Description:TECHNICAL FIELD
[001] The embodiments herein generally relate to battery and more particularly to a battery cell jelly roll with a reinforcement assembly for reinforcing the battery cell jelly roll.
BACKGROUND
[002] Generally, a cylindrical battery cell includes a cylindrical metal can, usually made of steel or aluminum, which serves as both the container and one of the electrodes (typically the negative terminal) of the cylindrical battery cell. An electrode assembly in the form of a jelly-roll configuration is formed by tightly winding the positive and negative electrodes (anode and cathode) with a separator in between, is placed inside the cylindrical metal can. An electrolyte is introduced in the jelly roll, which enables the movement of ions between the electrodes during charge and discharge cycles. The separator which is made from a microporous polymer keeps the two electrodes from touching while allowing the flow of ions. The cylindrical battery cell further includes current collectors which are connected to the electrodes to ensure efficient electron flow in and out of the cylindrical battery cell.
[003] Generally, in cylindrical battery cells, over a period of use, mechanical or thermal stress may affect a core of the electrode assembly, particularly the innermost layers of the jelly roll. The stress may arise during various stages of the battery’s life cycle, including manufacturing, charging, discharging, or from external factors like temperature fluctuations. The inner layers of the jelly roll tend to experience greater pressure compared to the outer layers due to the winding tension during assembly and the expansion of materials inside the cell during operation. Over time, this pressure can deform the separator, compromise the insulation between the electrodes, or cause the electrodes to come into contact. This internal short circuit can result in localized heating, degradation of cell materials, and in extreme cases, thermal runaway, where the battery heats uncontrollably, leading to possible rupture or even explosion. The deformation of the jelly roll at the core is further intensified under high power operations, rapid charging, or discharging, where the thermal stress is significantly higher, further straining the inner components.
[004] Further, the deformation of the jelly roll at the core is also called core collapse which compromises the safety, performance, and longevity of the battery. One of the primary problems is thermal instability, where increased internal resistance due to the impingement of the core causes localized heating, which can initiate further thermal breakdown of the electrolyte. This not only reduces the battery's efficiency but also poses significant safety risks. Another issue is capacity fade, where the battery’s ability to hold a charge diminishes over time as the impingement of the core leads to irreversible chemical changes in the electrodes. Mechanical deformation of the internal layers can also cause premature aging of the cell, increasing the likelihood of electrical shorts and reducing the overall lifespan of the battery. In high-energy applications like electric vehicles or grid storage systems, core impingement can lead to costly failures, necessitating more frequent battery replacements or complex battery management systems (BMS) to monitor and mitigate such risks.
[005] Conventional solutions for mitigating core impingement includes modifying the winding tension during the jelly roll assembly to reduce the mechanical stress on the inner layers. While this can alleviate the issue to some extent, it often results in a trade-off between energy density and mechanical stability. Another solution is the use of advanced separators with higher thermal and mechanical durability, which can withstand the internal pressures and prevent shorts even under severe conditions. However, these separators tend to be more expensive and may still degrade over time, particularly in high-temperature environments. Some cells use pressure-relief mechanisms, such as vents or tabs that release excess pressure before it can cause internal damage. While this is effective in preventing catastrophic failure, these pressure-relief mechanisms are ineffective in mitigating core impingement and may lead to reduced energy efficiency or increased complexity in battery design.
[006] Therefore, there exists a need for a reinforced battery cell jelly roll which obviates the aforementioned drawbacks.
OBJECTS
[007] The principal object of embodiments herein is to provide a battery cell jelly roll with a reinforcement assembly for reinforcing the battery cell jelly roll.
[008] Another object of embodiments herein is to prevent deformation of the battery cell jelly roll in a direction towards a core of the battery cell jelly roll.
[009] Another object of embodiments herein is to enhance the performance and lifetime of the battery cell jelly roll.
[0010] Another object of embodiments herein is to provide the battery cell jelly roll which is durable and is easy to manufacture.
[0011] Another object of embodiments herein is to increase the safety of the battery cell jelly roll.
