Single battery and battery pack

Abstract

The utility model discloses a single battery which is provided with a first direction and comprises a shell, an electrode assembly accommodated in the shell, a cover body assembly for sealing the shell and a liquid absorption part, the electrode assembly comprises at least one core body, and the electrode assembly is provided with an end face facing the cover body assembly. The liquid absorbing piece comprises a covering part and an extending part fixedly connected to the covering part, the covering part and the extending part are located on the two sides of the end face in the first direction respectively, and the covering part is attached to the peripheral side face of the core body. The covering part is provided with a first capillary channel and a liquid outlet hole communicated with the first capillary channel, the liquid outlet hole is arranged towards the core body, the extension part is internally provided with a second capillary channel and a liquid inlet hole communicated with the second capillary channel, and the first capillary channel is communicated with the second capillary channel. And after the battery cell is inverted, the gathered electrolyte flows back to the cell body along the liquid inlet hole, the second capillary channel, the first capillary channel and the liquid outlet hole under the capillary action, so that the electrolyte is fully utilized, the service life of the single battery is prolonged, and the performance of the single battery is improved.

Description

Technical Field

[0001] The present application relates to the technical field of power batteries, and in particular to a single cell and a battery pack. Background Art

[0002] Power batteries are the core components of new energy vehicles. The battery pack composed of power batteries is assembled under the chassis of the car. Generally, the top of the battery cell is facing upward. This setting will cause the pressure relief direction of the explosion-proof valve to face the inside of the car. When the battery cell is affected by external force or the power battery fails and causes thermal runaway, it will cause safety problems for people in the car.

[0003] Currently, for safety reasons, the battery cells are inverted when the battery pack is assembled into a car. However, inverted battery cells will cause the electrolyte inside the battery cells to collect in the gap between the battery cell cover and the battery cell under the action of gravity, rendering this part of the electrolyte unusable, resulting in reduced battery cell performance and shortened service life. Utility Model Content

[0004] The present application provides a single cell and a battery pack to solve the current technical problem that the electrolyte is difficult to be effectively utilized after the battery is inverted, thereby reducing the battery performance.

[0005] In a first aspect, the present application provides a single cell having a first direction, which includes:

[0006] The housing is provided with a receiving cavity;

[0007] An electrode assembly is accommodated in the accommodation cavity, and the electrode assembly includes at least one core;

[0008] A cover assembly, covering the accommodating cavity from the first direction;

[0009] Wherein, the electrode assembly has an end surface facing the cover assembly;

[0010] It also includes a liquid absorbing member, the liquid absorbing member includes a covering portion and an extending portion fixedly connected to the covering portion, the covering portion and the extending portion are respectively located on both sides of the end surface in the first direction, and the covering portion is attached to the outer peripheral side surface of the core body;

[0011] Among them, the covering part is provided with a first capillary channel and a liquid outlet hole connected to the first capillary channel, and the liquid outlet hole is arranged toward the core body. The extending part is provided with a second capillary channel and a liquid inlet hole connected to the second capillary channel, and the first capillary channel is connected to the second capillary channel.

[0012] To implement the above technical solution, when the battery cell is inverted, the electrolyte accumulates in the gap between the cover assembly and the electrode assembly. Since the extension portion is located on the side of the end face away from the core body and a second capillary channel and a liquid inlet hole are provided in the extension portion, the accumulated electrolyte can be sucked into the second capillary channel along the liquid inlet hole by capillary action, and then enter the first capillary channel and finally flow out from the liquid outlet hole. Since the covering portion is attached to the outer peripheral side of the core body, the accumulated electrolyte will eventually partially flow back to the core body. The above solution can make part of the electrolyte accumulated under the single battery after inversion due to gravity flow back to the core body through capillary action, so that the electrolyte can infiltrate the core body more evenly and comprehensively, and can achieve more sufficient utilization of the electrolyte, thereby improving the service life and performance of the single battery.

[0013] As one of the optional embodiments of this solution, the second capillary channel extends along the first direction.

