Claims:I/We Claim:

1. A grid plate (200, 300, 400, 500, 600, 700) in a battery, the grid plate (200, 300, 400, 500, 600, 700) comprising:
a rectangular backing member (201) with edges (204);
a combination of a plurality of two-dimensional shaped cavities (202, 203, 301, 302, 303, 401, 402, 501, 502, 503, 601, 602, 701, 702, 703) dispersed across a surface (201a) of the rectangular backing member (201);
a paste disposed in each two-dimensional shaped cavity of the combination of the plurality of two-dimensional shaped cavities (202, 203, 301, 302, 303, 401, 402, 501, 502, 503, 601, 602, 701, 702, 703); and
a connecting lug (205) extending from one of the edges (204) of the rectangular backing member (201) to form an electrical terminal of the battery.

2. The grid plate (200, 300, 400, 500, 600, 700) of claim 1, wherein the each two-dimensional shaped cavity of the combination of the plurality of two-dimensional cavities (202, 203, 301, 302, 303, 401, 402, 501, 502, 503, 601, 602, 701, 702, 703) comprises a supporting member to hold the paste.

3. The grid plate (200, 300, 400, 500, 600, 700) of claim 1, wherein shape of the each two-dimensional shaped cavity of the combination of the plurality of two-dimensional cavities (202, 203, 301, 302, 303, 401, 402, 501, 502, 503, 601, 602, 701, 702, 703) is one of a rectangle, a square, a rhombus, a parallelogram, a trapezium, an inverted trapezium, a triangle, a circle, a squarical, an oval, a hexagon, a octagon, and an irregular polygon.

4. The grid plate (200, 300, 400, 500, 600, 700) of claim 1, wherein the plurality of two-dimensional shaped cavities (202, 203, 301, 302, 303, 401, 402, 501, 502, 503, 601, 602, 701, 702, 703) on the surface (201a) of the rectangular backing member (201) are equally spaced and disposed symmetrically about a central axis (XX’) of the rectangular backing member (201).

5. The grid plate (200) of claim 1, wherein the combination of the plurality of two-dimensional shaped cavities is a combination of a plurality of square shaped cavities (203) and a plurality of irregular polygonal cavities (202).

6. The grid plate (300) of claim 1, wherein the combination of the plurality of two-dimensional shaped cavities is a combination of a plurality of hexagonal cavities (301), a plurality of rhombic cavities (302), and a plurality of triangular cavities (303).

7. The grid plate (400) of claim 1, wherein the combination of the plurality of two-dimensional shaped cavities is a combination of a plurality of circular cavities (401) and a plurality of oval cavities (402).

8. The grid plate (500) of claim 1, wherein the combination of the plurality of two-dimensional shaped cavities is a combination of a plurality of parallelogram shaped cavities (501), a plurality of rectangular cavities (503), and a plurality of triangular cavities (502).

9. The grid plate (600) of claim 1, wherein the combination of the plurality of two-dimensional shaped cavities is a combination of a plurality of trapezium shaped cavities (601) and a plurality of inverted trapezium shaped cavities (602).

10. The grid plate (700) of claim 1, wherein the combination of the plurality of two-dimensional shaped cavities is a combination of a plurality of parallelogram shaped cavities (701), a plurality of triangular cavities (702), and a plurality of irregular polygonal cavities (703).

11. The grid plate (200, 300, 400, 500, 600, 700) of claim 1, wherein material of the rectangular backing member (201) is a lead alloy.

12. The grid plate (200, 300, 400, 500, 600, 700) of claim 1, wherein the paste comprises binding agents for binding particles of an active material generated on forming of the paste in the grid plate (200, 300, 400, 500, 600, 700).

13. The grid plate (200, 300, 400, 500, 600, 700) of claim 1, wherein a surface area of an active material generated on forming of the paste in the grid plate (200, 300, 400, 500, 600, 700) ranges from about 8000 mm2 to about 12000 mm2.

14. The grid plate (200, 300, 400, 500, 600, 700) of claim 1, wherein a capacity of a battery plate formed from the grid plate (200, 300, 400, 500, 600, 700) ranges from about 3.5 Ampere-hour (Ah) to about 5 Ah.

