Description:FIELD
The present disclosure generally relates to the field of battery cells and their terminal assemblies.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
For a battery cell such as a cylindrical or prismatic type battery cell or even any other type of battery cells, secure and efficient electrical connections are essential to maintain reliability and performance. Traditional single-part crimped terminals, often used to connect current collector disks, present limitations in contact area with the disk, leading to increased direct current internal resistance (DCIR) and localized Joule heating, particularly during high-rate discharges. This heating not only reduces the efficiency of the system but can also cause damage or instability in high-power applications. Efforts to increase the contact area by enlarging the crimping region have encountered drawbacks, such as mechanical instability at the crimping zone and difficulties in maintaining a flat contact surface.
Therefore, there is felt a need for a two-part terminal assembly that alleviates the aforementioned drawbacks.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
An object of the present disclosure is to provide a two-part terminal assembly for a secondary battery cell.
Another object of the present disclosure is to provide a two-part terminal assembly which provides relatively enhanced electrical contact with the current collector system.
Yet another object of the present disclosure is to provide a two-part terminal assembly which significantly reduces Joule heating.
Still another object of the present disclosure is to provide a two-part terminal assembly which has a relatively improved mechanical stability.
A further object of the present disclosure is to provide a two-part terminal assembly which is easy to assemble.
Other objects and advantages of the present disclosure will be more apparent from the following description when read in conjunction with the accompanying figures, which are not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages a two-part terminal assembly for a secondary battery cell having a housing defining a first end and a second end and a jelly roll configured to be contained in the housing. The terminal assembly comprises a first terminal part having an inclined opening configured at an operative upper portion of the first end of the housing, and a hollow cylindrical body with a sealing rim disposed at an operative lower portion of the first end of the housing. The terminal assembly further comprises a second terminal part having a flange resting at the operative upper part of the first end of the housing, and a hollow cylindrical body having its operative lower portion connected to the upper surface of said sealing rim.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
A two-part terminal assembly, of the present disclosure, for a secondary battery cell will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates an isometric view of the two-part terminal assembly of the system of the present disclosure, provided on a can of the battery cell;
Figure 2 illustrates an isometric cross-sectional view of the terminal assembly of Figure 1;
Figure 3 illustrates a cross-sectional view of the terminal assembly of Figure 2;
Figure 4A and Figure 4B illustrate engineering drawings of the terminal assembly of Figure 2.
LIST OF REFERENCE NUMERALS
10 housing
100 terminal assembly
105 first terminal part
107 first cylindrical hollow body
109 inclined opening
111 sealing rim
115 second terminal part
116 second cylindrical body
118 flange
120 gasket
121 insulator

DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open-ended transitional phrases and therefore specify the presence of stated features, elements, modules, units, and/or components, but do not forbid the presence or addition of one or more other features, elements, components, and/or groups thereof.
A two-part terminal assembly (100), of the present disclosure, for a secondary battery cell will now be described in detail with reference to Figure 1 through Figure 4B.
The secondary battery cell has a housing defining a first end and a second end and a jelly roll configured to be contained in the housing. The terminal assembly (100) comprises a first terminal part (105) and a second terminal part (115). The first terminal part (105) has an inclined opening (109) configured at an operative upper portion of the first end of the housing. The first terminal part (105) further has a hollow cylindrical body (107) with a sealing rim (111) disposed at an operative lower portion of the first end of the housing.
The second terminal part (115) has a flange (118) resting at the operative upper part of the first end of the housing. The flange (118) is configured to allow the accommodation of the bus bar connection thereon. In an embodiment, the surface of the flange (111) which is contact with the current collector disc has a relatively higher surface finish.
The second terminal part (115) further comprises a hollow cylindrical body (116) having its operative lower portion connected to the upper surface of the sealing rim (111). The contact of the sealing rim (111) with the current collector disc gives the advantage of a relatively maximized area of contact, therby enhanching electrical conductivity of the terminal assembly (100).
In an embodiment, the assembly helps in achieving around 4-5 times more area when compared to the conventional assemblies. The terminal assembly (100) further helps in achieving approximately 25-30% reduction in Joule heating.
In an embodiment, the angle of the inclined opening (109) ranges from 30° to 70°. When the angle is kept between this range the flaring process provides the crimping force, as a result of which the surface contact between the two terminal parts increases. In an embodiment, the widest diameter (D) of the inclined opening (109) ranges from 10 mm to 12 mm.
