Battery cell, battery pack, and electric device

Abstract

The application provides an electric core, a battery pack and a power utilization device, and relates to the technical field of battery packs, and aims to reduce the risk of thermal runaway of the battery pack. The electric core comprises a shell, a pole and a first explosion-proof valve. The shell is surrounded to form a containing cavity; the shell comprises oppositely arranged first and second shell walls and adjacently arranged third and fourth shell walls, the end of the third shell wall away from the fourth shell wall is connected with the first shell wall, and the end of the fourth shell wall away from the third shell wall is connected with the second shell wall; the fourth shell wall is located on the side of the second shell wall facing the containing cavity and the side of the third shell wall facing the containing cavity; in the first direction, the ratio of the height of the fourth shell wall to the distance between the first and second shell walls is greater than or equal to 0.05; wherein the first direction is the arrangement direction of the first and second shell walls. The pole is arranged on the first shell wall. The first explosion-proof valve is arranged on the fourth shell wall and is in communication with the containing cavity. The electric core provided by the application is beneficial to reducing the risk of thermal runaway of the battery pack.

Description

Technical Field

[0001] This application relates to the field of new energy equipment technology, specifically to a battery cell, battery pack, and electrical equipment. Background Technology

[0002] With technological advancements, new energy equipment is gaining increasing popularity, especially those using batteries as a power source, which are experiencing a growing market share. Battery packs in new energy equipment typically consist of a casing and battery cells assembled within it. The cell casing usually features explosion-proof valves to release gas from the cell and then out of the casing when internal pressure becomes excessive. However, in related technologies, the venting channels between adjacent cells or between a cell and the casing wall are often small, resulting in a higher risk of thermal runaway. Utility Model Content

[0003] This application provides a battery cell, a battery pack, and an electrical device to address the problem of how to reduce the risk of thermal runaway in a battery pack.

[0004] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0005] In a first aspect, embodiments of this application provide a battery cell, which includes a housing, a terminal post, and a first explosion-proof valve. The housing encloses a receiving cavity; the housing includes a first housing wall and a second housing wall disposed opposite to each other, and a third housing wall and a fourth housing wall connected to each other. The end of the third housing wall away from the fourth housing wall is connected to the first housing wall, and the end of the fourth housing wall away from the third housing wall is connected to the second housing wall; the fourth housing wall is located on the side of the second housing wall facing the receiving cavity and on the side of the third housing wall facing the receiving cavity; along a first direction, the height B of the fourth housing wall and the distance H between it and the first and second housing walls satisfy: B / H≥0.05; wherein, the first direction is the arrangement direction of the first and second housing walls. The terminal post is disposed on the first housing wall. The first explosion-proof valve is disposed on the fourth housing wall and communicates with the receiving cavity.

[0006] In some possible implementations of the first aspect, along the first direction, the height B of the fourth shell wall and the distance H between the first shell wall and the second shell wall also satisfy: B / H≤0.38.

[0007] In some possible implementations of the first aspect, from the third shell wall to the second shell wall, the fourth shell wall extends in a direction that gradually moves away from the third shell wall and gradually moves away from the first shell wall.

[0008] In some possible implementations of the first aspect, the fourth shell wall is parallel to the second direction, which is a direction perpendicular to the first direction and parallel to the third shell wall.

[0009] In some possible implementations of the first aspect, the housing further includes a fifth housing wall and a sixth housing wall connected to each other, with one end of the fifth housing wall away from the sixth housing wall connected to the first housing wall, and one end of the sixth housing wall away from the fifth housing wall connected to the second housing wall; the sixth housing wall is located on the side of the second housing wall facing the receiving cavity and on the side of the fifth housing wall facing the receiving cavity. The battery cell also includes a second explosion-proof valve, which is disposed on the sixth housing wall and communicates with the receiving cavity.

[0010] In some possible implementations of the first aspect, the length A of the second shell wall along the third direction and the distance L between the third shell wall and the fifth shell wall along the third direction satisfy: 0.55≤A / L≤0.95; where the third direction is the arrangement direction of the third shell wall and the fifth shell wall, and the third direction is perpendicular to the first direction.

[0011] In some possible implementations of the first aspect, the electrode posts include positive and negative electrode posts spaced apart. The first shell wall has a liquid injection hole, the distance between the liquid injection hole and the positive electrode post being less than the distance between the liquid injection hole and the negative electrode post.

[0012] Secondly, embodiments of this application provide a battery pack, which includes a housing, battery cells, and a third explosion-proof valve. The battery cells are disposed within the housing, and the battery cells are those described in any of the above implementations. The fourth shell wall of the battery cell, together with the housing wall and / or the shell of an adjacent battery cell, forms an exhaust channel. The third explosion-proof valve is disposed on the housing wall and communicates with the exhaust channel.

