Battery cell and battery pack

Abstract

The application relates to the technical field of batteries, in particular to a battery monomer and a battery pack. The application provides a battery monomer which comprises a shell, an electric core and a flow guide piece. The shell is provided with a first wall and a liquid injection hole. The electric core is arranged in the shell and has a first surface facing the first wall along the thickness direction of the first wall. The flow guide piece is arranged between the first wall and the first surface along the thickness direction of the first wall. The projection of the liquid injection hole falls into the projection of the flow guide piece along the thickness direction of the first wall. The flow guide piece has a bottom wall along the thickness direction of the first wall. The projection area of the first surface along the thickness direction of the first wall is S1, the projection area of the bottom wall is S2, and the following condition is met: 0.01<=S2 / S1<=0.15. The electric core can be uniformly infiltrated, and the liquid sealing phenomenon can be reduced.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell and a battery pack. Background Technology

[0002] As the application fields of power batteries continue to expand, the market demand for them is also constantly increasing. In related technologies, after the battery cell is installed in the casing, electrolyte needs to be injected into the battery cell. After the electrolyte is injected, it seeps from the periphery of the battery cell towards the center, resulting in a liquid seal phenomenon. Utility Model Content

[0003] This application provides a battery cell and a battery pack that enable uniform wetting of the battery cells and reduce liquid sealing phenomena.

[0004] To achieve the above objectives, the main technical solutions adopted in this application include:

[0005] In a first aspect, embodiments of this application provide a battery cell, including a casing, a battery cell, and a current guide. The casing has a first wall with an injection hole. The battery cell is disposed within the casing, and along the thickness direction of the first wall, the battery cell has a first surface facing the first wall. The current guide is disposed between the first wall and the first surface, and along the thickness direction of the first wall, the projection of the injection hole falls within the projection of the current guide. Along the thickness direction of the first wall, the current guide has a bottom wall. The projected area of ​​the first surface along the thickness direction of the first wall is S1, and the projected area of ​​the bottom wall is S2, satisfying: 0.01 ≤ S2 / S1 ≤ 0.15.

[0006] The battery cell proposed in this application embodiment has a flow guide disposed between the first wall and the cell. Along the thickness direction of the first wall, the projection of the injection hole falls within the projection of the flow guide. The electrolyte injected into the injection hole can enter between the side wall of the casing and the side wall of the cell under the guidance of the first flow guide, and flow into the bottom wall of the cell under the action of gravity. As the electrolyte accumulates, it gradually wets from bottom to top, reducing the liquid sealing phenomenon that occurs when the electrolyte wets from the periphery to the middle area, thereby making all parts of the electrode uniformly wetted and improving the reliability of the battery cell.

[0007] Given a fixed projected area on the first side of the battery cell, if S2 / S1 is less than 0.01, it indicates that the area of ​​the bottom wall is too small, and the injected electrolyte cannot flow out in time, resulting in a slow injection speed. If S2 / S1 is greater than 0.15, it indicates that the area of ​​the bottom wall is too large, and the area of ​​the flow guide overlapping with the battery cell in the thickness direction of the first wall is too large, affecting the heat dissipation of the battery cell.

[0008] Secondly, embodiments of this application provide a battery pack comprising the battery cells described in any of the above embodiments.

[0009] The battery pack of this embodiment has the beneficial effects of the battery cells described in any of the above embodiments. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0011] Figure 1 This is a cross-sectional view of a single battery cell;

[0012] Figure 2 for Figure 1 Enlarged view of region A in the middle;

[0013] Figure 3 This is a schematic diagram of the flow guide component;

[0014] Figure 4 This is a schematic diagram of the structure of the first insulating component and the current guiding component.

[0015] [Explanation of Labels in the Attached Image]

[0016] 1. Shell; 11. First wall; 12. Injection hole; 13. First side wall;

[0017] 2. Battery cell; 21. First side; 211. First edge; 212. Second edge; 22. Battery cell body; 23. Electrode tab;

[0018] 3. Flow guide; 31. Bottom wall; 311. First region; 312. Second region; 313. Third region; 32. Side wall;

[0019] 4. Explosion-proof valve;

[0020] 5. First insulating element; 51. Opening; 52. Third sidewall; 53. Fourth sidewall;

[0021] 6. Flow diversion channel;

[0022] 7. Second insulating component;

[0023] 8. Electrode terminals;

[0024] 9. Adapter plate;

[0025] X, the thickness direction of the first wall; Y, the first direction; Z, the second direction. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0028] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0029] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0030] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0031] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0032] In related technologies, after the battery cell is installed in the casing, electrolyte needs to be injected into the battery cell. After the electrolyte is injected, the flow direction of the electrolyte is uncertain. The electrolyte soaks in from the periphery of the battery cell towards the center area, resulting in liquid sealing and affecting the reliability of the battery cell.

