Battery cell and battery pack

Abstract

This disclosure provides a battery cell and a battery pack. The battery cell includes a housing, an electrode assembly, an end cap, terminals, and a thermally conductive layer. The housing includes a sidewall and a bottom wall connected to the sidewall. The electrode assembly is disposed inside the housing and includes tabs. The end cap is connected to the sidewall and disposed opposite to the bottom wall, and the end cap has mounting holes. The terminals pass through the mounting holes and are electrically connected to the tabs. The thermally conductive layer is disposed on at least one of the sidewall near the electrode assembly and the side facing away from the electrode assembly. The thermally conductive layer includes a plurality of thermally conductive portions with different thermal conductivityes, each of which is connected to the sidewall, and adjacent thermally conductive portions are connected to each other, or gaps are formed between at least two adjacent thermally conductive portions. This reduces temperature differences within the housing, thereby contributing to a more uniform heat distribution within the housing, and improving the performance and cycle life of the battery cell.

Description

Technical Field

[0001] The embodiments disclosed herein relate to the field of battery technology, and in particular to a battery cell and a battery pack. Background Technology

[0002] Battery cells are widely used in various fields such as electronics, communications, mobile phones, automobiles, mobile computers, aerospace, and energy storage systems. Battery cells can be, but are not limited to, lithium-ion batteries. A typical battery cell includes an aluminum casing, end caps, and electrode assemblies housed within the aluminum casing. The aluminum casing and end caps serve to enclose the electrode assemblies and also provide heat dissipation. During use, especially during charging and discharging, uneven heat distribution within the casing can affect the battery cell's performance and cycle life. Utility Model Content

[0003] In a first aspect of this disclosure, a battery cell is provided, including a housing, an electrode assembly, an end cap, a terminal post, and a thermally conductive layer. The housing includes a sidewall and a bottom wall connected to the sidewall. The electrode assembly is disposed inside the housing and includes a tab. The end cap is connected to the sidewall and disposed opposite to the bottom wall, and the end cap has a mounting hole. The terminal post passes through the mounting hole and is electrically connected to the tab. The thermally conductive layer is disposed on at least one of the sidewall near the electrode assembly and the side facing away from the electrode assembly. The thermally conductive layer includes a plurality of thermally conductive portions with different thermal conductivityes, each of the plurality of thermally conductive portions being connected to the sidewall, and wherein adjacent thermally conductive portions of the plurality of thermally conductive portions are connected to each other, or a gap is formed between at least two adjacent thermally conductive portions of the plurality of thermally conductive portions.

[0004] In some embodiments, a plurality of heat-conducting portions are arranged along a direction from the side of the sidewall closest to the pole to the side furthest from the pole, and the thermal conductivity of the plurality of heat-conducting portions decreases from the side of the sidewall closest to the pole to the side furthest from the pole.

[0005] In some embodiments, the shape of the connection or gap between two adjacent heat-conducting parts includes at least one of straight line, broken line and arc.

[0006] In some embodiments, each of the plurality of heat-conducting portions is a ring structure arranged circumferentially around the sidewall and coupled to the sidewall.

[0007] In some embodiments, each of the plurality of thermally conductive portions is formed as a thermally conductive coating or a thermally conductive sheet.

[0008] In some embodiments, at least two heat-conducting sheets connected to each other are disposed on the side of the sidewall away from the electrode assembly and arranged sequentially along a direction from the side of the sidewall closer to the electrode post to the side away from the electrode post, and the battery cell also includes a first locking mechanism, through which two adjacent heat-conducting sheets are connected.

[0009] In some embodiments, the first locking mechanism includes: a pivot arm, one end of which is pivotally connected to one of two adjacent heat-conducting sheets; a convex buckle disposed at the other end of the pivot arm; and a buckle eye disposed on the other of the two adjacent heat-conducting sheets for engaging with the convex buckle.

[0010] In some embodiments, the thermally conductive layer is disposed on the side of the sidewall near the electrode assembly, and the battery cell further includes a first insulating layer disposed on the side of the thermally conductive layer near the electrode assembly; and / or the thermally conductive layer is disposed on the side of the sidewall opposite to the electrode assembly, and the battery cell further includes a second insulating layer disposed on the side of the thermally conductive layer opposite to the electrode assembly.

[0011] In some embodiments, the second insulating layer includes a plurality of annular insulating sheets, each of the plurality of annular insulating sheets surrounding a sidewall, and the plurality of annular insulating sheets are arranged sequentially and connected to each other along a direction from the side closer to the pole to the side farther from the pole.

[0012] In some embodiments, the battery cell further includes a second locking mechanism, through which two adjacent annular insulating sheets are connected.

[0013] In some embodiments, the battery cell further includes a first heat sink, which is disposed on the side of the end cap opposite to the electrode assembly and surrounds the terminal post.

[0014] In some embodiments, the battery cell further includes a second heat sink, which is arranged around the end cap and connected to the first heat sink.

[0015] In some embodiments, the thermal conductivity of the first heat sink is greater than that of the second heat sink.

[0016] In a second aspect of this disclosure, a battery pack is provided, comprising a battery cell according to a first aspect of this disclosure.

