DESC:FIELD OF THE INVENTION
[0001] The present disclosure is generally related to a battery module and more particularly to an isolation layer provided on rechargeable battery cells packed in a battery module for short circuit proofing during manufacturing.
BACKGROUND OF THE INVENTION
[0002] Most lithium ion cells of cylindrical form factor are either resistance spot welded, wire bonded, or laser welded. Of these resistance spot welding is the cheapest and simplest process. However, with resistance spot welding, the cells are usually connected by welding the busbars at the top for the positive and at the bottom for the negative connection. This means that not all the cells in a battery are facing the same direction and are in a ‘flip-flop’ arrangement. Also, busbars are required at bottom of the cell as well as the top to complete the series and parallel connections as shown in Figures 1 and 1A.
[0003] This arrangement reduces thermal performance as heat can only be extracted efficiently from the bottom of the cells. This problem can be solved by welding the busbars at the edge of the cells at the top for negative connection, as the edge of the cell along with the cylindrical surface of the cell is the negative terminal.
[0004] However, doing this increases the risk of a short circuit during welding due the presence of ‘legs’ of the positive tab which are very close to the negative edge of the cell. The metal feeders used to weld the cells’ negative terminal are at a high risk of touching ‘legs’ of the positive tab at the top of the cell.
[0005] Therefore, there is a need of a more efficient mechanism to address this problem in order to provide a safer connection process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The accompanying drawings illustrate various embodiments of systems, methods, and embodiments of various other aspects of the disclosure. Any person with ordinary skills in the art will appreciate that the illustrated element boundaries (e.g. boxes, groups of boxes, or other shapes) in the figures represent one example of the boundaries. It may be that in some examples one element may be designed as multiple elements or that multiple elements may be designed as one element. In some examples, an element shown as an internal component of one element may be implemented as an external component in another, and vice versa. Furthermore, elements may not be drawn to scale. Non-limiting and non-exhaustive descriptions are described with reference to the following drawings. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating principles.
[0007] Fig. 1A and 1B illustrates a diagram of a conventional prior art battery connection;
[0008] Fig. 2A and 2B illustrates a cell arrangement, in accordance with an embodiment of the invention; and
[0009] Fig. 3 illustrates a perspective top view of a cell from the plurality of cells in the battery module, according to an embodiment of the invention.
DETAILED DESCRIPTION
[0010] Embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings in which like numerals represent like elements throughout the several figures, and in which example embodiments are shown. Embodiments of the claims may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. The examples set forth herein are non-limiting examples and are merely examples among other possible examples.
[0011] Some embodiments of this invention, illustrating all its features, will now be discussed in detail. The words “comprising,” “having,” “containing,” and “including,” and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items.
[0012] It must also be noted that as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Although any systems and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present invention, the preferred, systems and methods are now described.
[0013] FIG. 1 illustrates an arrangement 100 in accordance with a conventional art in the technical field. In arrangement 500, multiple Li-ion cells 102-104. It is to be noted that the multiple Li-ion cells 102-104 are arranged in a ‘flip flop’ arrangement that is the Li-ion cells 102-104 are so placed such that series and parallel connections are made as shown in Fig 1A and 1B using busbars 106. 1A depicts a series connection and 1B depicts a parallel connection. For efficient thermal performance, the best way is to extract the heat from the bottom surface of the battery which is not possible in the conventional art.
[0014] Fig. 2, depicts an arrangement 200 that displays a battery module 200A with an efficient manner of positioning a plurality of Li-ion cells 202-204, in accordance with an embodiment of the invention, wherein all the Li-ion cells face upwards to be connected in parallel through positive busbars 208 and negative busbars 210 and in series by busbars 206. Fig. 2A depicts a first surface 201A, a second surface 201B and a cylindrical body 201C which extends from the first surface 201A to the second surface 201B.
[0015] Fig 2A depicts a parallel connection and Fig 2B depicts a series connection. In arrangement 200, the positive electrode of all the cells face upward as shown within the figure. This is made possible by utilizing the edge of the top of the cell which is a part of the negative electrode of the cell.
