FORM 2
THE PATENTS ACT 1970
(39 OF 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
TITLE BIPOLAR PLATE FOR PEM FUEL CELL
APPLICANT
TATA MOTORS LIMITED,
an Indian company having its registered office at
Bombay house, 24 Homi Mody Street,
Hutatma Chowk, Mumbai 400 001,
Maharashtra, INDIA.
INVENTORS
DEEPAK R R, MANI K. PAUL, YOGESHA S A
all are Indian Nationals of
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House, 24 Homi Mody Street,
Hutatma Chowk, Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is performed.

FIELD OF THE INVENTION
The present invention generally relates to Bipolar Plate used in PEM fuel cell stack.
BACKGROUND OF THE INVENTION
Fuel cells are expected to play a major role as a sustainable technology for power generation in the near future. It is anticipated that the development and deployment of economical and reliable fuel cells would bring sustainable hydrogen age. Modestly low operation temperature (< 100 ◦C) of the Polymer Electrolyte Membrane Fuel Cell (PEMFC) enables it for future automotive propulsion applications. The PEMFC system is an energy system that can convert hydrogen and oxygen (or air) to electricity with water as the only by-product, and hence is of great interest from an environmental point of view. A significant part of the PEMFC stack is the bipolar plates (BPs), which account for about 60% of total weight and 45% of stack cost. They are designed to accomplish many functions, such as distribute reactants uniformly over the active areas, remove heat from the active areas, carry current from cell to cell and prevent leakage of reactants and coolant. Furthermore, the plates must be of inexpensive, lightweight materials and must be easily (and inexpensively) manufactured. Efforts are underway to develop bipolar materials that satisfy these demands. The main materials studied to date for Bipolar plates includes electro graphite, sheet metal (coated and uncoated) and graphite polymer composites.
Bipolar Plates are mainly of three types:
Non-metal: Under these section, the non-metal plates comprises of non-porous graphite
plates.
Metals: Under these section, the metal plates comprises of non-coated type and coated
type of plates. Further the non-coated type of plates comprises of Stainless steel,

Austenitic and Ferrite metals. Coated type of plates are further categorized as bases and coatings. The bases are Aluminum, Titanium, Nickel and Stainless steel. Coatings are Carbon bases “Graphite, Conductive polymer, Diamond like carbon, self-assembled mono-polymers, Metal based with noble metals like Carbides and Nitrides.
Composites: Under these section, the plates comprises of metal based and carbon based. The metal based composites plates comprise of Graphite, poly-carbonate and Stainless steel. The carbon based composites plates comprise of resins, filler and fibres. Further the Resin comprises of Thermoplastics, Polyvinyldene fluoride, polyethylene, Thermosets, Epoxy resins, Phenolic resins, Furan resins, Vinyl Ester. Further the Fillers comprises of Carbon/graphite, Carbon black, Coke Graphite. Further the Fibers comprises of Carbon/graphite, Cellulose, Cotton flock.
Delivery of reactants, removal of products and efficient heat removal from the PEMFC stack is crucial for optimum performance and durability. Flow-field design of Bipolar is the main factor for these processes. Power capacity value of a PEMFC is greatly influenced by the flow field design. Homogeneous current density and temperature distribution along with effective water removal are crucial tasks, and thus require a careful flow field design in a PEMFC. The main task of designing a flow field network is to achieve the maximum possible homogeneity over the cell’s active area, which means using the hydrogen effectively, with respect to temperature, gas concentration, and humidity. The stoichiometry and composition of the reactants and the stack’s operating conditions have to be accurately accounted for.
Prior art of the inventions shows various flow-field designs of Bipolar plates, each with it’s own advantages and disadvantages. Some of those flow-field designs are discussed below. A Pin type bipolar plate design is available, in which the fluids flow through the grooves formed by the pins protruding from the plates.

