shape owing to have the plate 1 of

paddy portion

4,25 and

spine

5,25, thereby and connect paddy portion and be arranged in the perimeter frame 9 for the product of reactant and formation

forms flow channel

3,23 needed

channel parts

12,32, so can realize greater flexibility, and can select to save the manufacture process of material and cost as required, the structure height of the bipolar electrode of finishing can be than shorter in the past.Because these

channel parts

12,32 are formed in the seal 9, therefore can realize more diverse flow pattern, can only use a limited number of plates 1 of design simultaneously.

In the preferred implementation shown in Fig. 2 b, the paddy portion 4 of plate 1 one sides is than the opposite side broad and spine 5 is narrower, so the width B 1 of the passage 3 of each side is than width B 2 broads of the passage 23 of opposite side.Then, in fuel cells applications, for example air can import plate one side than in the broad valley portion, and hydrogen can import the plate opposite side than in the strid portion.

For counter-current process, be arranged to make way for the introducing hole 7 at first turning via introducing the straight passage 3 that is positioned at plate 1 one sides that enters of path 10.Via the channel part 12 that connects adjacent valleys 4, passage 3 will form circuitous stream, end near the delivery outlet 8 that is positioned at opposed second turning, diagonal angle via straight output channel 11.Adopt corresponding mode, introduce the passage 23 that opposite side is passed through in operation that is connected between hole 28 and second tap 27 in second of second corner.With the path 10 of upside, 11 opposite, the operation that the introducing/passing away 30,31 of bottom side will be angled with passage 23.

In the concurrent flow execution mode of bipolar electrode shown in the figure, used identical structure, but opposite situation also is effectively for introducing/discharge, promptly is used for reactant and introduces the

hole

7,27 of stream and be arranged to adjacent one another are and

hole

8,28 product that is used to form also is arranged to adjacent one another are.

Seal frame 9 also can be provided with: for example be used for the hole 19 of the introducing stream and the discharge currents of coolant, the coolant purpose is substitution reaction agent in the needs cooling, flows in the passage of plate 1 one sides; With the hole 20 that is used for pull bar, pull bar is not shown, and the plate in the fuel cell stack is kept together.Extra hole 19 can be connected with 24 with paddy portion 4 by unshowned breach in the seal frame 9.

In the above-described embodiment, the side 100 of plate 1 is encapsulated in the electric insulation seal frame 9 fully.Seal frame 9 is provided with the recess that forms the connecting portion that flows, a described mobile connecting portion part is introduced hole to

corresponding passage

3,23 from each that is used for reactant, a part is portalled to the respective row of the product that is used to form from every passage, and a part is the connecting portion between the paddy portion to be connected.Preferably,

seal frame

9,29 and 49,54 material are selected from the cohort that the material of the product of used reactant of abundant tolerance and formation constitutes respectively, and they are non-conductive.Preferably,

paddy portion

4,24 at least major part be flat shape and isometric.In Fig. 1 to 5 and 2b illustrated embodiment, channel pattern covers whole basically plate 1, so extend outside two relative sides 100 of plate 1,

paddy portion

4,24 has the complete degree of depth, and

spine

5,25 has complete height.The plate that meets this execution mode can for example be made by the bending sheet material by simple mode.

In Fig. 3 and 4, expressed the bipolar electrode in the fuel cell stack and surrounded by membrane electrode assembly 39 (MEA) in both sides.In addition, shown in the cross section among Fig. 1, promptly in Fig. 3,4 and 5, the height h ' of

channel part

12,32 introduces and passing away 10,11,30,31 height separately, is arranged to have such degree of depth, makes them can not surpass H/2, i.e. h '＜0.5H.Adopt this mode, the channel part 12 that is positioned at the top can be arranged in the same cross-sectional plane with the channel part 32 that is positioned at the bottom.The design of

channel part

12,32 can be selected, and this secretly is illustrated in the plane perpendicular to flow direction, and the cross-sections surfaces substantial constant is so flow resistance is substantially the same in every passage 3.This hints out, at the degree of depth h ' of

channel part

12,32 during basically less than the degree of depth h at

passage

3,23 middle parts of plate 1, the leg widths of U-shaped

part

12,32 should be preferably wideer than channel width B1, the B2 at plate 1 middle part basically, wishing under the situation that pressure descends, when for example realizing specific leakage flow by the gas diffusion layers of the MEA between the adjacency channel (thereby increasing " active surface "/output capacity), then

channel part

12,32 can be chosen as and have less sectional area.