15. The grid plate (200, 300, 400, 500, 600, 700) of claim 1, wherein a percentage increase in the capacity of the battery with the grid plate (200, 300, 400, 500, 600, 700) ranges from 3% to about 35%.

16. The grid plate (200, 300, 400, 500, 600, 700) of claim 1, wherein the rectangular backing member (201) with the combination of the plurality of two-dimensional shaped cavities (202, 203, 301, 302, 303, 401, 402, 501, 502, 503, 601, 602, 701, 702, 703) is casted in a mould and trimmed to apply the paste in the each two-dimensional shaped cavity.

17. The grid plate (200, 300, 400, 500, 600, 700) of claim 1, wherein an active material is spongy lead in a battery negative plate formed from the grid plate (200, 300, 400, 500, 600, 700) and the active material lead dioxide in a battery positive plate formed from the grid plate (200, 300, 400, 500, 600, 700). , Description:TECHNICAL FIELD
[0001] The present subject matter relates to a battery. More particularly, construction of a grid plate in the battery is disclosed.

BACKGROUND
[0002] In recent years, rechargeable energy storage devices have been widely used as an energy source for a number of electronic and electrical units. Commonly used rechargeable energy storage devices include, for example, lead acid batteries, nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and lithium rechargeable batteries. Lead acid batteries are a mature, reliable, and established technology, that are relatively inexpensive, and simple to manufacture.
[0003] Lead acid batteries comprise a battery acid, a number of battery negative plates, a number of battery positive plates, and a battery separator between each battery positive plate and battery negative plate. The battery acid is a high purity solution of sulphuric acid and water. The battery positive plates and the battery negative plates with the battery separator in the middle are alternately stacked and submerged in the battery acid. The battery separator insulates the battery positive plate from coming in contact with the battery negative plate. The battery positive plates and the battery negative plates are connected at the top using a cast-on strap that is welded to the plates.
[0004] The battery positive plate and the battery negative plate form the electrodes of an individual cell in the lead acid battery. Most commonly used battery positive plate and battery negative plate in the lead acid battery are pasted plates. A pasted plate comprises a grid plate with a paste applied in the pores/holes of the grid plate. Both positive and negative plates are constructed using an alloy of lead grids on which an active material of lead sulphate is applied by pasting. The active material of both the plates viz. lead sulphate is then formed using a rectifier. The rectifier charges the positive and the negative plates which are placed in jars containing sulphuric acid. During this process of charging, a redox reaction changes the lead sulphate of the positive plate by oxidation to lead dioxide and changes the lead sulphate of the negative plate by reduction to spongy lead. Thus, the battery positive plate is a metal grid with lead dioxide as active material and the battery negative plate is a metal grid with spongy lead as the active material.
[0005] The composition of the grid and the surface area of the active material available to participate in the electrochemical reactions within the battery are the quintessential factors for the mechanical strength, performance, and life of the battery.

BRIEF DESCRIPTION OF DRAWINGS
[0006] The detailed description is described with reference to the accompanying figures. The same numbers are used throughout the drawings to reference like features and components.

[0007] Figs. 1A-1B (Prior Art) exemplarily illustrate a perspective view and a partial enlarged elevation view of an existing grid plate;
[0008] Figs. 2A-2B exemplarily illustrate a perspective view and a partial enlarged elevation view of a grid plate, according to a first embodiment of the present invention;
[0009] Figs. 3A-3B exemplarily illustrate a perspective view and a partial enlarged elevation view of a grid plate, according to a second embodiment of the present invention;
[0010] Figs. 4A-4B exemplarily illustrate a perspective view and a partial enlarged elevation view of a grid plate, according to a third embodiment of the present invention;
[0011] Figs. 5A-5B exemplarily illustrate a perspective view and a partial enlarged elevation view of a grid plate, according to a fourth embodiment of the present invention;
[0012] Figs. 6A-6B exemplarily illustrate a perspective view and a partial enlarged elevation view of a grid plate, according to a fifth embodiment of the present invention;
[0013] Figs. 7A-7B exemplarily illustrate a perspective view and a partial enlarged elevation view of a grid plate, according to a sixth embodiment of the present invention; and
[0014] Figs. 8A-8C exemplarily illustrate graphical representations depicting performances of the different embodiments of the grid plates and performances of the batteries employing the different embodiments of the grid plates exemplarily illustrated in Figs. 1A-1B to Figs. 7A-7B.