[0017] In the battery cell provided in this embodiment, a thermally conductive layer is provided on at least one of the sidewalls of the casing near the electrode assembly and the side facing away from the electrode assembly. The thermally conductive layer includes multiple thermally conductive parts with different thermal conductivityes, and each of the multiple thermally conductive parts is connected to the sidewall. The thermal conductivity of each thermally conductive part of the thermally conductive layer can be designed to adapt to the heat distribution inside the casing during the battery cell's use. This improves the heat dissipation performance of the casing while allowing heat from high-temperature areas inside the casing to be quickly dissipated through the thermally conductive parts with higher thermal conductivity, thereby reducing temperature differences inside the casing. Furthermore, when multiple thermally conductive parts are connected to each other, heat from high-temperature areas inside the casing can also be transferred to low-temperature areas inside the casing through the multiple thermally conductive parts, further reducing temperature differences inside the casing. This contributes to a more uniform heat distribution inside the casing, thereby improving the performance and cycle life of the battery cell.

[0018] It should be understood that the content described in this section is not intended to limit the key or essential features of the embodiments of this disclosure, nor is it intended to restrict the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0019] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. In the drawings, the same or similar reference numerals denote the same or similar elements, wherein:

[0020] Figure 1 A perspective view of a battery cell according to some embodiments of the present disclosure is shown;

[0021] Figure 2 It shows Figure 1 The diagram shows an exploded view of a single battery cell.

[0022] Figure 3 It shows Figure 2 A schematic diagram of the AA section of the end cap;

[0023] Figure 4 It shows Figure 2 A top view of the side walls and bottom wall of the shell;

[0024] Figure 5 A schematic diagram of the structure of the thermally conductive layer of a battery cell according to some embodiments of the present disclosure is shown;

[0025] Figures 6 to 9 A perspective view of a battery cell according to some variations of the present disclosure is shown;

[0026] Figure 10 It shows Figures 6 to 9A schematic diagram showing the positional relationship of the sidewall, thermal conductive layer, and insulating layer of a single battery cell;

[0027] Figure 11 It shows Figures 6 to 9 This is a schematic diagram showing another positional relationship between the sidewall, thermal conductive layer, and insulating layer of a single battery cell.

[0028] Figure 12 A perspective view of a battery cell according to other disclosed embodiments is shown, the battery cell including a plurality of first locking mechanisms, each of the first locking mechanisms being in an unlocked state;

[0029] Figure 13 It shows Figure 12 The diagram shows a three-dimensional view of a single battery cell, in which each of the first locking mechanisms is in a locked state;

[0030] Figure 14 A perspective view of a battery cell according to some of the disclosed embodiments is shown. The battery cell includes a plurality of second locking mechanisms, each of which is in a locked state.

[0031] Figure 15 A perspective schematic diagram of a battery cell according to further embodiments of the present disclosure is shown; and

[0032] Figure 16 It shows Figure 15 The diagram shows an exploded view of a single battery cell. Detailed Implementation

[0033] Embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0034] The term "comprising" and its variations as used herein signify open inclusion, i.e., "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "at least partially based on". The terms "one example embodiment" and "one embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc., may refer to different or the same objects.

[0035] As described above, during the charging and discharging of a single battery cell (e.g., a prismatic aluminum-cased lithium battery, a cylindrical aluminum-cased lithium battery, etc.), the uneven heat distribution inside the casing occurs due to the non-uniformity of the electrochemical reactions within the electrode assembly and other factors, which affects the performance and lifespan of the battery cell. Embodiments of this disclosure provide a battery cell and a battery pack to effectively improve the problem of uneven heat distribution inside the casing during the use (charging and discharging) of the battery cell. In the following sections, [further details will be provided]. Figures 1 to 16 The principles of this disclosure are described.

[0036] Figure 1 A perspective schematic diagram of a battery cell 100 according to some embodiments of the present disclosure is shown. Figure 2 It shows Figure 1 An exploded view of the battery cell 100 shown. Figure 3 It shows Figure 2 A cross-sectional view of the end cap 30. Figure 4 It shows Figure 2 A top view of the side wall 11 and bottom wall 12 of the shell 10. Figure 5 A schematic diagram of the structure of the thermally conductive layer 13 of the battery cell 100 is shown.

[0037] See Figures 1 to 5 The battery cell 100 includes a housing 10, an electrode assembly 20, an end cap 30, two terminal posts 40, and a heat-conducting layer 13. The battery cell 100 can be, but is not limited to, a lithium-ion battery.

[0038] The housing 10 includes sidewalls 11 and a bottom wall 12 connected to the sidewalls 11. The housing 10 can be rectangular, cylindrical, irregular, or any suitable shape. In some embodiments, the housing 10 is generally rectangular, and its sidewalls 11 may include a first wall 1101 and a second wall 1102 opposite to each other, and a third wall 1103 and a fourth wall 1104 opposite to each other. In some embodiments, the area of ​​the first wall 1101 and the second wall 1102 is larger than the area of ​​the third wall 1103 and the fourth wall 1104. The sidewalls 11 define a first opening 111 and a second opening 112 opposite to each other. An end cap 30 is connected to the sidewalls 11 to close the first opening 111, and the bottom wall 12 is connected to the sidewalls 11 to close the second opening 112. The end cap 30 is disposed opposite to the bottom wall 12. Thus, the end cap 30, the bottom wall 12, and the sidewalls 11 define a receiving space 110 suitable for receiving the electrode assembly 20.

[0039] See Figure 2 and Figure 4In some embodiments, the sidewall 11 and the bottom wall 12 are integrally formed. The sidewall 11 and the bottom wall 12 may be made of aluminum, for example. Of course, in some alternative embodiments, the sidewall 11 and the bottom wall 12 may also be made of other suitable materials. In some embodiments, the end cap 30 is welded to the top of the sidewall 11, for example.

