Battery cells and battery packs

Abstract

This application discloses a battery cell and battery pack, including a battery casing and a cell assembly disposed within the battery casing. The cell assembly includes at least two cells. The battery cell also includes a heat-conducting component, which includes at least a heat transfer element and a heat conductor connected to each other. A heat conductor is disposed between at least two cells, and the heat transfer element abuts against at least one inner sidewall of the battery casing. The heat-conducting component of this application includes at least a heat transfer element and a heat conductor connected to each other, with a heat conductor disposed between the cells. Heat between the two cells can be dissipated through the heat conductor. Since the heat conductor is connected to the heat transfer element, the heat from the heat conductor can be conducted to the heat transfer element, and then to the battery casing. The battery casing then dissipates the heat, reducing the temperature of the cells and thus preventing thermal runaway, improving the safety and lifespan of the battery cell.

Description

Technical Field

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

[0002] Batteries generate a significant amount of heat during charging and discharging. If the temperature is too high, the chemical reaction rate accelerates, leading to an increased self-discharge rate, faster capacity decay, and a shorter lifespan. The heat from the battery cells is typically exchanged with the external environment through the battery casing for cooling. When multiple cells are housed within the casing, the internal heat can be even higher. Excessive battery temperature can trigger thermal runaway. Thermal runaway causes a rapid acceleration of internal chemical reactions, generating large amounts of heat and gas, potentially leading to battery bulging or even explosion.

[0003] Therefore, how to reduce the internal temperature of the battery, avoid thermal runaway, and improve the battery's lifespan is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0004] In view of this, the purpose of this application is to provide a battery cell to reduce the internal temperature of the battery, avoid thermal runaway, and improve the battery's service life.

[0005] Another objective of this application is to provide a battery pack having the aforementioned battery cells.

[0006] To achieve the above objectives, this application provides the following technical solution:

[0007] The first aspect of this application provides a battery cell, including a battery housing and a cell assembly disposed within the battery housing, wherein the cell assembly includes at least two cells;

[0008] The battery cell also includes a heat-conducting element, which includes at least a heat transfer element and a heat conductor connected to each other. The heat conductor is disposed between at least two of the battery cells, and the heat transfer element abuts against at least one inner sidewall of the battery casing.

[0009] The battery cell provided in this application incorporates a heat-conducting component inside its battery casing. This component includes at least a heat transfer element and a heat conductor connected to each other. The heat conductor is positioned between at least two battery cells. Heat between the two battery cells can be conducted to the heat conductor; that is, the battery cells can conduct heat to the heat conductor through contact with it. Since the heat conductor is connected to the heat transfer element, heat from the heat conductor can be conducted to the heat transfer element. The heat transfer element abuts against at least one inner wall of the battery casing, allowing its heat to be conducted to the battery casing through this contact. This achieves the goal of transferring heat from inside the battery cells to the battery casing, where it is then dissipated, thus reducing the temperature of the battery cells, preventing thermal runaway, improving the safety of the battery cell, and extending its lifespan.

[0010] A second aspect of this application provides a battery pack comprising battery cells as described in any of the preceding claims.

[0011] The battery pack provided in this application has all the technical effects of the aforementioned battery cells, and will not be described in detail here. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is an exploded view of a single battery cell disclosed in an embodiment of this application;

[0014] Figure 2 This is an exploded view of the battery cell assembly and heat-conducting component disclosed in the embodiments of this application;

[0015] Figure 3 This is a schematic diagram of the structure of the heat-conducting component disclosed in the embodiments of this application;

[0016] Figure 4 This is an exploded view of the battery casing and heat-conducting component disclosed in the embodiments of this application;

[0017] Figure 5 This is a top view of a battery cell disclosed in an embodiment of this application;

[0018] Figure 6 for Figure 5 Sectional view along AA;

[0019] Figure 7 for Figure 6A magnified view of part A in the image;

[0020] Figure 8 This is a front view of the heat-conducting component with an integrated structure disclosed in an embodiment of this application;

[0021] Figure 9 This is a front view of a heat-conducting component of a welded structure disclosed in an embodiment of this application;

[0022] Figure 10 This is a front view of a heat-conducting component of another welding structure disclosed in an embodiment of this application.