[0013] In some possible implementations of the second aspect, the housing includes a first housing wall that contacts a first shell wall, the first housing wall having a clearance groove, and the pole located within the clearance groove.

[0014] Thirdly, embodiments of this application provide an electrical device, which includes an electrical main body and a battery pack. The battery pack is the battery pack described in any of the above implementations, and the battery pack is electrically connected to the electrical main body.

[0015] The battery cell, battery pack, and electrical equipment provided in this application have the following beneficial effects:

[0016] The battery cell provided in this application, by arranging the first and second shell walls opposite each other, and the third and fourth shell walls connected together, with the third shell wall connecting between the fourth shell wall and the first shell wall, and the fourth shell wall connecting between the second and third shell walls, is located on the side of the second and third shell walls facing the receiving cavity. The height of the fourth shell wall along the first direction and the distance between the first and second shell walls are greater than or equal to 0.05, allows the fourth shell wall of the battery cell to form a large-area exhaust channel with the shell wall and / or adjacent battery cells when the battery cell is assembled in the battery pack housing. Based on this, by setting the first explosion-proof valve on the fourth shell wall, when the internal pressure of the battery cell increases, the first explosion-proof valve can release gas into the exhaust channel, thereby allowing the gas to be discharged from the battery pack more quickly, reducing the risk of thermal runaway of the battery pack and ensuring the safety and reliability of the battery pack.

[0017] Furthermore, by placing the terminals on the first housing wall, so that the terminals and the first explosion-proof valve are roughly located at opposite ends of the battery cell, the high-temperature gas discharged from the first explosion-proof valve can prevent it from affecting the reliability of the electrical connection at the terminals, thus achieving thermoelectric separation and further ensuring the safety performance of the battery pack. Finally, when the battery cells are assembled into the casing, by aligning the first housing wall with the first casing wall (which is the upper casing wall of the battery pack), the small amount of electrolyte discharged when the first explosion-proof valve operates will not come into contact with the terminals, reducing the risk of short circuits and further ensuring the safety and reliability of the battery pack.

[0018] The beneficial technical effects of the battery pack and electrical equipment provided in this application are the same as those of the battery cell provided in this application, and will not be repeated here. Attached Figure Description

[0019] Figure 1 Schematic diagrams of electrical equipment provided in some embodiments of this application;

[0020] Figure 2 for Figure 1 A cross-sectional structural diagram of the battery pack of the electrical equipment shown.

[0021] Figure 3 for Figure 2 A cross-sectional structural diagram of the battery pack of the electrical equipment shown.

[0022] Figure 4 for Figure 3 A three-dimensional structural diagram of the battery cells in the battery pack shown.

[0023] Figure 5 for Figure 4 A three-dimensional structural diagram of the battery cell as seen from another perspective;

[0024] Figure 6 for Figure 4 The front view of the battery cell shown;

[0025] Figure 7 for Figure 4 A top view of the battery cell shown;

[0026] Figure 8 Three-dimensional structural diagrams of the battery cell provided for other embodiments of this application;

[0027] Figure 9 Three-dimensional structural diagrams of the battery cell provided for some embodiments of this application;

[0028] Figure 10 for Figure 9 The diagram shows the three-dimensional structure of the battery cell as viewed from another angle.

[0029] Figure 11 This is a front view of the battery cell shown in Figure 9;

[0030] Figure 12 Three-dimensional structural diagrams of the battery cell provided for some embodiments of this application;

[0031] Figure 13 Cross-sectional structural diagram of a battery pack provided for other embodiments of this application.

[0032] Figure label:

[0033] Electrical equipment 100; Battery compartment 110a;

[0034] Electricity user 110;

[0035] Battery pack 120; Exhaust channel 120a;

[0036] Box body 121; first inner cavity 121a; first box wall 1211; clearance groove 1211a; second box wall 1212; third box wall 1213; fourth box wall 1214; fifth box wall 1215; sixth box wall 1216;

[0037] Battery cell 122; housing 10; receiving cavity 10a; first housing wall 11; liquid injection hole 11a; second housing wall 12; third housing wall 13; fourth housing wall 14; fifth housing wall 15; sixth housing wall 16; seventh housing wall 17; eighth housing wall 18; electrode group 20; electrode post 30; positive electrode post 31; negative electrode post 32; first explosion-proof valve 40; second explosion-proof valve 50;

[0038] The third explosion-proof valve 123. Detailed Implementation

[0039] In the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0040] In the embodiments of this application, it should be understood that the directional terms mentioned, such as "up", "down", "left", "right", "inner", "outer", etc., are only for reference to the direction of the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of this application, and are not intended to 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 embodiments of this application.

[0041] In the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0042] In embodiments of this application, 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 that element.