[0040] See Figure 3 In some embodiments, the end cap 30 has two mounting holes 301 for mounting two terminals 40. One of the terminals 40 is a positive terminal, and the other is a negative terminal. Each terminal 40 passes through a corresponding mounting hole 301 and is used for electrical connection with a corresponding tab 21 of the electrode assembly 20.

[0041] See Figure 2 The electrode assembly 20 may include two bare cells. Of course, in some alternative embodiments, the electrode assembly 20 may also have other implementations, such as including only one bare cell or including more bare cells. When the electrode assembly 20 includes multiple bare cells, the multiple bare cells can be arranged in any suitable shape as needed. In some embodiments, the electrode assembly 20 includes two tabs 21, which are a positive tab and a negative tab, respectively. The positive tab is used to connect to the positive terminal, and the negative tab is used to connect to the negative terminal. The electrode assembly 20 can be placed into the receiving space 110 through the first opening 111 of the housing 10 and is closed in the receiving space 110 by the end cap 30.

[0042] In some embodiments, the battery cell 100 may further include an insulating film 50 and a tray 60. The insulating film 50 is used to wrap the sides of the electrode assembly 20, thereby insulating the electrode assembly 20 from the sidewall 11. The tray 60 is used to be placed on the inner surface of the bottom wall 12, thereby insulating the electrode assembly 20 from the bottom wall 12.

[0043] In some embodiments, the battery cell 100 may further include an explosion-proof valve 70 or a pressure relief device, which may be disposed at any suitable location on the housing 10. In some embodiments, the explosion-proof valve 70 or pressure relief device may be disposed on the bottom wall 12. In some alternative embodiments, the explosion-proof valve 70 or pressure relief device may be disposed on the end cap 30. Of course, in some alternative embodiments, the battery cell 100 may not be provided with an explosion-proof valve and a pressure relief device.

[0044] A thermally conductive layer 13 is disposed on at least one of the side 113 of the sidewall 11 closest to the electrode assembly 20 and the side 114 opposite to the electrode assembly 20. The thermally conductive layer 13 may be in direct contact with or indirectly connected to the sidewall 11 to improve the heat dissipation performance of the housing 10 by utilizing its own thermal conductivity, thereby improving the problem of uneven heat distribution inside the housing 10.

[0045] Reference Figure 4 and Figure 5 In some embodiments, the thermally conductive layer 13 is disposed on the side 113 of the sidewall 11 near the electrode assembly 20. In some embodiments, the thermally conductive layer 13 may substantially completely cover one side 113 of the sidewall 11, i.e., the areas of the two sides are substantially equal. In some embodiments, the thermally conductive layer 13 may cover a portion of one side 113 of the sidewall 11 (e.g., the area of ​​the sidewall 11 near the electrode post 40). In some embodiments, the thermally conductive layer 13 disposed on the side 113 of the sidewall 11 near the electrode assembly 20 may also have insulating properties.

[0046] In some alternative embodiments, the thermally conductive layer 13 may be disposed on the side 114 of the sidewall 11 opposite to the electrode assembly 20. In some embodiments, the thermally conductive layer 13 may substantially completely cover one side 114 of the sidewall 11, i.e., the areas of both sides are substantially equal. In some embodiments, the thermally conductive layer 13 may cover a portion of one side 114 of the sidewall 11 (e.g., the area of ​​the sidewall 11 near the electrode post 40). In some embodiments, the thermally conductive layer 13 disposed on the side 114 of the sidewall 11 opposite to the electrode assembly 20 may also have insulating properties.

[0047] Of course, in some alternative embodiments, a thermally conductive layer 13 may be provided on both the side 113 of the sidewall 11 closest to the electrode assembly 20 and the side 114 opposite to the electrode assembly 20.

[0048] refer to Figures 3 to 5 The thermal conductivity of the heat-conducting layer 13 can be varied, that is, it includes a plurality of heat-conducting parts 131 with different thermal conductivity, and the plurality of heat-conducting parts 131 are respectively connected to the sidewall 11. Adjacent heat-conducting parts 131 among the plurality of heat-conducting parts 131 are connected to each other, or a gap is formed between at least two adjacent heat-conducting parts 131 among the plurality of heat-conducting parts 131.

[0049] The thermal conductivity of each thermally conductive portion 131 of the thermally conductive layer 13 can be designed according to the heat distribution inside the casing 10 of the battery cell 100 during use. For example, the thermally conductive portion 131 corresponding to the higher heat area inside the casing 10 can have a higher thermal conductivity, while the thermally conductive portion 131 corresponding to the lower heat area inside the casing 10 can have a lower thermal conductivity. Thus, while improving the heat dissipation performance of the casing 10, it also allows the heat from the high-temperature area inside the casing 10 to be quickly dissipated through the thermally conductive portion 131 with a higher thermal conductivity, thereby reducing the temperature difference inside the casing 10.

[0050] Furthermore, when multiple heat-conducting parts 131 are connected to each other, the heat from the high-temperature region inside the housing 10 can also be transferred to the low-temperature region inside the housing 10 through the multiple heat-conducting parts 131, which can further reduce the temperature difference inside the housing 10 and help to distribute the heat evenly inside the housing 10, thereby improving the performance and cycle life of the battery cell 100.