[0023] The meanings of the various reference numerals in the figure are as follows:

[0024] 100 - Battery casing; 110 - Casing body; 111 - Explosion-proof valve; 120 - Cover plate;

[0025] 200 - Battery cell assembly; 210 - Battery cell body;

[0026] 300 - Heat-conducting component; 310 - Heat transfer element; 311 - First hollowed-out part; 320 - Heat-conducting element; 321 - Second hollowed-out part; 300a - First part; 300b - Second part. Detailed Implementation

[0027] This application discloses a battery cell to reduce the internal temperature of the battery, prevent thermal runaway, and improve the battery's lifespan.

[0028] This application also discloses a battery pack having the above-described battery cells.

[0029] Hereinafter, embodiments will be described with reference to the accompanying drawings. Furthermore, the embodiments shown below do not limit the scope of the application as described in the claims. Additionally, the complete composition represented in the embodiments below is not limited to what is necessary as the solution to the application described in the claims. It should be noted that, for ease of description, only the parts relevant to the application are shown in the drawings. Unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0030] Batteries have internal resistance. When a battery is charging, the higher the current, the greater the internal resistance, and the longer the charging time, the more heat is generated. During fast charging, the charging current is significantly increased compared to regular charging, which causes the heat generated by the battery's internal resistance to increase rapidly, resulting in noticeable battery heating. Moreover, users' demand for fast charging is increasing, leading to greater internal heat generation in batteries.

[0031] To reduce battery temperature, the heat inside the battery needs to be quickly dissipated to the outside. For example... Figures 1-3As shown in the embodiment of this application, a battery cell is disclosed. The battery cell includes a battery housing 100 and a cell assembly 200 disposed within the battery housing 100. The cell assembly 200 includes at least two cells 210.

[0032] The battery casing 100 includes a casing body 110 and a cover plate 120. The battery casing 100 is used to encapsulate the battery cell assembly 200 and components such as the electrolyte. The casing body 110 can have various shapes and sizes, such as cuboid, cylindrical, and hexagonal prism. The shape of the casing body 110 can be determined according to the specific shape and size of the battery cell assembly 200. The casing body 110 can be made of various materials, including but not limited to copper, iron, aluminum, stainless steel, and aluminum alloy.

[0033] Cover 120 refers to a component that covers the opening of housing body 110 to isolate the accommodating space from the external environment. The shape of cover 120 can be adapted to the shape of housing body 110 to fit housing body 110. Cover 120 can be made of a material with a certain hardness and strength (such as aluminum alloy).

[0034] The battery casing 100 is a protective structure on the outer layer of the battery cell, serving to house and protect internal components (such as the cell assembly 200). The main function of the battery casing 100 is to prevent harmful substances such as moisture and oxygen from entering the interior, avoiding damage to the cell assembly 200, protecting the internal cell assembly 200 and other components from external physical impacts and chemical corrosion, and ensuring the safety and stability of the battery cell.

[0035] The battery cell assembly 200 is a charging and discharging unit, which includes at least two battery cells 210. Each battery cell 210 is formed by winding or stacking a positive electrode, a negative electrode, and a separator disposed between them. After the individual battery cells 210 are stacked in a certain direction, they are placed inside the battery casing 100.

[0036] The positive electrode sheet includes a positive current collector and a positive active material. The positive current collector can be made of metal materials such as aluminum foil, nickel foil, and stainless steel, or a composite foil formed by combining metals and insulating materials. The positive active material includes the main positive active material, conductive agent, binder, etc. The main positive active material includes one or more lithium-containing positive active materials such as lithium iron phosphate, ternary materials containing nickel, cobalt, and manganese, and lithium manganese iron phosphate.

[0037] Similarly, the negative electrode sheet includes a negative electrode current collector and a negative electrode active material. The negative electrode current collector can be made of metal materials such as copper foil, aluminum foil, and stainless steel, or it can be a composite foil material formed by combining metals and insulating materials. The negative electrode active material includes the negative electrode active material, conductive agent, binder, etc. The negative electrode active material includes one or more of the following: artificial graphite, natural graphite, silicon carbide, silicon oxide, lithium titanate, etc.