Another Bipolar plate uses parallel channel for fluid flow. A crisscross form of flow is induced in one bipolar plate in order for the gas to coalesce with water droplets. A Bipolar plate with single serpentine flow path is also available, in which the fluid flow through a continuous path from start to end. Bipolar plates with parallel serpentine flow path, serpentine flow path divided into linked segments, serpentine flow path that are mirror images etc. are also available. Another Bipolar plate design uses dead-ended discontinuous channels to force the gases through the Gas diffusion layer (GDL) under the landings to pass from the manifold inlet to outlet streams. A modified interdigitated bipolar plate in which larger channels are branched into smaller ones are also available. Bipolar plates with modified parallel or serpentine flow paths where the channels’ depths and/or widths decrease in a gradient towards the outlet are also available. IN another type of Bipolar plate, usual rectangular flow channels are replaced with radial flow rings. Bipolar plate made from porous material are also available. One type of Bipolar plate has fluid flowing through porous metal mesh and in another type, the fluid flows through a highly porous structure that eliminates the conventional channel/land flow field structure. A type of Bipolar plate has typical parallel or serpentine flow paths with landings containing many small hydrophilic capillary columns allowing water to wick from the GDL by capillary action.
All these Bipolar plates has their own advantages and disadvantages. Some are having low-pressure drop, uniform gas distribution and effective water removal. However, some of the disadvantages associated with above mentioned Bipolar plates are uneven current density, water blockage in channels resulting in obstructed flow, unstable voltage after extended usage, low channel velocity, uneven reactant distribution, corrosion issues.
In order to combine the above advantages and overcome the disadvantages, there is need of an efficient bipolar plate.

OBJECTS OF THE INVENTION
An object of the invention is to obviate above-mentioned drawbacks.
Another object of the invention is to provide low cost Bipolar plates, which account for almost 40% of the fuel cell stack cost, making fuel cell comparatively affordable and more efficient to be used in Hybrid vehicle technology.
Yet another object of the present invention is to provide an inbuilt self-humidification system to humidify the PEM fuel cell to eliminate an external humidification unit and extra machinery thereby saving cost and also providing better vehicle packaging.
BRIEF DESCRIPTION OF THE DRAWINGS
The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:
Figure 1 is an illustration of the air flow side of the Cathode Bipolar plate, in one embodiment of the present invention;
Figure 1.1 shows the air flow pattern over the air side of cathode bipolar plate, in one embodiment of the present invention;
Figure 2 is an illustration of the cooling water flow side of the Cathode Bipolar plate, in one embodiment of the present invention;

Figure 3 is an illustration of the H2 flow side of the anode bipolar plate, in one embodiment of the present invention;
Figure 4 is an illustration of the cooling water flow side of the anode bipolar plate, in one embodiment of the present invention; and
Figure 5 shows the exploded view of bipolar plates in an assembly with seal in between, in one embodiment of the present invention.
The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the system illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION OF THE INVENTION
The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the

following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.
Now referring to the drawings wherein the descriptions are for the purpose of illustrating preferred embodiments of the invention only, and not for the purpose of limiting the same.
The present invention discloses a bipolar plate for Polymer Electrolyte Membrane (PEM) fuel cell comprising at least one cathode side bipolar plate (1) configured with an air inlet (3) with air inlet channel (5) connected to it and an air outlet (8) with air outlet channel (9) connected to it; plurality of lobe shaped stampings (6) in an array provided on said cathode side bipolar plate (1) to configure airflow area (42) facilitated for air flow from one side of said cathode side bipolar plate (1); a set of stamping below the air inlet cavity (3) is constituted to form as condensed water flow channel (10) to connect it to a condensed water exit cavity (11) wherein said water flow channel (10) along with the inlet air is configured to form self-humidification unit to provide the predetermined humidification effect to said PEM fuel cell; at least one air boundary wall (12) constituted on cathode side bipolar plate (1) by stamping for enclosing said air inlet cavity (3), air outlet cavity (8), the lobed stamping (6), condensed water flow channel (10) and the condensed water exit cavity (11); at least one H2 gas inlet (13) and at least one H2 gas outlet (14) are constituted in proximity of said air boundary wall (12); at least one cooling water inlet (15) with at least one cooling water inlet channel (17) and at least one cooling water outlet (16) with at least one cooling water outlet channel (18) constituted in proximity of said air boundary wall (12) facilitated for flowing cooling water from other side of said cathode side bipolar plate (1); plurality of openings provided on said cathode side bipolar plate (1) to constitute cathode side cooling water entry points (20) and