[0051] See Figure 5 In some embodiments, a plurality of heat-conducting portions 131 are arranged along direction H from the side of the sidewall 11 near the terminal post 40 to the side away from the terminal post 40. Accordingly, the thermal conductivity of the plurality of heat-conducting portions 131 decreases from the side of the sidewall 11 near the terminal post 40 to the side away from the terminal post 40. During use, current flows through the terminal post 40 and the heat dissipation conditions at the terminal post 40 are poor, resulting in a higher temperature inside the casing 10 near the terminal post 40 than the temperature away from the terminal post 40. Embodiments of this disclosure adapt the thermal conductivity of the plurality of heat-conducting portions 131 to the heat distribution inside the casing 10 of the battery cell 100 during use by making the thermal conductivity of the plurality of heat-conducting portions 131 decrease from the side of the sidewall 11 near the terminal post 40 to the side away from the terminal post 40.

[0052] In some embodiments, the plurality of heat-conducting portions 131 of the heat-conducting layer 13 are connected to each other, for example, and the heat-conducting layer 13 substantially completely covers one side 113 of the sidewall 11. The heat from the high-temperature region within the housing 10 is transferred to the low-temperature region within the housing through the plurality of heat-conducting portions 131, which can further contribute to the uniform distribution of heat throughout the entire interior of the housing 10 and reduce the temperature difference within the housing 10.

[0053] It is understood that the multiple heat-conducting parts 131 can be implemented in various ways, as long as they can achieve the effect of locally improving or overall improving the heat dissipation of the battery cell 100, reducing the temperature difference inside the casing 10, and contributing to the uniform distribution of heat inside the casing 10. See also Figure 4 and Figure 5 In some embodiments, each of the plurality of heat-conducting portions 131 is arranged in a ring around the sidewall 11 and coupled to each other. This facilitates the layout of the individual heat-conducting portions 131. Of course, in some alternative embodiments, each of the plurality of heat-conducting portions 131 may have other implementations and is not limited to being arranged around the sidewall 11.

[0054] In some embodiments, the shape of the connection 1313 or gap between two adjacent heat-conducting parts 131 (the shape of the connection 1313 or gap may also be referred to as the boundary shape) includes at least one of straight line, broken line, and arc shape. Of course, the boundary shape can also be implemented in other ways and is not limited to the examples above. The boundary shape can be designed in conjunction with the temperature rise of the battery cell 100 during use to better improve the problem of uneven heat distribution inside the casing 10.

[0055] Reference Figure 2 and Figure 5 In some embodiments, a plurality of heat-conducting portions 131 are arranged sequentially and connected to each other along a direction H (more specifically, along the direction from the end cover 30 to the bottom wall 12) from the side near the pole 40 to the side away from the pole 40. The thermal conductivity of the plurality of heat-conducting portions 131 decreases along the direction from the end cover 30 to the bottom wall 12, that is, the thermal conductivity of the plurality of heat-conducting portions 131 decreases from the side of the side wall 11 near the pole 40 to the side away from the pole 40. It should be noted that the number of heat-conducting portions 131 can be adjusted according to the height of the side wall 11, and this disclosure does not limit the specific number of heat-conducting portions 131.

[0056] See also Figure 4 and Figure 5 In some embodiments, each of the plurality of thermally conductive portions 131 may be formed as a thermally conductive coating. The thermally conductive coating may be formed, for example, by, but not limited to, gradient plasma spraying. In some embodiments, the thermally conductive coating may have insulating properties.

[0057] In some embodiments, each of the plurality of heat-conducting portions 131 can be formed as a heat-conducting sheet. The heat-conducting sheet can be a metal sheet or a heat-conducting sheet with insulating properties. In some embodiments, the plurality of heat-conducting sheets can be fixed to each other by means of riveting, locking, or other methods. In some embodiments, the plurality of heat-conducting sheets can be attached to the sidewall 11 by adhesive bonding. In some embodiments, the material rigidity of each heat-conducting sheet is greater than the material rigidity of the sidewall 11, which can enhance the structural strength of the sidewall 11.

[0058] In some embodiments, a portion of the plurality of heat-conducting portions 131 may be formed as a heat-conducting coating, and another portion of the heat-conducting portions may be formed as a heat-conducting sheet, which is also within the scope of protection of this disclosure.

[0059] In some embodiments, when the thermally conductive layer 13 is disposed on one side 113 of the sidewall 11 but is not the outermost structure disposed on one side 113 of the sidewall 11, the thermally conductive layer 13 may not have insulating properties. In this case, one side 113 of the sidewall 11 may also be provided with an insulating layer as the outermost structure to improve the electrical safety of the battery cell 100. When the thermally conductive layer 13 is the outermost structure disposed on one side 113 of the sidewall 11, the thermally conductive layer 13 itself has insulating properties to improve the electrical safety of the battery cell 100.

[0060] In some alternative embodiments, when the thermally conductive layer 13 is disposed on one side 114 of the sidewall 11 but is not the outermost structure disposed on one side 114 of the sidewall 11, the thermally conductive layer 13 may not have insulating properties. In this case, one side 114 of the sidewall 11 may also be provided with an insulating layer as the outermost structure to improve the electrical safety of the battery cell 100. When the thermally conductive layer 13 is the outermost structure disposed on one side 114 of the sidewall 11, the thermally conductive layer 13 itself has insulating properties to improve the electrical safety of the battery cell 100.