[0043] In the embodiments of this application, "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, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0044] In the embodiments of this application, it should be noted that the descriptions of "vertical" and "parallel" respectively indicate approximately vertical and approximately parallel within a certain error range. This error range can be a range where the deviation angle relative to absolute verticality and absolute parallelism is less than or equal to 5°, 8°, 10° or 20°, respectively, and is not specifically limited here.

[0045] With technological advancements, new energy equipment is gaining increasing popularity, especially those using batteries as a power source, which are experiencing a growing market share. Battery packs in new energy equipment typically consist of a housing and battery cells assembled within it. The cell casing usually features explosion-proof valves to release gas from the cell and then out of the housing when internal pressure becomes excessive. However, in related technologies, the venting channels between adjacent cells or between a cell and the housing wall are often small, resulting in a higher risk of thermal runaway.

[0046] To address the aforementioned issues, this application provides a battery cell in which a shell wall located on the side of the inner cavity of the two shell walls facing different directions is connected between the two shell walls of the battery cell housing. This allows for the formation of exhaust channels with large flow areas between adjacent battery cells and between the battery cells and the battery pack's casing wall, which is beneficial for improving the safety of the battery pack, reducing the risk of thermal runaway of the battery pack, and thus reducing the risk of thermal runaway of electrical equipment.

[0047] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0048] Please see Figure 1 , Figure 1 This is a schematic diagram of an electrical device 100 provided in some embodiments of this application. Figure 1 In the illustrated embodiment, an electric vehicle is used as an example of the electrical device 100 for illustrative purposes, and this should not be construed as a specific limitation of this application. In other embodiments, the electrical device may also be a mobile phone, a laptop computer, a mobile charging station, or other similar devices.

[0049] Please continue reading. Figure 1 The electrical device 100 includes a power-consuming body 110 and a battery pack 120. The battery pack 120 is fixed to the power-consuming body 110 and electrically connected to the power-consuming components of the power-consuming body 110 to supply power to the power-consuming components of the power-consuming body 110. Specifically, the power-consuming body 110 may have a battery compartment 110a, and the battery pack 120 is fixed inside the battery compartment 110a.

[0050] Please see Figure 2 and Figure 3 , Figure 2 for Figure 1 The diagram shows a cross-sectional view of the battery pack 120 of the electrical device 100. Figure 3 for Figure 2The diagram shows a cross-sectional view of the battery pack 120 of the electrical device 100. The battery pack 120 may include a housing 121 and at least one row of battery cells 122. The battery cells 122 are disposed in the first inner cavity 121a of the housing 121 and are fixed relative to the housing 121. The housing 121 protects the battery cells 122 from external forces causing vibration and impact that could damage them. The housing 121 may be a metal structure or a plastic structure.

[0051] The enclosure 121 may include a first enclosure wall 1211 and a second enclosure wall 1212 arranged opposite to each other and spaced apart along a first direction, a third enclosure wall 1213 and a fourth enclosure wall 1214 arranged opposite to each other and spaced apart along a third direction, and a fifth enclosure wall 1215 and a sixth enclosure wall 1216 arranged opposite to each other and spaced apart along a second direction. The first enclosure wall 1211, the second enclosure wall 1212, the third enclosure wall 1213, the fourth enclosure wall 1214, the fifth enclosure wall 1215, and the sixth enclosure wall 1216 enclose a first inner cavity 121a of the enclosure 121. The first direction, the third direction, and the second direction may be perpendicular to each other. Figure 1 and Figure 2 In the illustrated embodiment, the second direction can be the arrangement direction of the front and rear of the electric vehicle, and the third direction can be the extension direction of the electric vehicle's axle. In other embodiments, the first direction, the third direction, and the second direction can also be other directions, and this application does not limit them.

[0052] Cell 122 is the most basic electrochemical unit, capable of storing and releasing electrical energy. Cell 122 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and this application embodiment does not limit it to this.

[0053] Figure 2 and Figure 3 In the illustrated embodiment, the battery pack 120 includes two rows of cells 122 arranged along a third direction, and each row of cells 122 includes multiple cells 122 arranged along a second direction. The cells 122 within the battery pack 120 can be electrically connected in series, in parallel, or in a mixed configuration. A mixed configuration means that the electrical connections among the multiple cells 122 include both series and parallel connections, which can be specifically designed according to the power requirements of the electrical device 100. In other embodiments, the battery pack 120 may also contain only one cell 122, i.e., the battery pack 120 includes one row of cells 122, and each row of cells 122 includes only one cell 122.

