WO2018229799A2

WO2018229799A2 - Bi-polar metal plate for a fuel cell stack

Info

Publication number: WO2018229799A2
Application number: PCT/IN2018/050392
Authority: WO
Inventors: Bhushan Ekanth VELIS; Sandeep Arjun KATORE
Original assignee: Kpit Technologies Ltd
Priority date: 2017-06-14
Filing date: 2018-06-13
Publication date: 2018-12-20
Also published as: WO2018229799A3

Abstract

The present invention herein provides a bi-polar metal plate. The bi-polar metal plate includes a first side and a second side being adapted to have a first set of predefined channels and a second set of predefined channels respectively. The first set of predefined channels is adapted to provide a first flow field for a first reactant. Similarly, the second set of predefined channels is adapted to provide a second flow field for a second reactant. One or more first channels of the first set of predefined channels terminating at a first inlet/outlet on the first side of bi-polar metal plate are adapted to have a first bypass flow field to maintain the one or more first channels active. Similarly, one or more second channels of the second set of predefined channels are adapted to have a second bypass flow field to maintain the one or more second channels active.

Description

BI-POLAR M ETAL PLAT E FOR A FUE L C E L L STAC K

R E LAT E D APPL ICATION

¾ Benefit is claimed to Indian Provisional Application No. 201721020722 titled "A META L BIPOLAR PLATE DESIGN" by K PIT Technologies Limited, filed on 14^th J une 2017, which is herein incorporated in its entirety by reference for all purposes.

FIE L D O F T H E INV E NTION

The present invention generally relates to a fuel cell stack, and more particularly relates to a bipolar metal pi ate for the fuel cell stack that is effective and simple in design.

BAC K G ROUND O F T H E INV E NTION

Nowadays, fuel cells are being used as a power source for many applications. Proton exchange membrane (PE M) (e.g. Hydrogen Fuel Cell) is a one of such fuel cells. PE M fuel cell stacks are commonly configured having a plurality of fuel cell elements in a stacked configuration. The fuel cell elements commonly include a pair of PE M elements separated by a conventional bi-polar it plate. The conventional bi-polar plates include a pair of plates joined by adhesive seal, by brazing, and by welding. These are the key components of PE M fuel cell stacks with multifunctional character. V ari ous materi al s coul d be used for the producti on of these conventi onal bi - pol ar pi ates. Such conventional bi-polar plates include non-porous graphite, coated metallic sheets, polymer composites, etc.

*¾

According to the prior art, the conventional bi-polar plate is formed by assembling or welding a pair of metal sheets such that a functional flow field is created on each side of the bi-polar plate assembly. These methods are expensive and are complex to adopt The fabrication methods of the conventional bi-polar plates are the main challenges in fuel cell. Selection of the plate material, Wi geometry of f I ow f i el d desi gn and the f abri cati on method are the mai n i ssues. T he maj or chal I enges that are faced while using the conventional metal bi-polar plates are perpendicular channels which obstruct f I ow of both H 2 and 02, no proper I andi ng space for gasket and di rect i mpact of i ncomi ng air on Kapton films which causes damage. Further, the conventional metal bi-polar plates include flow fields that may terminate the flow fields at inlet causing reduction in effective current generation area. The conventional metal bi-polar plates also lack management of pressure causing ¾ f I utteri ng of the K apton f i I ms.

Therefore, there is a need for a unique bi-polar metal plate that has an anode and cathode on either side of the plate, which is effective and simple in design. SUM MARY OF T H E INV E NTION

The present invention herein provides a bi-polar metal plate for a fuel cell stack and a method for constructing a fuel cell, comprises an anode and a cathode on either side of a bi-polar metal plate. In one aspect, the bi-polar metal plate includes a first side being adapted to have a first set of

¾ predefined channels and a second side being adapted to have a second set of predefined channels.

