Upper cover unit for single battery, single battery and battery module

Abstract

The utility model belongs to the field of batteries, and particularly relates to an upper cover unit for a single battery, the single battery and a battery module. The problem that the battery module cannot work continuously due to thermal runaway of part of single batteries is solved. The upper cover unit comprises an upper cover assembly and a polarity terminal fixed on the upper cover assembly; the upper cover assembly comprises an upper cover plate, a connecting plate and an insulating plate which are sequentially laminated; mounting holes which are communicated with each other are formed in the upper cover plate and the insulating plate in the lamination direction; the polarity terminal penetrates through the mounting hole and is fixedly sealed with the upper cover plate; the upper cover plate and the connecting plate are both electric conductors, and the insulating plate is an electric insulator; the upper cover plate is insulated from the polarity terminal, and a channel is arranged between the connecting plate and the polarity terminal; when the temperature reaches a set threshold temperature, the connecting plate is heated to deform, and part of the structure is filled in the channel and is connected between the polar terminal and the upper cover plate, so that the electric conduction between the upper cover plate and the polar terminal is realized.

Description

Technical Field

[0001] This utility model belongs to the field of batteries, specifically a cover unit for a single battery, a single battery, and a battery module. Background Technology

[0002] Currently, the market often uses multiple individual cells connected in parallel, series, or series-parallel to form battery modules (also known as battery packs).

[0003] During use, one or more individual cells in the battery module may experience thermal runaway, which may cause the entire battery module to cease operation. Summary of the Invention

[0004] The purpose of this invention is to provide a cover unit for a single battery, a single battery, and a battery module, overcoming the problem that the battery module cannot continue to work due to thermal runaway of some single batteries.

[0005] The first aspect of this utility model provides a top cover unit for a single battery cell, including a top cover assembly and a polar terminal fixed on the top cover assembly; the key feature is that: the top cover assembly includes a top cover plate, a connecting plate and an insulating plate arranged in sequence; in the stacking direction, mounting holes that are mutually penetrating are opened on the top cover plate and the insulating plate; the polar terminal passes through the mounting hole and is fixedly sealed with the top cover plate.

[0006] Both the top cover and the connecting plate are electrical conductors, while the insulating plate is an electrical insulator.

[0007] The top cover is insulated from the polarity terminals, and a channel is provided between the connecting plate and the polarity terminals;

[0008] When the temperature reaches the set threshold temperature, the connecting plate deforms due to heat, and part of the structure fills the channel, connecting between the polar terminal and the upper cover plate, thus realizing electrical conduction between the upper cover plate and the polar terminal.

[0009] In a battery module, when a single cell experiences thermal runaway, the temperature of the connecting plate of that single cell rises to or exceeds a set threshold temperature, causing the connecting plate to deform due to heat. Part of the structure fills the channel and connects the upper cover plate and the polar terminal through the channel, thereby achieving electrical conduction between the upper cover plate and the polar terminal. This makes the single cell a resistor in the circuit of the entire battery module. At least a portion of the discharge current of the single cells in the entire battery module that have not experienced thermal runaway flows through the upper cover assembly of the single cell to continue supplying power to the load.

[0010] Therefore, it can be seen that even if a single cell in the battery module experiences thermal runaway, the entire battery module can still continue to operate normally and supply power to the load.

[0011] Furthermore, the polarity terminal includes a limiting part and an electrical connection part; the electrical connection part of the polarity terminal passes through the mounting hole and is fixedly sealed between the terminal and the upper cover plate, and the electrical connection part is located on the side of the upper cover plate, while the limiting part is limited on the side of the insulating plate.

[0012] Furthermore, the aforementioned channel can be at least one through hole formed on the insulating plate, the through hole penetrating the insulating plate along the thickness direction of the insulating plate; and the through hole is located directly above the polarity terminal limiting portion;

[0013] When the temperature reaches the set threshold temperature, the connecting plate deforms due to heat, and part of the structure fills the through hole. It is connected between the polarity terminal limiting part and the upper cover plate through the through hole to realize the electrical connection between the upper cover plate and the polarity terminal.