[0054] Please see Figures 4-6 , Figure 4 for Figure 3A three-dimensional structural diagram of the battery cell 122 in the battery pack 120 is shown. Figure 5 for Figure 4 The diagram shows a three-dimensional structure of cell 122 as viewed from another angle. Figure 6 for Figure 4 The diagram shows a front view of the battery cell 122. The battery cell includes a housing 10, electrode assembly 20, terminal posts 30, and a first explosion-proof valve 40. The housing 10 can be a rigid component. The housing 10 can be a metal housing. In some examples, the housing 10 can be an aluminum alloy housing to reduce its weight, which is beneficial for the lightweight design of the battery cell 122 and consequently for the overall lightweight design of the electrical equipment 100. In other examples, the housing 10 can also be a stainless steel housing to increase its strength, thereby improving the overall strength of the battery cell 122 and providing better protection against puncture and vibration damage.

[0055] The housing 10 encloses a receiving cavity 10a. The electrode assembly 20 is disposed within the receiving cavity 10a and immersed in the electrolyte. The electrode assembly 20 includes a positive electrode (not shown), a negative electrode (not shown), and a separator (not shown). The positive electrode can be formed from a positive current collector and a positive active material coated on the positive current collector. In some examples, the positive current collector can be aluminum foil, and the positive active material can be lithium cobalt oxide (LCO), ternary materials (NCM / NCA), lithium iron phosphate (LFP), etc. The negative electrode can be formed from a negative current collector and a negative active material coated on the negative current collector. In some examples, the negative current collector can be copper foil, and the negative active material can be graphite, silicon-carbon composite material, etc. The separator is disposed between the positive and negative electrode to isolate them and prevent short circuits. The separator can be made of porous polyethylene (PE) or polypropylene (PP), etc.

[0056] Specifically, the housing 10 includes a first housing wall 11 and a second housing wall 12 that are opposite to and spaced apart, and a third housing wall 13 and a fourth housing wall 14 that are connected. The end of the third housing wall 13 away from the fourth housing wall 14 is connected to the first housing wall 11, and the end of the fourth housing wall 14 away from the third housing wall 13 is connected to the second housing wall 12. The fourth housing wall 14 is located on the side of the second housing wall 12 facing the receiving cavity 10a and on the side of the third housing wall 13 facing the receiving cavity 10a. Specifically, the first housing wall 11 and the second housing wall 12 are arranged along the aforementioned first direction, that is, the first direction is the arrangement direction of the first housing wall 11 and the second housing wall 12. The first housing wall 11 and the second housing wall 12 may both be perpendicular to the first direction, and the third housing wall 13 may be perpendicular to the third direction to reduce the design and manufacturing difficulty of the housing 10, that is, the third housing wall 13 is parallel to the second direction. In some other embodiments, the third housing wall 13 may not be perpendicular to the first housing wall 11 and the second housing wall 12. Based on this, along the first direction, the ratio of the height B of the fourth shell wall 14 to the distance H between the first shell wall 11 and the second shell wall 12 is greater than or equal to 0.05, that is, B / H≥0.05.

[0057] The electrode post 30 is disposed on the first shell wall 11, with one end of the electrode post 30 located inside the receiving cavity 10a and the other end of the electrode post 30 located on the side of the first shell wall 11 opposite to the receiving cavity 10a. Specifically, the electrode post 30 includes a positive electrode post 31 and a negative electrode post 32 arranged at intervals along the length direction of the first shell wall. The end of the positive electrode post 31 located in the receiving cavity 10a can be electrically connected to the positive electrode plate through a tab, and the end of the negative electrode post 32 located in the receiving cavity 10a can be electrically connected to the negative electrode plate through a tab. The battery cell 122 can be electrically connected to other components through the electrode post 30.

[0058] Based on this, the ratio of the center distance D between the positive electrode post 31 and the negative electrode post 32 to the length L of the first shell wall 11 is greater than or equal to 0.55 and less than or equal to 0.9, i.e., 0.55 ≤ D / L ≤ 0.9. For example, the ratio of D to L can be 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, etc. This ensures a large distance between the positive electrode post 31 and the negative electrode post 32, and also ensures a large distance between the positive electrode post 31 and the negative electrode post 32 and the edge of the first shell wall 11, facilitating the placement of electrode tabs and other electrical connection structures.

[0059] The first explosion-proof valve 40 is disposed on the fourth shell wall 14 and is connected to the receiving cavity 10a of the shell 10. When the internal pressure of the battery cell 122 increases due to overcharging, over-discharging, short circuit or external impact, the first explosion-proof valve 40 can release gas to prevent the battery cell 122 from exploding due to excessive pressure, thereby ensuring the safety of the battery cell 122 and thus ensuring the overall safety of the battery pack 120.