DETAILED DESCRIPTION OF THE INVENTION
[0015] Conventional grid plates, such as, 100 in lead acid batteries are developed by connecting rods of lead, such as, 101, at right angles as exemplarily illustrated in Figs. 1A-1B. Figs. 1A-1B (Prior Art) exemplarily illustrate a perspective view and a partial enlarged elevation view of the existing grid plate 100. The paste is applied in the rectangular slots 102 between the rods of lead 101. In such grid plates 100, the electrode active material available for electrochemical reactions is more. However, the mechanical strength of the grid plate 100 is at stake. The battery is formed with such grid plates 100 stacked together using an external compressive force and positioned within a casing. The grid plates, such as, 100 with lower mechanical strength, when subjected to such compressive force may fail and lead to the failure of the battery.
[0016] In other designs of the grid plates, a skeleton structure with pores in it to accommodate the paste are being used. To improve performance of the battery using such grid plates, utilization of active material of the grid plates needs to be higher. For higher utilization of the active material, higher availability of the active material is required. For higher availability of the active material, the surface area of the active material on the grid plate needs to be improved. To improve the surface area of the active material, in the conventional designs, the density of the pores, the dimensions of the pores, and the porosity of the active material is increased. The utilization of the active material is improved, but the strength of the skeleton structure gets reduced.
[0017] There exists a need for an improved grid plate design of the lead acid battery which yields higher surface area of the active material available, without compromising on the mechanical strength of the grid plate, thereby enabling improved and efficient performance of the lead acid battery, overcoming all problems disclosed above as well as other problems of known art.
[0018] In the present invention improved grid designs are proposed which have surface area of the active material larger than the conventional design. In an embodiment, a grid plate in a battery is disclosed. The grid plate comprises a rectangular backing member, a combination of a plurality of two-dimensional shaped cavities dispersed across a surface of the rectangular backing member; a paste disposed in each two-dimensional shaped cavity of the combination of at least two two-dimensional shaped cavities; and a connecting lug extending from one of the edges of the rectangular backing member to form an electrical terminal of the battery.
[0019] In an embodiment, each two-dimensional shaped cavity of the combination of the plurality of two-dimensional cavities comprises a supporting member to hold the paste. Shape of each two-dimensional shaped cavity is rectangle, a square, a rhombus, a parallelogram, a trapezium, an inverted trapezium, a triangle, a circle, a squarical, an oval, a hexagon, an octagon, or an irregular polygon. In an embodiment, the plurality of two-dimensional shaped cavities on the surface of the rectangular backing member are equally spaced and disposed symmetrically about a central axis of the rectangular backing member.
[0020] In an embodiment, the combination of the plurality of two-dimensional shaped cavities is a combination of a plurality of square shaped cavities and a plurality of irregular polygonal cavities.
[0021] In an embodiment, the combination of the plurality of two-dimensional shaped cavities is a combination of a plurality of hexagonal cavities, a plurality of rhombic cavities, and a plurality of triangular cavities.
[0022] In an embodiment, the combination of the plurality of two-dimensional shaped cavities is a combination of a plurality of circular cavities and a plurality of oval cavities.
[0023] In an embodiment, the combination of the plurality of two-dimensional shaped cavities is a combination of a plurality of parallelogram shaped cavities, a plurality of rectangular cavities, and a plurality of triangular cavities.
[0024] In an embodiment, the combination of the plurality of two-dimensional shaped cavities is a combination of a plurality of trapezium shaped cavities and a plurality of inverted trapezium shaped cavities.
[0025] In an embodiment, the combination of the plurality of two-dimensional shaped cavities is a combination of a plurality of parallelogram shaped cavities, a plurality of triangular cavities, and a plurality of irregular polygonal cavities.