[0014] To implement the above technical solution, since the electrolyte generally penetrates downward under the action of gravity, it means that the electrolyte content at a high position on the surface of the core is relatively small, and the extension direction of the second capillary channel located on the covering portion in this embodiment is relatively regular and neat along the first direction, thereby ensuring that the electrolyte refluxes in the direction opposite to the direction of gravity to improve the reflux efficiency of the electrolyte; if the extension direction of the second capillary channel is in different directions, this will cause the reflux direction of the electrolyte to be deviated from the direction of gravity, and the reflux efficiency of the electrolyte will be low.

[0015] As one of the optional embodiments of this solution, the liquid outlet is arranged at an end of the covering portion away from the end surface.

[0016] As one of the optional embodiments of this solution, the liquid inlet hole is arranged at an end of the extension portion away from the end surface.

[0017] To implement the above technical solution, the liquid inlet is arranged at one end of the extension part close to the electrolyte, so that the extension part can fully absorb the electrolyte, and the liquid outlet is arranged in an area with less electrolyte, so that the sucked electrolyte can efficiently flow back to a more suitable position, that is, a higher position of the core after inversion.

[0018] As one of the optional embodiments of the present solution, a plurality of the first capillary channels are provided in the covering portion, and the plurality of the first capillary channels are not connected to each other; and a plurality of the second capillary channels are provided in the extending portion, and the plurality of the second capillary channels are not connected to each other.

[0019] By implementing the above technical solution, mutual influence between the first capillary channels or between the second capillary channels during the electrolyte reflux process can be avoided, thereby further ensuring the stability of the electrolyte reflux.

[0020] As one of the optional embodiments of this solution, the extension portion is fixedly connected to the cover body assembly.

[0021] The above technical solution is implemented to ensure the stable connection between the covering part and the extending part and the cover assembly, and to avoid displacement of the covering part in the height direction, thereby avoiding displacement of the extending part and affecting the back suction effect.

[0022] As one of the optional embodiments of the present solution, the extension portion includes a first portion fixedly connected to the covering portion and a second portion fixedly connected to the first portion, and the second portion is parallel to the end surface and is fixedly attached to the cover assembly.

[0023] As one of the optional embodiments of this solution, the cover body assembly includes a top cover and a lower plastic, and the second part is sandwiched between the lower plastic and the top cover.

[0024] As one of the optional embodiments of the present solution, the electrode assembly includes at least two cores, a plurality of the cores are parallel to the first direction, a plurality of the cores are stacked to form the electrode assembly, and the covering portion is in contact with the outer peripheral side of the electrode assembly.

[0025] As one of the optional embodiments of the present solution, the electrode assembly includes at least two cores, a plurality of the cores are parallel to the first direction, a plurality of the cores are stacked to form the electrode assembly, and the covering portion is sandwiched between two opposite surfaces of the cores.

[0026] On the other hand, the present application also provides a battery pack, comprising:

[0027] The above-mentioned single cell;

[0028] A box body, wherein the single battery is accommodated in the box body.

[0029] One of the above technical solutions has the following advantages or beneficial effects:

[0030] 1. When the battery cell is inverted, the electrolyte accumulates in the gap between the cover assembly and the electrode assembly. Since the extension portion is located on the side of the end face away from the core body and a second capillary channel and a liquid inlet hole are provided in the extension portion, the accumulated electrolyte can be sucked into the second capillary channel along the liquid inlet hole through capillary action, and then enter the first capillary channel and finally flow out from the liquid outlet hole. Since the covering portion fits the outer peripheral side of the core body, the accumulated electrolyte will eventually partially flow back to the core body. The above scheme can allow part of the electrolyte that is accumulated under the single battery after inversion due to gravity to flow back to the core body through capillary action, so that the electrolyte can infiltrate the core body more evenly and comprehensively, and can achieve more sufficient utilization of the electrolyte, thereby improving the service life and performance of the single battery.