[0012] These and other objects of embodiments herein will be better appreciated and understood when considered in conjunction with following description and accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF DRAWINGS
[0013] The embodiments are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0014] Fig. 1 depicts an exploded view of a battery cell jelly roll with a reinforcement assembly, according to embodiments as disclosed herein;
[0015] Fig. 2 depicts sectional view of the battery cell jelly roll, according to embodiments as disclosed herein;
[0016] Fig. 3 depicts another exploded view of the battery cell jelly roll, according to embodiments as disclosed herein;
[0017] Fig. 4 depicts another sectional view of the battery cell jelly roll, according to embodiments as disclosed herein;
[0018] Fig. 5 depicts a perspective view of the reinforcement assembly of the battery cell jelly roll, according to embodiments as disclosed herein;
[0019] Fig. 6 depicts a perspective view of a reinforcement bush of the reinforcement assembly, according to embodiments as disclosed herein; and
[0020] Fig. 7 depicts a flowchart indicating steps of a method of reinforcing the battery cell jelly roll, according to embodiments as disclosed herein.
DETAILED DESCRIPTION
[0021] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and 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.
[0022] The embodiments herein achieve battery cell jelly roll with a reinforcement assembly for reinforcing the battery cell jelly roll thereby preventing deformation of the battery cell jelly roll in a direction towards its core. Further embodiments herein achieve the battery cell jelly roll which is durable and is easy to manufacture. Referring now to Figs. 1 to 7, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0023] Fig. 1 depicts an exploded view of a battery cell jelly roll (10) with a reinforcement assembly (100), according to embodiments as disclosed herein. Fig. 2 depicts sectional view of the battery cell jelly roll (10), according to embodiments as disclosed herein. In an embodiment, the battery cell jelly roll (10) includes a reinforcement assembly (100), at least one positive electrode (200) (anode), at least one negative electrode (300) (cathode) and at least one separator (400) (as shown in figs. 1 to 4). For the purpose of this description and ease of understanding, the battery cell jelly roll (10) is explained herein with below reference to be provided in a cylindrical battery cell. The separator (400) is disposed between the positive electrode (200) and the negative electrode (300). The positive electrode (200), the negative electrode (300) and the separator (400) are stacked upon each other and wounded to form a core (10C) (as shown in fig. 3) at a center of the battery cell jelly roll (10).
[0024] Fig. 5 depicts a perspective view of the reinforcement assembly (100) of the battery cell jelly roll (10), according to embodiments as disclosed herein. In an embodiment, the reinforcement assembly (100) is adapted to reinforce the battery cell jelly roll (10) thereby preventing deformation of the battery cell jelly roll (10) in a direction towards its core (10C). The reinforcement assembly (100) is adapted to be disposed inside the core (10C) of the battery cell jelly roll (10). In an embodiment, the reinforcement assembly (100) includes a first reinforcement member (102A), a second reinforcement member (102B) and a plurality of reinforcement bushes (104, 106). The first and second reinforcement members (102A, 102B) are adapted to be disposed in the battery cell jelly roll (10) at its core (10C). The first and second reinforcement members (102A, 102B) extend along an axial direction between a first end (10F) and a second end (10S) (as shown in fig. 2) of the battery cell jelly roll (10). The plurality of reinforcement bushes (104, 106) are adapted to be secured with the first and second reinforcement members (102A, 102B). The first and second reinforcement members (102A, 102B) and the reinforcement bushes (104, 106) are adapted to reinforce the battery cell jelly roll (10) thereby restricting deformation of the battery cell jelly roll (10) in a direction towards its core. Each reinforcement bush (104, 106) is adapted to be disposed between the first and the second reinforcement members (102A, 102B) at its corresponding end (102Y, 102Z) (as shown in fig. 5).