[0033] To address the aforementioned issues, this application modifies the wetting direction of the electrolyte, allowing it to wet from bottom to top. This reduces the liquid sealing phenomenon that occurs when the electrolyte wets from the periphery to the center, resulting in uniform wetting of all parts of the positive and negative electrode plates and improving the reliability of the battery cell.

[0034] In a first aspect, embodiments of this application provide a single battery cell, with reference to... Figure 1 and Figure 2 The battery cell includes a housing 1, a cell 2, and a current guide 3. The housing 1 has a first wall 11 with an injection hole 12. The cell 2 is disposed inside the housing 1 and has a first surface 21 facing the first wall 11 along the thickness direction X of the first wall 11. The current guide 3 is disposed between the first wall 11 and the first surface 21. The projection of the injection hole 12 falls into the projection of the current guide 3 along the thickness direction X of the first wall 11. The current guide 3 has a bottom wall 31 along the thickness direction X of the first wall 11. The projected area of ​​the first surface 21 along the thickness direction X of the first wall 11 is S1, and the projected area of ​​the bottom wall 31 is S2, satisfying: 0.01≤S2 / S1≤0.15.

[0035] The bottom wall 31 of the flow guide 3 is aligned with the injection hole 12, so that the electrolyte injected into the injection hole 12 is guided by the bottom wall 31 of the flow guide 3 into the space between the housing 1 and the battery cell 2. However, the area of ​​the bottom wall 31 of the flow guide 3 cannot be too small. If the area of ​​the bottom wall 31 is too small, the injected electrolyte cannot flow out in time, resulting in a slow injection speed. The area of ​​the bottom wall 31 cannot be too large either. If the area of ​​the bottom wall 31 is too large, the area of ​​the flow guide 3 overlapping with the battery cell 2 in the thickness direction X of the first wall 11 will be too large, affecting the heat dissipation of the battery cell 2. Therefore, in order to make the flow guide 3 have a good flow guiding effect and not affect the heat dissipation of the battery cell 2, it is necessary to control the ratio of the projected area of ​​the bottom wall 31 and the first surface 21 to be 0.01≤S2 / S1≤0.15. The ratio S2 / S1 of the projected areas of the bottom wall 31 and the first surface 21 can be 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.10, 0.11, 0.12, 0.13, 0.14 or 0.15, etc.

[0036] In the battery cell proposed in this application embodiment, the flow guide 3 is disposed between the first wall 11 and the cell 2. Along the thickness direction X of the first wall 11, the projection of the injection hole 12 falls into the projection of the flow guide 3. The electrolyte injected into the injection hole 12 can enter between the side wall of the casing 1 and the side wall of the cell 2 under the guidance of the first flow guide 3, and flow into the bottom wall 31 of the cell 2 under the action of gravity. As the electrolyte accumulates, it gradually wets from bottom to top, reducing the liquid sealing phenomenon that occurs when the electrolyte wets from the periphery to the middle area, thereby making all parts of the electrode uniformly wetted and improving the reliability of the battery cell.

[0037] Under the condition that the projected area of ​​the first surface 21 of the cell 2 is fixed, if S2 / S1 is less than 0.01, it means that the area of ​​the bottom wall 31 is too small, and the injected electrolyte cannot flow out in time, resulting in a slow injection speed; if S2 / S1 is greater than 0.15, it means that the area of ​​the bottom wall 31 is too large, and the area of ​​the guide 3 overlapping with the cell 2 in the thickness direction X of the first wall 11 is too large, which affects the heat dissipation of the cell 2.

[0038] Optionally, refer to Figure 1 The housing 1 includes two first sidewalls 13 and two second sidewalls (not shown in the figure). The two first sidewalls 13 are arranged opposite each other along the first direction Y, and the two second sidewalls are arranged opposite each other along the second direction Z. The distance between the two first sidewalls 13 is greater than the distance between the two second sidewalls. The guide member 3 is adapted to guide electrolyte between the second sidewalls and the battery cell 2. The first direction Y, the second direction Z, and the thickness direction X of the first wall 11 are perpendicular to each other. The first sidewalls 13 are smaller faces, and the second sidewalls are larger faces. The two first sidewalls 13 and the two second sidewalls form the peripheral wall of the housing 1, used to encapsulate components such as the battery cell 2.