cathode side cooling water exit points (21) for connecting the cooling water flow area (19) to said boundary wall (12); plurality of electrode support stamping (22) are provided in the proximity of said air inlet cavity (3) and said air outlet cavity (8) on said cathode side bipolar plate (1); at least one anode side bipolar plate (2) configured with a H2 Boundary wall (24) constituted for enclosing a H2 inlet (25), H2 outlet (26), H2 inlet channel (27), H2 outlet channel (28), serpentine shaped stamping (29) and H2 flow area (30); at least one air inlet passage (31), at least one air outlet passage (32), at least one condensed water inlet provision (48) at least one cooling water inlet cavity (33), at least one cooling water outlet cavity (34), at least one cooling water inlet channel (35) and at least one cooling water outlet channel (36) are configured to be provided outside said H2 boundary wall (24); at least one partial depression is constituted on the coolant water flow side of H2 boundary wall (24) for the anode side cooling water entry (39) and anode side cooling water exit (40) into the cooling water flow area (37); at least one seal (41) is configured to be placed between the cooling water flow side of cathode side bipolar plate and the cooling water flow side of anode side bipolar plate for separating both bipolar plates.
The airflow area (42) is provided with a different extended lobe profile (7) in the first and last row of lobe in area (42). The air inlet (3) and said air outlet cavity (8) are constituted in diagonally opposite to each other for uniform air flow over airflow area (42). The air inlet cavity (3), air outlet cavity (8), the lobed stamping (6), condensed water flow channel (10) and the condensed water exit cavity (11) are configured to be enclosed in stamping to act as a air boundary wall (12). The air boundary wall (12) near to the air inlet and outlet has a tapering (23) profile. The air flow area (42) and air boundary wall (12) constitute predetermined height difference for efficient air flow through the area (42) and without air leaking out of air boundary wall (12). The extended lobe pattern (7) and the tapering boundary wall (23) profile are configured for uniform air distribution over the air flow area (42). The lobed patterns (6) is configured to induce turbulence into the

flow nature of air by flowing through the zig zag passage (43) of the grooves formed by lobed patterns (6). The electrode support stamping (22) is provided as anti-sagging of cathode (44) sheet and to eliminate choking of air flow entry into the area (42). The lobed stamping (6) is configured for trickling down the water particles formed during the air flow will trickle down due to its denser nature and directing towards the condensed water exit cavity (11) through the condensed water flow channel (10). The height difference at the air flow side creates a height difference in the cooling water flow side configured for flowing of cooling water on the cooling water flow area. The H2 flow area (30) and H2 boundary wall (24) constitute predetermined height difference for efficient H2 flow through the area (30) along the horizontal serpentine passage way (45) formed between the serpentine shaped stampings (29) and without H2 leaking out of air boundary wall (24). The serpentine shaped stamping (29) are configured for providing a laminar flow pattern of H2 and for avoiding water stagnation in the horizontal serpentine profile to eliminate any blockage to H2 flow.
As illustrated, Figure 1 and 3 shows the Cathode side bipolar plate (1) and Anode side Bipolar plate (2). Cathode side bipolar plate (1) has provision for Air inlet cavity (3) given on stamping (4). The air inlet cavity (3) has some openings called air inlet channel (5) connected to it. The airflow area (42) consists of multiple lobe shaped stampings (6) arranged as an array. The first and last row of lobe in area (42) has a different extended lobe profile (7). Diagonally opposite to air inlet (3) has the air outlet (8) cavity which also has some openings called air outlet channel (9) connected to it. Below the air inlet cavity (3), a set stamping which acts as a channel called as condensed water flow channel (10) which leading to another opening called as condensed water exit cavity (11). The air inlet cavity (3), air outlet cavity (8), the lobed stamping (6), condensed water flow channel (10) and the condensed water exit cavity (11) are all enclosed in stamping which act as a boundary wall called air boundary wall (12). Outside this air boundary wall (12), there are more openings namely H2 inlet passage (13), H2 outlet passage (14), cooling

