Battery cell and battery pack

Abstract

The present application discloses a battery cell and a battery pack. The battery cell comprises a jelly roll, a casing, electrodes, and a first thermally conductive adhesive. Specifically, the casing comprises a casing sleeve and a cover plate, the jelly roll is accommodated in the casing sleeve, and the cover plate and the casing sleeve are connected to cover and seal the casing sleeve; each electrode comprises a pole and a pin which are electrically connected to each other, the pole is arranged on the cover plate, and one end of the pin away from the pole extends the length direction of the jelly roll and is electrically connected to the jelly roll; and the first thermally conductive adhesive is arranged between the pins and the inner surface of the casing sleeve.

Description

A single battery and a battery pack

[0001] This application claims priority to Chinese Patent Application No. 202422656306.4, filed with the Chinese Patent Office on October 31, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, and in particular to a single cell battery and a battery pack. Background Technology

[0003] A single cell typically consists of a casing and a core package housed within the casing. The core package is connected to the terminals on the surface of the casing via pins. The connection point between the core package and the pins is one of the areas in the entire single cell that generates the most heat. Technical issues

[0004] Due to design and manufacturing precision limitations, there is usually a gap of 1.0-1.5mm between the pins and the housing. This gap severely affects the heat dissipation at the connection between the cell and the pins, increasing the risk of thermal runaway of a single cell. Technical solutions

[0005] In a first aspect, this application provides a single-cell battery, which includes a core pack, a casing, electrodes, and a first thermally conductive adhesive. Specifically, the casing includes a sheath and a cover plate, the core pack is placed inside the sheath, and the cover plate is connected to the sheath to seal the casing; the electrodes include terminals and leads that are electrically connected to each other, the terminals are disposed on the cover plate, and the ends of the leads away from the terminals extend along the length of the core pack and are electrically connected to the core pack; the first thermally conductive adhesive is disposed between the leads and the inner surface of the sheath.

[0006] Secondly, this application provides a battery pack that includes any of the aforementioned individual battery cells. Beneficial effects

[0007] The beneficial effects provided by this application are: the core package is placed inside the housing, and the circuit of the core package is conducted to the terminals on the cover plate through the pins to facilitate connection with external devices. A first thermally conductive adhesive is provided between the pins and the housing, so that the heat on the pins can be quickly conducted to the housing and dissipated, which effectively improves the heat dissipation efficiency of the core package.

[0008] In related technologies, due to manufacturing processes and design limitations, there is typically a 1.0-1.5mm gap between the leads and the casing of individual cells. This gap significantly affects heat dissipation from the leads to the casing, making it difficult for heat to escape from the cell pack. The individual cell provided in this application allows heat from the cell pack to be rapidly transferred to the casing via the leads and the first thermally conductive adhesive, and then dissipated into the environment, greatly reducing the risk of thermal runaway in the cell pack. Attached Figure Description

[0009] Figure 1 is a schematic diagram of the overall structure of a single battery provided in an embodiment of this application;

[0010] Figure 2 is a cross-sectional schematic diagram of a single cell provided in an embodiment of this application;

[0011] Figure 3 is a magnified view of region A in Figure 2;

[0012] Figure 4 is a magnified view of region B in Figure 2;

[0013] Figure 5 is a schematic diagram of the pin and chip package assembly provided in an embodiment of this application;

[0014] Figure 6 is a cross-sectional schematic diagram of the mating structure in Figure 5;

[0015] Figure 7 is a schematic diagram of the interaction between the insulating thermally conductive film, the core package, and the pins provided in the embodiments of this application.