The first set of predefined channels on the first side of bi-polar metal plate is adapted to provide a first flow field for a first reactant, and the second set of predefined channels on the second side of the bi-polar metal plate is adapted to provide a second flow field for a second reactant. One or more first channels of the first set of predefined channels terminating at a first inlet outlet on the it f i rst si de of bi - pol ar metal pi ate are adapted to have a f i rst bypass f I ow f i el d to mai ntai n the one or more first channels active and one or more second channels of the second set of predefined channels terminating at a second inlet outlet on the second side of the bi-polar metal plate are adapted to have a second bypass flow field to maintain the one or more second channels active. ¾ A ccordi ng to one embodi ment, the f i rst reactant i s one of an anode and a cathode and the second reactant is one of the anode and the cathode.

According to an embodiment, the bi-polar metal plate includes an underpass flow field formed by at least one of one or more teeth protrusions on the first side of the bi-polar metal plates to enable Wi flowing of coolant In another embodiment, the underpass flow filed is formed by providing variation in height of ridges of a first flow field on the first side of the bi-polar metal plate. In yet another embodiment, the underpass flow field is formed by providing variation in height of ridges of a second flow field on the second side of the bi- polar metal plate.

In one aspect, a fuel cell stack is described herein. The fuel cell stack includes a plurality of bi- ¾ polar metal plates, a plurality of supporting plates, a plurality of membrane electrode assembly (MEA) and a plurality of gaskets. The plurality of bi-polar metal plates is placed parallel to each other. Each plate of the plurality of bi-polar metal plates includes a first set of predefined channels on a first side and a second set of predefined channels on a second side. Each supporting plate is positioned between two bi-polar metal plates of the plurality of bi-polar metal plates. Each

3a supporting plate includes a first bend along a flow direction and a second bend perpendicular to the flow direction to avoid cross flow of a second reactant from the second side to the first side. Each MEA is positioned between the two bi-polar metal plates of the plurality of bi-polar metal plates. The gasket is positioned on at least one side (i.e. the first side and/or the second side) of each plate of the plurality of bi-polar metal plates. Each gasket includes a plurality of protrusions

¾ on one side and a plurality of indentations on another side at regular intervals.

A ccordi ng to one embodi ment, the f i rst set of predef i ned channel s on the f i rst si de of each pi ate i s adapted to provide a first flow field for a first reactant and the second set of predefined channels on the second side of each plate is adapted to provide a second flow field for the second reactant da

A ccordi ng to another embodi ment, one or more f i rst channels of thef i rst set of predef i ned channels termi nati ng at a f i rst i nl et outl et on the f i rst si de of each plate i s adapted to have a f i rst bypass f I ow field to maintain the one or more first channels active and one or more second channels of the second set of predefined channels terminating at a second inlet outlet on the second side of each ¾ plate is adapted to have a second bypass flow field to maintain the one or more second channels active.

According to yet another embodiment, the fuel cell stack includes an underpass flow field to balance pressure on a pair of bi-polar metal plates of the plurality of bi-polar plates and provide cool i ng effect to the pai r of bi - pol ar metal pi ates. According to yet another embodiment, the underpass flow field is achieved by at least one of one or more teeth protrusions on the first side of each plate of the bi-polar metal plates to enable flowing of coolant in between the pair of bi-polar metal plates and variation in height of ridges of a second flow field and a first flow field between the pair of bi-polar metal plates.

According to yet another embodiment, each gasket of the plurality of gasket is integrated with one or more stiffeners to give stiffness and eliminate cross flow of a first reactant and the second reactant

3a A ccordi ng to yet another embodi ment, the f i rst reactant i s one of an anode and a cathode and the second reactant is one of the anode and the cathode.