[0016] Now referring to Fig. 3 depicting a perspective top view of the cell 202. The top part includes a first surface 201A which includes a top plate 302 which is a positive terminal and multiple metal legs 306, as shown in the figure. The metal legs 306, raise the top plate 302 slightly above the first surface. The cell 202 further includes an insulating ring 308 placed to cover a periphery of the plate 302. Further, the cell includes a top negative edge 304. In an embodiment of the invention, positive terminal i.e. the top plate 302 and the metal legs 304 are disposed towards the interior of the first surface 201A whereas the negative terminal 304 is disposed on an edge of the first surface 201A. As shown in the figure, the top plate 302 of the cell 202 is completely covered from periphery such that the legs 306 are completely under the insulating ring 308, wherein the periphery is proximate to the negative terminal 304. According to an embodiment of the invention, the insulating ring 308 may be made up of any insulating material like plastic, foam etc. Due to this arrangement, the tab 310 may be welded or bonded to the top negative edge 304 without any concern of short circuits which are possible due to dimensional and manufacturing variations. The metal tab 310 may be of nickel in accordance with an embodiment of the invention. However, any other metal may also be used. This metal tab 310, may be utilized for connecting the cell 202 with other adjacent cells. In an embodiment of the present inventions, the metal tabs 310 in plurality of cells are connected through a printed circuit board having conductive traces. The printed circuit board is placed on top on the cells such that the conductive traces are in contact with the metal tabs in adjacent cells thereby establishing electrical connection between cells. In another embodiment, the metal tab 310 may be a bus bar that is directly welded on to adjacent cells to provide electrical connection. The positive terminal of the cells are interconnected by a busbar or a positive side metal tab 208 welded on to the top plate 302.
[0017] According to another embodiment of the invention, an insulating cover for battery arrangement may include multiple insulating rings like in form of a mesh wherein each of the insulating rings \. It is to be noted that the mesh can be placed over battery arrangement to isolate top part of battery completely.
[0018] According to another embodiment of the invention a network of interconnected insulating rings could be used to cover multiple cells and may be used to selectively identify only those points that are required to make connections.
[0019] Such an arrangement helps in good heat dissipation which is conducted through the second surface 201B. In an embodiment of the present invention, a heat exchange medium/coolant is passed over the second surface 201B to dissipate the heat.
[0020] Moreover, although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one will readily appreciate from the disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.
,CLAIMS:1. A battery module, comprising:
a plurality of cells wherein each cell of the plurality of cells includes:
a first surface;
a second surface; and
a cylindrical body extending from the first surface to the second surface, wherein the first surface includes:
an internally disposed positive terminal;
an outwardly disposed negative terminal defined by an edge of the first surface; and
an insulation ring disposed on top of the positive terminal configured to cover peripheral surface of the positive terminal wherein the peripheral surface is proximate to the negative terminal.

2. The battery module as claimed in claim 1, further includes a plurality of metal legs on the periphery of positive terminal, and the insulation ring is disposed on the plurality of metal legs, wherein the plurality of metal tags raise the positive terminal to a certain height above the first surface.

3. The battery module as claimed in claim 1, wherein at least one metal tab is connected to the negative terminal on the first surface.

4. The battery module as claimed in claim 3, wherein the at least one metal tab is welded on to the negative terminal on the first surface.

5. The battery module as claimed in claim 3, wherein the at least one metal tab is configured to provide connection with a plurality of adjacent cells.

6. The battery module as claimed in claim 1, wherein the insulating ring is in the shape of a circle and made up of anyone of a plastic, rubber, foam, or fiber or a combination thereof.

7. The battery module as claimed in claim 1, wherein the insulating ring is in the form of a mesh of rings configured to be placed on the plurality of cells.

8. The battery module as claimed in claim 1, wherein the plurality of cells are connected in series or in parallel configuration.

9. The battery module as claimed in claim 1, wherein heat dissipation is conducted through the second surface.

10. The battery module as claimed in claim 9, wherein the heat dissipation is through a heat exchange medium.