[0025] Fig. 6 depicts a perspective view of a reinforcement bush (104, 106) of the reinforcement assembly (100), according to embodiments as disclosed herein. Each reinforcement bush (104, 106) includes a hollow main body (104A, 106A), a collar (104B, 106B) and a pair of locking protrusions (104C, 106C) (only one of which is shown in figs. 5 and 6). The hollow main body (104A, 106A) of each reinforcement bush (104, 106) is adapted to be received by the first and second reinforcement members (102A, 102B). The collar (104B, 106B) of each reinforcement bush (104, 106) extends outwardly from the hollow main body (104A, 106A). The hollow main body (104A, 106A) of each reinforcement bush (104, 106) is tapered inwards in a direction towards a central axis of the hollow main body (104A, 106A). The collar (104B, 106B) of each reinforcement bush (104, 106) is engaged with corresponding end (102Y, 102Z) of the first and second reinforcement members (102A, 102B). The locking protrusions (104C, 106C) of each reinforcement bush (104, 106) are provided on the collar (104B, 106B) at its sides. The locking protrusions (104C, 106C) of each reinforcement bush (104, 106) are adapted to facilitate locking of the first and second reinforcement members (102A, 102B) with the reinforcement bush (104, 106) thereby retaining the first and second reinforcement members (102A, 102B) in its position. Each locking protrusion (104C, 106C) of each reinforcement bush (104, 106) is located between corresponding side of the first and second reinforcement members (102A, 102B) at its corresponding end (102Y, 102Z). The first and second reinforcement members (102A, 102B) and the locking protrusions of the reinforcement bushes (104, 106) defines a clearance (102C) (as shown in fig. 5) therebetween at its both sides. The hollow main body (104A) of corresponding reinforcement bush (104) is adapted to allow electrolyte flow therein to facilitate uniform flow of electrolyte to the core (10C) during an electrolyte filling process. The clearance (102C) defined at both sides of the first and second reinforcement members (102A, 102B) and the reinforcement bushes (104, 106) is adapted to facilitate electrolyte flow into the jelly roll (100) during the electrolyte filling process. The plurality of reinforcement bushes (104, 106) includes a first reinforcement bush (104) and a second reinforcement bush (106). The first reinforcement bush (104) is adapted to be disposed between the first and the second reinforcement members (102A, 102B) at its top end (102Y). The second reinforcement bush (104) is adapted to be disposed between the first and the second reinforcement members (102A, 102B) at its bottom end (102Z). The first and second reinforcement bushes (104, 106) are adapted to reinforce the first and second reinforcement members (102A, 102B).
[0026] The first and second reinforcement members (102A, 102B) are not in contact with each other such that first and second reinforcement members (102A, 102B) are locked against the locking protrusions (104C, 106C) of the reinforcement bushes (104, 106). The first and second reinforcement members (102A, 102B) extends along a lengthwise direction of the battery cell jelly roll (10). The first reinforcement member (102A) defines a hollow half cylinder shape. Further, the second reinforcement member (102B) defines a hollow half cylinder shape. Each of the reinforcement member (102A, 102B) and each of the reinforcement bush (104, 1060 are made of non-metallic material selected from one of a first group consisting of polypropylene, polyethylene, polyethylene terephthalate and polyimide, and a second group consisting of low density polyethylene and polypropylene.
[0027] For the purpose of this description and ease of understanding, the battery cell jelly roll (10) and the sizes of the components of the battery cell jelly roll (10) is considered herein with respect to a large format cylindrical battery cell such as 4680 battery. However, it is also within the scope of the invention to consider the battery cell jelly roll (100) to be provided in any other sizes and configurations of the cylindrical battery cell. A length of each of the first and second reinforcement member (102A, 102B) is 70 to 75 mm. A radius of each of the first and second reinforcement member (102A, 102B) is 3.25±0.1 mm. A wall thickness of each of the first and second reinforcement member (102A, 102B) is 0.83±0.05 mm. The clearance (102C) between the first and second reinforcement members (102A, 102B) at its each side is 0.5±0.1 mm. A length of each reinforcement bush is 8±0.1 mm. An outer radius of the hollow main body (104A, 106A) of each reinforcement bush (104, 106) is 2.4±0.05 mm. An inner radius of the hollow main body (104A, 106A) of each reinforcement bush (104, 106) is 1.5±0.05 mm. A thickness of the collar (104B, 106B) of each reinforcement bush (104, 106) is 1.5±0.05 mm. A radius of the collar (104B, 106B) of each reinforcement bush (104, 106) is 3.25±0.05 mm.