In another aspect, a method for constructing a fuel cell comprising an anode and a cathode on ei ther si de of a bi - pol ar metal pi ate i s descri bed herei n. T he method i ncl udes creati ng an i mpressi on

¾ on a f i rst si de of a pai r of bi - pol ar metal pi ates to form a f i rst set of predef i ned channel s on the f i rst side and a second set of predefined channels on a second side of the pair of bi-polar metal plates, positioning a supporting plate on the second side of a first bi-polar metal plate of the pair of bipolar metal plates, wherein the supporting plate comprises a first bend along a flow direction and a second bend perpendicular to the flow direction for avoiding cross flow of a second reactant it from the second si de to the f i rst si de, positi oni ng a membrane el ectrode assembly ( M E A ) between the pair of bi-polar metal plates and positioning a gasket on the first side and the second side of each bi-polar metal plate of the pair of bi-polar metal plates, wherein the gasket comprises a plurality of protrusions on one side and a plurality of indentations on another side at regular intervals for attaching with each plate of the pair of bi-polar metal plates.

*¾

According to one embodiment, the method includes creating a first bypass flow field on the first side for maintaining one or more first channels of the first set of predefined channels active and creati ng a second bypass f I ow f i el d on the second si de for mai ntai ni ng one or more second channel s of the second set of predefined channels active. According to another embodiment, the method includes creating an underpass flow field for balancing pressure in each plate of the pair of bi-polar metal plates by at least one of one or more teeth protrusions on the first side of each plate of the bi-polar metal plates to enable flowing of coolant in between the pair of bi-polar metal plates, and variation in height of ridges of a second ¾ f I ow f i el d and a f i rst f I ow f i el d between the pai r of bi - pol ar metal pi ates.

The foregoing has outlined, in general, the various aspects of the invention and is to serve as an aid to better understand the more complete detailed description which is to follow. In reference to such, there is to be a clear understanding that the present invention is not limited to the method or 3a application of use described and illustrated herein. It is intended that any other advantages and objects of the present invention that become apparent or obvious from the detailed description or i 11 ustrati ons contai ned herei n are wi thi n the scope of the present i nventi on.

Other features of the embodiments will be apparent from the accompanying drawings and from ¾ the detai I ed descri pti on that f ol I ows.

BRIE F DE SC RIPTION O F T H E ACC OM PANY ING DRAWINGS

T he other obj ects, features and advantages wi 11 occur to those ski 11 ed i n the art from the f ol I owi ng it descri pti on of the preferred embodi ment and the accompanyi ng drawi ngs i n whi ch:

Figure 1 depicts a bi-polar metal plate having a first flow field and a second flow field on either side of the bi-polar metal plate, according to an embodiment of the present invention.

Figure 2 depicts a bi-polar metal plate having a first bypass flow field near a first inlet outlet for effective i ncrease i n current generati on area, accordi ng to an embodi ment of the present invention.

F igure 3 depicts a pair of bi-polar metal plates having an underpass flow field to balance pressure and provide cooling effect to the pair of bi-polar metal plates of a fuel cell stack, according to an embodiment of the present invention. Figure 4A & 4B depicts a bi-polar metal plate having a supporting plate for supporting a membrane electrode assembly (M EA) and distributing uniform pressure along a gasket, according to an embodiment of the present invention.

¾

Figure 5 depicts a bi-polar metal plate having a gasket for avoiding buckling of the bi-polar metal plate, according to an embodiment of the present invention.

F igure 6 depicts a bi-polar metal plate having a gasket that provides underpass for a first reactant 3a and a second reactant, accordi ng to an embodi ment of the present i nventi on.

Figure 7 is a schematic diagram of arrangement of a pair of bi-polar metal plates in a fuel cell stack, accordi ng to an embodi ment of the present i nventi on.

¾ Figure 8 is a schematic diagram of a bi-polar metal plate illustrating flipping axis and flipping direction while assembling a pair of bi-polar metal plates in a fuel cell stack, according to an embodiment of the present invention.

T he drawi ngs descri bed herei n are f or i 11 ustrati on purposes only and are not i ntended to I i mit the it scope of the present di scl osure i n any way.

