Novel lithium ion battery structure

Abstract

The utility model discloses a novel lithium ion battery structure and belongs to the technical field of lithium batteries. The battery comprises a cover plate assembly and a battery cell, the battery cell comprises a roll core and tabs connected with the roll core, and each tab is divided into at least one tab cluster; the cover plate assembly comprises a substrate and a pole; at least one through hole is formed in the pole; the battery cell is located on the inner side of the substrate, and the tab cluster penetrates through a through hole in the pole from the inner side of the pole to the outer side of the pole and is bent to a pole platform of the pole to be directly connected with the pole. According to the novel lithium ion battery structure provided in the scheme, the tab cluster is bent, and the tab cluster penetrates through the pole to be bent to the pole platform to be connected with the pole platform in a welded mode, so that the space occupied by bending of thick and large tabs is reduced, and the problem that the thick and large tabs are difficult to bend is solved. Meanwhile, a connecting piece structure is omitted, and the tabs are directly connected with the pole columns, so that the physical impedance of the battery is greatly reduced, and the over-current capability of the battery cell is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium - ion batteries, and more specifically, to a new structure of lithium - ion battery. Background Art

[0002] Lithium - ion batteries are a commonly used secondary battery, which have the characteristics of high energy density, no memory effect, long single - cycle life, high efficiency, cleanliness and no pollution, and are widely used in the new energy field, such as new - energy electric vehicles, etc. With the wide application of lithium - ion batteries, the market has higher and higher requirements for the battery life and energy of lithium - ion batteries. To improve the battery life and energy of lithium - ion batteries, one way is to further increase the volume and weight of the battery pack. However, this method usually results in larger and thicker tabs, which makes the tabs prone to break when bent, and it is difficult to achieve automated bending production; moreover, due to the thick tabs, when the tabs are bent by conventional methods, the tab area will occupy a large space inside the battery, which is not conducive to improving the energy density of the battery; the thick tab thickness will also cause the inability to perform ultrasonic welding or laser welding, reducing the production density of the battery.

[0003] In addition, the existing battery structure usually has the tabs of the wound core connected to the connecting piece and the terminal post in sequence, with a long connection path, thus bringing an increase in the physical impedance of the battery and a decrease in the over - current capacity.

[0004] After retrieval, the patent with publication number CN115117569A discloses a square aluminum - shell lithium - ion power battery, including a battery shell, tabs, a core package, a terminal post and a top cover plate. In this solution, the tabs are bent inside the battery, and after bending, the top end of the tab is welded and fixed to the bottom end of the terminal post. For larger and thicker tabs, the tab bending in this solution will occupy a large space, which is not conducive to improving the energy density of the battery.

[0005] Therefore, the existing battery structure still needs further improvement and optimization. Summary of the Utility Model

[0006] The utility model provides a new structure of lithium - ion battery to solve the problems that it is difficult to bend thicker and larger tabs, the space occupied after bending is large, and the existing battery structure is not compact enough.

[0007] To achieve the above - mentioned purpose, the technical solution provided by the utility model is as follows:

[0008] A new structure of lithium - ion battery, including a cover plate assembly and an electric core,

[0009] The electric core includes a wound core and tabs connected to the wound core, and each tab is divided into at least one tab cluster;

[0010] The cover plate assembly includes a base plate and a terminal post;

[0011] At least one through hole is provided on the pole;

[0012] The battery core is located on the inner side of the substrate, and the tab cluster passes through the through hole on the pole from the inner side of the pole to the outer side of the pole, and is bent to the pole platform of the pole to be directly connected to the pole.

[0013] This new lithium-ion battery structure offers a bent tab cluster that passes through the terminal post and is then welded to the terminal platform. This reduces the space required to bend thick tabs and solves the difficulty of bending thick tabs. The connecting tab is also eliminated, allowing the tab to connect directly to the terminal post, significantly reducing the battery's physical impedance and improving the cell's current handling capacity.