In another embodiment, the diameter of the sealing rim (111) is 3/4th the diameter of the jelly roll. In yet another embodiment, the overall diameter of the terminal assembly (100) is 12 to 26 mm.
In one embodiment, an operative lower part of the first terminal part (105) has a width which is 40 to 80% of the cell diameter. In another embodiment, the width of the upper flange (118) of the second terminal part (115) ranges between 3 to 7 mm.
In still another embodiment, the first terminal part (105) and the second terminal part (115) are connected to each other by flaring process or clinching process. In an embodiment, the thickness of the flare/clinch ranges between 1.75 mm to 2.75 mm.
In an embodiment, the second terminal part (115) includes a sealing gasket (120) disposed between the operative upper portion of the first end of the housing and the flange (118).
In yet another embodiment, the thickness of the first terminal part (105) is smaller than that of the second terminal part (115). The first terminal part (105) is kept at a lower/lesser thickness (0.4 to 2 mm) to enable the flaring process to be easier. However, the thickness of the second terminal part (115) is kept higher/more (3 - 6mm) than the first terminal part (105) so that it will not transmit the crimping load to the sealing gasket (120) during flaring process.
In another embodiment, the first terminal end is connected to the second terminal part (115) by welding. Typically, the first terminal end is connected to the second terminal part (115) by laser welding. In an embodiment, the thickness of the region (C) available for laser welding with the current collector disk to ensure the current collector does not move in any direction and remains firmly in contact with the flange (118) ranges between 6 mm and 8 mm.
In yet another embodiment, the second terminal part (115) includes a stepped portion which has a preformed configuration, or can be formed during the assembly. The step is provided so that there is a uniform flat surface available at the rim (111) for the bus bar connection. Since both the terminal parts are welded together, the uniformity in the flatness after welding could be lost. Hence it is necessary to provide the stepped portion. In another embodiment, the thickness of the step (A) ranges from 0.15 mm to 0.25 mm.
In still another embodiment, the stepped portion of the second terminal part (115) and an operative edge of the inclined opening (109) of the first terminal part (105) are coplanar.
In a further still embodiment, the terminal assembly (100) includes an insulator (121) provided between an operative lower part of the first end and the sealing rim (111). In another embodiment, the insulator (121) is of liquid crystal polymers (LCP), polypropylene (PP), PPS (polyphenylene sulphide), polybutylene terephthalate (PBT), polyethylene terephthalate (PET).
The terminal assembly (100) provides several technical advantages that are as follows:
• Enhanced Electrical Contact: The larger, flat contact surface of the first terminal part (105) increases the effective contact area with the current collector disk. This enhanced contact area minimizes direct current internal resistance (DCIR), reducing energy loss and improving conductivity;
• Reduced Joule Heating: By distributing electrical current over a broader contact surface, the assembly reduces localized heating (Joule heating) by approximately 25% at high discharge rates. This reduction in heating improves the safety, efficiency, and lifespan of battery systems or other high-power applications;
• Improved Mechanical Stability: The two-part design uses a clinching or flaring operation to create a strong mechanical interlock, complemented by a laser weld at the joining edge. This results in a secure and stable connection that withstands mechanical stresses and vibrations, essential for durability in demanding environments;
• Maintenance of Flatness: Unlike crimped single terminals, which can deform and lose flatness at the contact surface, the two-part terminal maintains a stable, flat configuration. This feature ensures consistent and reliable contact with the current collector disk, further reducing resistance and improving overall performance;
• Customizable Design Flexibility: The bottom part of the second terminal part (115) can be adapted to match various current collector disk designs, offering design flexibility to meet specific application requirements. The laser weld adds an extra layer of customizability for different structural needs and operational conditions; and
• Ease of Assembly: The two-part terminal with interference fit and clinching offers easier assembly with secure interlocking, which can simplify manufacturing processes and reduce the potential for assembly errors.
These advantages collectively support higher performance, greater efficiency, and improved durability in electronic and battery systems, particularly in high-discharge or high-stress environments where energy management and reliability are critical.