DETAIL E D DE SC RIPTION OF T H E INV E NTIO N

The present invention provides a bi-polar metal plate of a fuel cell which comprises an anode and ¾ a cathode on ei ther si de. In the f ol I owi ng detai I ed descri pti on of the embodi ments of the i nventi on, reference i s made to the accompanyi ng drawi ngs that form a part hereof, and i n whi ch are shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to betaken in a limiting sense, and the scope of the present invention is defined only by the appended claims.

The specification may refer to ^'an_., ^'one_. or ^'some_, embodiments) in several locations. This ¾ does not necessarily imply that each such reference is to the same embodi ment(s), or that the feature only appl i es to a si ngl e embodi ment S i ngl e features of different embodi ments may al so be combined to provide other embodiments.

As used herein, the singular forms ^'a_, ^'an_. and ^'the_. are intended to include the plural forms as 3a well, unless expressly stated otherwise. It will be further understood that the terms ^'includes_., 'comprises_., ^'including_, and/or ^'comprising_, when used in this specification, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof . As used herein, the term ^'and/or_. includes any and ¾ al I combi nations and arrangements of one or more of the associated I isted items.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will be further understood that terms, such as those defined in commonly used it dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the rel evant art and wi 11 not be i nterpreted i n an i deal i zed or overly formal sense unl ess expressly so defined herein.

The embodiments herein and the various features and advantages details thereof are explained ¾ morefully with reference to the non- limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processi ng techni ques are omitted so as to not unnecessari ly obscure the embodi ments herei n. T he examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein can be practiced and to further enable those of ski 11 in the art to practice the tin embodi ments herei n. A ccordi ngly, the exampl es shoul d not be construed as I i miti ng the scope of the embodi ments herei n. Figure 1 depicts a bi-polar metal plate 102 having a first flow field 104 and a second flow field 106 on either side of the bi-polar metal plate 102, according to an embodiment of the present invention. According to Figure 1, the bi-polar metal plate 102 includes a first set of predefined ¾ channels on a f i rst si de and a second set of predef i ned channels on a second si de. T he f i rst set of predefined channels is adapted to provide the first flow field 104 for a first reactant The second set of predefined channels is adapted to provide the second flow field 106 for a second reactant. In one embodiment, the first reactant is an anode and the second reactant is a cathode. In another embodiment the first reactant is the cathode and the second reactant is the anode. The first set of

3a predef i ned channel s on the f i rst si de i s formed by an i mpressi on on the f i rst si de duri ng stampi ng.

The impression on the first side of the bi-polar metal plate 102 creates corresponding ribs on the second side. The created ribs form the second set of predefined channels on the second side. In an embodiment a reactant (e.g. the first reactant or the second reactant) on a side of the cathode is ¾ In another embodi ment, the reactant ( e.g. the f i rst reactant or the second reactant) on a si de of

¾ the anode is % As the bi-polar metal plate 102 includes the anode and the cathode on either side, requirement of welding is completely eliminated and turnaround time is minimized during production of the bi-polar metal plate 102 in order to minimize manufacturing cost and manufacturing complexity. it Figure 2 depicts a bi-polar metal plate 102 having a first bypass flow field 204 near a first inlet outlet 202 to increase effective current generation area, according to an embodiment of the present invention. According to Figure 2, the bi-polar metal plate 102 includes one or more first channels and one or more second channels within a first set of predefined channels and a second set of predefined channels respectively. The one or more first channels on a first side terminate ¾ near the first inlet outlet 202 (e.g. H2 inlet outlet) which leads to decrease in current generation area. The bi-polar metal plate 102 includes the first bypass flow field 204 to maintain the one or more terminated first channels active and increase the effective current generation area. The first bypass flow field 204 connects the one or more terminated first channels to one of channels of the first set of predefined channels to enable circulation of a first reactant on the first side. Similarly, a second bypass f I ow f i el d connects one or more termi nated second channel s to one of channel s of second set of predefined channels to enable circulation of a second reactant on a second side. Figure 3 depicts a pair of bi-polar metal plates having an underpass flow field 304 to balance pressure and prov i de cool i ng effect to the pai r of bi - pol ar metal pi ates of a fuel eel I stack, accordi ng to an embodiment of the present invention. According an embodiment of the present invention, ¾ the pair of bi-polar metal plates achieves the underpass flow field 304 by providing one or more teeth protrusions on a first side of each plate of the pair of bi-polar metal plates to enable flowing of coolant in between the pair of bi-polar metal plates. According to another embodiment of the present invention, the pair of bi-polar metal plates achieves the underpass flow field by providing variation in height of ridges 302 of a second flow field and a first flow field between the pair of 3a bi - pol ar metal pi ates. T he underpass f I ow f i el d 304 i s adapted to bal ance the pressure and prov i de the cooling effect to the pair of bi-polar metal plates of the fuel cell stack. In an embodiment, a supporting plate, a membrane electrode assembly (MEA) and a gasket are positioned in between the pair of bi-polar metal plates.