[0039] Optionally, refer to Figure 1 The battery cell also includes an explosion-proof valve 4, which is located on the first wall 11 along the first direction Y. The distance between the explosion-proof valve 4 and the flow guide 3 is a, which satisfies: a≥3mm.

[0040] The explosion-proof valve 4 is used to release pressure when gas inside the battery cell 2 breaks through the valve during thermal runaway. Along the first direction Y, the distance between the guide element 3 and the explosion-proof valve 4 needs to be controlled to reduce the impact of the guide element 3 on the explosion-proof valve 4. The distance 'a' between the explosion-proof valve 4 and the guide element 3 can be 3mm, 3.2mm, 3.4mm, 3.6mm, 3.8mm, 4.0mm, 4.2mm, 4.4mm, 4.6mm, 4.8mm, 5.0mm, 5.2mm, 5.5mm, 5.7mm, 5.9mm, or 6.0mm, etc. The maximum value of the distance between the explosion-proof valve 4 and the guide element 3 can be determined according to the size of the battery cell. If the distance between the guide element 3 and the explosion-proof valve 4 is too close, the guide element 3 will affect the normal opening of the explosion-proof valve 4 during thermal runaway, thus affecting the discharge of gas from the battery cell 2.

[0041] Optionally, the battery cell 2 includes a battery cell body 22 and a tab 23, with the tab 23 disposed on the battery cell body 22; the first wall 11 is provided with an electrode terminal 8, which is connected to the tab 23 through an adapter piece 9, and the electrode terminal 8 and the adapter piece 9 are welded to form a first solder mark, and the distance between the first solder mark and the current guide 3 along the first direction Y is b, which satisfies: b > 5mm.

[0042] If the distance between the first solder mark and the current guide 3 is too small, the heat generated when the adapter 9 is soldered to the electrode terminal 8 will damage the current guide 3. Specifically, along the first direction Y, the distance b between the first solder mark and the current guide 3 can be 5.05mm, 5.1mm, 5.3mm, 5.5mm, 5.6mm, 5.8mm, 6.0mm, 6.1mm, 6.3mm, 6.5mm, 6.8mm, 7.0mm, 7.2mm, 7.5mm, or 8.0mm, etc. The maximum value of the distance b between the first solder mark and the current guide 3 along the first direction Y can be determined according to the size of the battery cell. If the positive and negative electrodes are led out from the same side of the battery body 22, and two electrode terminals 8 are provided on the first wall 11, with the two electrode terminals 8 connected to the positive and negative electrodes respectively, then the distance b between the current guide 3 and the closer electrode terminal is greater than 5mm.

[0043] Optionally, refer to Figure 3 The bottom wall 31 has a first region 311, a second region 312 and a third region 313. Along the thickness direction X of the first wall 11, the first region 311 is disposed opposite to the injection hole 12. Along the second direction Z, the second region 312 and the third region 313 are located on opposite sides of the first region 311. Along the first direction Y, the size of the first region 311 is smaller than the size of the second region 312 and the size of the third region 313.

[0044] Along the second direction Z, the flow guide 3 is constructed with a narrow middle and wide sides. After the electrolyte is injected from the injection hole 12, it first contacts the narrower first region 311. The electrolyte flows from the first region 311 to the second region 312. The larger second region 312 and third region 313 along the first direction Y can increase the diffusion area of ​​the electrolyte flow, so that the larger area of ​​the battery cell 2 can quickly contact the electrolyte, thereby improving the wetting efficiency.

[0045] It should be understood that the size of the guide 3 can vary in steps from the first region 311 to the second region 312 and from the first region 311 to the third region 313, or it can increase uniformly and gradually.

[0046] Optionally, along the second direction Z, one end of the current guide 3 is flush with one end of the battery cell 2 on the same side, and / or the other end of the current guide 3 is flush with the other end of the battery cell 2 on the same side.

[0047] Along the second direction Z, the guide member 3 can be flush with one end of the same side as the cell 2, or both ends can be flush with the cell 2. With at least one end of the guide member 3 flush with the same side as the cell 2, the electrolyte can flow out along the guide member 3 and then along the side wall of the cell 2 to the bottom of the cell 2. As the electrolyte accumulates, it gradually wets from bottom to top, reducing the liquid sealing phenomenon that occurs when the electrolyte wets from the periphery to the center area. This ensures uniform wetting of all parts of the electrode and improves the reliability of the battery cell.