[0014] In one embodiment, the tabs include a positive tab and a negative tab, and the positive and negative tabs are located on the same side of the winding core. Placing the positive and negative tabs on the same side of the winding core helps reduce the space occupied by a single battery and improve the energy density of the battery pack.

[0015] In another embodiment, the tabs include a positive tab and a negative tab, and the positive tab and the negative tab are located on opposite sides of the winding core, respectively, so that the novel lithium-ion battery structure in this solution is applicable to more battery structures.

[0016] As a further improvement, the electrode comprises a positive electrode and a negative electrode, wherein the positive electrode is provided with a first through-hole and a second through-hole at the electrode platform; the structure of the negative electrode is consistent with that of the positive electrode, and a through-hole is provided on the electrode for the tab cluster to pass through.

[0017] In one embodiment, the cover plate assembly further includes a pressure plate, and the pressure plate includes a positive pressure plate and a negative pressure plate; the positive pressure plate is located on the outside of the positive electrode column, and the negative pressure plate is located on the outside of the negative electrode column. A pole step is provided at the joint between the outer side of the positive electrode column and the positive pressure plate, and the edges of the positive pressure plate are connected to the pole step; the connection method between the negative electrode column and the negative pressure plate is consistent with the connection method between the positive electrode column and the positive pressure plate. A positive pressure plate is provided to weld and seal the positive electrode column, and a negative pressure plate is provided to weld and seal the negative electrode column.

[0018] As a preferred embodiment, the negative pressure plate is a composite pressure plate, and the negative pressure plate includes a first negative pressure plate and a second negative pressure plate connected to each other; the first negative pressure plate is also connected to the negative electrode column, and the first negative pressure plate surrounds the second negative pressure plate. One side of the first negative pressure plate is recessed to form a groove, and the second negative pressure plate is accommodated in the groove. The negative pressure plate adopts an inlaid copper-aluminum composite pressure plate. The first negative pressure plate is connected to the negative electrode column for sealing, and the second negative pressure plate can support PACK welding and serve as an outlet for overcurrent.

[0019] In another embodiment, an insulating seal is further provided between the substrate and the pole post. The insulating seal is located between the substrate and the pole post to insulate and seal between the substrate and the pole post, avoiding the risk of battery short circuit.

[0020] Preferably, the substrate, the pole post and the insulating seal are connected together by an integral molding method to improve the structural strength of the cover plate assembly. Description of the Drawings

[0021] Figure 1 Schematic diagram of the battery cover plate structure in one embodiment;

[0022] Figure 2 Schematic diagram of the positive pole post or negative pole post structure;

[0023] Figure 3 Schematic diagram of the negative pressure plate structure;

[0024] Figure 4 Front view of the battery cover plate in one embodiment;

[0025] Figure 5 For Figure 4 Cross-sectional view taken along line C-C in;

[0026] Figure 6 For Figure 4 Cross-sectional view taken along line E-E in.

[0027] Reference Numeral Description:

[0028] 1. Positive pressure plate; 2. Negative pressure plate; 21. First negative pressure plate; 211. Bottom of the negative pressure plate; 22. Second negative pressure plate; 3. Positive pole post; 31. First through hole; 32. Second through hole; 33. Pole post platform; 34. Pole post step; 4. Negative pole post; 5. Insulating seal; 6. Substrate; 7. Stopper; 8. Tab. Detailed Embodiments

[0029] To further understand the content of the present invention, the present invention will be described in detail with reference to the drawings and embodiments.

[0030] The structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limiting conditions under which the present invention can be implemented. Therefore, they do not have a technical essence. Any modification of the structure, change in the proportional relationship or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present invention.

[0031] Meanwhile, terms such as "upper", "lower", "left", "right", "middle", "inner", "outer", etc. cited in this specification are only for the convenience of clear narration and are not used to limit the scope of implementation. The change or adjustment of their relative relationship, without substantial change in the technical content, should also be regarded as the scope of implementation of this utility model. Moreover, in addition to being used to represent the orientation or position relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to the specific situation.

[0032] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of this application are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so as to implement the embodiments of this application described herein.