[0028] Fig. 7 depicts a flowchart indicating steps of a method (500) of reinforcing the battery cell jelly roll (100), according to embodiments as disclosed herein. At step (502), the method (500) includes inserting a first reinforcement member (102A) into the battery cell jelly roll (10) at its core (10C). At step (504), the method (500) includes inserting a second reinforcement member (102B) into the battery cell jelly roll (10) at its core (10C) in which the second reinforcement member (102B) is facing the first reinforcement member (102A). At step (506), the method (500) includes inserting a first reinforcement bush (104) between the first and second reinforcement members (102A, 102B) at its top end (102Y). At step (508), the method (500) includes inserting a second reinforcement bush (106) between the first and second reinforcement members (102A, 102B) at its bottom end (102Z).
[0029] The technical advantages of the battery cell jelly roll (10) are as follows. The battery cell jelly roll (10) with the reinforcement assembly (100) prevents deformation of the battery cell jelly roll (10) in a direction towards a core (10C) of the battery cell jelly roll (10). The reinforcing assembly is easy to manufacture and includes two parts which are easy to insert inside the core of the jelly roll. The reinforcement assembly (100) enhances the performance and lifetime of the battery cell jelly roll (10) as well as increases the safety of the battery cell jelly roll (10).
[0030] The reinforcement assembly (100) is designed in such a way that the diameter of the reinforcement assembly (100) is equal to or slightly greater than the diameter of the jelly roll core. This will prevent core collapse during charge and discharge as the reinforcing members (102A, 102B) are fitted tightly inside the core (10C). As the reinforcing members (102A, 102B) is in a split tube structure, the reinforcing members (102A, 102B) can be squeezed and fit inside the core (10C).
[0031] The foregoing description of the specific embodiments will so fully reveal 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 embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modifications within the spirit and scope of the embodiments as described herein.
, Claims:We claim:
1. A battery cell jelly roll (10) comprising:
at least one positive electrode (200);
at least one negative electrode (300);
at least one separator (400) disposed between the positive electrode (200) and the negative electrode (300), wherein the positive electrode (200), the negative electrode (300) and the separator (400) are stacked upon each other and wounded to form a core (10C) at a center of the battery cell jelly roll (10); and
a reinforcement assembly (100) adapted to be disposed inside the core (10C) of the battery cell jelly roll (10), wherein the reinforcement assembly (100) includes:
a first reinforcement member (102A) and a second reinforcement member (102B) adapted to be disposed in the battery cell jelly roll (10) at its core (10C), wherein the first and second reinforcement members (102A, 102B) extend along an axial direction between a first end (10F) and a second end (10S) of the battery cell jelly roll (10); and
a plurality of reinforcement bushes (104, 106) adapted to be secured with the first and second reinforcement members (102A, 102B),
wherein
the first and second reinforcement members (102A, 102B) and the reinforcement bushes (104, 106) are adapted to reinforce the battery cell jelly roll (10).
2. The battery cell jelly roll (10) as claimed in claim 1, wherein each of the reinforcement bush (104, 106) is adapted to be disposed between the first and the second reinforcement members (102A, 102B) at its corresponding end (102Y, 102Z).
3. The battery cell jelly roll (10) as claimed in claim 1, wherein each of the reinforcement bush (104, 106) includes:
a hollow main body (104A, 106A) adapted to be received by the first and second reinforcement members (102A, 102B);
a collar (104B, 106B) extending outwardly from the hollow main body (104A, 106A), wherein the collar (104B, 106B) is engaged with corresponding end (102Y, 102Z) of the first and second reinforcement members (102A, 102B); and
a pair of locking protrusions (104C, 106C) provided on the collar (104B, 106B) at its sides, wherein the locking protrusions (104C, 106C) are adapted to facilitate locking of the first and second reinforcement members (102A, 102B) with the reinforcement bush (104, 106) thereby retaining the first and second reinforcement members (102A, 102B) in its position.