[0031] 2. The extension part is fixedly connected to the cover assembly to ensure the stable connection between the covering part and the extension part and the cover assembly, so as to avoid the displacement of the covering part in the height direction, thereby avoiding the displacement of the extension part and affecting the back suction effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0033] Figure 1 is an overall exploded structural diagram of a single cell provided in Example 1 of the present application;

[0034] Figure 2 It is an overall structural diagram for reflecting the structure of the liquid-absorbing member provided in Example 1 of the present application;

[0035] Figure 3 is a cross-sectional view provided in Example 1 of the present application for illustrating the internal structure of a single cell after being inverted;

[0036] Figure 4 It is a cross-sectional view of the structure of the liquid absorbent member provided in Example 1 of the present application;

[0037] Figure 5 is a cross-sectional view showing another perspective of the liquid-absorbing member structure provided in Example 1 of the present application;

[0038] Figure 6 is a cross-sectional view from another perspective for reflecting the internal structure of a single cell provided in Example 1 of the present application;

[0039] Figure 7 It is a schematic diagram mainly used to reflect the structure of the liquid-absorbing member provided in Example 2 of the present application;

[0040] Figure 8 It is a cross-sectional view provided in Example 2 of the present application and mainly used to show the internal structure of a single cell;

[0041] Fig. 9 is a cross-sectional view provided in Embodiment 2 of the present application mainly for showing the internal structure of a single cell from another perspective;

[0042] Fig.10 This is another optional structural schematic diagram of the liquid absorbent provided in Example 1 of the present application.

[0043] Reference numerals: 1, housing; 11, accommodating cavity;

[0044] 2. electrode assembly; 21. core body; 211. main body; 212. pole ear; 2a. end face;

[0045] 3. Cover assembly; 31. Top cover; 32. Lower plastic;

[0046] 4. liquid absorbing member; 41. covering portion; 41a. liquid outlet; 42. extending portion; 421. first portion; 422. second portion; 42a. liquid inlet;

[0047] 51. a first capillary channel; 52. a second capillary channel;

[0048] X, first direction. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0050] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the term "and / or" in this article is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article, unless otherwise specified, generally indicates that the associated objects before and after are in an "or" relationship.

[0051] The following is combined with Figure 1-10 The present application is further described.

[0052] Example 1

[0053] Reference Figure 1 and Figure 2 , is a single cell provided by the present application, having a first direction X, and comprising a housing 1, an electrode assembly 2, a cover assembly 3 and a liquid absorbent 4. Among them, a receiving cavity 11 is opened in the housing 1 along the first direction X, and the electrode assembly 2 is accommodated in the receiving cavity 11. The electrode assembly 2 comprises at least one core 21. In this embodiment, the electrode assembly 2 comprises two cores 21, and the two cores 21 are stacked in a direction perpendicular to the first direction X to form the electrode assembly 2. Among them, each core 21 comprises a main body 211 formed by stacking or winding a plurality of positive plates, negative plates and diaphragms, and a pole ear 212 arranged on the main body 211. The cover assembly 3 comprises a lower plastic 32 and a top cover 31. The cover assembly 3 is covered in the receiving cavity 11 along the first direction X to enclose the electrode assembly 2 in the housing 1. Among them, the electrode assembly 2 has an end face 2a facing the cover assembly 3, and a portion of the liquid absorbent 4 covers and fits the outer side of the core 21.

[0054] Reference Figure 2-Figure 3Specifically, the liquid-absorbing member 4 includes a covering portion 41 and an extending portion 42 fixedly connected to the covering portion 41. The covering portion 41 and the extending portion 42 are respectively located on both sides of the end surface 2a in the first direction X. The covering portion 41 is attached to the outer peripheral side surface of the core body 21. After the single battery is inverted, the extending portion 42 is located in the gap formed between the cover body assembly 3 and the end surface 2a.