water inlet cavity (15) and Cooling water outlet cavity (16). The cooling water inlet cavity (15) and cooling water outlet cavity (16) have some channels connected to it namely cooling water inlet channel (17) and cooling water outlet channel (18). The back side of the cathode side bipolar plate has got cooling water flow area (19). There are some more opening called cathode side cooling water entry points (20) and cathode side cooling water exit points (21) which connect the cooling water flow area (19) to boundary wall (12). Near to air inlet cavity (3) and air outlet cavity (8) some stamping called electrode support stamping (22) are present. Also the boundary wall near to the air inlet and outlet has a tapering (23) profile.
Similar to the Cathode side Bipolar plate (1), anode side bipolar plate (2) also has a H2 Boundary wall (24) which encloses a H2 inlet cavity (25), H2 outlet cavity (26), H2 inlet channel (27), H2 outlet channel (28), serpentine shaped stamping (29) and H2 flow area (30). Outside the boundary wall (24) is present Air inlet passage (31), air outlet passage (32), Condensed water inlet provision (48) cooling water inlet cavity (33), cooling water outlet cavity (34), cooling water inlet channel (35) and cooling water outlet channel (36). Partial depression is given on the coolant water flow side of H2 boundary wall (24), through which the cooling water entry and exit into the cooling water flow area (37) occurs. These openings are named as anode side cooling water entry (39) and anode side cooling water exit (40).
As shown in Figure 6, when assembled, cathode side bipolar plate and anode side bipolar plate are separated by a seal (41). Seal (41) is kept between the cooling water flow side of both bipolar plates.
The working of the invention can be understood from the following paragraph. In Cathode side bipolar plate (1) air enters through the air inlet cavity (3) and through the air inlet channel (5) enters the air flow area (42). There is height difference maintained between the air flow area (42) and air boundary wall (12) sufficient enough for the air to flow through the area (42) without air leaking out of air boundary wall (12). Air is

distributed uniformly over the air flow area (42) because of the extended lobe pattern (7) and the tapering boundary wall (23) profile. Because of the lobed patterns (6) present, sufficient turbulence is induced into the flow nature of air and it flows through the groove like zig zag passage (43) formed due to the lobed patterns (6). Once the air passes over the air flow area (42), at the end of flow, the air is exits through the air outlet cavity (8) and air outlet channel (9) because of the tapering boundary wall (23) profile and the extended lobe pattern (7) at the outlet. During this time H2 will not be able to leak in due to the stamping (4) provided. The air boundary wall (12), the stampings (4) and lobed patterns (6) are at same height. While assembled, these stamping will remain in contact with the Cathode (44) which is usually a graphite sheet and is not to be limited for the same. The ratio between the contact area and flow area is close to 1:1. The electrode support stamping (22) prevent sagging of cathode (44) sheet and thus eliminates choking of air flow entry into the area (42). Water particles which are formed during the air flow will trickle down due to its denser nature through the lobed stamping (6) and will be directed towards the condensed water exit cavity (11) through the condensed water flow channel (10).
During this some fine water particles move up with the air and will spread over the area (42).
Along the other side of the cathode side bipolar plate (1), cooling water enters through the cooling water inlet cavity (15). It enters the passage way (47) formed on the other side of the air boundary wall (12) through the cooling water inlet channels (17). Cooling water then enters the cooling water flow area (19) through the cathode side cooling water entry point (20) and distributes over the cooling water flow area (19). The height difference kept at the air flow side also creates a height difference in the cooling water flow side allowing the flow of cooling water comfortably. Once the cooling water flow area is filled, the fluid flow out of the cooling water flow area (19) through the cathode side