[0048] For example, the first surface 21 has a third side and a fourth side that are disposed opposite to each other, and the guide member 3 has a first end and a second end that are disposed opposite to each other. Along the thickness direction X of the first wall 11, the first end is disposed opposite to the third side, the second end is disposed opposite to the fourth side, the first end is flush with the third side, and the second end is flush with the fourth side.

[0049] Optionally, along the second direction Z, one end of the current guide 3 protrudes from one end of the same side of the battery cell 2, and / or the other end of the current guide 3 protrudes from the other end of the same side of the battery cell 2.

[0050] Along the second direction Z, the guide member 3 can protrude from one end of the same side of the battery cell 2, or both ends can protrude from the battery cell 2. The guide member 3 protruding from the battery cell 2 allows the electrolyte to flow directly and completely into the bottom of the battery cell 2 under the action of gravity, thereby enabling the electrolyte to quickly wet the electrode sheets and improve the wetting efficiency and uniformity of the battery cell 2 from bottom to top.

[0051] For example, the first surface 21 has a third side and a fourth side that are disposed opposite to each other, and the guide member 3 has a first end and a second end that are disposed opposite to each other. Along the thickness direction X of the first wall 11, the first end is disposed opposite to the third side, the second end is disposed opposite to the fourth side, the first end protrudes from the third side, and the second end protrudes from the fourth side.

[0052] Optionally, refer to Figure 4 The battery cell also includes a first insulating member 5, which is disposed inside the housing 1. The first insulating member 5 has a receiving cavity and an opening 51 communicating with the receiving cavity. The receiving cavity is used to receive the battery cell 2. The opening 51 faces the first wall 11. The current guide 3 is disposed in the opening 51 and connected to the first insulating member 5.

[0053] The first insulating member 5 has an opening 51 and covers the outside of the battery cell 2, serving to encapsulate the battery cell 2 and the electrolyte. The bottom of the first insulating member 5 has multiple holes. A current guide 3 is disposed at the opening 51 along the second direction Z. The current guide 3 connects to the two sidewalls of the first insulating member 5 along the second direction Z at the opening 51. That is, the current guide 3 spans across the opening 51 and covers a portion of the opening 51, wherein the extension length of the current guide 3 along the second direction Z is greater than the dimension of the opening 51 in the second direction Z, allowing the current guide 3 to be supported on the sidewalls of the first insulating member 5. It should be understood that the two ends of the current guide 3 along the second direction Z can protrude from the first insulating member 5 or be flush with it.

[0054] Optionally, refer to Figure 4 The first insulating member 5 includes two third sidewalls 52 and two fourth sidewalls 53. The two third sidewalls 52 are arranged opposite each other along the first direction Y, and the two fourth sidewalls 53 are arranged opposite each other along the second direction Z. The distance between the two third sidewalls 52 is greater than the distance between the two fourth sidewalls 53. The two ends of the flow guide 3 along the second direction Z are respectively fixed to the two fourth sidewalls 53. The fourth sidewalls 53 and / or the second sidewalls are provided with flow guide channels 6, which are adapted to receive the electrolyte discharged by the flow guide 3.

[0055] The two fourth sidewalls 53 are large surfaces, and the two third sidewalls 52 are small surfaces. One of the second sidewalls and the fourth sidewalls 53 is provided with a flow channel 6, or both the second sidewall and the fourth sidewall 53 are provided with flow channels 6. After the electrolyte flows out from the flow guide 3, it flows on the fourth sidewall 53 and / or the second sidewall. The flow channels 6 on the fourth sidewall 53 and / or the second sidewall further guide the electrolyte and increase the flow rate of the electrolyte.

[0056] For example, the flow channel 6 on the fourth sidewall 53 can be a scratch, indentation, etc., and the flow channel 6 on the second sidewall can be a ridge, etc.

[0057] For example, along the second direction Z, one end of the guide member 3 is flush with the fourth side wall 53. The electrolyte flowing out from the guide member 3 flows into the bottom of the cell 2 along the guide channel 6 on the fourth side wall 53. The other end of the guide member 3 protrudes from the fourth side wall 53. The electrolyte flowing out from the guide member 3 flows into the bottom of the cell 2 along the guide channel 6 on the second side wall. As the electrolyte accumulates, the electrolyte passes through the hole at the bottom of the first insulating member 5 and enters the cell 2 to wet the electrode.