[0055] Reference Figure 4 and Figure 5 , a first capillary channel 51 is provided in the covering portion 41, a liquid outlet 41a connected to the first capillary channel 51 is provided on the covering portion 41, and the liquid outlet 41a is arranged toward the core body 21, a second capillary channel 52 is provided in the extending portion 42, and a liquid inlet 42a connected to the second capillary channel 52 is provided on the extending portion 42, and the first capillary channel 51 is connected to the second capillary channel 52. Among them, the first capillary channel 51 and the second capillary channel 52 refer to channels that can realize the capillary phenomenon. For example, in this embodiment, the cross-sections of the first capillary channel 51 and the second capillary channel 52 are both circular, and the diameters are both represented by a, then 0.02mm≤a≤0.5mm, and the final result is based on the ability to realize the capillary phenomenon. In other optional embodiments, it is not excluded that the cross-section of the capillary is a triangle, a square or other shapes.

[0056] It should be noted that the covering portion 41 in this embodiment that is fitted to the outer peripheral side of the core body 21 should be understood as the covering portion 41 being arranged on the other exposed surface except the side of the core body 21 that is close to each other. In addition, the fitting here can be understood as the covering portion 41 being strictly fitted to the side of the core body 21, and it can also be understood that there is a certain distance between the covering portion 41 and the side of the core body 21 to form an effect close to fitting.

[0057] Combination Figure 6 When the battery cell is inverted, the electrolyte is accumulated in the gap between the cover assembly 3 and the main body 211. Since the extension 42 is located on the side of the end face 2a away from the core 21 and the second capillary channel 52 and the liquid inlet hole 42a are provided in the extension 42, the accumulated electrolyte can be sucked into the second capillary channel 52 along the liquid inlet hole 42a by capillary action, and then enter the first capillary channel 51 and finally flow out from the liquid outlet hole 41a. Since the cover 41 is attached to the outer peripheral side of the core 21 and the liquid outlet hole 41a faces the core 21, the accumulated electrolyte will eventually flow back to the core 21. The above setting can make part of the electrolyte accumulated under the inverted single battery due to gravity flow back to the core 21 by capillary action, so that the electrolyte can infiltrate the core 21 more evenly and comprehensively, and can achieve more sufficient utilization of the electrolyte, thereby improving the service life and performance of the single battery.

[0058] In this embodiment, the thickness s of the extension portion 42 is set in the range of 0.1mm-1mm, so as to facilitate the processing of the second capillary channel 52 and the installation and arrangement of the extension portion 42 in the housing 1. The total length c of the extension portion 42 is set in the range of 20mm-300mm, which needs to be set according to the size of the single battery, and the width d of the extension portion 42 is set in the range of 5mm-400mm. Among them, the length and width of the extension portion 42 need to be smaller than the length and width of the core 21 so that the extension portion 42 can be better arranged and processed, and the first direction X is the height of the core 21.

[0059] Reference Figure 3-Figure 6 , the extension part 42 is fixedly connected to the cover assembly 3. Specifically, the extension part 42 includes a first part 421 fixedly connected to the cover part 41 and a second part 422 fixedly connected to the first part 421. The first part 421 and the second part 422 are both arranged in a thin sheet shape, and the second part 422 is parallel to the end face 2a and is fixed to the cover assembly 3. The fixing here may include but is not limited to a bonding fixing structure. The purpose of this setting is to ensure the stable connection between the cover part 41 and the extension part 42 and the cover assembly 3, and then ensure the stability of the connection between the liquid absorbent 4 and the core 21, so as to avoid the displacement of the height direction between the cover part 41 and the core 21 under complex working conditions, thereby affecting the back suction and reflux effect of the electrolyte. And the above setting can make the extension part 42 close to the cover assembly 3 to the greatest extent, and when a small amount of electrolyte accumulates on the cover assembly 3, it can use the capillary phenomenon to enter the second capillary channel 52 through the liquid inlet hole 42a to achieve efficient reflux. In some optional embodiments, the extension portion 42 may also be sandwiched between the lower plastic 32 of the cover assembly 3 and the top cover 31 to further improve the stability of the connection between the extension portion 42 and the cover assembly 3 .