[0061] exist Figure 3 and Figure 4 In the illustrated embodiment, the thermally conductive layer 13 is disposed on the side 113 of the sidewall 11 near the electrode assembly 20. The battery cell 100 also includes a first insulating layer 141 disposed on the side of the thermally conductive layer 13 near the electrode assembly 20. Furthermore, a fourth insulating layer 144 may also be disposed on the side 114 of the sidewall 11 opposite to the electrode assembly 20 (the fourth insulating layer 144 is...). Figure 2 Not shown in the image, in Figure 4 (shown as dashed lines in the middle).

[0062] In some embodiments, the first insulating layer 141 and / or the fourth insulating layer 144 may be an insulating coating formed by spraying. Alternatively, in some embodiments, the first insulating layer 141 and / or the fourth insulating layer 144 may include a sheet-like insulating element. The sheet-like insulating element may have various implementations. For example, in some embodiments, the sheet-like insulating element may be PP plastic or an insulating blue film. In some embodiments, the sheet-like insulating element includes a plurality of annular insulating sheets, each of the plurality of annular insulating sheets surrounding the sidewall 11, and the plurality of annular insulating sheets are arranged sequentially and connected to each other along a direction H from the side closest to the pole post 40 to the side furthest from the pole post 40. More specifically, the plurality of annular insulating sheets may, for example, be arranged sequentially and connected to each other along a direction from the end cap 30 to the bottom wall 12. The shape of the connection or gap between two adjacent annular insulating sheets may be linear or other suitable shapes. Each annular insulating sheet and the sidewall 11 are coupled to each other.

[0063] In addition, in some alternative embodiments, the surface of the back electrode assembly 20 of the sidewall 11 may be subjected to micro-arc oxidation to form a fourth insulating layer 144.

[0064] In some embodiments, the battery cell 100 can also be cooled by liquid cooling. In some embodiments, the liquid-cooled coolant channels are located near the bottom of the housing 10, for example, below the bottom wall 12.

[0065] Figures 6 to 9 A perspective view of a battery cell 100 according to some variations of the present disclosure is shown. Figures 6 to 9 The battery cell 100 includes a casing, electrode assembly, end cap 30, terminal post 40, and heat-conducting layer 13. The structures of the casing, electrode assembly, end cap 30, and terminal post 40 can be referred to the above description. Figures 1 to 5 The following text will mainly describe the battery cell 100 shown. Figures 6 to 9 The differences between the battery cell 100 shown and the battery cell 100 mentioned above will be explained, while the same parts will not be described again.

[0066] See Figures 6 to 9 A heat-conducting layer 13 is provided on the side 114 of the sidewall 11 opposite to the electrode assembly 20. The heat-conducting layer 13 includes a plurality of heat-conducting portions 131 with different thermal conductivity. The thermal conductivity of the plurality of heat-conducting portions 131 decreases from the side of the sidewall 11 closest to the electrode post 40 to the side furthest from the electrode post 40. As can be seen from the above, when the heat-conducting layer 13 is not the outermost structure provided on the side 114 of the sidewall 11, the heat-conducting layer 13 may not have insulating properties. In this case, an insulating layer can also be provided on the side 114 of the sidewall 11 as the outermost structure. Figures 6 to 9 (Not shown in the image). When the thermally conductive layer 13 is the outermost structure disposed on one side 114 of the sidewall 11, the thermally conductive layer 13 itself can have insulating properties.

[0067] In addition, Figure 6 In the illustrated embodiment, each of the plurality of heat-conducting portions 131 can be formed by a heat-conducting coating 1311, which can be formed, for example, by, but not limited to, gradient plasma spraying. Specifically, the plurality of heat-conducting coatings 1311 are arranged sequentially and connected to each other along a direction from the end cap 30 to the bottom wall 12, and the thermal conductivity of the plurality of heat-conducting coatings 1311 decreases along the direction from the end cap 30 to the bottom wall 12. Each heat-conducting coating 1311 can be in the form of a ring structure circumferentially arranged around the sidewall 11. The boundary shape between two adjacent heat-conducting coatings 1311 is, for example, a straight line or other suitable shape.

[0068] exist Figure 7In the illustrated embodiment, each of the plurality of heat-conducting portions 131 can be formed by a heat-conducting sheet 1312. The plurality of heat-conducting sheets 1312 are arranged sequentially and connected to each other along a direction H (more specifically, along the direction from the end cap 30 to the bottom wall 12) from the side of the sidewall 11 near the pole 40 to the side away from the pole 40. The thermal conductivity of the plurality of heat-conducting sheets 1312 decreases along the direction from the end cap 30 to the bottom wall 12. Each heat-conducting sheet 1312 can be a metal sheet or a heat-conducting sheet with insulating properties. In some embodiments, the plurality of heat-conducting sheets 1312 can be fixed to each other by riveting, locking, or other means. In some embodiments, the plurality of heat-conducting sheets 1312 can be attached to the sidewall 11 by adhesive bonding. In some embodiments, the material rigidity of each heat-conducting sheet 1312 is greater than the material rigidity of the sidewall 11, thereby enhancing the structural strength of the sidewall 11. The boundary shape between two adjacent heat-conducting sheets 1312 is, for example, a straight line or other suitable shape.

[0069] exist Figure 8 In the illustrated embodiment, each of the plurality of heat-conducting portions 131 can be formed as a heat-conducting coating, or each of the plurality of heat-conducting portions 131 can be formed as a heat-conducting sheet, or a portion of the plurality of heat-conducting portions 131 can be formed as a heat-conducting coating and another portion of the heat-conducting portions 131 can be formed as a heat-conducting sheet. The performance of the heat-conducting coating and the heat-conducting sheet can be referred to the description of the heat-conducting coating and the heat-conducting sheet above, and will not be repeated here.