[0060] Please return to the reference. Figure 3 When the battery cell 122 is assembled inside the housing 121, the first shell wall 11 can face the first box wall 1211, which can be the upper box wall of the battery pack 120. The second shell wall 12 is fixed to the second box wall 1212 so that the battery cell 122 is fixed in the first inner cavity 121a of the housing 121. In this way, the surface of the fourth shell wall 14 of the battery cell 122 facing away from the receiving cavity 10a can be oriented towards the third box wall 1213 or the fourth box wall 1214 of the housing 121. Thus, the fourth shell wall 14 of the cell 122 adjacent to the third box wall 1213 or the fourth box wall 1214 of the box 121 forms an exhaust channel 120a with the box wall of the box 121; when the battery pack 120 includes multiple rows of cells 122, the fourth shell wall 14 of a portion of the cells 122 can form an exhaust channel 120a with the shell 10 of the adjacent cells 122 and the second box wall 1212; when the battery pack 120 includes two layers of cells 122 arranged along the first direction, and each layer of cells 122 includes multiple rows of cells 122, a portion of the cells 122 can form an exhaust channel 120a with the shell 10 of the adjacent cells 122.

[0061] Based on this, the battery pack 120 also includes a third explosion-proof valve 123, which can be installed on the wall of the housing 121 and communicate with the first inner cavity 121a. Specifically, the third explosion-proof valve 123 can be one-to-one with and communicate with the exhaust channel 120a, and one third explosion-proof valve 123 can also be connected to multiple exhaust channels 120a.

[0062] In summary, the battery cell 122 provided in this application, by having the first shell wall 11 and the second shell wall 12 arranged opposite to each other, and the third shell wall 13 and the fourth shell wall 14 connected, with the third shell wall 13 connected between the fourth shell wall 14 and the first shell wall 11, and the fourth shell wall 14 connected between the second shell wall 12 and the third shell wall 13, and the fourth shell wall 14 located on the side of the second shell wall 12 and the third shell wall 13 facing the receiving cavity 10a, and the distance between the height of the fourth shell wall 14 along the first direction and the first shell wall 11 and the second shell wall 12 being greater than or equal to 0.05, allows the fourth shell wall 14 of the battery cell 122 to form an exhaust channel 120a with a large flow area when the battery cell 122 is assembled in the housing 121, together with the housing wall of the housing 121 and / or the adjacent battery cell 122. Based on this, by setting the first explosion-proof valve 40 on the fourth shell wall 14, when the internal pressure of the battery cell 122 increases, the first explosion-proof valve 40 can release gas into the exhaust channel 120a, and then quickly discharge it outside the battery pack 120 through the third explosion-proof valve 123 set on the box wall of the box 121, thereby reducing the risk of thermal runaway of the battery pack 120 and ensuring the safety and reliability of the battery pack 120.

[0063] Furthermore, by placing the terminal post 30 on the first housing wall 11, so that the terminal post 30 and the first explosion-proof valve 40 are approximately located at opposite ends of the battery cell 122, the high-temperature gas discharged from the first explosion-proof valve 40 can prevent it from affecting the reliability of the electrical connection at the terminal post 30, thus achieving thermoelectric separation and further ensuring the safety performance of the battery pack 120. Finally, when the battery cell 122 is assembled inside the housing 121, the first housing wall 11 can be positioned opposite the first housing wall 1211, which is the upper housing wall of the battery pack 120. This ensures that when the first explosion-proof valve 40 is operating, the discharged electrolyte will not come into contact with the terminal post 30, reducing the risk of short circuits and further ensuring the safety and reliability of the battery pack 120.

[0064] Based on the above, along the first direction, the ratio of the height B of the fourth shell wall 14 to the distance H between the first shell wall 11 and the second shell wall 12 is less than or equal to 38%, i.e., B / H ≤ 0.38. For example, the ratio of B to H can be 0.05, 0.08, 0.1, 0.13, 0.15, 0.18, 0.2, 0.22, 0.25, 0.28, 0.3, 0.34, 0.38, etc. Figures 4-6 In the illustrated embodiment, the distance H between the first shell wall 11 and the second shell wall 12 in the first direction is less than the length of the first shell wall 11 in the third direction, and the ratio of B to H can be greater than or equal to 0.08. In some other embodiments, the distance H between the first shell wall 11 and the second shell wall 12 in the first direction is less than the length of the first shell wall 11 in the third direction, and the ratio of B to H can also be less than 0.08.

[0065] In this way, the flow area of ​​the exhaust channel 120a formed by the fourth shell wall 14 and the box wall of the box 121 and / or the shell 10 of the adjacent cell 122 can be maximized, the area of ​​the fourth shell wall 14 can be maximized to facilitate the installation of the first explosion-proof valve 40 with a larger discharge area, and the volume of the receiving cavity 10a formed by the shell 10 can be maximized to increase the size of the electrode group 20 and ensure the capacity of the cell 122.