cooling water exit (21) and exits through the cooling water outlet cavity (16) and cooling water outlet channel (18).
Working of anode side bipolar plate (2) is similar to that of cathode side bipolar plate (1). In anode side bipolar plate (2) H2 enters through the H2 inlet cavity (25) and through the H2 inlet channel (27) enters the H2 flow area (30). The height difference kept between the H2 flow area (30) and H2 boundary wall (24) is sufficient to make the flow over the H2 flow area (30) without H2 leaking out of H2 boundary wall (24). H2 flow along the horizontal serpentine passage way (45) formed between the serpentine shaped stampings (29). The serpentine shaped stamping (29) are formed in such a way that H2 will follow a laminar flow pattern and water stagnation is avoided natural in the horizontal serpentine profile and will be exhausted by gravity thus eliminating any blockage to H2 flow and reaches the end of the passage way (45), H2 exits through the H2 outlet cavity (26) and H2 outlet channel (28). During this time air will not be able to leak in due to the stamping (46) provided. The H2 boundary wall (24), the stampings (46) and the serpentine shaped stamping (29) are at same height. While assembled, these stamping will remain in contact with the anode (38) which is also a graphite sheet. The contact area to flow area ratio is also maintained close to 1:1.
Along the other side of the anode side bipolar plate (2), cooling water enters through the cooling water inlet cavity (33). It enters the passage way formed on the other side of the H2 boundary wall (24) through the cooling water inlet channels (35). Cooling water then enters the cooling water flow area (37) through the anode side cooling water entry (39) and distributes over the cooling water flow area (37). The height difference kept at the H2 flow side also creates a height difference in the cooling water flow side allowing the flow of cooling water. Once the cooling water flow area is filled, the fluid flow out of the cooling water flow area (37) through the anode side cooling water exit (40) and exits through the cooling water outlet cavity (34) and cooling water outlet channel (36).

Advantages of the present invention are:
• Increased current density.
• Uniform and homogeneous distribution of reactant gases with lower pressure drop.
• Efficient heat removal.
• Effective removal of condensed water leading to elimination of water stagnation.
• Low cost and ease in manufacturability.
• Self humidification
List of Parts:

Part No: Part Description
1 Cathode side bipolar plate
2 Anode side bipolar plate
3 Air inlet cavity
4 Projected stampings
5 Air inlet channel
6 Lobe shaped stamping
7 Extended lobe pattern
8 Air outlet cavity
9 Air outlet channel
10 Condensed water flow channel
11 Condensed water exit cavity
12 Air boundary wall
13 H2 Inlet passage
14 H2 outlet passage
15 Cooling water inlet cavity
16 Cooling water outlet cavity

17 Cooling water inlet channel
18 Cooling water outlet channel
19 Cooling water flow area for cathode side bipolar plate
20 Cathode side Cooling water entry point
21 Cathode side cooling water exit points
22 Electrode support stamping
23 Tapering boundary wall
24 H2 boundary wall
25 H2 inlet cavity
26 H2 outlet cavity
27 H2 inlet channel
28 H2 outlet channel
29 Serpentine shaped stampings
30 H2 flow area
31 Air inlet passage
32 Air outlet passage
33 Cooling water inlet cavity
34 Cooling water outlet cavity
35 Cooling water inlet channel
36 Cooling water outlet channel
37 Cooling water flow area for anode side bipolar plate
38 Anode
39 Anode side cooling water entry
40 Anode side cooling water exit
41 Seal
42 Air flow area
43 Zig zag passage

44 Cathode
45 Serpentine passage way
46 Stampings
47 Passage way due to air boundary wall
48 Condensed water inlet provision
Equivalents
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted

to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."
While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

We Claim:
1. Bipolar plate for Polymer Electrolyte Membrane (PEM) fuel cell comprising
at least one cathode side bipolar plate (1) configured with an air inlet (3) with air inlet channel (5) connected to it and an air outlet (8) with air outlet channel (9) connected to it;
plurality of lobe shaped stampings (6) in an array provided on said cathode side bipolar plate (1) to configure airflow area (42) facilitated for air flow from one side of said cathode side bipolar plate (1);
a set of stamping below the air inlet cavity (3) is constituted to form as condensed water flow channel (10) to connect it to a condensed water exit cavity (11) wherein said water flow channel (10) along with the inlet air is configured to form self-humidification unit to provide the predetermined humidification effect to said PEM fuel cell;
at least one air boundary wall (12) constituted on cathode side bipolar plate (1) by stamping for enclosing said air inlet cavity (3), air outlet cavity (8), the lobed stamping (6), condensed water flow channel (10) and the condensed water exit cavity (11);
at least one H2 gas inlet (13) and at least one H2 gas outlet (14) are constituted in proximity of said air boundary wall (12);
at least one cooling water inlet (15) with at least one cooling water inlet channel (17) and at least one cooling water outlet (16) with at least one cooling water outlet channel (18) constituted in proximity of said air boundary wall (12) facilitated for flowing cooling water from other side of said cathode side bipolar plate (1);
plurality of openings provided on said cathode side bipolar plate (1) to constitute cathode side cooling water entry points (20) and cathode side cooling water exit points (21) for connecting the cooling water flow area (19) to said boundary wall (12);