¾ Figure4A & 4B depicts a bi-polar metal plate 102 having a supporting pi ate 402 for supporting a membrane electrode assembly (MEA) 404 and distributing uniform pressure along a gasket, according to an embodiment of the present invention. In a fuel cell stack, each supporting plate 402 is positioned between two bi-polar metal plates of a plurality of bi-polar metal plates for supporting the M EA 402 during compression of the fuel cell stack. The supporting plate 402 it includes bent edges, a first bend along a flow direction and a second bend perpendicular to the f I ow di recti on for avoi di ng cross f I ow 406 of either a second reactant from a second si de to a f i rst si de or a f i rst reactant from the f i rst si de to the second si de. In an embodi ment the supporti ng pi ate 402 is made of electrically insulating material. The supporting plate 402 is adapted to reduce leakage of a coolant and further provide landing space for a gasket The supporting plate 402 t further di stri butes uni form pressure 408 al ong the gasket by utilizing the f i rst bend and the second bend and avoids fluttering of the supporting plate 402 in the fuel cell stack.

Figure 5 depicts a bi-polar metal plate 102 having a gasket 502 for avoiding buckling of the bipolar metal plate 102, according to an embodiment of the present invention. In a fuel cell stack, the gasket 502 is positioned on a first side and a second side of each bi-polar metal plate of a pair of bi-polar metal plates. The gasket 502 includes one or more protrusions 504 on one side and one or more i ndentati ons 506 on other si de at regular i ntervals for attachi ng with each plate of the pai r of bi-polar metal plates. In an embodiment, each plate of the pair of bi-polar metal plates includes one or more protrusions on one side and one or more indentations 506 on other side for attaching with the gasket 502 of a pi ural ity of gaskets i n the fuel eel I stack. In an embodi ment, each gasket ¾ of the plurality of gaskets is positioned on the first side and the second side of each plate of the pair of bi-polar metal plates. The gasket 502 is adapted to secure the pair of bi-polar metal plates and avoid buckling during compression of the fuel cell stack. In an embodiment, the one or more protrusions 504 on the gasket 502 is adapted to provide free flow of one of a first reactant and a second reactant In an embodiment, the gasket 502 is integrated with one or more stiffeners to 3a prov i de sti ff ness and el i mi nate cross f I ow of a f i rst reactant and a second reactant.

Figure 6 depicts a bi-polar metal plate 102 having a gasket 502 that provides underpass for a first reactant and a second reactant, according to an embodiment of the present invention. According to Figure 6, the gasket 502 that is attached with the bi-polar metal plate 102 provides underpass ¾ (as depicted in 602 and 604) for either the first reactant (e.g. ¾ or the second reactant (e.g. i¾ near si des, edges, a f i rst i nl et outl et and a second i nl et outl et through one or more protrusi ons 504 on the gasket 502.