[0038] The cell body 210 has a cell output terminal, which is generally a tab assembly. Depending on the polarity, the tab assembly typically includes a positive tab assembly and a negative tab assembly. The positive tab assembly is electrically connected to the positive output terminal on the battery casing 100, and the negative tab assembly is electrically connected to the negative output terminal on the battery casing 100. The positive tab assembly and the positive electrode sheet are either integrally connected or separately connected, and the negative tab assembly and the negative electrode sheet are either integrally connected or separately connected. The separator, as an insulating layer, prevents short circuits within the battery cell caused by contact between the positive and negative electrode sheets. Furthermore, as a semi-permeable layer, the separator prevents larger molecules from passing through while allowing smaller charged ions to pass through.

[0039] When the battery cell assembly 200 includes multiple battery cells 210, the surface of the battery cell 210 facing the battery casing 100 can conduct heat from the battery cell 210 to the battery casing 100, and the battery casing 100 dissipates the heat to the external environment. The surface between two adjacent battery cells 210 is far from the inner wall of the battery casing 100 and therefore does not dissipate heat easily, resulting in a higher temperature.

[0040] Based on this, the battery cell disclosed in this embodiment also includes a heat-conducting element 300, which includes at least a heat transfer element 310 and a heat conductor 320 connected to each other. The heat transfer element 310 and the heat conductor 320 are connected to each other, so heat can be transferred between them, that is, temperature can be transferred from the high-temperature side to the low-temperature side.

[0041] A heat conductor 320 is disposed between at least two battery cells 210. When the battery cell assembly 200 includes two battery cells 210, a heat conductor 320 is disposed between the two battery cells 210. When the battery cell assembly 200 has three or more battery cells 210, a heat conductor 320 may be disposed between only two of the battery cells 210, or a heat conductor 320 may be disposed between each of the battery cells 210. When there are multiple heat conductors 320, each heat conductor 320 may be connected to the same heat transfer element 310, or it may be connected to different heat transfer elements 310.

[0042] The heat transfer element 310 abuts against at least one inner wall of the battery housing 100, that is, the heat transfer element 310 abuts against the inner wall of one side of the battery housing 100, or it can abut against multiple inner walls simultaneously through its own bending or its own structure.

[0043] like Figures 5-7 As shown in the embodiments of this application, the battery cell disclosed has a heat-conducting component 300 added inside the battery casing 100. The heat-conducting component 300 includes at least a heat transfer element 310 and a heat conductor 320 connected to each other, wherein the heat conductor 320 is disposed between two battery cells 210.

[0044] When there are multiple battery cells 210, the heat between the battery cells 210 cannot be effectively conducted to the outside of the battery casing 100, resulting in a high temperature at the joint of the battery cells 210. In this embodiment, by providing a heat-conducting element 300, the heat between two battery cells 210 can be conducted out through the heat-conducting body 320. That is, the battery cells 210 can conduct heat to the heat-conducting body 320 by contacting it.

[0045] Since the heat conductor 320 is connected to the heat transfer element 310, the heat from the heat conductor 320 can be conducted to the heat transfer element 310. The heat transfer element 310 abuts against at least one inner wall of the battery casing 100. Therefore, the heat from the heat transfer element 310 can be conducted to the battery casing 100 through contact with it, and then dissipated through the battery casing 100. The battery casing 100 can be cooled by air cooling, natural cooling, or cold plate cooling. This embodiment does not limit the heat dissipation method of the battery casing 100.

[0046] In this embodiment, the heat inside the battery cell can be transferred to the battery casing 100, which can reduce the temperature of the battery cell 210, thereby preventing thermal runaway of the battery, improving the safety of the battery cell, and increasing the service life of the battery cell.

[0047] The heat-conducting component 300 disclosed in this application embodiment can be made of metal, phase change material, or a material with certain flame-retardant properties. In battery cells with some explosion-proof valve bottom outlet structures, the heat transfer element 310 of the heat-conducting component 300 can also act as an explosion-proof valve support, preventing substances ejected from the cell 210 from clogging the explosion-proof valve port.