[0014] Furthermore, the aforementioned channel can also be a second annular gap between the polar terminal and the insulating plate; specifically, when the diameter of the mounting hole on the insulating plate is larger than the diameter of the mounting hole on the upper cover plate; after the polar terminal passes through the mounting hole, the aforementioned second annular gap exists between it and the insulating plate.

[0015] When the temperature reaches the set threshold temperature, the connecting plate deforms due to heat, and part of the structure fills the second annular gap. It is connected between the polar terminal and the upper cover plate through the second annular gap, realizing the electrical connection between the upper cover plate and the polar terminal.

[0016] Furthermore, the connecting plate is a metal plate, which is readily available and relatively inexpensive compared to other conductive materials; the melting point of the metal plate is less than or equal to a set threshold temperature. When a single cell experiences thermal runaway, the temperature of the metal plate rises to the melting point and becomes molten, connecting the upper cover plate and the polar terminal through the aforementioned channel.

[0017] Furthermore, the metal plate is an annular metal plate; the polar terminal passes through the inner hole of the annular metal plate and has a gap between it and the inner hole to ensure electrical insulation between the polar terminal and the annular metal plate under normal working conditions.

[0018] Furthermore, the aforementioned top cover unit for a single battery also includes an insulating sealing ring; the insulating sealing ring is sleeved on the polar terminal and clamped between the top cover plate and the polar terminal limiting part, thereby improving the sealing performance between the polar terminal and the top cover plate.

[0019] Furthermore, the upper cover assembly may also be provided with a first opening component. The first opening component forms an opening in the upper cover assembly under the action of external force or electrolyte.

[0020] The second aspect of this utility model also provides a single battery, including an outer cylinder, an upper cover assembly, a lower cover assembly, and an electrode assembly; the outer cylinder, the upper cover assembly, and the lower cover assembly enclose a single battery housing, and the electrode assembly is located inside the housing; the special feature is that the upper cover assembly adopts the above-mentioned upper cover unit for single batteries, and the polarity terminal is electrically connected to the electrode tab of the electrode assembly.

[0021] Furthermore, the lower cover assembly includes a lower cover plate and a second opening component disposed on the lower cover plate. The second opening component forms an opening in the lower cover plate under the action of external force or electrolyte; its structure may be the same as or different from the first opening component.

[0022] The third aspect of this utility model also provides a battery module, which is characterized in that it includes n individual batteries arranged in the same direction; wherein the individual batteries are the aforementioned individual batteries; and n is an integer greater than 1.

[0023] Furthermore, the aforementioned battery module also includes a housing; n individual batteries are arranged in the same direction in the inner cavity of the housing, and the housing has at least one shared chamber, the inner cavity of which is connected to the inner cavities of all individual batteries; a clearance hole is provided on the top plate of the housing corresponding to the polarity terminal of each individual battery; the polarity terminal of each individual battery extends out of the clearance hole, and the area of ​​the top plate of the housing corresponding to the clearance hole is fixedly sealed to the housing body of the individual battery.

[0024] The beneficial effects of this utility model are:

[0025] In a battery module, when a single cell experiences thermal runaway, the temperature of the connecting plate of that single cell rises to or exceeds a set threshold temperature, causing the connecting plate to deform due to heat. Part of the structure fills the channel and connects between the top cover and the polar terminal through the channel, thereby achieving an electrical connection between the top cover and the polar terminal. This makes the single cell a resistor in the circuit of the entire battery module. At least a portion of the discharge current of the single cells in the entire battery module that have not experienced thermal runaway flows through the top cover assembly of the single cell to continue supplying power to the load.

[0026] Therefore, it can be seen that even if a single cell in the battery module experiences thermal runaway, the entire battery module can still continue to operate normally and supply power to the load. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the top cover unit for a single battery cell in Example 1;

[0028] Figure 2 This is a cross-sectional view of the top cover unit for a single battery cell in Example 1;

[0029] Figure 3This is an exploded view of the top cover unit for a single battery cell in Example 1;

[0030] Figure 4 This is a cross-sectional view of the top cover unit for a single cell that experienced thermal runaway in Example 1;

[0031] Figure 5 This is a cross-sectional view of another single-cell battery cover unit in another embodiment;

[0032] Figure 6 This is an exploded view of another type of single-cell battery cover unit in other embodiments;

[0033] Figure 7 This is a cross-sectional view of the top cover unit for a single battery cell in Example 2;