[0058] Optionally, there may be multiple flow channels 6, which are spaced apart. Both the second sidewall and the fourth sidewall 53 may be provided with multiple spaced flow channels 6 to improve the electrolyte injection efficiency. It should be understood that the flow channels 6 may extend vertically along the thickness direction X of the first wall 11 or may be inclined, as long as they can increase the area reached by the electrolyte flow, thereby improving the electrolyte injection efficiency.

[0059] Optionally, the guide member 3 further includes two side walls 32. Along the first direction Y, the two side walls 32 are disposed on opposite sides of the bottom wall 31. Along the first direction Y, the distance between the two side walls 32 is d1. Along the first direction Y, the first surface 21 has a first side 211 and a second side 212 disposed opposite to each other. Along the first direction Y, the distance between the first side 211 and the second side 212 is d2, satisfying: 0.01≤d1 / d2≤0.15.

[0060] In this embodiment, the flow guide 3 includes two side walls 32 and a bottom wall 31 connected between the two side walls 32, that is, the flow guide 3 is constructed as a flow guide groove.

[0061] Given that the size of the cell 2 along the first direction Y is constant, if the value of d1 / d2 is too small, it means that the distance between the two side walls 32 of the guide 3 is too small, that is, the size of the bottom wall 31 of the guide 3 is too small, resulting in poor flow guiding effect. If the value of d1 / d2 is too large, it means that the distance between the two side walls 32 of the guide 3 is too large, that is, the size of the bottom wall 31 of the guide 3 is too large. If the size of the guide 3 is too large, it is easy to cause interference with other components.

[0062] The value of d1 / d2 can be 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.10, 0.11, 0.12, 0.13, 0.14, or 0.15, etc.

[0063] Optionally, along the first direction Y, the dimension of the sidewall 32 is e, satisfying: 0.2mm < e ≤ 2mm. Wherein, the dimension e of the sidewall 32 along the first direction Y can be 0.205mm, 0.21mm, 0.215mm, 0.22mm, 0.225mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, 0.30mm, 0.31mm, 0.32mm, 0.33mm, 0.35mm, 0.36mm, 0.38mm, 0.39mm, 0.4mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.5mm, 1.7mm, 1.8mm, 1.9mm, or 2.0mm, etc. If the thickness of the sidewall 32 is too large, it is easy to interfere with other components; if the thickness of the sidewall 32 is too small, the strength will be insufficient.

[0064] Optionally, the battery cell further includes a second insulating member 7, which is disposed between the first wall 11 and the first surface 21, and the current guide member 3 is disposed on the second insulating member 7.

[0065] The second insulating member 7 is disposed between the battery cell 2 and the first wall 11 for insulation between the battery cell 2 and the first wall 11. The current guide 3 is disposed on the second insulating member 7, which may be the two side walls 32 of the current guide 3 connected to the second insulating member 7. The insulating member has a through hole disposed opposite to the injection hole 12 to inject electrolyte onto the current guide 3.

[0066] Optionally, the first wall 11 is provided with electrode terminals 8, and the battery cell 2 includes a battery cell body 22 and a tab 23. The tab 23 is provided on the battery cell body 22 and connected to the electrode terminals 8. Along the thickness direction X of the first wall 11, the projection of the current guide 3 does not coincide with the projection of the tab 23.

[0067] Along the thickness direction X of the first wall 11, if the projection of the guide member 3 coincides with the projection of the tab 23, during electrolyte injection, the guide member 3 may be pressed against the overlapping portion of the tab 23 by the impact of the electrolyte, resulting in the tab 23 being inserted backwards or torn. In this application, the guide member 3 and the tab 23 are not aligned, thereby reducing the pressure of the guide member 3 on the tab 23, and thus reducing the possibility of the tab 23 being inserted backwards or torn.

[0068] Optionally, the current guide 3 is constructed as an insulating component. The current guide 3 being made of insulating material can reduce the risk of short circuits between the battery cell 2 and the casing 1.

[0069] Secondly, embodiments of this application provide a battery pack comprising the battery cells described in any of the above embodiments. The battery pack of this embodiment possesses the beneficial effects of the battery cells described in any of the above embodiments.

[0070] Thirdly, embodiments of this application provide an electrical device including a single battery cell as described in any of the above embodiments or a battery pack as described in the above embodiments. The battery pack of this embodiment has the beneficial effects of the battery pack and single battery cell described in any of the above embodiments.