[0026] In an embodiment, a surface area of an active material generated on forming of the paste in the grid plate ranges from about 8000 mm2 to about 12000mm2. In another embodiment, a capacity of a battery plate formed from the grid plate ranges from about 3.5 Ampere-hour (Ah) to about 5 Ah. In an embodiment, a percentage increase in the capacity of the battery with the grid plate ranges from 3% to about 35%.
[0027] The material of the rectangular backing member is a lead alloy. In an embodiment, the paste comprises binding agents for binding particles of an active material generated on forming of the paste in the grid plate. In an embodiment, an active material is spongy lead in a battery negative plate formed from the grid plate and the active material lead dioxide in a battery positive plate formed from the grid plate. In an embodiment, the rectangular backing member with the combination of the plurality of two-dimensional shaped cavities is casted in a mould and trimmed to apply the paste in each two-dimensional shaped cavity.
[0028] Figs. 2A-2B exemplarily illustrate a perspective view and a partial enlarged elevation view of a grid plate 200, according to a first embodiment of the present invention. As exemplarily illustrated, the grid plate 200 comprises a rectangular backing member 201, a combination of multiple cavities 202 and 203, and a connecting lug 205. The rectangular backing member 201 is made of an alloy of lead. In an embodiment, the rectangular backing member 201 is made of a lead antimony alloy. The connecting lug 205 extends from an edge 204 of the backing member 201. The connecting lug 205 extends to form the terminal of the battery employing the grid plate 200. The connecting lug 205 extends from an upper corner of the backing member 201 and carries current to a cast-on strap (not shown) of the battery. The cast-on strap is provided with posts to which intercell connectors and terminal connectors of the battery are attached.
[0029] The rectangular backing member 201 has a planar surface 201a with two-dimensional shaped cavities 202 and 203 dispersed across the surface 201a. As exemplarily illustrated in Figs. 2A-2B, the two-dimensional shaped cavities 202 and 203 are irregular polygonal cavities 202 and the square shaped cavities 203. A combination of the irregular polygonal, that is, I- shaped cavities 202 and the square shaped cavities 203 are created on the planar surface 201a of the backing member 201. The combination of the cavities 202 and 203 is equally spaced and disposed symmetrically about the central axis X-X’ of the backing member 201. The I-shaped cavities 202 are uniformly created all over the surface 201a of the backing member 201 and the square cavities 203 are interspersed in the gap between the I-shaped cavities 202. The cavities 202 and 203 are see-through holes that have a depth equal to the thickness of the backing member 201 In an embodiment, the cavities 202 and 203 may comprise a supporting member to hold the paste from falling off. The space between the I-shaped cavities 202 and the square shaped cavities 203 is also uniformly maintained throughout the surface 201a of the backing member 201. The paste is disposed in the I-shaped cavities 202 and the square shaped cavities 203. The dimensions of the I-shaped cavities 202 and the dimensions of the square shaped cavities 203 are also maintained uniform throughout the surface 201a of the backing member 201. Within the dimensions of the rectangular backing member 201, the uniformly distributed I-shaped cavities 202 and the square cavities 203 holding the paste ensure the mechanical strength of the backing member 201 and also increase the amount of active material available to participate in the reactions of the battery.
[0030] Figs. 3A-3B exemplarily illustrate a perspective view and a partial enlarged elevation view of the grid plate 300, according to a second embodiment of the present invention. As exemplarily illustrated, the grid plate 300 also comprises the rectangular backing member 201, a combination of multiple cavities 301, 302, and 303, and the connecting lug 205. The construction of the rectangular backing member 201 and the connecting lug is as disclosed in the detailed description of Figs. 2A-2B. The two-dimensional shaped cavities 301, 302, 303 are hexagonal cavities 301, rhombic cavities 302, and triangular cavities 303. A combination of the hexagonal cavities 301, the rhombic cavities 302, and the triangular cavities 303 are created on the planar surface 201a of the backing member 201. The triangular cavities 303 are created at regions proximal to the edges, such as, 204 of the backing member 201. The combination of the cavities 301, 302, and 303 is equally spaced and disposed symmetrically about the central axis X-X’ of the backing member 201. The hexagonal cavities 301 