[0070] In addition, by Figure 8 As can be seen, the boundary shape between two adjacent heat-conducting parts 131 is arc-shaped. Among the multiple heat-conducting parts 131 arranged sequentially in direction H from the side of the sidewall 11 closest to the electrode post 40 to the side furthest from the electrode post 40, the thermal conductivity of the heat-conducting part 131 closest to the electrode post 40 is greater than that of the heat-conducting part 131 furthest from the electrode post 40. The shape and size of the multiple heat-conducting parts 131 can be designed according to the heat distribution inside the casing 10 of the battery cell 100 during use.

[0071] exist Figure 9 In the illustrated embodiment, the formation of each of the plurality of heat-conducting parts 131 can be referred to the above-mentioned method. Figure 8 The formation method of each heat-conducting part 131 in the illustrated embodiment will not be described again here. Figure 9 As can be seen, the boundary shape between two adjacent heat-conducting parts 131 is a zigzag shape. Multiple heat-conducting parts 131 are arranged sequentially and connected to each other along the direction from the end cover 30 to the bottom wall 12, and the thermal conductivity of the multiple heat-conducting parts 131 decreases from the side of the side wall 11 near the pole post 40 to the side away from the pole post 40.

[0072] Figure 10 It shows Figures 6 to 9 This diagram illustrates the positional relationship of the sidewall 11, thermally conductive layer 13, and insulating layer of a battery cell 100. Specifically, in some embodiments, the battery cell 100 further includes a second insulating layer 142 and a third insulating layer 143. The thermally conductive layer 13 is disposed on the side 114 of the sidewall 11 opposite to the electrode assembly 20. The thermally conductive layer 13 can directly contact the sidewall 11. The second insulating layer 142 is disposed on the side of the thermally conductive layer 13 opposite to the electrode assembly 20. The third insulating layer 143 is disposed on the side 113 of the sidewall 11 near the electrode assembly 20. Thus, insulating layers are provided on both sides of the sidewall 11, further ensuring the electrical safety of the battery cell 100. The structure of the thermally conductive layer 13 can be referred to the description above and will not be repeated here.

[0073] In some embodiments, the second insulating layer 142 and / or the third insulating layer 143 may be an insulating coating formed by spraying. Alternatively, in some embodiments, the second insulating layer 142 and / or the third insulating layer 143 may include a sheet-like insulating element. The sheet-like insulating element may have various implementations. For example, in some embodiments, the sheet-like insulating element may be PP plastic or an insulating blue film. In some embodiments, the sheet-like insulating element includes a plurality of annular insulating sheets, each of the plurality of annular insulating sheets surrounding the sidewall 11, and the plurality of annular insulating sheets are arranged sequentially and connected to each other along a direction H from the side closest to the pole post 40 to the side furthest from the pole post 40. More specifically, the plurality of annular insulating sheets may, for example, be arranged sequentially and connected to each other along a direction from the end cap 30 to the bottom wall 12. The boundary shape of two adjacent annular insulating sheets may be linear or other suitable shapes. Each annular insulating sheet and the sidewall 11 are coupled to each other.

[0074] In addition, in some alternative embodiments, the surface of the sidewall 11 near the electrode assembly 20 may be subjected to micro-arc oxidation to form a third insulating layer 143.

[0075] Figure 11 It shows Figures 6 to 9This diagram illustrates another positional relationship between the sidewall 11, the thermally conductive layer 13, and the insulating layer of the battery cell 100. Specifically, in some embodiments, a thermally conductive layer 13 is provided on both the side 114 facing away from the electrode assembly 20 and the side 113 near the electrode assembly 20 of the sidewall 11. Both thermally conductive layers 13 can be in direct contact with the sidewall 11. The thermally conductive layer 13 on the side 113 near the electrode assembly 20 of the sidewall 11 can be referred to as the first thermally conductive layer, and the thermally conductive layer 13 on the side 114 facing away from the electrode assembly 20 of the sidewall 11 can be referred to as the second thermally conductive layer. The battery cell 100 correspondingly includes a first insulating layer 141 and a second insulating layer 142. The first insulating layer 141 is provided on the side of the first thermally conductive layer near the electrode assembly 20, and the second insulating layer 142 is provided on the side of the second thermally conductive layer facing away from the electrode assembly 20. The structures of the first and second thermally conductive layers can be referred to the description of the thermally conductive layers above, and will not be repeated here.

[0076] Figure 12 and Figure 13 A perspective view of a battery cell 100 according to further embodiments of the present disclosure is shown. The battery cell 100 includes a housing, an electrode assembly, an end cap 30, a terminal post 40, and a thermally conductive layer 13. Figure 12 and Figure 13 The structure of the battery cell 100 shown is similar to Figure 7 The battery cells 100 shown have similar structures. The following text will mainly describe the differences between the two, while the same parts will not be described again.

[0077] See Figure 12 and Figure 13 Each of the plurality of heat-conducting portions 131 is formed by an annular heat-conducting sheet 1312 arranged circumferentially around the sidewall 11, and each heat-conducting sheet 1312 has insulating properties. The battery cell 100 also includes a plurality of first locking mechanisms 15, each first locking mechanism 15 for reliably connecting two adjacent heat-conducting sheets 1312 together. Figure 12 Each of the first locking mechanisms 15 is in the unlocked state. Figure 13 Each of the first locking mechanisms 15 is in a locked state.