[0071] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0072] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0073] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

[0074] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery cell, characterized in that, include: The shell has a first wall, and the first wall is provided with a liquid injection hole; A battery cell is disposed within the housing, and along the thickness direction of the first wall, the battery cell has a first surface facing the first wall; A flow guide is disposed between the first wall and the first surface. Along the thickness direction of the first wall, the projection of the injection hole falls into the projection of the flow guide. Along the thickness direction of the first wall, the flow guide has a bottom wall. Wherein, along the thickness direction of the first wall, the projected area of ​​the first surface is S1, and the projected area of ​​the bottom wall is S2, satisfying: 0.01≤S2 / S1≤0.

15.

2. The battery cell according to claim 1, characterized in that, The housing includes two first sidewalls and two second sidewalls. The two first sidewalls are arranged opposite each other along a first direction and the two second sidewalls are arranged opposite each other along a second direction. The distance between the two first sidewalls is greater than the distance between the two second sidewalls. The flow guide is adapted to guide electrolyte between the second sidewalls and the battery cell. The first direction, the second direction and the thickness direction of the first wall are perpendicular to each other.

3. The battery cell according to claim 2, characterized in that, It also includes an explosion-proof valve, which is disposed on the first wall along the first direction, and the distance between the explosion-proof valve and the flow guide is a, satisfying: a≥3mm.

4. The battery cell according to claim 2, characterized in that, The battery cell includes a battery cell body and a tab, wherein the tab is disposed on the battery cell body; The first wall is provided with an electrode terminal, which is connected to the electrode tab through an adapter piece. The electrode terminal and the adapter piece are welded to form a first solder mark. Along the first direction, the distance between the first solder mark and the current guide is b, which satisfies: b > 5 mm.

5. The battery cell according to claim 2, characterized in that, The bottom wall has a first region, a second region, and a third region. Along the thickness direction of the first wall, the first region is disposed opposite to the injection hole. Along the second direction, the second region and the third region are respectively located on opposite sides of the first region. Along the first direction, the size of the first region is smaller than the size of the second region and the size of the third region.

6. The battery cell according to claim 2, characterized in that, Along the second direction, one end of the current guide is flush with one end of the battery cell on the same side, and / or the other end of the current guide is flush with the other end of the battery cell on the same side.

7. The battery cell according to claim 2, characterized in that, Along the second direction, one end of the current guide protrudes from one end of the battery cell on the same side, and / or the other end of the current guide protrudes from the other end of the battery cell on the same side.

8. The battery cell according to claim 2, characterized in that, It also includes a first insulating member disposed within the housing. The first insulating member has a receiving cavity and an opening communicating with the receiving cavity. The receiving cavity is used to receive the battery cell. The opening faces the first wall. The current guide is disposed at the opening and connected to the first insulating member.

9. The battery cell according to claim 8, characterized in that, The first insulating member includes two third sidewalls and two fourth sidewalls. The two third sidewalls are arranged opposite each other along a first direction, and the two fourth sidewalls are arranged opposite each other along a second direction. The distance between the two third sidewalls is greater than the distance between the two fourth sidewalls. The two ends of the flow guide along the second direction are respectively fixed to the two fourth sidewalls. The fourth sidewalls and / or the second sidewalls are provided with flow channels, which are adapted to receive the electrolyte discharged by the flow guide.

10. The battery cell according to claim 9, characterized in that, There are multiple flow channels, and the multiple flow channels are arranged at intervals.

11. The battery cell according to claim 2, characterized in that, The guide also includes two sidewalls, which are disposed on opposite sides of the bottom wall along the first direction, and the distance between the two sidewalls is d1 along the first direction. Along the first direction, the first surface has a first side and a second side arranged opposite to each other. Along the first direction, the distance between the first side and the second side is d2, which satisfies: 0.01≤d1 / d2≤0.

15.

12. The battery cell according to claim 11, characterized in that, Along the thickness direction of the first wall, the dimension of the sidewall is e, which satisfies: 0.2mm < e ≤ 2mm.

13. The battery cell according to claim 1, characterized in that, It also includes a second insulating member disposed between the first wall and the first surface, and the flow guide is disposed on the second insulating member.

14. The battery cell according to claim 1, characterized in that, The first wall is provided with electrode terminals. The battery cell includes a battery cell body and a tab. The tab is disposed on the battery cell body and connected to the electrode terminals. Along the thickness direction of the first wall, the projection of the current guide does not coincide with the projection of the tab.

15. The battery cell according to claim 1, characterized in that, The flow guide is constructed as an insulating component.

16. A battery pack, characterized in that, Includes the battery cell according to any one of claims 1-15.

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