[0048] like Figures 5-7 As shown, the first end of the heat conductor 320 is connected to the heat transfer body 310, and the first and second ends of the heat conductor 320 are opposite ends. Each battery cell 210 is arranged along a first direction, that is, the arrangement direction of each battery cell 210 is the first direction. The direction between the first and second ends of the heat conductor 320 is the second direction, and the first, second, and third directions are mutually perpendicular.

[0049] Along the first direction, the heat conductor 320 abuts against two adjacent battery cells 210. For ease of understanding, the two sides of the heat conductor 320 are defined as the first side and the second side, respectively, and the two battery cells 210 on both sides of the heat conductor 320 are defined as the first battery cell and the second battery cell, respectively. The heat conductor 320 is located between the first battery cell and the second battery cell, such that heat from the side of the first battery cell facing the second battery cell can be conducted to the heat conductor 320 through the first side, and heat from the side of the second battery cell facing the first battery cell can be conducted to the heat conductor 320 through the second side.

[0050] In this embodiment, along the first direction, the heat conductor 320 abuts against two adjacent battery cells 210 respectively. Compared with the gap between the heat conductor 320 and the battery cell 210, the two are in close contact, which can increase the contact area and help to conduct the heat of the battery cell 210 to the heat conductor 320, thus helping the battery cell 210 to dissipate heat.

[0051] Along the second direction, the second end of the heat conductor 320 is coplanar with the end of the battery cell 210 away from the heat transfer element 310. In this embodiment, the coplanarity of the second end of the heat conductor 320 with the end of the battery cell 210 away from the heat transfer element 310 in the second direction allows the heat conductor 320 to cover the entire dimension of the battery cell 210 in the second direction, thereby further increasing the contact area between the heat conductor 320 and the battery cell 210 and improving the heat dissipation efficiency of the battery cell 210.

[0052] It should be noted that, along the second direction, the second end of the heat conductor 320 can also be closer to the heat transfer element 310 than the end of the battery cell 210 that is furthest from the heat transfer element 310. For ease of understanding, taking the end of the battery cell 210 furthest from the heat transfer element 310 as the upper end of the battery cell 210 as an example, the second end of the heat conductor 320 is lower than the upper end of the battery cell 210. Although this reduces the contact area with the battery cell 210, it facilitates the installation of the battery cell 210 and the cover plate 120. This prevents the second end of the heat conductor 320 from extending beyond the outside of the battery cell 210 due to processing errors, thus avoiding interference between the heat conductor 320 and the cover plate 120 on the upper part of the battery casing 100. When the second end of the heat conductor 320 is lower than the upper end of the battery cell 210, even with processing errors, it is less likely for the second end of the heat conductor 320 to extend beyond the outside of the battery cell 210, facilitating the assembly of the battery cells.

[0053] Furthermore, along the third direction, at least one side of the heat conductor 320 is coplanar with the corresponding side of the battery cell 210. For ease of understanding, taking the third direction as the left-right direction as an example, the left side of the heat conductor 320 can be designed to be coplanar with the left side of the battery cell 210, while the right side of the heat conductor 320 can be designed to be recessed within the right side of the battery cell 210; alternatively, the right side of the heat conductor 320 can be designed to be coplanar with the right side of the battery cell 210, while the left side of the heat conductor 320 can be designed to be recessed within the left side of the battery cell 210; furthermore, the right side of the heat conductor 320 can be designed to be coplanar with the right side of the battery cell 210, and the left side of the heat conductor 320 can also be coplanar with the left side of the battery cell 210. This arrangement further increases the contact area between the heat conductor 320 and the battery cell 210, improving the heat dissipation efficiency of the battery cell 210.

[0054] In one specific embodiment of this application, the battery casing 100 includes a first end face and a second end face disposed opposite to each other. An electrode post is disposed on the first end face, and a heat transfer element 310 abuts against the second end face. If the first end face is a cover plate 120, then the second end face is the bottom plate of the battery casing 100. If the first end face is one of the side walls of the casing body 110, then the second end face is the opposite side wall of that side wall. In this embodiment, the first and second end faces can be either side of the battery casing 100, as long as they are two oppositely disposed surfaces.