are uniformly created all over the surface 201a of the backing member 201 and the rhombic cavities 302 are interspersed in the gap between the hexagonal cavities 301. The gap between the hexagonal cavities 301 and the rhombic cavities 302 is also uniformly maintained across the surface 201a of the backing member 201. The gap between the hexagonal cavities 301 and the triangular cavities 303 and gap between the rhombic cavities 302 and the triangular cavities 303 which are disposed proximal to the edges, such as, 204 of the backing member 201, are maintained uniform and equal across the surface 201a of the backing member 201. The dimensions of the hexagonal cavities 202, the rhombic cavities 302, and the triangular cavities 303 are also maintained uniform throughout the surface 201a of the backing member 201. The paste is disposed in the cavities 301, 302, 303. The cavities 301, 302, and 303 are see-through holes that have a depth equal to the thickness of the backing member 201 to hold the paste. In an embodiment, the cavities 301, 302, 303 may comprise a supporting member to hold the paste from falling off. Within the dimensions of the rectangular backing member 201, the uniformly distributed hexagonal cavities 202, the rhombic cavities 302, and the triangular cavities 303 holding the paste ensure the mechanical strength of the backing member 201 and also increase the amount of active material available to participate in the reactions of the battery.
[0031] Figs. 4A-4B exemplarily illustrate a perspective view and a partial enlarged elevation view of the grid plate 400, according to a third embodiment of the present invention. As exemplarily illustrated, the grid plate 400 also comprises the rectangular backing member 201, a combination of multiple cavities 401 and 402, and the connecting lug 205. The construction of the rectangular backing member 201 and the connecting lug 205 is as disclosed in the detailed description of Figs. 2A-2B. The two-dimensional shaped cavities 401 and 402 are circular cavities 401 and oval-shaped cavities 402. A combination of the circular cavities 401 and the oval-shaped cavities 402 is created on the planar surface 201a of the backing member 201. The combination of the cavities 401 and 402 is equally spaced and disposed symmetrically about the central axis X-X’ of the backing member 201. The oval-shaped cavities 402 are interspersed in the gap between the circular cavities 401. The gap between the oval-shaped cavities 402 and the circular cavities 401 is also uniformly maintained across the surface 201a of the backing member 201. The dimensions of the circular cavities 401 and the oval-shaped cavities 402, such as radii and circumference of the cavities are maintained uniform across the surface 201a of the backing member 201. The paste is disposed in the cavities 401 and 402. The cavities 401 and 402 are see-through holes that have a depth equal to the thickness of the backing member 201 to hold the paste. In an embodiment, the cavities 401 and 402 may comprise a supporting member to hold the paste from falling off. Within the dimensions of the rectangular backing member 201, the uniformly distributed circular cavities 401 and the oval-shaped cavities 402 holding the paste ensure the mechanical strength of the backing member 201 and also increase the amount of active material available to participate in the reactions of the battery.
[0032] Figs. 5A-5B exemplarily illustrate a perspective view and a partial enlarged elevation view of the grid plate 500, according to a fourth embodiment of the present invention. As exemplarily illustrated, the grid plate 500 also comprises the rectangular backing member 201, a combination of multiple cavities 501, 502, and 503, and the connecting lug 205. The construction of the rectangular backing member 201 and the connecting lug 205 is as disclosed in the detailed description of Figs. 2A-2B. The two-dimensional shaped cavities 501, 502, and 503 are parallelogram shaped cavities 501, triangular cavities 502, and rectangular cavities 503. A combination of these cavities 501, 502, and 503 is equally spaced and disposed symmetrically about the central axis X-X’ of the backing member 201. The triangular cavities 502 are formed proximal to the edges, such as, 204 of the backing member 201. The rectangular cavities 503 are centrally located along the length of the backing member 201, parallel to the X-X’ axis. The gap between the rectangular cavities 503 is equal, the gap between the parallelogram shaped cavities 501 is equal, and the gap between the triangular cavities 502 and the parallelogram shaped cavities 501 is equal. The dimensions of the cavities 501, 502, and 503, such as lengths of