Figure 7 is a schematic diagram of arrangement of a pair of bi-polar metal plates in a fuel cell it stack, according to an embodiment of the present invention. According to Figure 7, a schematic view of a bi-polar metal plate 102 is depicted in 702. The fuel cell stack includes a plurality of bipolar metal plates. The plurality of bi-polar metal plates includes one or more pairs of bi-polar metal plates that are placed parallel to each other. Each pair of bi-polar metal plates includes a first bi-polar metal plate 704 and a second bi-polar metal plate 712. Each pair of bi-polar metal plates ¾ further includes a supporting plate 706, an MEA 708 and a gasket 710. The supporting plate 706 is positioned between the first bi-polar metal plate 704 and the second bi-polar metal plate 712 of each pair of bi-polar metal plates. The supporting plate 706 includes a first bend along a flow direction and a second bend perpendicular to the flow direction to avoid cross flow of a second reactant from a second side to a first side. The M EA 708 is positioned between the first bi-polar metal plate 704 and the second bi-polar metal plate 712. In an embodiment, the supporting plate, the MEA and the gasket are positioned between each pair of the plurality of bi-polar metal plates as descri bed above to construct the fuel eel I stack. In another embodi ment, the gasket is i ntegrated with one or more stiffeners to provide stiffness and eliminate cross flow of a first reactant and the second reactant In an embodiment, the fuel cells stack includes an arrangement of combination of serpenti ne anode and parallel cathode.

¾

Figure8 is a schemati c di agram of a bi - pol ar metal pi ate 102 i 11 ustrati ng f I i ppi ng axi s and f I i ppi ng direction while assembling a pair of bi-polar metal plates in a fuel cell stack, according to an embodiment of the present invention. According to this embodiment, the bi-polar metal plate 102 depicts a first inlet outlet port 802A, a second inlet outlet port 802B, a flipping direction 804 and

3a a flipping axis 806. In an embodiment, the bi-polar metal plate is adapted to have positioning and placement of the first inlet outlet port 802A and the second inlet outlet port 802B at one or more places within the bi-polar metal plate 102. The flipping axis 806 of the bi-polar metal plate 102 is adapted to vertically flip (i.e. in the flipping direction 804) the bi-polar metal plate 102 while assembling to ensure rib to rib contact with the other bi-polar metal pi ate in the fuel cell stack. The

¾ f I i ppi ng di recti on 804 i s depi cted i n F i gure.8

While the specification has been described in detail with respect to specific embodiments of the i nventi on, it wi 11 be appreci ated that those ski 11 ed i n the art, upon attai ni ng an understand! ng of the foregoing, may readily conceive of alterations to, variations of, and equivalents to these it embodiments. These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the scope of the present invention. Furthermore, those of ordinary skill in the art will appreciate that the foregoing descri pti on is by way of example only and is not i ntended to I i mit the i nventi on. T hus, it is i ntended that the present subject matter covers such modifications and variations.

*¾

Claims

We claim:

A bi-polar metal plate for a fuel cell stack, the bi-polar metal plate comprising:

a first side being adapted to have a first set of predefined channels; and a second side being adapted to have a second set of predefined channels, wherein the first set of predefined channels on the first side of bi-polar metal plate being adapted to provide a first flow field for a first reactant, and the second set of predefined channels on the second side of the bi-polar metal plate being adapted to provide a second flow field for a second reactant,

one or more f i rst channels of the f i rst set of predef i ned channels termi nati ng at a f i rst inlet outlet on the first side of bi-polar metal plate being adapted to have a first bypass flow field to maintain the one or more first channels active, and

one or more second channels of the second set of predefined channels terminating at a second inlet/outlet on the second side of the bi-polar metal plate being adapted to have a second bypass flow field to maintain the one or more second channels active.

The bi-polar metal plate as claimed in claim 1, wherein the first reactant is one of an anode and a cathode and the second reactant is one of the anode and the cathode.

The bi-polar metal plate as claimed in claim 1 further comprising an underpass flow field formed by at least one of

one or more teeth protrusions on the first side of the bi-polar metal plates to enable flowing of coolant; and

variation in height of ridges of a first flow field and a second flow field on the first side and the second side of the bi-polar metal plate.