[0034] Figure 8 This is a cross-sectional view of the top cover unit for a single cell that experienced thermal runaway in Example 2;

[0035] Figure 9 This is a cross-sectional view of a top cover unit for a single battery cell in Example 3;

[0036] Figure 10 This is a cross-sectional view of another type of single-cell battery cover unit in Example 3;

[0037] Figure 11 This is a schematic diagram of the structure of a single cell in Example 4;

[0038] Figure 12 This is a schematic diagram of the battery module structure in Example 5;

[0039] Figure 13 This is a schematic diagram of the battery module structure in Example 6;

[0040] Figure 14 This is a cross-sectional view of the battery module in Example 6;

[0041] Figure 15 for Figure 14 A magnified view of the region shown in section a;

[0042] Figure 16 This is a partial cross-sectional view of the battery module after thermal runaway occurred in Example 6;

[0043] The reference numerals in the figure are as follows: 1. Top cover unit; 11. Top cover assembly; 111. Top cover plate; 112. Connecting plate; 113. Insulating plate; 12. Polar terminal; 121. First polar terminal; 122. Second polar terminal; 123. Limiting part; 124. Electrical connection part; 125. Base; 126. Column; 13. First mounting hole; 14. Second mounting hole; 15. Insulating component; 16. Through hole; 17. Second annular gap; 18. Insulating sealing ring; 19. First annular gap; 2. Single cell; 21. Lower cover plate; 22. Second opening part; 3. Outer shell; 31. Top plate of outer shell; 32. Clearance hole; 33. Bottom plate of outer shell; 34. Support member; 35. Electrolyte sharing chamber; 36. Gas sharing chamber; 37. Sealing connection member. Detailed Implementation

[0044] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0045] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0046] In the description of this utility model, it should be noted that the terms "top," "bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0047] A battery module consists of multiple individual cells. During use, one or more individual cells in the battery module may experience thermal runaway, which may cause the entire battery module to stop working.

[0048] In order to enable the entire battery module to continue to operate normally and supply power to the load in the event of thermal runaway of a single cell in the battery module, this utility model discloses a cover unit for a single cell, a single cell, and a battery module.

[0049] Specifically, the top cover unit for a single battery provided by this utility model includes a top cover assembly and a polar terminal fixed on the top cover assembly; the top cover assembly includes a top cover plate, a connecting plate and an insulating plate stacked in sequence; in the stacking direction, mounting holes that are mutually connected are opened on the top cover plate and the insulating plate; the polar terminal passes through the mounting holes and is sealed between the top cover plate and the top cover plate; both the top cover plate and the connecting plate are electrical conductors, and the insulating plate is an electrical insulator;

[0050] The top cover is insulated from the polarity terminals, and a channel is provided between the connecting plate and the polarity terminals;

[0051] When the temperature reaches the set threshold temperature, the connecting plate deforms due to heat, and part of the structure fills the channel. It is connected between the polar terminal and the upper cover plate through the channel to achieve electrical conduction between the upper cover plate and the polar terminal.

[0052] The single battery provided by this utility model includes an outer cylinder, an upper cover assembly, a lower cover assembly, and an electrode assembly; the outer cylinder, the upper cover assembly, and the lower cover assembly are arranged to form a single battery shell, and the electrode assembly is located inside the shell; the upper cover assembly adopts the above-mentioned upper cover assembly, and the electrode tabs of the electrode assembly are electrically connected to the polarity terminals.

[0053] The battery module provided by this utility model includes n individual batteries arranged in the same direction; the n individual batteries are electrically connected based on polarity terminals; wherein the individual batteries are the aforementioned individual batteries; and n is an integer greater than 1. The electrical connections include parallel connection, series connection, and mixed connection.

[0054] As can be seen from the above description, in this utility model, the connecting plate has the following two states:

[0055] First state: When the single cell is in normal working condition, its temperature can be assumed to be T1. The connecting plate is fixed between the top cover plate and the insulating plate and is not connected to the polarity terminal.

[0056] Second state: When the temperature of a single cell is T2, where T2 > T1; the temperature of the connecting plate reaches the set threshold temperature. At this temperature, the connecting plate deforms, and part of the structure fills the channel between the connecting plate and the polar terminal, connecting the upper cover plate and the polar terminal, thus realizing the electrical conduction between the upper cover plate and the polar terminal.