the sides of the cavities are maintained uniform across the surface 201a of the backing member 201. The cavities 501, 502, and 503 are see-through holes that have a depth equal to the thickness of the backing member 201 to hold the paste. In an embodiment, the cavities 501, 502, and 503 may comprise a supporting member to hold the paste from falling off. The orientation and the position of the parallelogram cavities 501 is symmetrical about the X-X’ axis. In an embodiment, the orientation and the position of the parallelogram cavities 501 is also symmetrical about the A-A’ axis. The X-X’ axis and the A-A’ axis divide the grid plate 500 into four sections. The combination of cavities 501, 502, and 503 and their position from the edges, such as, 204 of the grid plate 500 are duplicated in the other three sections. Within the dimensions of the rectangular backing member 201, the uniformly distributed rectangular cavities 503, the parallelogram shaped cavities 501, and the triangular cavities 502 holding the paste ensure the mechanical strength of the backing member 201 and also increase the amount of active material available to participate in the reactions of the battery.
[0033] Figs. 6A-6B exemplarily illustrate a perspective view and a partial enlarged elevation view of the grid plate 600, according to a fifth embodiment of the present invention. As exemplarily illustrated, the grid plate 600 also comprises the rectangular backing member 201, a combination of multiple cavities 601 and 602 and the connecting lug 205. The construction of the rectangular backing member 201 and the connecting lug 205 is as disclosed in the detailed description of Figs. 2A-2B. The two-dimensional shaped cavities 601 and 602 are trapezium shaped cavities 601 and inverted-trapezium shaped cavities 602. A combination of these cavities 601 and 602 is equally spaced and disposed symmetrically about the central axis X-X’ of the backing member 201. Alternating vertical sequences of the trapezium shaped cavities 601 and the inverted trapezium shaped cavities 602 are formed across the surface 201a of the backing member 201. The gap between the cavities 601 and 602 is maintained uniform and equal. The dimensions of the cavities 601 and 602, such as lengths of the sides of the cavities 601 and 602 are maintained uniform across the surface 201a of the backing member 201. The cavities 601 and 602 are see-through holes that have a depth equal to the thickness of the backing member 201 to hold the paste. In an embodiment, the cavities 601 and 602 may comprise a supporting member to hold the paste from falling off. Within the dimensions of the rectangular backing member 201, the uniformly distributed trapezium shaped cavities 601 and the inverted-trapezium shaped cavities 602 holding the paste ensure the mechanical strength of the backing member 201 and also increase the amount of active material available to participate in the reactions of the battery.
[0034] Figs. 7A-7B exemplarily illustrate a perspective view and a partial enlarged elevation view of the grid plate 700, according to a sixth embodiment of the present invention. As exemplarily illustrated, the grid plate 700 also comprises the rectangular backing member 201, a combination of multiple cavities 701, 702, and 703, and the connecting lug 205. The construction of the rectangular backing member 201 and the connecting lug 205 is as disclosed in the detailed description of Figs. 2A-2B. The two-dimensional shaped cavities 701, 702, 703 are parallelogram shaped cavities 701, triangular cavities 702, and irregular polygon shaped cavities 703. A combination of the parallelogram shaped cavities 701, the triangular cavities 702, and the irregular polygon shaped cavities 703 are created on the planar surface 201a of the backing member 201. The triangular cavities 702 and the irregular polygon shaped cavities 703 are created at regions proximal to the edges, such as, 204 of the backing member 201. The combination of the cavities 701, 702, and 703 is equally spaced and disposed symmetrically about the central axis X-X’ of the backing member 201. The gap between the cavities 701, 702, and 703 is uniformly maintained across the surface 201a of the backing member 201. The gap between the parallelogram shaped cavities 701 is equal across the surface 201a of the backing member 201. The dimensions of the parallelogram shaped cavities 701, the triangular cavities 702, and the irregular polygon shaped cavities 703 are also maintained uniform throughout the surface 201a of the backing member 201. The cavities 701, 702, and 703 are see-through holes that have a depth equal to the thickness of the backing member 201 to hold the paste. In an embodiment, the cavities 701, 702, and 703 may comprise a supporting member to hold the paste from falling off. Within the dimensions of the rectangular backing member 201, the uniformly distributed parallelogram shaped cavities 701, the triangular cavities 702, and the irregular polygon shaped cavities 703 holding the paste, ensure the mechanical strength of the backing member 201 and also increase the amount of active material available to participate in the reactions of the battery.