Film itself refers to 33, is provided with the known mode of gas diffusion layers 34,35 utilizations itself in both sides, the reaction of carrying out in film 33 and gas diffusion layers 34, the 35 adaptive fuel cells.Gas diffusion layers 34,35 can conduct electricity, and for example can be made of carbon fibre web sheet or graphite paper.Be sometimes referred to as MEA (membrane electrode assembly) with film 33 unit 39 and that gas diffusion layers 34,35 constitutes own.In addition, be to have a frame area that is encapsulated in the seal frame 36 advantageously, the seal frame of wherein said film unit is hermetically against the seal frame of bipolar electrode.In fuel cell stack, gas diffusion layers 34 is against the top of the spine 5 of bipolar electrode one side, be used to define the passage 4 between the spine 5, and another gaseous diffuser 35 is used to define the paddy portion 24 between the spine 25 against the top of the spine 25 of bipolar electrode opposite side.Certainly, film unit 39 or its seal frame 36 also are provided with the hole corresponding with the hole of bipolar electrode.

In meeting the execution mode of Fig. 6 to 13, channel pattern 2,22 is arranged in the core of plate 1, show that in Fig. 6 to 8 ground is the clearest, and surrounded by

frame part

6,26, in

frame part

6,26, arrange the hole that is used for introducing the introducing stream 7,27 (concurrent flows) of reactant to the

passage

3,23 of plate 1 both sides.Plate 1 also is provided with the hole that is used for drawing from the

passage

3,23 of plate both sides the

discharge currents

8,28 of product, and

passage

3,23 is most of at least straight, has equal length and ends at frame part 6,26.Still in this case, connect

paddy portion

4,26 and be arranged in the perimeter frame 9, shown in Fig. 9 to 13 with the

channel part

12,32 of the flow channel of the product that is formed for reactant and formation.But in this embodiment, paddy portion/spine is folded in the plate, so that fluid-tight end wall 4 ', 24 ' connects

paddy portion

4,24 and

frame part

6,26.

According to preferred implementation, plate 1 is 1mm to the maximum with material thickness, is preferably 0.1 to 0.8mm metallic plate and suitably constitutes, and is lower thereby manufacturing cost and structure height can keep.

Be used to realize that the suitable especially drawing method of channel pattern 2,22 is adiabatic compactings, so WO0183132 is included in herein by reference.

In alternate embodiments, plate 1 constitutes with the good polymer of conductivity, and this polymer has tolerance to the reactant that offers fuel cell stack or form in fuel cell stack.

Frame part

6,26 is positioned at the plane P of bipolar electrode, and this plane is between the top of the spine 25 of the top of the spine 5 of electrode one side and opposite side.This plane can be between the top of the spine of the top of the spine of plate one side and opposite side midway.As required, can also be offset described plane towards the top-direction of the spine of a side, fall with the pressure that increases plate one side, the pressure that meanwhile can reduce the plate opposite side falls.

At plate shown in Fig. 6 to 13 1 as the fuel electromagnetism during bipolar electrode in the folded group, in order to realize best anticorrosion and electric insulating effect, clearly illustrate as Fig. 9 to 13, should suitably allow frame part 6 integral body be encapsulated in the electric insulation seal frame 9, partly connect each

reactant inlet

7,27 and

respective channel

3,23 with

breach

10,30, connect every

passage

3,23 and corresponding reacting product outlet with breach 11,31.Fig. 9 shows that in a preferred embodiment, the encapsulant of the sealed framework 9 of each bore edges on the plate (for example referring to 7 ') surrounds, thereby significantly increases path between conductive surface.