[0033] This utility model provides a novel lithium-ion battery structure, which is mainly installed on a power vehicle to drive its operation. The novel lithium-ion battery structure has a relatively high energy density, and the connecting piece structure is cancelled in its cover plate assembly, making the structure of the cover plate assembly more simplified and the battery structure more compact. At the same time, the tab of the battery cell in the novel lithium-ion battery structure is relatively thick and large. Through the cooperation of the tab and the terminal post, the bending of the tab is realized, reducing the space occupied by the bending of the tab. The specific structure of the novel lithium-ion battery structure will be described in detail in combination with the embodiments.

[0034] Embodiment 1

[0035] As Figure 1 shown, a novel lithium-ion battery structure provided in this embodiment includes a cover plate assembly and a battery cell. The battery cell includes a wound core (not shown in the figure) and tabs 8 connected to the wound core. Each tab 8 is divided into at least one tab cluster. According to the thickness, the tab 8 can be divided into multiple tab clusters. For example, in this embodiment, a tab 8 is divided into two tab clusters. When bending, each single tab cluster is bent separately, which can effectively avoid the situation that it is difficult to bend a relatively thick tab 8. In other cases, a tab 8 can also be divided into other numbers of tab clusters.

[0036] The cover plate assembly includes a substrate 6 and a terminal post. At least one through hole is opened on the terminal post, and the number of opened through holes corresponds to the number of tab clusters. For example, in this embodiment, two through holes are opened on the terminal post.

[0037] The battery cell is located inside the substrate 6. When the battery cell and the cover plate assembly are connected to form a battery, the side close to the battery cell is the "inner side", and the opposite side is the "outer side". The tab cluster passes through the through hole on the pole column from the inner side of the pole column to the outer side of the pole column, and is bent to the pole column platform 33 of the pole column and directly connected to the pole column. One side of the pole column is the pole column platform 33. Specifically, one side of the pole column is recessed to form a pole column groove, and the bottom surface of the pole column groove is the pole column platform 33.

[0038] For a battery with a high energy density, it usually has a relatively large volume and weight, the tabs 8 are thicker and larger, and when the entire tab 8 is bent and connected, there are usually problems such as difficulty in bending or a large space occupied by the bending. In this embodiment, a single tab 8 is divided into two tab clusters. The divided tab clusters are thinner than the tab 8, and each tab cluster is bent separately, so it is easier to bend, and the space occupied by the bending is smaller. After bending, the tab clusters can be laser welded or ultrasonic welded. Further, as shown in Figure 4 、 Figure 5 and Figure 6 In this embodiment, the tab cluster passes through the through hole on the pole column and is bent to the pole column platform 33 of the pole column. The space occupied by the bending of the tab cluster is within the space where the pole column is located, so that the bending of the tab cluster does not occupy or occupies less space outside the pole column, making the battery structure more compact, thereby further improving the energy density of the battery. In addition, in this embodiment, the tab cluster is bent to the pole column platform 33 of the pole column, and can be connected to the pole column platform 33 by welding or other means, so that the tab 8 is directly connected to the pole column. Compared with the conventional battery structure, the connection piece structure is cancelled. After cancelling the connection piece, the tab 8 and the pole column are directly in current conduction, greatly reducing the physical impedance and improving the overcurrent capacity of the battery cell; at the same time, with the cancellation of the connection piece, each tab cluster is welded on the pole column platform 33, greatly reducing the bending space of the tabs and improving the utilization rate of the internal space of the battery cell. Synchronously simplifies the production process of the battery cell, improves the manufacturing efficiency and yield.

[0039] In one implementation, the tab 8 includes a positive tab and a negative tab, and the positive tab and the negative tab are located on the same side of the wound core, as shown in Figure 1 When the positive tab and the negative tab are on the same side of the wound core, the height of a single battery can be reduced, which is more conducive to improving the energy density of the battery.