[0066] Please continue reading. Figures 4-6 The surface of the fourth shell wall 14 facing away from the receiving cavity 10a can be a continuous smooth curved surface; from the third shell wall 13 to the second shell wall 12, the fourth shell wall 14 extends in a direction that gradually moves away from the third shell wall 13 and gradually moves away from the first shell wall 11. Figures 4-6In the illustrated embodiment, the fourth shell wall 14 is generally flat, meaning the surface of the fourth shell wall 14 facing away from the receiving cavity 10a is a curved surface with zero curvature. In other embodiments, the fourth shell wall 14 may also be an arc-shaped plate that arches towards or away from the receiving cavity 10a. This allows for a larger flow area in the aforementioned exhaust channel 120a while maintaining the volume of the receiving cavity 10a for the battery cell 122, thereby ensuring the capacity of the battery cell 122. It also simplifies the design and assembly of the housing 10.

[0067] In some other embodiments, the fourth shell wall 14 may first extend in a direction close to the first shell wall 11 and away from the third shell wall 13, and then extend in a direction away from both the first shell wall 11 and the third shell wall 13. In still other embodiments, the fourth shell wall 14 may first extend in a direction away from the third shell wall 13 and parallel to the first shell wall 11, and then extend in a direction away from the first shell wall 11 and parallel to the third shell wall 13.

[0068] Please continue reading. Figures 4-6 The fourth shell wall 14 is parallel to the second direction. This further simplifies the design and manufacturing difficulty of the shell 10. In addition, when a row of cells 122 includes multiple cells 122, the fourth shell walls 14 of the multiple cells 122 form multiple exhaust channels 120a connected along the second direction to form a set of exhaust channels 120a. At this time, the flow area of ​​the set of exhaust channels 120a is consistent, ensuring the overall discharge efficiency of the battery pack 120.

[0069] In some other embodiments, the fourth shell wall 14 may also intersect the second direction, with the included angle between them being less than 90°.

[0070] Please continue reading. Figures 4-6 The angle θ between the plane containing the fourth shell wall 14 and the third shell wall 13 can be greater than or equal to 30° and less than or equal to 75°, i.e., 30°≤θ≤75°. For example, the angle θ between the plane containing the fourth shell wall 14 and the third shell wall 13 can be 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, etc. In this way, with a fixed area of ​​the fourth shell wall 14, the flow area of ​​the exhaust channel 120a can be maximized to ensure the discharge efficiency of the battery pack 120, thereby ensuring the safety and reliability of the battery pack 120.

[0071] Please continue reading. Figures 4-6The length C of the orthographic projection of the fourth shell wall 14 onto the first reference plane can be greater than or equal to 8 mm and less than or equal to 85 mm; wherein, the first reference plane is a plane perpendicular to the second direction, i.e., 8 mm ≤ C ≤ 85 mm. For example, the length C of the orthographic projection of the fourth shell wall 14 onto the first reference plane can be 8 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, 85 mm, etc. Specifically, the value of C can be selected according to the overall size and capacity of the cell 122. Generally, the larger the overall size or capacity of the cell 122, the larger the value of C can be.

[0072] In this way, with the thickness of the battery cell 122 along the second direction being constant, the area of ​​the fourth shell wall 14 can be made larger so that a first explosion-proof valve 40 of appropriate size can be selected to ensure the discharge efficiency, and the area of ​​the fourth shell wall can be prevented from being too large and affecting the volume of the battery cell 122.

[0073] Based on the above, please continue to refer to... Figures 4-6 The housing 10 also includes a fifth housing wall 15 and a sixth housing wall 16 that are in contact with each other. The end of the fifth housing wall 15 away from the sixth housing wall 16 is connected to the first housing wall 11, and the end of the sixth housing wall 16 away from the fifth housing wall 15 is connected to the second housing wall 12. The sixth housing wall 16 is located on the side of the second housing wall 12 facing the receiving cavity 10a and on the side of the fifth housing wall 15 facing the receiving cavity 10a. Specifically, the fifth housing wall 15 may be parallel to the third housing wall 13.

[0074] Based on this, the battery cell 122 also includes a second explosion-proof valve 50, which is disposed on the sixth shell wall 16 and connected to the receiving cavity 10a. In this way, when the battery cell 122 is assembled inside the housing 121, the sixth shell wall 16 of the battery cell 122 can form an exhaust channel 120a with the housing wall of the housing 121 and / or the fourth shell wall 14 of adjacent battery cells 122. Thus, more exhaust channels 120a can be formed between the battery cell 122 and the housing wall, or the exhaust channels 120a formed between adjacent battery cells 122 can have a larger flow area. This allows the first explosion-proof valve 40 and the second explosion-proof valve 50 to release gas into the exhaust channel 120a more quickly when the internal pressure of the battery cell 122 increases, and then discharge the gas to the outside of the battery pack 120 more quickly through the exhaust channel 120a, thereby further reducing the risk of thermal runaway of the battery pack 120 and ensuring the safety and reliability of the battery pack 120.