[0060] In some optional embodiments, for example Fig.10 As shown in FIG. 1 , the extension portion 42 can also be directly connected to the lower plastic 32 . The extension portion 42 is connected to both sides of the lower plastic 32 in the length direction so that the covering portion 41 can cover the outer peripheral side of the electrode assembly 2 .

[0061] It should be noted that in the present embodiment, the fixed connection between the extension portion 42 and the cover assembly 3 is a preferred embodiment. In some other embodiments, the extension portion 42 may not be connected to the cover assembly 3. For example, after the single battery is inverted, the extension portion 42 is freely suspended on the side of the end surface 2a close to the cover assembly 3, or one end of the extension portion 42 is abutted against one side of the cover assembly 3.

[0062] Reference Figure 3 and Figure 4In this embodiment, the liquid inlet 42a is arranged at one end of the extension part 42 away from the end face 2a, and the liquid outlet 41a is arranged at one end of the cover part 41 away from the end face 2a. Specifically, in this embodiment, the liquid outlet 41a is a rectangular hole, which is connected to multiple first capillary channels 51 at the same time, and the liquid inlet 42a is arranged on the end face 2a of the second part 422. The above setting makes the liquid inlet 42a arranged at one end of the extension part 42 close to the electrolyte, so that the extension part 42 can fully and efficiently absorb the electrolyte. After the single battery is inverted, the electrolyte will be deposited toward the cover assembly 3 under the action of gravity, resulting in a lower electrolyte concentration in the area of ​​the core 21 away from the end face 2a, and the liquid outlet 41a is arranged in an area with less electrolyte, so that the sucked electrolyte can efficiently flow back to a more suitable position, that is, a higher position of the core 21 after inversion, so as to fully and evenly utilize the electrolyte.

[0063] It should be noted that the liquid inlet hole 42a is arranged at the end of the extension part 42 away from the end surface 2a and the liquid outlet hole 41a is arranged at the end of the covering part 41 away from the end surface 2a. This does not mean that the liquid inlet hole 42a and the liquid outlet hole 41a can only be located on the end surface 2a of the extension part 42 or the covering part 41, but that the liquid inlet hole 42a and the liquid outlet hole 41a are both at a certain distance from the end surface 2a in the first direction X, and this distance can be adjusted according to actual usage.

[0064] Reference Figure 4 , the second capillary channel 52 extends along the first direction X, a plurality of first capillary channels 51 are provided in the covering portion 41, and the plurality of first capillary channels 51 are not connected to each other, and a plurality of second capillary channels 52 are provided in the extending portion 42, and the plurality of second capillary channels 52 are not connected to each other. Because the electrolyte generally penetrates downward under the action of gravity, it means that the electrolyte content at a high position on the surface of the core 21 is relatively small, and in this embodiment, the extension direction of the second capillary channel 52 along the first direction X is relatively regular and neat, thereby ensuring that the reflux direction of the electrolyte refluxes in the direction opposite to the gravity direction, so as to improve the reflux efficiency of the electrolyte; if the extension direction of the second capillary channel 52 is in different directions, this will cause the reflux direction of the electrolyte to be deviated from the gravity direction, and the reflux efficiency of the electrolyte is low in the same time. The first capillary channels 51 and the second capillary channels 52 are not interconnected to avoid mutual influence between the first capillary channels 51 or the second capillary channels 52 during the electrolyte reflux process, further ensuring the stability of the electrolyte reflux. In this embodiment, part of the first capillary channels 51 also extends along the first direction X to further improve the reflux efficiency of the electrolyte.

[0065] Example 2

[0066] Reference Figure 7-Figure 9The electrode assembly 2 includes two core bodies 21, which are stacked to form the electrode assembly 2, and the covering portion 41 is sandwiched between the two facing surfaces of the core bodies 21. Specifically, the extension portion 42 is integrally connected to the lower plastic 32, and the position of the extension portion 42 is located in the middle of the lower plastic 32, so that the covering portion 41 is sandwiched by the two opposite surfaces of the two core bodies 21 after the core body 21 is formed into a core product. In this embodiment, the liquid absorbing member 4 can suck the electrolyte back to the facing surface of the two core bodies 21, and the arrangement of the liquid absorbing member 4 can be realized in a small space.