[0040] As shown in Figure 2As shown, the terminal post includes a positive terminal post 3 and a negative terminal post 4. The positive terminal post 3 is provided with a first through hole 31 and a second through hole 32 at the terminal post platform 33. The two clusters of terminal tabs divided from the positive terminal tab respectively pass through the first through hole 31 and the second through hole 32 and are bent to the terminal post platform 33. The structure of the negative terminal post 4 is the same as that of the positive terminal post 3. Similarly, the two clusters of terminal tabs divided from the negative terminal tab respectively pass through the two through holes on the negative terminal post 4 and are bent to the terminal post platform. More specifically, the structures of the positive terminal post 3 and the negative terminal post 4 are the same, but their materials are different. The positive terminal post 3 is made of aluminum, and the negative terminal post 4 is made of copper.

[0041] As a further improvement, the cover plate assembly further includes a pressing plate, and the pressing plate includes a positive pressing plate 1 and a negative pressing plate 2; the positive pressing plate 1 is located outside the positive terminal post 3, and the negative pressing plate 2 is located outside the negative terminal post 4. Specifically, a terminal post step 34 is provided at the joint where the outside of the positive terminal post 3 cooperates with the positive pressing plate 1, and the periphery of the edge of the positive pressing plate 1 is connected with the terminal post step 34. The setting of the terminal post step 34 enables the positive pressing plate 1 to be more convenient for welding and sealing with the positive terminal post 3. The connection method between the negative terminal post 4 and the negative pressing plate 2 is the same as the connection method between the positive terminal post 3 and the positive pressing plate 1.

[0042] As a preferred embodiment, as Figure 3 shown, the negative pressing plate 2 is a composite pressing plate, and the negative pressing plate 2 includes a connected first negative pressing plate 21 and a second negative pressing plate 22. The first negative pressing plate 21 is also connected to the negative terminal post 4, and the first negative pressing plate 21 surrounds the second negative pressing plate 22 on all sides. Specifically, a groove is formed by the depression on one side of the first negative pressing plate 21, and the second negative pressing plate 22 is accommodated in the groove. The bottom surface of the groove is the negative pressing plate bottom 211, and the second negative pressing plate 22 is supported on the negative pressing plate bottom 211 in the groove, so that the negative pressing plate 2 forms an inlaid copper-aluminum composite pressing plate. The first negative pressing plate 21 and the second negative pressing plate 22 are made of different materials. The first negative pressing plate 21 is made of copper, and the second negative pressing plate 22 is made of aluminum. The negative terminal post 4 is made of copper, and the first negative pressing plate 21 is connected to the negative terminal post 4 by welding to seal the negative terminal post 4. The negative pressing plate 2 adopts an inlaid copper-aluminum composite pressing plate. The first negative pressing plate 21 is connected to the negative terminal post 4 for sealing, and the second negative pressing plate 22 can support the PACK welding to play a role in overcurrent conduction.

[0043] Combined with Figure 1 shown, the new lithium-ion battery structure further includes an insulating seal 5, a stop bracket 7 and a housing (not shown in the figure). The insulating seal 5 is located between the substrate 6 and the terminal post to insulate and seal between the substrate 6 and the terminal post.

[0044] In one case, the substrate 6, the terminal post and the insulating seal 5 are connected together by an integral molding method. For example, the substrate 6, the terminal post and the insulating seal 5 are integrally molded by injection molding, which can improve the structural strength of the cover plate assembly.

[0045] The assembly method of the new lithium-ion battery structure in this solution is that after the rolled cores are stacked, glue is applied and they are wrapped with an insulating bag. The tabs are divided into two tab clusters, and the tab clusters pass through two through holes on the terminal posts respectively and are bent to the terminal post platforms for welding with the terminal post platforms. The positive pressure plate 1 and the positive terminal post 3, as well as the negative pressure plate 2 and the negative terminal post 4, are welded and sealed. Finally, the battery cell is installed in the housing.