[0078] Figure 12 and Figure 13An exemplary embodiment of the first locking mechanism 15 is shown. In some embodiments, as shown, the first locking mechanism 15 includes, for example, a pivot arm 151, a buckle 152, and a snap eye 153. One end 1511 of the pivot arm 151 is pivotally connected to one of two adjacent heat-conducting sheets 1312, and the other end 1512 of the pivot arm 151 is provided with the buckle 152. The snap eye 153 is provided on the other heat-conducting sheet of the two adjacent heat-conducting sheets 1312, and the snap eye 153 is used to engage with the buckle 152. By rotating the pivot arm 151, the buckle 152 and the snap eye 153 are engaged or disengaged, allowing the first locking mechanism 15 to switch between a locked state and an unlocked state. In this way, two adjacent heat-conducting sheets 1312 can be easily connected to each other. Thus, even if the housing 10 bulges or deforms, the two adjacent heat-conducting sheets 1312 can remain connected under the constraint of the first locking mechanism 15, thereby allowing heat to be transferred between the two adjacent heat-conducting sheets 1312. Of course, in some alternative embodiments, the first locking structure can be implemented in other ways, as long as it can connect two adjacent heat-conducting sheets 1312 to each other.

[0079] Figure 14 A perspective view of a battery cell 100 according to yet another disclosed embodiment is shown. Figure 14 The structure of the battery cell 100 shown is similar to Figures 6 to 11 The structure of the battery cell 100 shown is similar, and the following text will mainly describe it. Figure 14 The battery cell 100 shown is Figures 6 to 11 The battery cell 100 shown is different, but the same parts will not be described again.

[0080] See Figure 14 The second insulating layer 142 includes a plurality of annular insulating elements 1421. Each of the plurality of annular insulating elements 1421 surrounds the sidewall 11, and the plurality of annular insulating sheets 1421 are arranged sequentially and connected to each other along a direction H from the side closest to the terminal post 40 to the side furthest from the terminal post 40. More specifically, the plurality of annular insulating sheets 1421 are arranged sequentially and connected to each other along a direction from the end cap 30 to the bottom wall 12. The battery cell 100 also includes a second locking mechanism 25, through which two adjacent annular insulating sheets 1421 are connected together. Figure 14 Each of the second locking mechanisms 25 is in a locked state.

[0081] Figure 14An exemplary embodiment of the second locking mechanism 25 is shown. The structure of the second locking mechanism 25 is similar to that of the first locking mechanism 15. The second locking mechanism 25 includes, for example, a pivot arm 251 and a snap eye. One end of the pivot arm 251 is pivotally connected to one of two adjacent annular insulating members 1421, and the other end of the pivot arm 251 is provided with a protruding buckle. The snap eye is provided on the other of the two adjacent annular insulating members 1421, and the snap eye is used to engage with the protruding buckle. By rotating the pivot arm 251, the protruding buckle and the snap eye are engaged or disengaged, so that the second locking mechanism 25 can be switched between a locked state and an unlocked state. In this way, two adjacent annular insulating members 1421 can be conveniently connected to each other. Of course, in some alternative embodiments, the second locking structure 25 can have other implementations, as long as it can connect two adjacent annular insulating members 1421 to each other.

[0082] It should be noted that, Figure 14 The structure of the second insulating layer 142 shown is also applicable to Figure 4 The fourth insulating layer 144 of the battery cell 100 shown can be connected together by two adjacent annular insulating members through a second locking mechanism.

[0083] Figure 15 A perspective view of a battery cell 100 according to further embodiments of the present disclosure is shown. Figure 16 It shows Figure 15 An exploded view of the battery cell 100 shown. Figure 15 and Figure 16 The structure of the battery cell 100 shown is similar to Figure 6 The battery cells 100 shown have similar structures. The following text will mainly describe the differences between the two, while the same parts will not be described again.

[0084] See Figure 15 and Figure 16 The battery cell 100 may further include a sealing ring 90, a first heat sink 81, and a second heat sink 82. The sealing ring 90 is disposed on the side of the end cover 30 opposite to the electrode assembly 20 and surrounds the corresponding terminal post 40. The first heat sink 81 is disposed on the side of the end cover 30 opposite to the electrode assembly 20 and surrounds the corresponding sealing ring 90, thereby surrounding the corresponding terminal post 40. The sealing ring 90 insulates the first heat sink 81 and the terminal post 40 from each other. The second heat sink 82 is arranged around the end cover 30 and is connected to the first heat sink 81. The thermal conductivity of the first heat sink 81 is greater than that of the second heat sink 82, and the second heat sink 82 is connected to the thermally conductive layer 13.

[0085] As discussed above, during the use (charging and discharging) of the battery cell 100, the temperature near the terminal post 40 inside the casing 10 is higher than other locations. In this embodiment, the thermal conductivity of the first heat sink 81 is greater than that of the second heat sink 82. This facilitates the diffusion of heat accumulated near the terminal post 40 through the first heat sink 81 to the surrounding area, and also allows it to diffuse through the second heat sink 82 to the heat conduction layer 13. Therefore, the problem of uneven heat distribution within the casing 10 can be further improved.

[0086] Of course, in some alternative embodiments, the second heat sink 82 can be omitted on the end cap 30, and the heat accumulated near the pole post 40 can be dissipated by the first heat sink 81, which can also improve the uneven heat distribution inside the housing 10.

[0087] In some embodiments, the first heat sink 81 may itself have insulating properties, thus eliminating the need for the sealing ring 90. In some embodiments, the second heat sink 82 may also have insulating properties.