[0055] The first end face of the electrode generates a lot of heat and requires welding of components such as the current collector, which is not conducive to the heat dissipation of the heat transfer body 310. On the other hand, the second end face without the electrode has a simple structure and no other components, so it generates less heat. By attaching the heat transfer body 310 to the second end face, it is easier to conduct the heat absorbed by the heat conductor 300 to the battery casing 100 and dissipate it to the surrounding environment through the battery casing 100.

[0056] like Figure 3 and Figure 4 As shown in a specific embodiment of this application, an explosion-proof valve 111 is provided on the second end face, and the heat transfer body 310 has a first hollow area at least at a position corresponding to the explosion-proof valve 111. The first hollow area has a first hollow portion 311 that penetrates the wall thickness. In this embodiment, the first hollow area is provided at the position corresponding to the explosion-proof valve 111 on the heat transfer body 310 to prevent the heat transfer body 310 from blocking the explosion-proof valve 111. Once a battery cell experiences thermal runaway, the internal pressure of the battery cell rises sharply. The first hollow area allows the high pressure to act on the explosion-proof valve 111, enabling the explosion-proof valve 111 to open normally and release pressure. The high-temperature and high-pressure gas inside the battery cell can be discharged from the explosion-proof valve 111 in a timely manner through the first hollow portion 311 of the first hollow area, avoiding the risk of explosion of the battery cell.

[0057] Furthermore, the heat conductor 320 is provided with a second hollow area, and the second hollow area has a second hollow portion 321 that penetrates the wall thickness. The second hollow portion 321 is connected to the first hollow portion 311. In this embodiment, by setting a second hollow area and making the second hollow portion 321 of the second hollow area connected to the first hollow portion 311 of the first hollow area, the high-pressure gas above can enter the first hollow portion 311 through the second hollow portion 321 when the cell 210 experiences thermal runaway, and be discharged from the explosion-proof valve 111 in time, avoiding the risk of explosion of the battery cell and preventing the high-pressure gas above from being blocked by the heat conductor 320 and unable to descend, thus preventing the battery from exploding.

[0058] To meet the pressure relief requirements of the explosion-proof valve 111, the first perforated portion 311 of the first perforated area needs to have sufficient flow area; otherwise, it will hinder the pressure relief of the explosion-proof valve 111, leading to a risk of battery explosion. If the opening width of the first perforated portion 311 is increased, it will affect the effective heat transfer from the heat transfer body 310 to the battery casing, and the heat transfer area of ​​the heat transfer body 310 will be unevenly distributed (heat transfer cannot occur at the location of the first perforated portion 311).

[0059] Based on this, the first hollow area is provided with a plurality of first hollow sections 311 arranged at intervals, and the second hollow area is provided with a plurality of second hollow sections 321 corresponding one-to-one with each of the first hollow sections 311. The first hollow area is provided with a plurality of first hollow sections 311, which, while meeting the flow area requirements of the first hollow area, not only meets the requirements for the safe discharge of high-pressure gas, but also reduces the width of a single first hollow section 311, making the heat transfer efficiency of each area of ​​the heat transfer body 310 more uniform, and preventing the problem of low heat dissipation efficiency caused by a certain area not being able to dissipate heat.

[0060] In this embodiment, both the first cutout portion 311 and the second cutout portion 321 can be rectangular holes, with the width of the rectangular holes ranging from 1.5mm to 10mm. It should be noted that the widths of the first cutout portion 311 and the second cutout portion 321 can be equal or unequal. For example, the width of the first cutout portion 311 can be designed to be greater than the width of the second cutout portion 321 to facilitate the passage of high-pressure gas through the first cutout portion 311 and its discharge from the explosion-proof valve 111.

[0061] In this embodiment, the widths of the first hollow portion 311 and the second hollow portion 321 are selected within the range of 1.5mm to 10mm. This avoids the first hollow portion 311 and the second hollow portion 321 being too wide, which would affect the normal heat dissipation of the heat-conducting component 300. It also avoids the first hollow portion 311 and the second hollow portion 321 being too narrow, which would affect the safe discharge of high-pressure gas and lead to poor battery safety.

[0062] For example, the widths of the first cutout portion 311 and the second cutout portion 321 can be 1.5mm, 2mm, 3mm, 3.5mm, 4mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 8mm, 8.5mm, 9mm, 10mm, etc. This embodiment does not limit the widths of the first cutout portion 311 and the second cutout portion 321, and is not limited to the specific examples mentioned above. Those skilled in the art can select widths within the range of 1.5mm to 10mm according to their needs.

[0063] The interval between two adjacent first hollow portions 311 ranges from 1.5mm to 20mm; for example, the interval between two adjacent first hollow portions 311 can be 1.5mm, 3mm, 5mm, 7mm, 9mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, etc. This embodiment does not limit the interval between two adjacent first hollow portions 311 and is not limited to the specific examples above. Those skilled in the art can select an interval within the range of 1.5mm to 20mm according to their needs.

[0064] The interval between two adjacent second hollow portions 321 ranges from 1.5mm to 20mm; for example, the interval between two adjacent second hollow portions 321 can be 1.5mm, 3mm, 5mm, 7mm, 9mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, etc. This embodiment does not limit the interval between two adjacent second hollow portions 321 and is not limited to the specific examples mentioned above. Those skilled in the art can select an interval within the range of 1.5mm to 20mm according to their needs. Furthermore, the extension direction of the first hollow portion 311 can be parallel to the first direction, or it can be at a certain angle to the first direction, such as an acute angle. The extension direction of the second hollow portion 321 can be parallel to the second direction, or it can be at a certain angle to the second direction, such as an acute angle. Those skilled in the art can select the extension directions of the first hollow portion 311 and the second hollow portion 321 based on their needs.

[0065] It should be noted that the first hollow portion 311 and the second hollow portion 321 can also be holes of other shapes, such as round holes, square holes, oval holes, etc. This embodiment does not limit the specific shape of the first hollow portion 311 and the second hollow portion 321.

[0066] In one specific embodiment of this application, the dimension of the first hollow portion 311 along its extension direction ranges from a to b, where a is 1 / 4 of the thickness of the battery cell assembly 200, and b is the dimension of the heat transfer body 310 along the extension direction of the first hollow portion 311 minus 1.5 mm. Taking the extension direction of the first hollow portion 311 being parallel to the first direction as an example, the dimension of the first hollow portion 311 along the first direction ranges from 1 / 4 of the thickness of the battery cell assembly 200 to the dimension of the heat transfer body 310 along the extension direction of the first hollow portion 311 minus 1.5 mm. Each of the first hollow portions 311 can be arranged along a direction perpendicular to the first direction.

[0067] The lower limit of the dimension of the first hollow portion 311 along its extension direction is 1 / 4 of the thickness of the battery cell assembly 200, to ensure that the first hollow portion 311 has sufficient coverage area to guarantee the discharge rate of high-pressure gas. The upper limit of the dimension of the first hollow portion 311 along its extension direction is the dimension of the heat transfer body 310 along its extension direction minus 1.5mm, so that the dimension of the first hollow portion 311 along its extension direction does not exceed the width of the heat transfer body 310 along that direction, preventing the first hollow portion 311 from penetrating the edge of the heat transfer body 310 and affecting the strength of the heat transfer body 310.

[0068] The dimension of the second hollow portion 321 along its extension direction is ≥ 1 / 4 times the height of the battery cell 210. Taking the extension direction of the second hollow portion 321 as parallel to the second direction as an example, the dimension of the second hollow portion 321 along the second direction is not less than 1 / 4 times the height of the battery cell 210, to avoid the second hollow portion 321 being too small along the second direction, which would affect the gas emission rate. Each of the second hollow portions 321 can be arranged along a direction perpendicular to the second direction.

[0069] In this embodiment of the application, by controlling the dimensions of the first hollow portion 311 along its extension direction and the second hollow portion 321 along its extension direction within the aforementioned range, it is possible to avoid the problem that the normal heat dissipation of the heat-conducting component 300 is affected by the excessively large dimensions of the first hollow portion 311 and the second hollow portion 321 along their extension direction; it is also possible to avoid the problem that the gas emission rate is affected by the excessively small dimensions of the first hollow portion 311 and the second hollow portion 321 along their extension direction, resulting in poor battery safety.

[0070] In a specific embodiment of this application, the heat transfer element 310 and the heat conductor 320 can be perpendicular, and the heat transfer element 310 extends from both sides of the heat conductor 320, that is, the heat conductor 300 is T-shaped in general, so that the heat transfer element 310 can be in close contact with both battery cells 210 on both sides of the heat conductor 320, increasing the contact area and making it easier for the heat conductor 300 to conduct heat to the battery casing, thereby achieving heat dissipation of the battery.

[0071] It should be noted that the heat transfer element 310 can also extend only from one side of the heat conductor 320, that is, the heat conductor 300 is L-shaped as a whole, so that the heat transfer element 310 can be in close contact with the battery cell 210 on one side of the heat conductor 320. Of course, in order to increase the contact area between the heat transfer element 310 and the battery casing, two L-shaped heat conductors 300 can be set between the two battery cells 210. The heat conductors 320 of the two heat conductors 300 are in close contact and set between the two battery cells 210. The heat transfer elements 310 of the two heat conductors 300 extend to opposite sides and are in close contact with the two battery cells 210 on both sides of the heat conductor 320, which can also increase the contact area and achieve efficient heat dissipation of the battery.

[0072] When the cell 210 adopts a stacked side-out configuration, i.e., the battery cell is stacked side-out, the terminals are located on the side of the battery casing, and there is no current collector on the top of the casing. To improve heat dissipation efficiency, the heat-conducting component 300 can be designed with an I-shaped structure (e.g., Figure 10 As shown in the figure, the heat-conducting component 300 includes two heat transfer bodies 310, which are respectively connected to the two ends of the heat-conducting body 320. The two heat transfer bodies 310 abut against the two end faces of the battery casing 100, which can further improve the heat dissipation efficiency.

[0073] In one specific embodiment of this application, the heat transfer element 310 abuts against the end face of the battery cell 210, and the abutment area accounts for 50% to 100% of the end face area of ​​the battery cell 210. This arrangement can prevent the assembly of the heat-conducting element 300 and the battery casing 100 from being affected by the abutment area being too large as to affect the end face area of ​​the battery cell 210; it can also prevent the effective heat dissipation of the heat-conducting element 300 from being affected by the abutment area being too small as to affect the end face area of ​​the battery cell 210.

[0074] For example, the ratio of the contact area to the end face area of ​​the battery cell 210 can be 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, etc. This embodiment does not limit the ratio of the contact area to the end face area of ​​the battery cell 210, and is not limited to the specific examples mentioned above. Those skilled in the art can select a ratio within the range of 50% to 100% according to their needs.

[0075] In one specific embodiment of this application, a gap may also exist between the heat transfer element 310 and the battery cell 210, meaning that the heat transfer element 310 only contacts the battery casing and does not contact the end face of the battery cell 210. In this embodiment, controlling the gap between the heat transfer element 310 and the battery cell 210 within the range of 0.1mm to 1mm ensures sufficient wetting of the electrolyte.

[0076] For example, the gap between the heat transfer element 310 and the battery cell 210 can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc. This embodiment does not limit the gap between the heat transfer element 310 and the battery cell 210, and is not limited to the specific examples mentioned above. Those skilled in the art can select a gap within the range of 0.1mm to 1mm according to their needs.

[0077] Thermal conductive component 300 can be Figure 8 The integrated structure shown can also include a heat-conducting component 300. Figure 9 and Figure 10The illustrated component is formed by welding together at least two parts. For example, the heat-conducting element 300 may include a first part 300a and a second part 300b welded together, the first part 300a and the second part 300b being a symmetrical structure.

[0078] When the heat-conducting component is 300 Figure 9 When the T-shaped structure is shown, the first part 300a and the second part 300b are two L-shaped parts that are joined back-to-back and welded together. When the heat-conducting part 300 is an I-shaped structure, the first part 300a and the second part 300b can be two C-shaped parts that are joined back-to-back and welded together.

[0079] This application also discloses a battery pack, which includes the battery cells disclosed in the above embodiments. Therefore, it has all the technical effects of the battery cells mentioned above, and will not be repeated here.

[0080] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "a," and / or "the" are not specifically singular and may include the plural. Generally, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0081] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0082] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0083] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A battery cell, characterized by, The battery includes a battery housing (100) and a cell assembly (200) disposed within the battery housing (100), wherein the cell assembly (200) includes at least two cell bodies (210); The battery cell further includes a heat-conducting element (300), which includes at least a heat transfer element (310) and a heat conductor (320) connected to each other. The heat conductor (320) is disposed between at least two of the battery cells (210), and the heat transfer element (310) abuts against at least one inner sidewall of the battery casing (100).

2. The battery cell of claim 1, wherein, The first end of the heat conductor (320) is connected to the heat transfer body (310), and the first end and the second end of the heat conductor (320) are opposite ends; Each of the battery cells (210) is arranged along a first direction, and the direction between the first end and the second end of the heat conductor (320) is a second direction, and the first direction, the second direction and the third direction are perpendicular to each other; Along the first direction, the heat conductor (320) abuts against two adjacent battery cells (210).

3. The battery cell of claim 2, wherein, Along the second direction, the second end of the heat conductor (320) is coplanar with the end of the battery cell (210) away from the heat transfer body (310).

4. The battery cell as described in claim 2, characterized in that, Along the second direction, the second end of the heat conductor (320) is closer to the heat transfer body (310) than the end of the battery cell (210) that is farther away from the heat transfer body (310).

5. The battery cell as described in claim 2, characterized in that, Along the third direction upward, at least one side of the heat conductor (320) is located within the corresponding side of the battery cell (210).

6. The battery cell as described in claim 2, characterized in that, Along the third direction, at least one side of the heat conductor (320) is coplanar with the corresponding side of the battery cell (210).

7. The battery cell as described in claim 1, characterized in that, The battery casing (100) includes a first end face and a second end face disposed opposite to each other. An electrode post is disposed on the first end face, and the heat transfer body (310) abuts against the second end face.

8. The battery cell as described in claim 7, characterized in that, The second end face is provided with an explosion-proof valve (111), and the heat transfer body (310) is provided with a first hollow area at least at the position corresponding to the explosion-proof valve (111), and the first hollow area is provided with a first hollow part (311) that penetrates the wall thickness.

9. The battery cell as described in claim 8, characterized in that, The heat conductor (320) is provided with a second hollow area, and the second hollow area has a second hollow part (321) that penetrates the wall thickness. The second hollow part (321) is connected to the first hollow part (311).

10. The battery cell as described in claim 9, characterized in that, The first hollow area is provided with a plurality of first hollow parts (311) arranged at intervals, and the second hollow area is provided with a plurality of second hollow parts (321) corresponding one-to-one with each of the first hollow parts (311).

11. The battery cell as described in claim 9, characterized in that, Both the first cutout portion (311) and the second cutout portion (321) are rectangular holes, and the width of the rectangular holes ranges from 1.5mm to 10mm.

12. The battery cell as described in claim 9, characterized in that, The interval between two adjacent first hollow portions (311) is 1.5mm to 20mm; The interval between two adjacent second hollow portions (321) is 1.5mm to 20mm.

13. The battery cell as described in claim 9, characterized in that, The size range of the first hollow portion (311) along its extension direction is: a~b, where a is 1 / 4 times the thickness of the battery cell assembly (200), and b is the size of the heat transfer body (310) along the extension direction of the first hollow portion (311) minus 1.5mm; The second hollow portion (321) has a dimension ≥ 1 / 4 times the height of the battery cell (210) along its extension direction.

14. The battery cell according to any one of claims 1-13, characterized in that, The heat transfer element (310) abuts against the end face of the battery cell (210), and the abutment area accounts for 50% to 100% of the end face area of ​​the battery cell (210).

15. The battery cell according to any one of claims 1-13, characterized in that, There is a gap between the heat transfer element (310) and the battery cell (210), and the size of the gap is in the range of 0.1 mm to 1 mm.

16. The battery cell according to any one of claims 1-13, characterized in that, When the battery cell (210) adopts a stacked side-out method, the heat-conducting component (300) includes two heat transfer bodies (310), which are respectively connected to the two ends of the heat-conducting body (320) and respectively abut against the two end faces of the battery casing (100).

17. The battery cell according to any one of claims 1-13, characterized in that, The heat-conducting component (300) is an integral structure; or, The heat-conducting component (300) is welded together from at least two parts.

18. A battery pack, characterized in that, Includes the battery cell as described in any one of claims 1-17.

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