[0035] In each of the grid plates 200, 300, 400, 500, 600, 700 exemplarily illustrated in Figs. 2A- 7A, the uniform gap between the cavities has the material of the backing member 201. The material of the backing member 201 is a lead alloy. The uniform distribution of the lead alloy between the cavities and around the edges ensures mechanical strength to the grid plates 200, 300, …, 700. The grid plate 200, 300, …, 700 with the combination cavities is obtained on casting of the material of the backing member 201 in a mould. The mould for different shapes of cavities and different combinations of shapes of the cavities is obtained and the lead alloy is poured in it. On cooling, the cast rectangular backing member 201 with the combination of the two-dimensional shaped cavities is trimmed and the paste is applied in each cavity of the grid plate 200, 300, …, 700. The paste comprises lead sulphate. The grid plate 200, 300, …, 700 with the applied paste is formed to obtain a battery plate with an active material in each cavity. In an embodiment, the paste comprises binding agents for binding particles of the active material. In an embodiment, the same design of the grid plate 200, 300, …, 700 is used to form a battery positive plate and a battery negative plate. The active material used in the battery negative plate is spongy lead and the active material used in the battery positive plate is lead dioxide.
[0036] The positive active material and the negative active material in the cavities participate in the electrochemical reactions in the battery and get discharged during the course of the reaction. The depth of the cavities in the backing member 201 allows expansion of the active material and the uniform distribution of the backing member 201 around the cavities limits the stress experienced by the walls of the cavities due to the expansion of the active material. Due to the expansion of the active material in the cavities of the grid plate 201, sulphate ions from the battery acid find it hard to enter the cavities, thereby decreasing the discharge rate of the grid plate 200, 300, …, 700 and in turn the battery. Also, the depth of the cavities and the distribution density of the cavities across the surface 201a of the backing member 201 ensures more active material is available to participate in the reactions, increasing the utilization capacity of the active material in the grid plates 200, 300, …, 700. In an embodiment, the supporting member in each cavity of each of the grid plates 200, 300,….,700 holds the paste from falling off. In an embodiment, the supporting member may be raised edges of the cavity, protrusions within space of the cavity, etc.
[0037] In an embodiment, a minimum distance of 0.5 millimeter (mm) to 2mm between the cavities 202, 203, 301, 302, 303, 401, 402, 501, 502, 503, 601, 602, 701, 702, 703 in the grid plates 200, 300,….,700 is maintained in order to maintain mechanical strength of the grid plates 200, 300,….,700, depending on the shape of the cavity, so as to obtain increased surface area of the active material in the cavities 202, 203, 301, 302, 303, 401, 402, 501, 502, 503, 601, 602, 701, 702, 703. The dimensions of the rectangular backing member 201 in each of the grid plates 200, 300, 400, 500, 600, and 700 are same as the dimensions, that is, length and breadth of the convention grid plate 100. The surface area of the active material generated on forming of the paste in the grid plates 200, 300,….,700 ranges from about 8000 mm2 to about 12000 mm2. Consider the surface area of the active material in the rectangular slots 102 of the conventional grid plate 100 is A mm2. Relative to the surface area of the active material in the grid plate 100: the surface area of the active material in the cavities 202 and 203 in the grid plate 200 is 1.3A (1.3 times of A) mm2; the surface area of the active material in the cavities 301, 302, and 303 in the grid plate 300 is 1.2A mm2; the surface area of the active material in the cavities 401 and 402 of the grid plate 400 is 1.08A mm2; the surface area of the active material in the cavities 501, 502, 503 of the grid plate 500 is 1.04A mm2; the surface area of the active material in the cavities 601, 602 of the grid