4. The battery cell jelly roll (10) as claimed in claim 3, wherein the hollow main body (104A, 106A) of each of the reinforcement bush (104, 106) is tapered inwards in a direction towards a central axis of the hollow main body (104A, 106A);
the first and second reinforcement members (102A, 102B) and the locking protrusions of the reinforcement bushes (104, 106) defines a clearance (102C) therebetween at its both sides;
each locking protrusion (104C, 106C) of each reinforcement bush (104, 106) is located between corresponding side of the first and second reinforcement members (102A, 102B) at its corresponding end (102Y, 102Z);
the hollow main body (104A) of corresponding reinforcement bush (104) is adapted to allow electrolyte flow therein to facilitate uniform flow of electrolyte to the core (10C) during an electrolyte filling process; and
the clearance (102C) defined at both sides of the first and second reinforcement members (102A, 102B) and the reinforcement bushes (104, 106) is adapted to facilitate electrolyte flow into the jelly roll (100) during the electrolyte filling process.
5. The battery cell jelly roll (10) as claimed in claim 1, wherein the first and second reinforcement members (102A, 102B) are not in contact with each other such that first and second reinforcement members (102A, 102B) are locked against the locking protrusions (104C, 106C) of the reinforcement bushes (104, 106);
the first and second reinforcement members (102A, 102B) extends along a lengthwise direction of the battery cell jelly roll (10); and
the first and second reinforcement members (102A, 102B) and the reinforcement bushes (104, 106) are adapted to be restrict deformation of the battery cell jelly roll (10) in a direction towards its core (10C).
6. The battery cell jelly roll (10) as claimed in claim 1, wherein the plurality of reinforcement bushes (104, 106) includes:
a first reinforcement bush (104) adapted to be disposed between the first and the second reinforcement members (102A, 102B) at its top end (102Y); and
a second reinforcement bush (106) adapted to be disposed between the first and the second reinforcement members (102A, 102B) at its bottom end (102Z),
wherein
the first and second reinforcement bushes (104, 106) are adapted to reinforce the first and second reinforcement members (102A, 102B).
7. The battery cell jelly roll (10) as claimed in claim 1, wherein the first reinforcement member (102A) defines a hollow half cylinder shape; and
the second reinforcement member (102B) defines a hollow half cylinder shape; and
each of the reinforcement member (102A, 102B) and each of the reinforcement bush (104, 1060 are made of non-metallic material selected from one of a first group consisting of polypropylene, polyethylene, polyethylene terephthalate and polyimide, and a second group consisting of low density polyethylene and polypropylene.
8. The battery cell jelly roll (10) as claimed in claim 1, wherein a length of each of the first and second reinforcement member (102A, 102B) is 70 to 75 mm;
a radius of each of the first and second reinforcement member (102A, 102B) is 3.25±0.1 mm;
a wall thickness of each of the first and second reinforcement member (102A, 102B) is 0.83±0.05 mm; and
the clearance (102C) between the first and second reinforcement members (102A, 102B) at its each side is 0.5±0.1 mm.
9. The battery cell jelly roll (10) as claimed in claim 1, wherein a length of each reinforcement bush is 8±0.1 mm;
an outer radius of the hollow main body (104A, 106A) of each reinforcement bush (104, 106) is 2.4±0.05 mm;
an inner radius of the hollow main body (104A, 106A) of each reinforcement bush (104, 106) is 1.5±0.05 mm;
a thickness of the collar (104B, 106B) of each reinforcement bush (104, 106) is 1.5±0.05 mm; and
a radius of the collar (104B, 106B) of each reinforcement bush (104, 106) is 3.25±0.05 mm.
10. A method (500) of reinforcing a battery cell jelly roll (10), the method (500) comprising:
inserting a first reinforcement member (102A) into the battery cell jelly roll (10) at its core (10C);
inserting a second reinforcement member (102B) into the battery cell jelly roll (10) at its core (10C) in which the second reinforcement member (102B) is facing the first reinforcement member (102A);
inserting a first reinforcement bush (104) between the first and second reinforcement members (102A, 102B) at its top end (102Y); and
inserting a second reinforcement bush (106) between the first and second reinforcement members (102A, 102B) at its bottom end (102Z),
wherein
the first and second reinforcement members (102A, 102B) and the reinforcement bushes (104, 106) are adapted to reinforce the battery cell jelly roll (10); and
the reinforcement bushes (104, 106) are adapted to facilitate locking of the first and second reinforcement members (102A, 102B) therewith to retain first and second reinforcement members (102A, 102B) in its position.