[0067] In some optional embodiments, the position of the covering portion 41 can adopt the arrangement methods of both Embodiment 1 and Embodiment 2 to further improve the comprehensiveness of electrolyte reflux and make more effective use of the electrolyte.

[0068] On the other hand, the present application also provides a battery pack, which includes the above-mentioned single battery and a box body, and the single battery is accommodated in the box body.

[0069] The above description is only a partial implementation method of the embodiments of the present application and does not constitute any form of limitation on the application. The protection scope of the embodiments of the present application is not limited thereto. Any simple modifications, equivalent changes and modifications that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the embodiments of the present application should be covered within the protection scope of the embodiments of the present application.

Claims

1. A single battery having a first direction (X), characterized in that: include: The housing (1) is provided with a receiving cavity (11); An electrode assembly (2) is accommodated in the accommodation cavity (11), and the electrode assembly (2) comprises at least one core (21); A cover assembly (3) is arranged to cover the accommodating cavity (11) from the first direction (X); Wherein, the electrode assembly (2) has an end surface (2a) facing the cover assembly (3); The device further comprises a liquid absorbing member (4), wherein the liquid absorbing member (4) comprises a covering portion (41) and an extending portion (42) fixedly connected to the covering portion (41), wherein the covering portion (41) and the extending portion (42) are respectively located on both sides of the end surface (2a) in the first direction (X), and the covering portion (41) is attached to the outer peripheral side surface of the core body (21); The covering portion (41) is provided with a first capillary channel (51) and a liquid outlet hole (41a) connected to the first capillary channel (51), and the liquid outlet hole (41a) is arranged toward the core body (21); the extending portion (42) is provided with a second capillary channel (52) and a liquid inlet hole (42a) connected to the second capillary channel (52), and the first capillary channel (51) is connected to the second capillary channel (52).

2. The single cell according to claim 1, characterized in that: The second capillary channel (52) extends along the first direction (X).

3. The single cell according to claim 2, characterized in that: The liquid outlet hole (41a) is arranged at an end of the covering portion (41) away from the end surface (2a).

4. The single cell according to claim 2, characterized in that: The liquid inlet hole (42a) is arranged at an end of the extension portion (42) away from the end surface (2a).

5. The single cell according to claim 1, characterized in that: The covering portion (41) is provided with a plurality of the first capillary channels (51), the plurality of the first capillary channels (51) are not connected to each other, and the extending portion (42) is provided with a plurality of the second capillary channels (52), the plurality of the second capillary channels (52) are not connected to each other.

6. The single cell according to claim 1, characterized in that: The extension portion (42) is fixedly connected to the cover assembly (3).

7. The single cell according to claim 6, characterized in that: The extension portion (42) comprises a first portion (421) fixedly connected to the covering portion (41) and a second portion (422) fixedly connected to the first portion (421), wherein the second portion (422) is parallel to the end surface (2a) and is fixedly attached to the cover assembly (3).

8. The single cell according to claim 7, characterized in that: The cover assembly (3) comprises a top cover (31) and a lower plastic (32), and the second portion (422) is sandwiched between the lower plastic (32) and the top cover (31).

9. The single cell according to any one of claims 1 to 8, characterized in that: The electrode assembly (2) comprises at least two core bodies (21), the plurality of core bodies (21) are parallel to the first direction (X), the plurality of core bodies (21) are stacked to form the electrode assembly (2), and the covering portion (41) is in contact with the outer peripheral side surface of the electrode assembly (2).

10. The single cell according to any one of claims 1 to 8, characterized in that: The electrode assembly (2) comprises at least two cores (21), the plurality of cores (21) are parallel to the first direction (X), the plurality of cores (21) are stacked to form the electrode assembly (2), and the covering portion (41) is sandwiched between two opposite surfaces of the core (21).

11. A battery pack, characterized in that: include: The single cell according to any one of claims 1 to 10; A box body, wherein the single battery is accommodated in the box body.

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