plate 600 is 1.04A mm2; and the surface area of the active material in the cavities 701, 702, 703 of the grid plate 700 is 1.03A mm2. In an embodiment, the capacity of the battery plates formed from the grid plates 200, 300,….,700 ranges from about 3.5 Ampere-hour (Ah) to about 5 Ah. In an embodiment, a percentage increase in the capacity of the battery with the grid plates 200, 300,….,700 ranges from 3% to about 35%. Increasing the surface area (mm2) increases the volume (mm3) of the active material of the battery plate, which in turn increases the mass (grams) of active material, with which the capacity (Ah) of the battery plate is increased. This will enhance the utilization capacity, that is, the efficiency of the battery plate in the battery.
[0038] Figs. 8A-8C exemplarily illustrate graphical representations depicting performances of the different embodiments of the grid plates 100, 200, 300, 400, 500, 600, and 700 and performances of the batteries employing the different embodiments of the grid plates 100, 200, 300, 400, 500, 600, and 700 exemplarily illustrated in Figs. 1A-1B (Prior Art) to Figs. 7A-7B. As exemplarily illustrated in Fig. 8A, the grid plate 200 with a combination of the I-shaped cavities 202 and the square shaped cavities 203 has the highest surface area of the active material and the grid plate 700 with a combination of the parallelogram shaped cavities 701, the irregular polygonal cavities 703, and the triangular cavities 702 has the least surface area of the active material. The grid plate 700 is densely packed with porous active material, however, the amount of the active material packed in the I-shaped cavities 202 and the square shaped cavities 203 of the grid plate 200 is higher due to the dimensions of the cavities 202 and 203 in the grid plate 200. The surface area of the active material of the grid plates 300, 400, 500, 600 ranges between the surface areas of the grid plate 200 and 700. Further, the surface areas of the active material in the grid plates 200, 300,…,700 is larger than that of the conventional grid plate 100.
[0039] As exemplarily illustrated in Fig. 8B, the battery plate formed from the grid plate 200 with a combination of the I-shaped cavities 202 and the square shaped cavities 203 has highest capacity attributed to the highest surface area of the active material. The battery plate formed from the grid plate 700 with the combination of the parallelogram shaped cavities 701, the irregular polygonal cavities 703, and the triangular cavities 702 has the least capacity attributed to the surface area of the active material in the grid plate 700. The battery plates formed from the grid plates 300, 400, 500, 600 have capacity ranging between the capacity of the battery plates from the grid plates 200 and 700. Further, the capacity of the battery plates formed from the grid plates 200, 300,…,700 is larger than that of the conventional grid plate 100.
[0040] Fig. 8C exemplarily illustrates the percentage increase in the capacity of the battery employing the grid plates 200, 300, …, 700 with respect to the capacity of the battery employing the conventional grid plate 100. As exemplarily illustrated, the battery employing the grid plate 200 with a combination of the I-shaped cavities and the square shaped cavities shows a higher percentage increase in capacity relative to the battery employing the conventional grid plate 100. Further, the batteries employing the grid plates 200, 300,…,700 show a substantial increase in the battery capacity with respect to the battery employing the conventional grid plate 100.
[0041] Improvements and modifications may be incorporated herein without deviating from the scope of the invention.

LIST OF REFERENCE NUMERALS:

100 Conventional Grid Plate
101 Rods of Lead
102 Rectangular Slots
200 Grid Plate of a First Embodiment of the Present Invention
201 Rectangular Backing Member
201a Surface of the Rectangular Backing Member
202 Square Shaped Cavities
203 I-Shaped Cavities
204 Edge of the Rectangular Backing Member
205 Connecting Lug
300 Grid Plate of a Second Embodiment of the Present Invention
301 Hexagonal Cavities
302 Rhombic Cavities
303 Triangular Cavities
400 Grid Plate of a Third Embodiment of the Present Invention
401 Circular Cavities
402 Oval Cavities
500 Grid Plate of a Fourth Embodiment of the Present Invention
501 Parallelogram Shaped Cavities
502 Triangular Cavities
503 Rectangular Cavities
600 Grid Plate of a Fifth Embodiment of the Present Invention
601 Trapezium Shaped Cavities
602 Inverted Trapezium Shaped Cavities
700 Grid Plate of a Sixth Embodiment of the Present Invention
701 Parallelogram Shaped Cavities
702 Triangular Cavities
703 Irregular Polygonal Cavities