[0075] Furthermore, the second explosion-proof valve 50 and the terminal post 30 also achieve thermoelectric separation, further ensuring the safety and reliability of the battery pack 120. Finally, compared to simply increasing the area of ​​the fourth shell wall 14 to increase the discharge area of ​​the first explosion-proof valve 40 and the total flow area of ​​the exhaust channel 120a, since the fourth shell wall 14 and the sixth shell wall 16 are located at the two corners of the cell 122, they have a smaller impact on the volume of the receiving cavity 10a, thereby ensuring the volume of the cell 122.

[0076] Along the first direction, the range of values ​​for the ratio of the height B2 of the sixth shell wall 16 to the distance H between the first shell wall 11 and the second shell wall 12 can be referenced to the aforementioned range of values ​​for the ratio of B to H, and will not be repeated here; wherein, the ratio of B2 to H can be the same as or different from the ratio of B to H. The range of values ​​for the angle θ2 between the planes containing the sixth shell wall 16 and the fifth shell wall 15 can be referenced to the aforementioned range of values ​​for θ, and will not be repeated here; θ2 and θ can be the same as or different. The range of values ​​for the length C2 of the orthographic projection of the sixth shell wall 16 in the aforementioned first reference plane can be referenced to the aforementioned range of values ​​for C, and will not be repeated here; C2 can be the same as or different from C. The shape of the sixth shell wall 16 can be referenced to the shape of the fourth shell wall 14, and will not be repeated here. The sixth shell wall 16 can be parallel to or not parallel to the second direction.

[0077] Please continue reading. Figures 4-6 The housing 10 also includes a seventh housing wall 17 and an eighth housing wall 18, which are arranged along the aforementioned second direction and are both connected to the aforementioned first housing wall 11, second housing wall 12, third housing wall 13, fourth housing wall 14, fifth housing wall 15 and sixth housing wall 16 to enclose the aforementioned receiving cavity 10a. In this way, the battery cell 122 is roughly rectangular with chamfered corners. The shape of the battery cell 122 is relatively regular, and the design and manufacturing difficulty is lower. Figures 4-6 In the illustrated embodiment, the first direction is the width direction of the battery cell 122, the second direction is the thickness direction of the battery cell 122, and the third direction is the length direction of the battery cell 122. In some other embodiments, the first direction may also be the length direction of the battery cell 122, and the third direction may be the width direction of the battery cell 122.

[0078] Please continue reading. Figures 4-6The ratio of the length A of the second shell wall 12 along a third direction to the length L of the third shell wall 13 and the fifth shell wall 15 along a third direction is greater than or equal to 0.55 and less than or equal to 0.95, i.e., 0.55 ≤ A / L ≤ 0.95. For example, the ratio of A to L can be 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.95, etc. In this way, while ensuring the flow area of ​​the aforementioned exhaust channel 120a, it is also possible to ensure that the length A of the second shell wall 11 is as large as possible to ensure the volume of the receiving cavity 10a, thereby ensuring the capacity of the battery cell 122. In addition, while the battery cell 122 is fixed to the housing 121 through the second shell wall 12, the connection area and heat dissipation area between the battery cell 122 and the housing 121 are ensured, thereby ensuring the reliability and safety of the connection between the battery cell 122 and the housing 121.

[0079] Based on the above, please refer to Figure 4 and Figure 7 , Figure 7 for Figure 4 The diagram shows a top view of the battery cell 122. The first shell wall 11 has an injection hole 11a, which is used to inject electrolyte into the receiving cavity 10a during the assembly of the battery cell 122. The center distance P between the injection hole 11a and the positive electrode post 31 is less than the distance Q between the injection hole 11a and the negative electrode post 32, i.e., P < Q. This helps prevent electrolyte leakage and external conductivity of the battery cell 122, further improving the safety of the battery cell 122 in use.

[0080] Figure 4 and Figure 7 In the illustrated embodiment, the injection port 11a is located between the positive electrode post 31 and the negative electrode post 32. For other embodiments, please refer to... Figure 8 , Figure 8 This is a three-dimensional structural diagram of a battery cell provided in other embodiments of this application. Figure 8 The illustrated embodiments and Figure 7 The difference in the embodiment shown is that the injection hole 11a is located on the side of the positive electrode post 31 away from the negative electrode post 32.

[0081] Please see Figures 9-11 , Figure 9 This is a perspective structural diagram of the battery cell 122 provided in some embodiments of this application. Figure 10 for Figure 9 The diagram shows the three-dimensional structure of cell 122 as viewed from another angle. Figure 11 This is a front view of cell 122 shown in Figure 9. Figures 9-11 The illustrated embodiments and Figures 4-7The difference in the embodiment shown is that the housing 10 does not include the sixth housing wall 16, and the two ends of the third housing wall 13 are respectively connected to the first housing wall 11 and the second housing wall 12.