From the plane graph of Fig. 7 to 13 and sectional view, as can be seen, the invention provides a kind of possibility, promptly, have very large flexibility using frame part at 6,16 o'clock.For example, wherein use the plate 1 of substantially the same type, but seal frame 9 has significantly different design with

framework

6,26 referring to Fig. 7 and Figure 12.In Fig. 9, channel part 12 is arranged in the seal frame 9, and the recess that takes the shape of the letter U basically is as described referring to figs. 1 through 5.But opposite with Fig. 1 to 5, from the viewpoint of sealing, the hermetic unit 9 ' that is placed between the shank of U-shaped is genuine necessary.

In meeting the execution mode of Fig. 6 to 13, promptly

passage

3,23 is furnished with fluid-tight end surfaces that control flows 4 ', 24 ' and plate 1 does not exist under the situation in hole, and the risk of the cross-current of opposite side can not take place to flow to by

paddy portion

4,24 from a side.On the contrary, in many application scenarios, wish still to arrange this U-shaped part 9 ' that encapsulant is made, prop up the described film that leans on described electrode with extra support.

According to execution mode shown in Figure 9, fluid stream is forced to (via concurrent flow) and flows into via introducing hole 7, and by the recess 10 in the encapsulant, enters coupled paddy portion, and described paddy portion forms the starting point of the passage of the top side (referring to Fig. 9) of described electrode locating 3.After this, according to foregoing, described passage will make a circulation to run to the tap (not shown).The passage of opposite side can adopt corresponding manner to arrange.Figure 12 illustrates and replace flowing of circuitous shape,, also can realize concurrent flow easily, be on the direction that connects each parallel paddy portion 4 so introduce hole 7 by opening the flow path in the seal frame 9 simply.The effect that realizes is according to this principle model, and dissimilar combinations allows flow pattern to have very large variation, particularly can be positioned at the possibility of different distance with plane P and/or use different in width B1, the B2 of the passage of each sidepiece to combine.

By different flow channels simply is shown in Figure 14 to 16, numerous flexibilities that can utilize the present invention to realize have been demonstrated, some embodiments possible examples have only been expressed, wherein one row show according to the present invention one side of the electrode of design in the left side, and one row show its back side on the right side.

In Figure 14, show according to the present invention, can utilize so-called " cecum " to realize many parallel channels in a side, described many parallel channels can be preferred for certain applications, for example at hydrogen.Meanwhile, at its opposite side, can paddy portion be connected into circuitous pattern every a paddy portion, so that the overall flow path of dorsal part significantly is shorter than the front side, this is the application scheme of wishing under specific circumstances.In Figure 15, show a kind of variant, only there are some existing paddy portions to be used for the percolation of a side shown in it, dorsal part (15A) then has been endowed more traditional circuitous pattern.

In Figure 16, show and adopt mode same as described above, for example connect every three paddy portions, and connect every an adjacent valleys at opposite side shown in Figure 16 A in a side shown in Figure 16, utilize identical plate, can realize the flow path that is changed significantly respectively in dorsal part and front side.Therefore the possibility of this change flow pattern is huge advantage of the present invention.

In alternate embodiments as shown in figure 17, plate 41 is for annular and be essentially circular.In plate 41, the pattern 42 of the open channel 43 of plate one side and the unshowned channel pattern of plate opposite side are arranged such that the paddy portion 44 between the spine 45 of pattern of plate one side forms the spine between the paddy portion of opposite sides, and vice versa.More precisely, described channel pattern is only formed by the adjacency channel that a spine and spiral extend internally.As required, certainly allow two or more parallel spines and adjacent valleys, so that the passage of respective amount is formed on each side of plate at the area of the pattern spiral extension.Frame area 46 along the plate periphery is provided with first hole 47, and described first hole is used to be positioned at plate 41 1 sides and the introducing stream and the discharge currents of the passage 43 that is connected with first hole 47; Second hole with the introducing stream and the discharge currents of the passage that is used for plate 41 opposite sides.Central interior region 53 is provided with: first hole 48, described first hole 48 are used for being positioned at plate one side and the discharge currents of the passage 43 that is connected with first hole 48 of middle section 53 or introduce stream; With the discharge currents of the passage that is used for the plate opposite side and second hole 68 of introducing stream.