[0057] T2 is close to the thermal runaway temperature of a single cell. The set threshold temperature can be adjusted according to the specific implementation situation, and a thermosensitive material adapted to the required set threshold temperature can be selected to achieve deformation at the corresponding set threshold temperature and achieve the expected effect.

[0058] In the battery module, when a single cell experiences thermal runaway, the temperature of the connecting plate of that single cell rises to or exceeds a set threshold temperature, causing the connecting plate to deform due to heat. It then connects to the top cover and the polar terminals through a channel, thereby achieving an electrical connection between the top cover and the polar terminals. This makes the single cell a resistor in the circuit of the entire battery module. At least a portion of the discharge current of the single cells in the entire battery module that have not experienced thermal runaway flows through the top cover assembly of that single cell to continue supplying power to the load.

[0059] Therefore, it can be seen that even if a single cell in the battery module experiences thermal runaway, the entire battery module can still continue to operate normally and supply power to the load.

[0060] It should be noted that:

[0061] 1. The above polarity terminal can be a single battery terminal. In order to avoid the single battery terminal height not meeting the set requirements, a terminal adapter can be connected to the single battery terminal, and the overall structure of the single battery terminal and the terminal adapter can be used as the single battery polarity terminal.

[0062] 2. The deformation of the connecting plate upon heating can be understood as thermal expansion, or as a change in state, such as from a solid to a molten state. In this invention, materials with such properties are referred to as temperature-sensitive materials, typically temperature-sensitive metal materials or temperature-sensitive conductive polymer materials, etc.

[0063] 3. The aforementioned channel can be a through hole opened on the insulating plate, or it can be a gap between the insulating plate and the polarity terminal. As long as it can be ensured that the electrical connection between the upper cover plate and the polarity terminal is achieved through the channel after the connecting plate is deformed by heat.

[0064] 4. The connecting plate mentioned above can be an annular plate sandwiched between the upper cover plate and the insulating plate. The polarity terminal passes through the mounting hole and also through the inner hole of the annular plate. There is a gap between the annular plate and the inner hole wall to ensure the insulation between the two. The connecting plate mentioned above can also be a rectangular plate or a circular plate sandwiched between the upper cover plate and the insulating plate. The rectangular plate or circular plate needs to avoid the mounting hole position to ensure that the polarity terminal can pass through the mounting hole.

[0065] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0066] Example 1

[0067] This embodiment is a top cover unit 1 for a single battery cell 2, and its structure is as follows: Figure 1 , Figure 2 and Figure 3As shown, it includes a top cover assembly 11 and a polar terminal 12 fixed on the top cover assembly 11.

[0068] The upper cover assembly 11 is used to enclose the lower cover assembly of the single cell 2 and the outer cylinder to form the outer shell of the single cell 2.

[0069] from Figure 1 and Figure 2 As can be seen from the image, the polarity terminal 12 in this embodiment is a single cell 2-terminal, which is taller than the conventional single cell 2-terminal.

[0070] In some other embodiments, when the height of the single cell 2 terminal does not meet the set requirements, a terminal adapter can be connected to the single cell 2 terminal, and the overall structure of the single cell 2 terminal and the terminal adapter can be used as the polarity terminal 12 of the single cell 2.

[0071] Combination Figure 2 and Figure 3 As can be seen, in this embodiment, the upper cover assembly 11 includes an upper cover plate 111, a connecting plate 112 and an insulating plate 113 stacked in sequence; that is, the connecting plate 112 is sandwiched between the upper cover plate 111 and the insulating plate 113.

[0072] In this embodiment, both the top cover plate 111 and the insulating plate 113 are rectangular plates. The top cover plate 111 is made of a conductive metallic material, typically aluminum. The insulating plate 113 is made of an insulating material, typically high-temperature resistant plastic or rubber. Here, high temperature generally refers to the thermal runaway temperature of the battery.

[0073] Through mounting holes are made on the upper cover plate 111 and the insulating plate 113 corresponding to the positions of the polarity terminals 12. For ease of description, in this embodiment, the mounting hole on the upper cover plate 111 is defined as the first mounting hole 13, and the mounting hole on the insulating plate 113 is defined as the second mounting hole 14.