[0082] Please see Figure 12 , Figure 12 This is a perspective structural diagram of the battery cell 122 provided in some embodiments of this application. Figure 12 The illustrated embodiments and Figures 9-11 The difference in the embodiment shown is that the injection hole 11a is located on the side of the positive electrode post 31 away from the negative electrode post 32.

[0083] Please see Figure 13 , Figure 13 A cross-sectional structural diagram of a battery pack 120 provided for other embodiments of this application. Figure 13 The illustrated embodiments and Figure 3 The difference in the illustrated embodiment is that the first wall 1211 of the housing 121 is the lower wall, meaning the first wall 1211 is located between the second wall 1212 and the ground. The first wall 1211 has a clearance groove 1211a, and the electrode post 30 is located within the clearance groove 1211a. Specifically, the first wall 1211 has multiple clearance grooves 1211a spaced apart along a third direction, and the clearance grooves 1211a extend along a second direction. A row of electrode posts 30 is located within one clearance groove 1211a. In this way, when the first wall 1211 is the upper wall and the first wall 1211 is the lower wall, the clearance grooves 1211a can occupy the space between the housing 121 and the ground. There is no need to reserve a deformation gap between the first wall 1211, the second wall 1212, and the battery cell 122 to prevent damage to the electrode post 30. This is beneficial for increasing the height of the battery cell 122 along the first direction, thereby increasing the capacity of the battery cell 122. In addition, the battery cell 122 can support the second box wall 1212, which enhances the overall strength of the battery pack 120.

[0084] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A battery cell, characterized in that, include: A housing, the housing enclosing a receiving cavity; the housing includes a first shell wall and a second shell wall disposed opposite to each other, and a third shell wall and a fourth shell wall connected together, the end of the third shell wall away from the fourth shell wall being connected to the first shell wall, and the end of the fourth shell wall away from the third shell wall being connected to the second shell wall; the fourth shell wall is located on the side of the second shell wall facing the receiving cavity and the side of the third shell wall facing the receiving cavity; along a first direction, the height B of the fourth shell wall and the distance H between the first shell wall and the second shell wall satisfy: B / H≥0.05; wherein, the first direction is the arrangement direction of the first shell wall and the second shell wall; The electrode post is disposed on the first shell wall; The first explosion-proof valve is disposed on the fourth shell wall and is connected to the receiving cavity.

2. The battery cell according to claim 1, characterized in that, Along the first direction, the height B of the fourth shell wall and the distance H between the first shell wall and the second shell wall also satisfy: B / H≤0.

38.

3. The battery cell according to claim 2, characterized in that, From the third shell wall to the second shell wall, the fourth shell wall extends in a direction that gradually moves away from the third shell wall and gradually moves away from the first shell wall.

4. The battery cell according to any one of claims 1-3, characterized in that, The fourth shell wall is parallel to the second direction, which is perpendicular to the first direction and parallel to the third shell wall.

5. The battery cell according to any one of claims 1-3, characterized in that, The housing further includes a fifth shell wall and a sixth shell wall that are in contact with each other. The end of the fifth shell wall that is away from the sixth shell wall is connected to the first shell wall, and the end of the sixth shell wall that is away from the fifth shell wall is connected to the second shell wall. The sixth shell wall is located on the side of the second shell wall facing the receiving cavity and on the side of the fifth shell wall facing the receiving cavity. The battery cell also includes a second explosion-proof valve, which is disposed on the sixth shell wall and communicates with the receiving cavity.

6. The battery cell according to claim 5, characterized in that, The length A of the second shell wall along the third direction and the distance L between the third shell wall and the fifth shell wall along the third direction satisfy: 0.55≤A / L≤0.95; wherein, the third direction is the arrangement direction of the third shell wall and the fifth shell wall, and the third direction is perpendicular to the first direction.

7. The battery cell according to any one of claims 1-3, characterized in that, The electrode includes positive electrode and negative electrode arranged at intervals; The first shell wall has a liquid injection hole, and the distance between the liquid injection hole and the positive electrode post is less than the distance between the liquid injection hole and the negative electrode post.

8. A battery pack, characterized in that, include: Box; A battery cell, wherein the battery cell is disposed within the housing, and the battery cell is any one of claims 1-7; The fourth shell wall of the battery cell, together with the box wall of the housing and / or the shell of the adjacent battery cell, forms an exhaust channel; The third explosion-proof valve is installed on the wall of the enclosure and is connected to the exhaust channel.

9. The battery pack according to claim 8, characterized in that, The enclosure includes a first enclosure wall that contacts the first shell wall. The first enclosure wall has a clearance groove, and the pole is located within the clearance groove.

10. An electrical appliance, characterized in that, include: Electricity-consuming entities; A battery pack, wherein the battery pack is the battery pack according to claim 8 or 9, and the battery pack is electrically connected to the power-consuming body.

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