plurality of electrode support stamping (22) are provided in the proximity of said air inlet cavity (3) and said air outlet cavity (8) on said cathode side bipolar plate (1);
at least one anode side bipolar plate (2) configured with a H2 Boundary wall (24) constituted for enclosing a H2 inlet (25), H2 outlet (26), H2 inlet channel (27), H2 outlet channel (28), serpentine shaped stamping (29) and H2 flow area (30);
at least one air inlet passage (31), at least one air outlet passage (32), at least one condensed water inlet provision (48) at least one cooling water inlet cavity (33), at least one cooling water outlet cavity (34), at least one cooling water inlet channel (35) and at least one cooling water outlet channel (36) are configured to be provided outside said H2 boundary wall (24);
at least one partial depression is constituted on the coolant water flow side of H2 boundary wall (24) for the anode side cooling water entry (39) and anode side cooling water exit (40) into the cooling water flow area (37);
at least one seal (41) is configured to be placed between the cooling water flow side of cathode side bipolar plate and the cooling water flow side of anode side bipolar plate for separating both bipolar plates.
2. The bipolar plate for PEM fuel cell as claimed in claim 1 wherein said airflow area (42) is provided with a different extended lobe profile (7) in the first and last row of lobe in area (42).
3. The bipolar plate for PEM fuel cell as claimed in claim 1 wherein said air inlet (3) and said air outlet cavity (8) are constituted in diagonally opposite to each other for uniform air flow over airflow area (42).
4. The bipolar plate for PEM fuel cell as claimed in claim 1 wherein said air inlet cavity (3), air outlet cavity (8), the lobed stamping (6), condensed water flow channel (10)

and the condensed water exit cavity (11) are configured to be enclosed in stamping to act as a air boundary wall (12).
5. The bipolar plate for PEM fuel cell as claimed in claim 1 wherein said air boundary wall (12) near to the air inlet and outlet has a tapering (23) profile.
6. The bipolar plate for PEM fuel cell as claimed in claim 1 wherein said air flow area (42) and air boundary wall (12) constitute predetermined height difference for efficient air flow through the area (42) and without air leaking out of air boundary wall (12).
7. The bipolar plate for PEM fuel cell as claimed in claim 1 wherein said extended lobe pattern (7) and the tapering boundary wall (23) profile are configured for uniform air distribution over the air flow area (42).
8. The bipolar plate for PEM fuel cell as claimed in claim 1 wherein said lobed patterns (6) is configured to induce turbulence into the flow nature of air by flowing through the zig zag passage (43) of the grooves formed by lobed patterns (6).
9. The bipolar plate for PEM fuel cell as claimed in claim 1 wherein said electrode support stamping (22) is provided as anti-sagging of cathode (44) sheet and to eliminate choking of air flow entry into the area (42).
10. The bipolar plate for PEM fuel cell as claimed in claim 1 wherein said lobed stamping (6) is configured for trickling down the water particles formed during the air flow will trickle down due to its denser nature and directing towards the condensed water exit cavity (11) through the condensed water flow channel (10).

11. The bipolar plate for PEM fuel cell as claimed in claim 1 wherein said height difference at the air flow side creates a height difference in the cooling water flow side configured for flowing of cooling water on the cooling water flow area.
12. The bipolar plate for PEM fuel cell as claimed in claim 1 wherein said H2 flow area (30) and H2 boundary wall (24) constitute predetermined height difference for efficient H2 flow through the area (30) along the horizontal serpentine passage way (45) formed between the serpentine shaped stampings (29) and without H2 leaking out of air boundary wall (24).
13. The bipolar plate for PEM fuel cell as claimed in claim 1 wherein said serpentine shaped stamping (29) are configured for providing a laminar flow pattern of H2 and for avoiding water stagnation in the horizontal serpentine profile to eliminate any blockage to H2 flow.