The present disclosure envisages a secondary battery cell comprising a housing defining a first end provided with a through hole and a second end provided with an open surface. A jelly roll is configured to be contained in the housing. A first electrode plate is electrically coupled to the jelly roll at one end of the jelly roll. The secondary battery cell further comprises a current collector unit having a two-part terminal assembly (100) comprising a first terminal part (105) having an inclined opening (109) configured at an operative upper portion of the first end of the housing, and a hollow cylindrical body (107) with a sealing rim (111) disposed at an operative lower portion of the first end of the housing. The terminal assembly (100) further comprises a second terminal part (115) having a flange (118) resting at the operative upper part of the first end of the housing, and a hollow cylindrical body (116) having its operative lower portion connected to the upper surface of the sealing rim (111).
In an embodiment, the secondary battery has a prismatic configuration or a cylindrical configuration.
The secondary battery cell provided with the system is configured to be employed to cater to varied current loads or custom battery configurations, specifically high-stress applications, ensuring durability in battery cells exposed to high discharge cycles, heavy mechanical load, or vibration, thus making it especially suitable for automotive, aerospace, and industrial applications where performance and reliability are crucial.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE
The present disclosure described herein above has several technical advantages including, but not limited to a two-part terminal assembly for a secondary battery cell, that:
• provides relatively enhanced electrical contact of the terminal assembly with the current collector system;
• reduces Joule heating significantly, leading to decreased electrical resistance;
• has a relatively improved mechanical sealability & stability; and
• is easy to be assembled.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveals the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, or group of elements, but not the exclusion of any other element, or group of elements.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.
, Claims:WE CLAIM:
1. A two-part terminal assembly (100) for a secondary battery cell having a housing defining a first end and a second end and a jelly roll configured to be contained in the housing, said terminal assembly (100) comprising:
• a first terminal part (105) having:
o an inclined opening (109) configured at an operative upper portion of the first end of the housing,
o a hollow cylindrical body (107) with a sealing rim (111) disposed at an operative lower portion of the first end of the housing;
• a second terminal part (115) having a flange (118) resting at the operative upper part of the first end of the housing, and a hollow cylindrical body (116) having its operative lower portion connected to the upper surface of said sealing rim (111).
2. The two-part terminal assembly (100) as claimed in claim 1, wherein the angle of said inclined opening (109) ranges from 30° to 70°.
3. The two-part terminal assembly (100) as claimed in claim 1, wherein the diameter of said sealing rim (111) is 3/4th the diameter of the jelly roll.
4. The two-part terminal assembly (100) as claimed in claim 1, wherein said first terminal part (105) and said second terminal part (115) are connected to each other by flaring process or clinching process.
5. The two-part terminal assembly (100) as claimed in claim 1, wherein said second terminal part (115) includes a sealing gasket (120) disposed between said operative upper portion of the first end of the housing and said flange (118).
6. The two-part terminal assembly (100) as claimed in claim 1, wherein said first terminal end is connected to the second terminal part (115) by welding.
7. The two-part terminal assembly (100) as claimed in claim 1, wherein said second terminal part (115) includes a stepped portion which has a preformed configuration, or can be formed during the assembly.
8. The two-part terminal assembly (100) as claimed in claim 1, wherein said stepped portion of the second terminal part (115) and an operative edge of said inclined opening (109) of the first terminal part (105) are coplanar.
9. The two-part terminal assembly (100) as claimed in claim 1, which includes an insulator (121) provided between an operative lower part of the first end and said sealing rim (111).
10. A secondary battery cell comprising:
• a housing defining a first end provided with a through hole and a second end provided with an open surface;
• a jelly roll configured to be contained in the housing;
• a first electrode plate electrically coupled to the jelly roll at one end of the jelly roll;
• a current collector unit comprising a two-part terminal assembly (100) comprising:
o a first terminal part (105) having:
 an inclined opening (109) configured at an operative upper portion of the first end of the housing,
 a hollow cylindrical body (107) with a sealing rim (111) disposed at an operative lower portion of the first end of the housing;
o a second terminal part (115) having a flange (118) resting at the operative upper part of the first end of the housing, and a hollow cylindrical body (116) having its operative lower portion connected to the upper surface of said sealing rim (111).
11. The secondary battery as claimed in claim 10, wherein the secondary battery has a prismatic configuration or a cylindrical configuration.

Dated this 12th day of December, 2024

_______________________________
MOHAN RAJKUMAR DEWAN, IN/PA – 25
OF R. K. DEWAN & CO.
AUTHORIZED AGENT OF APPLICANT

TO,
THE CONTROLLER OF PATENTS
THE PATENT OFFICE, CHENNAI