Frame area 46 and central interior region 53 boths are positioned at the plane of bipolar electrode, and this plane is between the top of the spine of the top of the spine 45 of described electrode one side and opposite side.Be similar to Fig. 3 to 6 illustrated embodiment, described plane can be made of midway mid-plane between the top of the spine of the top of the spine of described plate one side and opposite side.As required, can also allow described plane be offset towards the top-direction of the spine of a side.

In the execution mode of plate 41 shown in Figure 17, extra hole is arranged in the frame part 46, for example promptly is used to supply/discharge for example hole 59 of cooling water of circulatory mediator; Be used to insert unshowned tie rod so that the hole 60 that fuel cell stack is axially kept together.

In addition, frame part shown in the figure 46 and central interior region 53 are as above described at other execution modes, suitably be encapsulated in fully have respectively breach 50 and 70 and the electric insulation seal frame 49 and inner sealing framework 54 of

breach

51,71 in, described

breach

50,70 partly connects the adjacency channel 41 of each

reactant inlet

46,47 and passage 43 and opposite side respectively, and described

breach

51,71 is connected described passage with the

corresponding outlet

48,68 that is used for product.Seal frame 49 and inner sealing framework 54 are present in the both sides of plate 41 certainly.In addition, in this case, inner sealing framework 54 is not suitable for being called framework a little, because in this embodiment, it does not have frame to live any middle section.

If the flaky material of

plate

1,41 is subjected to reactant by meeting or the material of the product that forms influence constitutes, then adequate measures are to allow

plate

1,41 both sides that the thin protective layer made from impregnable material all is set.When the outward flange of plate and

hole

7,8,27,28,19,20,47,48,59,60,67,68 for example form by stamping; the inboard in described outward flange and described hole will show not protected zone, so this zone may be subjected to the influence of reactant and/or product.Therefore; adequate measures are that

seal frame

9,49 and 54 is also sealed the edge of plate and the edge in

hole

7,8,27,28,19,20,47,48,59,60,67,68, the influence of reactant and/or product and the protective layer of

plate

1,41 and the bimetallic corrosion between the basis material so that they are protected.Sealing outward flange also provides and has prevented undesirable protection that electrically contacts.

Bipolar electrode according to the invention provides following advantage, for example when the structure fuel cell stack.

Simply and cheaply make the bipolar electrode/flow-field plate that possesses complex pattern.By the insulating material of selecting to help installing that is used for framework, solve the insulation of constructing outward flange, screw hole or the like when folding group easily.Demand for loose sealing reduces.Eliminated the corrosion in the hole, because all hole and the edges of plate all are casted in the main body of framework.The seal form of relevant entrance and exit is fairly simple, because may produce design relatively more expensive for the metal manufacturing.

In the folded group of tradition, by the flow channel from the battery to the battery, between plate electrical overloads may take place, because insulation distance is only corresponding to the thickness of film.When framework was made with insulating material, described insulation distance enlarged markedly.

The present invention is not limited to foregoing description, but can change in the scope of subsidiary claims.Should be appreciated that inventive principle provides such possibility, promptly in the outward flange of the mobile plate of any geometry and inner pattern, arrange flow channel.

By selecting suitable frame material, the pressure in the folded group will be evenly distributed on whole folded group.

Different flow pattern can be formed on the both sides of bipolar electrode/flow-field plate, and for example a side is an a parallel channels and long single passage is only arranged at opposite side.

Different materials can mix in framework, so that from chemistry and mechanical viewpoint, make framework have accurate attribute in correct position.

Plate itself can utilize the distinct methods manufacturing with multiple different materials, for example compacting/bending metal sheet.

Two different flow-field plate can connect and be nested, so that realize different patterns in both sides and/or form extra passage between plate, for example are used for cooling.

Can embed directing pin easily, so that can not install described folded group mistakenly.

Industrial applicibility

The flow-field plate main purpose that meets the invention described above is for the type of fuel cell that is used as oxide isolation by hydrogen driving and air or oxygen, described flow-field plate is changed on ground but those skilled in the art can need creative work certainly simply and not in the scope of following claims, closes on application so that it can be used in.