[0046] For the new lithium-ion battery structure provided in this embodiment, the tabs are divided into tab clusters, the tab clusters are bent, and the tab clusters pass through the terminal posts and are bent to the terminal post platforms for welded connection, reducing the space occupied by the bending of thick tabs and solving the problem of difficult bending of thick tabs. At the same time, the connecting piece structure is cancelled, and the tabs are directly connected to the terminal posts, greatly reducing the physical impedance of the battery and improving the overcurrent capacity of the battery cell.

[0047] Embodiment 2

[0048] In this embodiment, the tabs 8 of the new lithium-ion battery structure include a positive tab and a negative tab, and the positive tab and the negative tab are respectively located on opposite sides of the rolled core. Other components and settings in the new lithium-ion battery structure in this embodiment are the same as those in Embodiment 1.

[0049] In other embodiments, the new lithium-ion battery structure in this embodiment is applicable not only to square batteries but also to cylindrical batteries.

[0050] The terms "installation", "setting", "provided with", and "connection" referred to here should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or there is an internal connection between two devices, components or parts. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0051] The above schematically describes the present invention and its embodiments, and this description is not restrictive. What is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. Therefore, if those of ordinary skill in the art are inspired by it and design similar structural methods and embodiments without creative efforts without departing from the creative purpose of the present invention, they shall fall within the protection scope of the present invention.

Claims

1. A new lithium-ion battery structure, characterized in that: It includes a cover plate assembly and an electric core. The electric core includes a wound core and tabs (8) connected to the wound core. Each tab (8) is divided into at least one tab cluster. The cover plate assembly includes a substrate (6) and a terminal post. At least one through hole is formed in the terminal post. The electric core is located inside the substrate (6). The tab cluster passes through the through hole in the terminal post from the inside of the terminal post to the outside of the terminal post, and is bent to the terminal post platform (33) of the terminal post and directly connected to the terminal post.

2. The novel lithium-ion battery structure according to claim 1, wherein: The tab (8) includes a positive tab and a negative tab, and the positive tab and the negative tab are located on the same side of the wound core.

3. The novel lithium-ion battery structure according to claim 1, characterized in that: The tab (8) includes a positive tab and a negative tab, and the positive tab and the negative tab are respectively located on opposite sides of the wound core.

4. The novel lithium-ion battery structure according to claim 2 or 3, characterized in that: The terminal post includes a positive terminal post (3) and a negative terminal post (4). A first through hole (31) and a second through hole (32) are formed in the positive terminal post (3) at the terminal post platform (33). The structure of the negative terminal post (4) is the same as that of the positive terminal post (3).

5. The novel lithium-ion battery structure according to claim 4, wherein: The cover plate assembly further includes a pressing plate, and the pressing plate includes a positive pressing plate (1) and a negative pressing plate (2). The positive pressing plate (1) is located outside the positive terminal post (3), and the negative pressing plate (2) is located outside the negative terminal post (4).

6. The novel lithium-ion battery structure according to claim 5, wherein: A terminal post step (34) is formed at the mating connection between the outside of the positive terminal post (3) and the positive pressing plate (1), and the periphery of the edge of the positive pressing plate (1) is mated and connected to the terminal post step (34). The mating connection manner between the negative terminal post (4) and the negative pressing plate (2) is the same as the mating connection manner between the positive terminal post (3) and the positive pressing plate (1).

7. The novel lithium-ion battery structure according to claim 5, wherein: The negative pressing plate (2) is a composite pressing plate, and the negative pressing plate (2) includes a connected first negative pressing plate (21) and a second negative pressing plate (22). The first negative pressing plate (21) is also connected to the negative terminal post (4), and the first negative pressing plate (21) surrounds the second negative pressing plate (22) on all sides.

8. The novel lithium-ion battery structure according to claim 7, wherein: A groove is formed by a depression on one side of the first negative pressing plate (21), and the second negative pressing plate (22) is received in the groove.

9. The novel lithium-ion battery structure according to claim 1, characterized in that: An insulating seal (5) is further provided between the substrate (6) and the terminal post.

10. The novel lithium-ion battery structure according to claim 9, characterized in that: The substrate (6), the terminal post and the insulating seal (5) are connected together by an integral molding method.

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