[0088] It should be noted that, Figure 15 and Figure 16 The end cap 30 in the illustrated embodiment is applicable to the battery cell 100 provided in any of the embodiments above.

[0089] In some embodiments, the thickness of the thermally conductive coating and the insulating coating on the sidewall 11 can each range from 10 μm to 1000 μm. In some embodiments, the total thickness of the sidewall 11 and the thermally conductive coating and the insulating coating stacked on the sidewall 11 can range from 10 μm to 1000 μm.

[0090] In some embodiments, the thickness of the thermally conductive coating and the insulating coating on the sidewall 11 can each range from 30 μm to 60 μm. In some embodiments, the total thickness of the sidewall 11 and the thermally conductive coating and the insulating coating stacked on the sidewall 11 can range from 30 μm to 60 μm.

[0091] The embodiments of this disclosure also provide a battery pack, which may include the housing 10 of the battery cell 100 according to the above embodiments of this disclosure or the battery cell 100 according to the above embodiments of this disclosure.

[0092] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A battery cell, characterized in that, include: The housing (10) includes a side wall (11) and a bottom wall (12) connected to the side wall (11); An electrode assembly (20) is disposed inside the housing (10) and includes tabs (21); An end cap (30) is connected to the side wall (11) and disposed opposite to the bottom wall (12), the end cap (30) having a mounting hole (301); The pole post (40) passes through the mounting hole (301) and is electrically connected to the tab (21); and A thermally conductive layer (13) is disposed on at least one of the sidewall (11) near the electrode assembly (20) (113) and the side facing away from the electrode assembly (20) (114). The thermally conductive layer (13) includes a plurality of thermally conductive portions (131) with different thermal conductivityes, and the plurality of thermally conductive portions (131) are respectively connected to the sidewall (11). The adjacent heat-conducting parts (131) of the plurality of heat-conducting parts (131) are connected to each other, or a gap is formed between at least two adjacent heat-conducting parts (131) of the plurality of heat-conducting parts (131).

2. The battery cell according to claim 1, characterized in that, The plurality of heat-conducting parts (131) are arranged along a direction (H) from the side of the sidewall (11) near the pole post (40) to the side away from the pole post (40), and The thermal conductivity of the plurality of heat-conducting parts (131) decreases from the side of the sidewall (11) near the pole (40) to the side away from the pole (40).

3. The battery cell according to claim 1, characterized in that, The shape of the connection (1313) or gap between two adjacent heat-conducting parts (131) includes at least one of straight line, broken line and arc.

4. The battery cell according to claim 1 or 2, characterized in that, Each of the plurality of heat-conducting parts (131) is a ring structure arranged circumferentially around the sidewall (11) and coupled to the sidewall (11) with each other.

5. The battery cell according to claim 4, characterized in that, Each of the plurality of heat-conducting parts (131) is formed as a heat-conducting coating (1311) or a heat-conducting sheet (1312).

6. The battery cell according to claim 5, characterized in that, At least two of the heat-conducting plates (1312) connected to each other are disposed on the side of the sidewall (11) away from the electrode assembly (20) and arranged sequentially in a direction (H) from the side of the sidewall (11) near the electrode post (40) to the side away from the electrode post (40), and The battery cell also includes a first locking mechanism (15), and two adjacent heat-conducting sheets (1312) are connected through the first locking mechanism (15).

7. The battery cell according to claim 6, characterized in that, The first locking mechanism (15) includes: A pivot arm (151), one end (1511) of which is pivotally connected to one of the two adjacent heat-conducting plates (1312); A convex buckle (152) is provided at the other end (1512) of the pivot arm (151); and A buttonhole (153) is provided on another of the two adjacent heat-conducting sheets (1312) for engaging with the protruding buckle (152).

8. The battery cell according to claim 1 or 2, characterized in that, The thermally conductive layer (13) is disposed on the side of the sidewall (11) near the electrode assembly (20). The battery cell (100) further includes a first insulating layer (141), which is disposed on the side of the thermally conductive layer (13) near the electrode assembly (20); and / or The thermally conductive layer (13) is disposed on the side (114) of the sidewall (11) opposite to the electrode assembly (20), and the battery cell (100) further includes a second insulating layer (142), which is disposed on the side of the thermally conductive layer (13) opposite to the electrode assembly (20).

9. The battery cell according to claim 8, characterized in that, The second insulating layer (142) includes a plurality of annular insulating sheets (1421), each of the plurality of annular insulating sheets (1421) surrounding the sidewall (11), and the plurality of annular insulating sheets (1421) are arranged sequentially and connected to each other along a direction (H) from the side closer to the pole (40) to the side away from the pole (40).

10. The battery cell according to claim 9, characterized in that, The battery cell also includes a second locking mechanism (25), and two adjacent annular insulating sheets (1421) are connected through the second locking mechanism (25).

11. The battery cell according to claim 1 or 2, characterized in that, The battery cell also includes a first heat sink (81), which is disposed on the side of the end cap (30) opposite to the electrode assembly (20) and surrounds the terminal post (40).

12. The battery cell according to claim 11, characterized in that, The battery cell also includes a second heat sink (82), which is arranged around the end cap (30) and is connected to the first heat sink (81).

13. The battery cell according to claim 12, characterized in that, The thermal conductivity of the first heat sink (81) is greater than that of the second heat sink (82).

14. A battery pack, characterized in that, Includes the battery cell (100) according to any one of claims 1 to 13.

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