Claims

1. flow-field plate that is used for fuel cell stack, described flow-field plate comprises that at least one each side has the mobile part (1) of paddy portion (4,24) plate-like; Be arranged in the seal frame (9) that described mobile part (1) is located, wherein said flow portion branch comprises the plate (1) in the seal frame (9) that is arranged in preferred electric insulation, described seal frame is provided with the channel part (12,32) that at least some described paddy portions (4,24) is connected into flow pattern, it is characterized in that described seal frame (9) is provided with and is respectively applied for reactant and enters at least two that the passage (3,23) of described plate (1) both sides and product therefrom discharge and introduce hole and at least two taps (8,28,7,27); With first and second breach (11,31,10,30) that lay respectively in the described seal frame (9), be used between the end of each introducing hole/tap (8,28,7,27) and paddy portion (being respectively 4 and 24), realizing flow path.

2. flow-field plate as claimed in claim 1 is characterized in that, described plate (1) is manufactured with open channel (3,23), and described open channel arranges that by this way the paddy portion (4) of promptly described plate one side forms the spine (25) of opposite side, and vice versa.

3. flow-field plate as claimed in claim 2 is characterized in that, the material thickness of described plate (1) is 2mm to the maximum, preferred 0.05 to 0.8mm, and more preferably maximum 0.5mm.

4. as each described flow-field plate of claim 1 to 3, it is characterized in that, each is connected a plurality of channel parts (12,32) any paddy portion (4,24) of described plate (1) with the paddy portion follow-up, previous or coupled in parallel of described plate (1) the same side, so that the described flow pattern that forms in each side is: begin from each introducing hole to arrive corresponding tap through whole plate (1) at least basically.

5. as each described flow-field plate of claim 1 to 4, it is characterized in that the described paddy portion of described plate (1) one side is than the paddy portion broad of opposite side, and the spine of a described side is narrower than described opposite side spine.

6. each described flow-field plate of claim as described above is characterized in that the thickness (H) of described seal frame (9) equates basically with the height (h) of described plate (1).

7. flow-field plate as claimed in claim 6 is characterized in that, and the height of the main extension of described channel part (12,32) (h ') less than H/2.

8. as each described flow-field plate of claim 1 to 7, it is characterized in that most of at least paddy portion (4,24) is straight basically, and preferably has equal length.

9. as each described flow-field plate of claim 1 to 7, it is characterized in that, described plate (1) is circular, and described seal frame (9) comprises external frame along the periphery of described plate, is arranged to the inner frame spaced apart with described external frame, and described passage (3,23) bending.

10. as each described flow-field plate of claim 1 to 9, it is characterized in that, described seal frame (9) is provided with the introducing stream that is used for the preferred coolant of extra media and the extra hole (19) of discharge currents, and described extra medium is used for the substitution reaction agent and flows into the described passage (3,23) of described plate one or both sides.

11. as each described flow-field plate of claim 1 to 10, it is characterized in that, described channel pattern (2,22) covers whole at least basically described plate (1), so that towards relative two edges (100) of described plate (1), described paddy portion (4,24) has the complete degree of depth and described spine (5,25) has complete height.

12. each described flow-field plate of claim as described above, it is characterized in that, described plate (1) comprises the frame area (6,26) of periphery, and described frame area is positioned at the plane (P) between the top of described spine (25) of the top of described spine (5) of described bipolar electrode one side and opposite side.

13., it is characterized in that described seal frame (9) is arranged to seal the part edge at least of described plate (1) as each described flow-field plate of claim 1 to 12.

14. flow-field plate as claimed in claim 13 is characterized in that, described seal frame (9) is arranged to seal a plurality of at least bore edges in the described plate (1).

15. flow-field plate as claimed in claim 14 is characterized in that, whole edges of the described plate of described seal frame (9) extend past (1) comprise described bore edges.

16. each described flow-field plate of claim is characterized in that as described above, described channel part (12,32) is arranged to difformity in described both sides, so that realize different channel pattern/flow pattern in described both sides.