[0016] Explanation of icon numbers:

[0017] 10. Core package; 11. Package body; 12. Tab; 20. Housing; 21. Sheath; 22. Cover plate; 221. First electrode hole; 30. Electrode; 31. Electrode post; 32. Lead; 321. First lead; 322. Second lead; 323. Third lead; 324. Bending section; 41. First thermally conductive adhesive; 42. Second thermally conductive adhesive; 50. Insulating bracket; 51. Insulating washer; 52. Second electrode hole; 53. Thermally conductive hole; 60. Thermally conductive sheet; 61. First thermally conductive sheet; 62. Second thermally conductive sheet; 63. Third electrode hole; 70. Thermal sensing element; 80. Insulating thermally conductive film.

[0018] Implementation methods of this application

[0019] Please refer to Figures 1 to 4. Figure 1 is a schematic diagram of the overall structure of a single cell provided in the embodiment of this application; Figure 2 is a schematic cross-sectional view of a single cell provided in the embodiment of this application; Figure 3 is a partial enlarged view of region A in Figure 2; and Figure 4 is a partial enlarged view of region B in Figure 2.

[0020] This application provides a single-cell battery, which includes a core pack 10, a housing 20, electrodes 30, and a first thermally conductive adhesive 41. Specifically, the housing 20 includes a shell 21 and a cover plate 22. The core pack 10 is housed within the shell 21, and the cover plate 22 is connected to the shell 21 to seal the shell 21. The electrodes 30 include an electrode post 31 and a lead 32 that are electrically connected to each other. The electrode post 31 is disposed on the cover plate 22, and the end of the lead 32 away from the electrode post 31 extends along the length of the core pack 10 and is electrically connected to the core pack 10. The first thermally conductive adhesive 41 is disposed between the lead 32 and the inner surface of the shell 21.

[0021] In this embodiment, the current in the core pack 10 is conducted to the terminal 31 via the pin 32 to facilitate communication with upstream and downstream devices. The heat of the core pack 10 is transferred to the housing 20 via the pin 32 and the first thermally conductive adhesive 41, or directly via the first thermally conductive adhesive 41, and dissipates into the environment. Compared with single-cell batteries in related technologies where there is a gap between the pin 32 and the housing 20, the core pack 10 in this embodiment dissipates heat more rapidly. Therefore, the technical solution of this embodiment can effectively reduce the risk of thermal runaway of a single-cell battery.

[0022] For example, each individual cell has two sets of electrodes 30, with two pins 32 electrically connected to the two ends of the core package 10, respectively, and then guiding the current to the two terminals 31 of the positive and negative electrodes. Of course, in some other embodiments, there may be a case where only one electrode 30 is provided, and the other electrode of the core package 10 is connected to the casing 20 as the other electrode of the individual cell. This should not be used to limit the scope of protection of this application.

[0023] Specifically, the single cell also includes an insulating gasket 51. The cover plate 22 has a first electrode hole 221 for the electrode post 31 to pass through. The insulating gasket 51 is locked in the first electrode hole 221. The electrode post 31 passes through the insulating gasket 51 and the first electrode hole 221. The insulating gasket 51 is used to achieve electrical isolation between the electrode post 31 and the cover plate 22.

[0024] Optionally, the pin 32 and the terminal 31 can be fixed after being abutted together. In some embodiments, a mating groove can also be formed on the pin 32, and the terminal 31 can be partially inserted into the mating groove to increase the mating area between the terminal 31 and the pin 32.

[0025] In some embodiments, pin 32 includes a first pin 321 and a second pin 322 that are bent and connected relative to each other. The first pin 321 is electrically connected to the pole post 31, and the second pin 322 is electrically connected to the core package 10. A first thermally conductive adhesive 41 is disposed between the second pin 322 and the inner surface of the housing 21.

[0026] Specifically, as shown in the figure, the upper part is the upper surface of the core package 10, and the side surface of the core package 10 is adjacent to the upper surface. The first pin 321 is located near the upper surface of the core package 10, and the second pin 322 is located near the side surface of the core package 10. The connection between the first pin 321 and the second pin 322 spans one edge of the core package 10.

[0027] In the operation of a single battery cell, there are typically two areas where heat is concentrated: one is the connection between pin 32 and the core pack 10, and the other is the terminal post 31. If these two heat sources are too close together, the heat dissipation performance of the single battery cell will deteriorate. Therefore, in this embodiment, pin 32 includes a first pin 321 and a second pin 322, which are located on different surfaces of the core pack 10. This increases the distance between the two heat sources, avoiding heat accumulation caused by concentrated heat sources.

[0028] Please refer to Figures 5 and 6 together. Figure 5 is a schematic diagram of the fit between pin 32 and core package 10 provided in the embodiment of this application; Figure 6 is a cross-sectional schematic diagram of the fit structure in Figure 5.

[0029] Optionally, pin 32 further includes a third pin 323 electrically connected to the second pin 322, the third pin 323 being located on the side of the second pin 322 facing away from the core package 10; the core package 10 includes a package body 11 and an electrode tab 12, the package body 11 being electrically connected to the pin 32 via the electrode tab 12, the electrode tab 12 being wound around the second pin 322 and the third pin 323, and the electrode tab 12 being electrically connected to both the second pin 322 and the third pin 323 simultaneously, and a first thermally conductive adhesive 41 being disposed between the electrode tab 12 and the inner surface of the housing 21. Specifically, the opposite sides of the first thermally conductive adhesive 41 are respectively attached to the inner surface of the housing 21 and the electrode tab 12.

[0030] As the hub for current output of the cell pack 10, the tab 12 carries a large energy density during the operation of the single cell. On the one hand, the tab 12, wound around the second pin 322 and the third pin 323, increases the current-carrying area, reduces the energy density, and alleviates the heat generation phenomenon of the tab 12. On the other hand, the tab 12 is in direct contact with the first thermally conductive adhesive 41. Compared with the technical solution of indirect heat transfer through the pin 32 and the second thermally conductive adhesive 42, the tab 12 in this embodiment can transfer heat to the outside more quickly and has better heat dissipation performance.

[0031] It should be noted that there are two third pins 323 shown in the figure, which are folded from both sides of the second pin 322. The tab 12 can be wound with one or two third pins 323, which can be configured according to actual needs. For single cells with low current carrying pressure, the single-sided winding scheme shown in the figure is more convenient for production.

[0032] Optionally, the two surfaces of the second pin 322 and the third pin 323 are parallel to each other, and a bend 324 is formed between the second pin 322 and the third pin 323. The thickness of the bend 324 is less than the thickness of the second pin 322 and the third pin 323, respectively.

[0033] The thinning of the bending portion 324 makes it easier to process the relative shapes of the second pin 322 and the third pin 323, reduces the likelihood of tearing during bending, and minimizes the springback of the bending portion 324 after processing, which is beneficial for mass production.

[0034] For example, a single cell includes a second thermally conductive adhesive 42, and there is a gap between two opposing surfaces of the second pin 322 and the third pin 323, the gap being filled with the second thermally conductive adhesive 42.

[0035] In actual operation, due to the difference in heat dissipation conditions, the temperature of the tab 12 near the second pin 322 is higher than the temperature of the tab 12 near the third pin 323, and the temperature of the second pin 322 is also higher than the temperature of the third pin 323. Therefore, setting the second thermal conductive adhesive 42 between the second pin 322 and the third pin 323 is beneficial to transfer the heat of the second pin 322 to the outside more quickly and optimize the heat dissipation performance of the single cell.

[0036] In some embodiments, the single-cell battery further includes an insulating support 50 and a heat-conducting sheet 60. The insulating support 50 is disposed between the core pack 10 and the cover plate 22, and a heat-conducting hole 53 is formed on the insulating support 50. The heat-conducting sheet 60 is connected to one side of the core pack 10 along its length and extends through the heat-conducting hole 53 to the space between the insulating support 50 and the cover plate 22. Correspondingly, a second electrode hole 52 is formed on the insulating support 50, and a third electrode hole 63 is formed on the heat-conducting sheet 60. The electrode post 31 passes through the second electrode hole 52 and the third electrode hole 63, and the electrode post 31 is insulated from the heat-conducting sheet 60 and the insulating support 50.

[0037] Considering production costs, the heat-conducting sheet 60 can be an integrally formed L-shaped structure or it can be formed by connecting two separate components. Specifically, the heat-conducting sheet 60 includes a first heat-conducting sheet 61 and a second heat-conducting sheet 62 that are connected to each other. The first heat-conducting sheet 61 has a heat-conducting hole 53 that extends between the pin 32 and the housing 21. The second heat-conducting sheet 62 extends between the insulating bracket 50 and the cover plate 22.

[0038] The placement of the heat-conducting plate 60 opens up channels for heat dissipation. Especially in the embodiment with the added insulating support 50, heat is difficult to penetrate the insulating support 50, which makes the temperature of the cover plate 22 significantly lower than that of the casing 21. The placement of the heat-conducting plate 60 transfers the temperature of the core pack 10 to the cover plate 22, and the low-temperature zone of the cover plate 22 enhances the heat dissipation efficiency of the individual battery.

[0039] Optionally, the individual battery cell also includes a thermal sensor 70, which is attached to the cover plate 22.

[0040] The thermal sensor 70 is mounted on the cover plate 22. It can detect the temperature of the core package 10 and also provide more sensitive monitoring of the temperature of the electrode post 31, allowing for more timely feedback on unexpected situations. The placement of the heat-conducting plate 60 also makes the temperature detection by the thermal sensor 70 more accurate.

[0041] Optionally, in a direction perpendicular to the cover plate 22, the projection of the thermal element 70 onto the cover plate 22 falls within the projection range of the heat-conducting sheet 60 onto the cover plate 22.

[0042] Because the heat-conducting sheet 60 can conduct heat from the core package 10 to the cover plate 22, the heat-conducting sheet 60 can provide relatively accurate feedback on the real-time temperature of the core package 10. The projection of the heat-sensing element 70 on the cover plate 22 falls within the projection range of the heat-conducting sheet 60 on the cover plate 22, which makes the temperature measured by the heat-sensing element 70 as close as possible to the actual temperature of the heat-conducting sheet 60.

[0043] In some embodiments, the thickness of the first thermally conductive adhesive 41 is between 0.3 mm and 1 mm.

[0044] Compared to the 1.0mm-1.5mm gap between the related pins 32 and the housing 20, which is limited by design and manufacturing, in this embodiment, the opposite sides of the first thermally conductive adhesive 41 can abut against the pins 32 and the housing 20 respectively. The thickness of 0.3mm-1.0mm can meet the functional requirements and adapt to the processing precision commonly used in the current technology field, making the structure of the single cell more compact.

[0045] Please also refer to Figure 7, which is a schematic diagram of the cooperation between the insulating thermally conductive film 80, the core package 10, and the pins 32 provided in the embodiments of this application.

[0046] In some embodiments, the single cell further includes an insulating thermally conductive film 80, which wraps around the core package 10 and part of the leads 32 to achieve electrical isolation between the leads 32 and the housing 21. The insulating thermally conductive film 80 can be disposed between the leads 32 and the first thermally conductive adhesive 41, or it can be attached to the inner wall of the housing 21. The placement of the insulating thermally conductive film 80 enhances the safety of the single cell without compromising thermal conductivity.

[0047] The battery cells in all the above embodiments may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells, or magnesium-ion battery cells, etc., and some embodiments of this application are not limited to this. The battery cells may be cylindrical, flat, cuboid, or other shapes, etc. The figure shows a flat battery for easy combination, but it is not limited to this.

[0048] This application also provides a battery pack, which includes the single battery cells provided in any of the above embodiments.

[0049] The battery pack mentioned in the embodiments of this application refers to a physical module comprising one or more battery cells to provide higher voltage and capacity. Multiple battery cells can be connected in series, parallel, or a combination thereof; a combination thereof means that multiple battery cells are connected in both series and parallel. Multiple battery cells can be directly connected in series, parallel, or a combination thereof, and then the entire assembly of the multiple battery cells is housed within a casing. Alternatively, the battery pack can also be composed of multiple battery cells first connected in series, parallel, or a combination thereof to form battery modules, and then these battery modules are connected in series, parallel, or a combination thereof to form a whole, housed within a casing. The casing can prevent liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0050] In a battery pack, there can be multiple battery cells. The battery pack may also include other structures, such as a busbar component, through which multiple battery cells can be electrically connected to each other, enabling series, parallel, or mixed connections. The busbar component can be a metallic conductor, such as copper, iron, aluminum, stainless steel, or aluminum alloy.

[0051] The battery pack includes battery cells provided in any of the above embodiments. Therefore, the battery pack of this embodiment also has the technical effects of the above battery cells. That is, the battery pack of this embodiment has good heat dissipation performance, which can reduce the risk of thermal runaway of the battery pack to a certain extent.

Claims

1. A single-cell battery, comprising: Core package; The housing includes a shell sleeve and a cover plate, wherein the core is contained within the shell sleeve, and the cover plate is connected to the shell sleeve to seal the shell sleeve; An electrode, comprising an electrode post and a pin electrically connected to each other, the electrode post being disposed on the cover plate, and the end of the pin away from the electrode post extending along the length of the core package and electrically connected to the core package; A first thermally conductive adhesive is disposed between the pin and the inner surface of the housing.

2. The single-cell battery according to claim 1, wherein, The pins include a first pin and a second pin that are bent and connected relative to each other. The first pin is electrically connected to the electrode post, and the second pin is electrically connected to the core package. The first thermally conductive adhesive is disposed between the second pin and the inner surface of the shell.

3. The single-cell battery according to claim 2, wherein, The pin also includes a third pin electrically connected to the second pin, the third pin being located on the side of the second pin opposite to the core package; The core package includes a package body and a tab. The package body is connected to the pin through the tab. The tab is wound around the second pin and the third pin. The tab is electrically connected to both the second pin and the third pin. The first thermally conductive adhesive is disposed between the tab and the inner surface of the shell.

4. The single-cell battery according to claim 3, wherein, The two surfaces opposite to the second pin and the third pin are parallel to each other, and a bend is formed between the second pin and the third pin. The thickness of the bend is less than the thickness of the second pin and the third pin, respectively.

5. The single-cell battery according to claim 3, wherein, The single cell includes a second thermally conductive adhesive, and there is a gap between the two surfaces opposite to the second pin and the third pin, the gap being filled with the second thermally conductive adhesive.

6. The single-cell battery according to any one of claims 1 to 5, wherein, The single battery cell also includes: An insulating support is provided between the core package and the cover plate, and heat conduction holes are provided on the insulating support; A heat-conducting sheet is connected to one side of the core package along its length and extends through the heat-conducting hole to the space between the insulating support and the cover plate.

7. The single-cell battery according to claim 6, wherein, The individual battery also includes a thermal sensor, which is attached to the cover plate.

8. The single-cell battery according to claim 7, wherein, In a direction perpendicular to the cover plate, the projection of the thermal sensing element on the cover plate falls within the projection range of the thermally conductive sheet on the cover plate.

9. The single-cell battery according to any one of claims 1 to 5, wherein, The thickness of the first thermally conductive adhesive is between 0.3 mm and 1 mm.

10. The single-cell battery according to any one of claims 1 to 5, wherein, The single cell also includes an insulating and thermally conductive film, which is wrapped around the core and part of the pins to achieve electrical isolation between the pins and the casing.

11. A battery pack, comprising: The single-cell battery as described in any one of claims 1 to 10.

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