A fuel cell stack comprising:

a plurality of bi-polar metal plates placed parallel to each other, wherein each plate of the plurality of bi-polar metal plates includes a first set of predefined channels on a first side and a second set of predefined channels on a second side;

a plurality of supporting plates, wherein each supporting plate positioned between two bi-polar metal plates of the plurality of bi-polar metal plates, wherein each supporting plate compri ses a f i rst bend al ong a f I ow di recti on and a second bend perpendi c ul ar to the f I ow di recti on to avoi d cross f I ow of a second reactant from the second si de to the f i rst si de; a plurality of membrane electrode assembly (M EA), wherein each MEA positioned between the two bi- polar metal plates of the plurality of bi- polar metal plates; and ¾ a plurality of gaskets, wherein each gasket positioned on the first side and the second side of each plate of the plurality of bi- polar metal plates, wherein each gasket comprises a plurality of protrusions on one side and a plurality of indentations on another side at regular intervals. a 5. The fuel cell stack as claimed in claim 4, wherein the first set of predefined channels on the f i rst si de of each pi ate i s adapted to prov i de a f i rst f I ow f i el d for a f i rst reactant, and the second set of predefined channels on the second side of each plate is adapted to provide a second flow field for the second reactant.

The fuel cell stack as claimed in claim 4, wherein one or more first channels of the first set of predefined channels terminating at a first inlet outlet on the first side of each plate is adapted to have a first bypass flow field to maintain the one or more first channels active, wherein one or more second channels of the second set of predefined channels terminating at a second inlet outlet on the second side of each plate is adapted to have a second bypass flow field to maintain the one or more second channels active.

The fuel cell stack as claimed in claim 4 further comprising an underpass flow field to balance pressure on a pair of bi-polar metal plates of the plurality of bi-polar plates and provide cooling effect to the pair of bi-polar metal plates.

The fuel cell stack as claimed in claim 7, wherein the underpass flow field is achieved by at least one of

one or more teeth protrusions on the first side of each plate of the bi-polar metal plates to enable flowing of coolant in between the pair of bi-polar metal plates; and variation in height of ridges of a second flow field and a first flow field between the pair of bi-polar metal plates.

9. T he fuel eel I stack as clai med i n clai m 4, wherei n each gasket of the pi urality of gasket is integrated with one or more stiffeners to give stiffness and eliminate cross flow of a first reactant and the second reactant.

¾

10. The fuel cell stack as claimed in claim 5, wherein the first reactant is one of an anode and a cathode and the second reactant is one of the anode and the cathode.

11. A method for construct! ng a fuel eel I compri si ng an anode and a cathode on ei ther si de of 3a a bi - pol ar metal pi ate, the method compri si ng:

creating an impression on a first side of a pair of bi-polar metal plates to form a first set of predef i ned channels on the f i rst si de and a second set of predef i ned channels on a second side of the pair of bi-polar metal plates;

positioning a supporting plate on the second side of a first bi-polar metal plate of the ¾ pair of bi-polar metal plates, wherein the supporting plate comprises a first bend along a flow direction and a second bend perpendicular to the flow direction for avoiding cross flow of a second reactant from the second side to the first side;

positioning a membrane electrode assembly (MEA) between the pair of bi-polar metal plates; and

it positioning a gasket on the first side and the second side of each bi-polar metal plate of the pai r of bi - pol ar metal pi ates, wherei n the gasket compri ses a plurality of protrusi ons on one side and a plurality of indentations on another side at regular intervals for attaching with each plate of the pair of bi-polar metal plates. t 12. The method as claimed in claim 11 further comprising:

creating a first bypass flow field on the first side for maintaining one or more first channels of the first set of predefined channels active; and

creating a second bypass flow field on the second side for maintaining one or more second channels of the second set of predefined channels active.

13. The method as claimed in claim 11 further comprising: creating an underpass flow field for balancing pressure in each plate of the pair of bipolar metal plates by at least one of: