Battery and battery module

Abstract

The application belongs to the technical field of batteries, and discloses a battery and a battery module. The battery comprises a plurality of electrode assemblies, each electrode assembly comprising a positive electrode sheet, a negative electrode sheet and a separator, the separator being clamped between the positive electrode sheet and the negative electrode sheet, one end of the separator along a first direction extending beyond the positive electrode sheet and the negative electrode sheet and forming a liquid absorption part, the liquid absorption part being provided with a liquid absorption adhesive tape, the liquid absorption adhesive tape being configured to be able to adhere and fix the liquid absorption part and another adjacent liquid absorption part, electrolyte being able to gradually infiltrate the electrode assembly along the liquid absorption adhesive tape and the separator; the first direction being the length direction when the battery is placed on one side. The battery can improve its liquid absorption capacity, ensure good electrolyte infiltration effect of the battery in different placement states, and improve the service life and use reliability of the battery.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more particularly to a battery and a battery module. Background Technology

[0002] Lithium-ion batteries, as energy storage units in electric vehicles, are placed in various ways during use, such as upright, sideways, or flat. Currently, the most common placement in battery modules is upright. When the battery is upright, the electrolyte can rise linearly along the separator to the desired position through capillary action. However, when the battery is placed sideways or flat, the electrolyte needs to flow along the winding direction of the separator to reach the desired position to wet the entire battery, increasing the travel distance. With repeated use, the electrolyte at the bottom of the battery casing is gradually consumed, causing the electrolyte level to gradually decrease. This further increases the electrolyte's travel distance and reduces the wetting effect on the electrodes, leading to poorer battery cycle performance.

[0003] Therefore, there is an urgent need to improve existing technologies to solve the aforementioned technical problems in existing batteries. Summary of the Invention

[0004] The purpose of this invention is to provide a battery that can improve the battery's liquid absorption capacity, ensure good electrolyte wetting effect when the battery is placed in different states, and improve the battery's service life and reliability.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] The battery includes multiple electrode assemblies, each comprising a negative electrode, a positive electrode, and a separator. The separator is sandwiched between the negative and positive electrode. One end of the separator along a first direction has a liquid-absorbing portion extending beyond the negative and positive electrode. The liquid-absorbing portion is provided with absorbent paper, which is configured to adhere and fix the liquid-absorbing portion to an adjacent liquid-absorbing portion. At least one of the liquid-absorbing portions can contact the electrolyte, and the electrolyte can gradually wet the electrode assembly along the absorbent paper and the separator. The first direction is the length direction of the battery when it is placed on its side.

[0007] Optionally, the liquid-absorbing portion bends toward the center of the battery, and the liquid-absorbing portion can completely or partially cover the end of the negative electrode and the end of the positive electrode. Adjacent liquid-absorbing portions and / or a single liquid-absorbing portion form a capillary channel for the electrolyte to be wetted.

[0008] Optionally, the negative electrode sheet may extend beyond the edge of the positive electrode sheet by 0.5mm-3mm at either end or both ends along the first direction.

[0009] Optionally, the separator extends beyond the negative electrode and the positive electrode at either end along the first direction and the second direction, the second direction being the width direction when the battery is placed upright, and the first direction being perpendicular to the second direction.

[0010] Optionally, the diaphragm and the liquid absorption part are integrally formed.

[0011] Optionally, the absorbent tape is affixed to the absorbent portion and sandwiched between two adjacent absorbent portions.

[0012] Optionally, the absorbent paper is wrapped around the absorbent portion.

[0013] Optionally, the electrode assembly further includes a negative electrode tab connected to the negative electrode plate and a positive electrode tab connected to the positive electrode plate, wherein the negative electrode tab and the positive electrode tab are disposed on the same side and located at one end of the electrode assembly away from the liquid absorption portion along the first direction.

[0014] Optionally, the battery further includes a housing having a cavity for accommodating the electrode assembly and the electrolyte, the housing being made of aluminum, aluminum alloy, or plastic.

[0015] Another object of the present invention is to provide a battery module comprising a battery as described in any of the above embodiments.

[0016] Beneficial effects:

[0017] In this invention, the battery uses absorbent adhesive tape to bond and fix the separator of multiple electrode components. The bonding position is located at one end of the separator along a first direction. At this end, the separator has an absorbent portion that extends beyond the negative and positive electrode plates, allowing the electrolyte to gradually wet the electrode components along the absorbent adhesive tape and the separator. Due to the wettability and capillary action of the absorbent adhesive tape and the separator, this battery configuration can fix adjacent absorbent portions together, allowing the electrolyte to flow from one absorbent portion to another via the absorbent adhesive tape. This shortens the electrolyte wetting path and ensures that each absorbent portion of the battery is stably bonded and fixed, whether the battery is lying flat or on its side. This improves the battery's absorbency and ensures good electrolyte wetting in different placement states. Simultaneously, it suppresses lithium plating, improving the battery's cycle life and reliability. Attached Figure Description

[0018] Figure 1 This is an isometric view of the battery when it is placed upright, provided in a specific embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the battery structure provided in a specific embodiment of the present invention;

[0020] Figure 3This is a schematic diagram of the electrode assembly provided in a specific embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram showing the installation of multiple electrode assemblies provided in a specific embodiment of the present invention.

[0022] Figure 5 This is a schematic diagram of the structure of a battery when it is laid flat, according to a specific embodiment of the present invention;

[0023] Figure 6 This is a schematic diagram of the battery being placed on its side according to a specific embodiment of the present invention.

[0024] In the picture:

[0025] 10. Shell; 20. Top cover; 21. Liquid injection hole; 30. Electrode assembly; 31. Negative electrode plate; 311. Negative electrode tab; 32. Positive electrode plate; 321. Positive electrode tab; 33. Diaphragm; 331. Liquid absorption section; 34. Liquid absorption tape. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0027] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0029] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0030] In this embodiment, the first direction is Figure 1 and Figure 4 The X direction shown is the length direction when the battery is placed on its side, and also the height direction when the battery is placed upright (with the electrodes facing upwards). The second direction is... Figure 1 and Figure 4 The Y direction in the figure is the width direction when the battery is placed upright, and the third direction is... Figure 1 The Z direction shown is the length direction when the battery is placed upright. The first direction, the second direction, and the third direction are all perpendicular to each other.

[0031] Please refer to Figure 1 and Figure 2 In this embodiment, the battery is a square aluminum-cased battery, which consists of an upper cover 20 and a lower casing 10 forming a cavity for accommodating the electrolyte and multiple electrode assemblies 30. The upper cover 20 is also provided with an injection hole 21 for injecting electrolyte. When the battery is placed upright, its electrodes face vertically upward. In this embodiment, the casing 10 is made of aluminum, aluminum alloy, or plastic. No specific limitation is made in this embodiment, and those skilled in the art can select the material of the casing 10 according to their needs.

[0032] Please continue to refer to this. Figure 3 and Figure 4 The battery includes multiple electrode assemblies 30, each electrode assembly 30 including a negative electrode 31, a positive electrode 32, and a separator 33. The separator 33 is sandwiched between the negative electrode 31 and the positive electrode 32. One end of the separator 33 along a first direction is provided with a liquid-absorbing portion 331 that extends beyond the negative electrode 31 and the positive electrode 32. The liquid-absorbing portion 331 is provided with liquid-absorbing adhesive tape 34, which is configured to adhere and fix the liquid-absorbing portion 331 to another adjacent liquid-absorbing portion 331. At least one of the liquid-absorbing portions 331 can contact the electrolyte, and the electrolyte can gradually wet the electrode assembly 30 along the liquid-absorbing adhesive tape 34 and the separator 33. The first direction is the length direction when the battery is placed on its side.

[0033] In this embodiment, the battery uses absorbent adhesive tape 34 to bond and fix the separator 33 of multiple electrode assemblies 30. The bonding position is located at one end of the separator 33 along a first direction. At this end, the separator 33 has an absorbent portion 331 that extends beyond the negative electrode 31 and the positive electrode 32. The electrolyte can gradually wet the electrode assemblies 30 along the absorbent adhesive tape 34 and the separator 33. Due to the wettability and capillary action of the absorbent adhesive tape 34 and the separator 33, the electrolyte in this configuration can wet from one electrode assembly 30 to another along the absorbent adhesive tape 34 and the separator 33, and diffuse to all parts of each electrode assembly 30, whether the battery is lying flat or on its side. This improves the battery's electrolyte absorption capacity, ensures good electrolyte wetting effect in different placement states, suppresses lithium plating, and improves the battery's cycle life and reliability.

[0034] Especially when multiple electrode assemblies 30 are stacked, the internal wetting effect is even worse. In this case, using absorbent tape 34 to bond the absorbent portions 331 of the stacked electrode assemblies 30 together can fix adjacent absorbent portions 331 together, allowing the electrolyte to be absorbed from one absorbent portion 331 to another through the absorbent tape 34. This shortens the electrolyte wetting path, ensuring that adjacent absorbent portions 331 are stably bonded and fixed whether the battery is lying flat or on its side, thereby improving the battery's absorbency and significantly enhancing its wetting performance. In this embodiment, when the battery is lying flat or on its side, the absorbent portion 331 can be bent and extended towards the inner wall of the housing 10 so that at least one absorbent portion 331 can contact the electrolyte. This will not be elaborated further in this embodiment.

[0035] The following is combined with Figure 4 , Figure 5 and Figure 6 This embodiment details the electrolyte wetting path of the battery under different placement states. When the battery is laid flat, i.e., its large surface is parallel to the horizontal plane, the multiple electrode components 30 inside the battery are stacked vertically along the height direction. The lower electrode components 30 are completely submerged in electrolyte, while some of the upper electrode components 30 are not submerged. Due to the presence of absorbent paper 34, after the lower electrode components 30 are wetted by electrolyte, the electrolyte flows along the capillary action of the absorbent paper 34. Figure 5 The liquid absorption section 331 of the electrode assembly 30 is raised to the upper part in the direction of the middle arrow, and is then soaked into the entire electrode assembly 30 along with the separator 33; when the battery is placed on its side, the multiple electrode assemblies 30 inside the battery are arranged horizontally, and at this time, one side of each electrode assembly 30 along the third direction is immersed, that is, the liquid absorption section 331 and the liquid absorption tape 34 are partially wetted by electrolyte. At this time, the electrolyte not only soaks into the separator 33 along the liquid absorption section 331, but also along the third direction. Figure 6The direction of the middle arrow indicates that the electrolyte is wetted along the separator 33 to the entire electrode assembly 30. In this embodiment, the battery ensures proper wetting when lying flat or on its side, guaranteeing that the electrolyte completely wets the required locations on the electrode assembly 30, thus extending the battery's lifespan.

[0036] Optionally, such as Figure 3 As shown, the electrode assembly 30 further includes a negative electrode tab 311 connected to the negative electrode plate 31 and a positive electrode tab 321 connected to the positive electrode plate 32. The negative electrode tab 311 and the positive electrode tab 321 are disposed on the same side and located at the end of the electrode assembly 30 away from the liquid absorption part 331 along the first direction. This arrangement of the electrode assembly 30 can avoid interference between the negative electrode tab 311, the positive electrode tab 321 and the liquid absorption part 331, making the layout of the motor assembly more reasonable.

[0037] Please continue to refer to this. Figure 4 The aforementioned liquid-absorbing portion 331 bends towards the center of the battery, and can completely or partially cover the ends of the negative electrode 31 and the positive electrode 32. Adjacent liquid-absorbing portions 331 and / or a single liquid-absorbing portion 331 form a capillary channel for electrolyte wetting. Thus, the electrolyte can diffuse and wet the entire electrode assembly 30 along the capillary channel between the two liquid-absorbing portions 331 under capillary action, improving the wetting effect of the electrolyte between the electrode assemblies 30 and inside the motor assembly. This ensures good wetting effect regardless of the battery's placement, further improving battery life.

[0038] Furthermore, the negative electrode 31 extends 0.5mm-3mm beyond the edge of the positive electrode 32 at either end or both ends along the first direction. This arrangement of the negative electrode 31 and the positive electrode 32 prevents lithium plating and further improves the cycle life of the battery, which will not be elaborated further here.

[0039] In a preferred embodiment, the separator 33 extends beyond the negative electrode 31 and the positive electrode 32 at either end along the first direction and at either end along the second direction, where the second direction is the width direction when the battery is placed upright, and the first direction is perpendicular to the second direction. This configuration of the separator 33 effectively isolates the negative electrode 31 and the positive electrode 32, preventing them from contacting and causing an internal short circuit in the battery.

[0040] Optionally, the diaphragm 33 and the liquid absorption part 331 are integrally formed, thereby reducing the processing difficulty and production cost.

[0041] In this embodiment, the absorbent tape 34 is affixed to the absorbent portion 331 and sandwiched between two adjacent absorbent portions 331. Furthermore, the absorbent tape 34 is affixed around the absorbent portion 331 to further enhance its absorbency and wetting effect. The affixing position and width of the absorbent tape 34 are determined by those skilled in the art based on the battery structure and electrolyte capacity, and will not be elaborated upon in this embodiment.

[0042] This embodiment also provides a battery module, which includes the battery as described in any of the above embodiments. When using the battery, whether the battery is placed on its side or flat, the electrolyte can penetrate all parts of each electrode assembly 30, thereby improving the cycle life and reliability of the battery module.

[0043] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A battery comprising at least one electrode assembly (30), the electrode assembly (30) comprising a negative electrode sheet (31), a positive electrode sheet (32) and a separator (33) sandwiched between the negative electrode sheet (31) and the positive electrode sheet (32), characterized in that: the separator (33) is provided with a liquid absorbing portion (331) beyond the negative electrode sheet (31) and the positive electrode sheet (32) at one end in a first direction, the liquid absorbing portion (331) is provided with a liquid absorbing adhesive paper (34) configured to be able to adhere and fix the liquid absorbing portion (331) and an adjacent other liquid absorbing portion (331), at least one liquid absorbing portion (331) is capable of contacting electrolyte, and electrolyte is capable of gradually infiltrating the electrode assembly (30) along the liquid absorbing adhesive paper (34) and the separator (33); the first direction is the length direction when the battery is placed on one side; the liquid absorbing portion (331) is bent towards the center of the battery, the liquid absorbing portion (331) is capable of completely or partially covering the end of the negative electrode sheet (31) and the end of the positive electrode sheet (32), a capillary channel for electrolyte infiltration is formed between adjacent two liquid absorbing portions (331) and / or a single liquid absorbing portion (331), and adjacent two liquid absorbing portions (331) are fixedly attached, so that electrolyte can be infiltrated from one liquid absorbing portion (331) to another liquid absorbing portion (331) by the liquid absorbing adhesive paper (34). The edge of the negative electrode sheet (31) beyond the positive electrode sheet (32) is 0.5mm-3mm at either end or both ends in the first direction. Either end in the first direction and either end in the second direction of the separator (33) beyond the negative electrode sheet (31) and the positive electrode sheet (32), the second direction is the width direction when the battery is placed vertically, and the first direction is perpendicular to the second direction.

2. The battery of claim 1, wherein, The separator (33) and the liquid absorbing portion (331) are integrally formed.

3. The battery of claim 2, wherein, The liquid absorbing adhesive paper (34) is attached to the liquid absorbing portion (331) and sandwiched between adjacent two liquid absorbing portions (331).

4. The battery of claim 1, wherein, The liquid absorbing adhesive paper (34) is attached to the liquid absorbing portion (331) in a ring shape.

5. The battery of claim 1, wherein, The electrode assembly (30) further comprises a negative electrode tab (311) connected to the negative electrode sheet (31) and a positive electrode tab (321) connected to the positive electrode sheet (32), the negative electrode tab (311) and the positive electrode tab (321) are provided on the same side and located at one end of the electrode assembly (30) away from the liquid absorbing portion (331) in the first direction.

6. The battery of claim 5, wherein, The battery further comprises a shell (10) having a receiving cavity for receiving the electrode assembly (30) and the electrolyte, the shell (10) is made of an aluminum shell, an aluminum alloy shell or a plastic shell.

7. The battery according to any one of claims 1 to 6, wherein The battery comprises any one of claims 1-8.

8. The battery according to any one of claims 1 to 6, wherein ​ 9. A battery module, characterized by ​

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