[0074] The number of connecting plates 112 is the same as the number of polar terminals 12, and the connecting plates 112 and polar terminals 12 correspond one-to-one. In this embodiment, two polar terminals 12 are used as an example. For ease of description, in this embodiment, the two polar terminals 12 are defined as the first polar terminal 121 and the second polar terminal 122, respectively. The first polar terminal 121 and the second polar terminal 122 are respectively used as the positive and negative polar terminals of the single cell 2.

[0075] from Figure 3 As can be seen from the figure, the connecting plate 112 in this embodiment is an annular plate, sandwiched between the upper cover plate 111 and the insulating plate 113, and the inner hole of the connecting plate 112 is in communication with the first mounting hole 13 and the second mounting hole 14.

[0076] In this embodiment, the connecting plate 112 is made of a low-melting-point metal. The melting point of the low-melting-point metal is less than or equal to a set threshold temperature. At the set temperature threshold, the metal becomes molten.

[0077] In this embodiment, the temperature threshold corresponds to the temperature that the upper cover unit 1 will reach when the single cell 2 experiences thermal runaway. The corresponding connecting plate 112 can be made of a metal or alloy with a melting point between 200 and 300 degrees Celsius. For example, metals such as tin and bismuth can be selected.

[0078] In some other embodiments, the temperature threshold is not limited to a specific temperature value, but can be a temperature value that is adjusted according to the specific operating conditions of the individual battery cell 2 (e.g., battery voltage, load size, resistance of components in the circuit), ambient environmental parameters (e.g., ambient temperature, humidity), etc. The threshold temperature can be adjusted according to the specific implementation, and a temperature-sensitive material adapted to the required threshold temperature can be selected to achieve the expected thermal runaway response measures.

[0079] In some other embodiments, other temperature-sensitive conductors may be selected, which expand when heated at a set threshold temperature.

[0080] Combination Figure 2 and Figure 3 As can be seen, in this embodiment, the polarity terminal 12 has a limiting portion 123 and an electrical connection portion 124. The electrical connection portion 124 of the polarity terminal 12 passes sequentially through the second mounting hole 14, the inner hole of the connecting plate 112, and the first mounting hole 13, and is fixed to the upper cover plate 111 on the side away from the insulating plate 113 by an insulating member 15. The limiting portion 123 of the polarity terminal 12 is limited on the side of the insulating plate 113 away from the upper cover plate 111.

[0081] The insulating component 15 serves both to insulate the polarity terminal 12 from the upper cover plate 111 and to provide a fixed seal between them. The insulating component 15 can be a ring-shaped insulating layer formed by pouring insulating adhesive between the polarity terminal 12 and the upper cover plate 111, or an insulating sleeve disposed between them. The insulating component 15 can be made of the insulating material used between the polarity terminal 12 and the upper cover assembly 11 in the prior art. Furthermore, the connection method between the insulating component 15 and the polarity terminal 12 and the upper cover plate 111 can also employ relevant existing technologies; this embodiment does not impose specific limitations.

[0082] A first annular gap 19 is provided between the electrical connection portion 124 of the polarity terminal 12 and the inner hole of the connecting plate 112 to ensure the insulation between the polarity terminal 12 and the connecting plate 112 when the single cell 2 is in normal working condition.

[0083] from Figure 2 and Figure 3 As can be seen from the figure, the polar terminal 12 in this embodiment includes a base 125 and a column 126. The column 126 is fixedly connected to the base 125. The portion of the base 125 that extends radially out of the column 126 forms a limiting portion 123. The end of the column 126 away from the base 125 forms an electrical connection portion 124.

[0084] In this embodiment, the base 125 and the column 126 are an integral structure, and the polar terminal 12 can be obtained by die casting or machining. In other embodiments, the base 125 and the column 126 can be separate structures. In this case, the base 125 can be obtained by stamping, and the column 126 can be obtained by die casting or machining. The obtained base 125 and column 126 are then fixed to obtain the polar terminal 12.

[0085] For the integrated base 125 and column 126, both are made of the same material, such as conductive materials like aluminum or copper. For the separate base 125 and column 126, their materials can be the same or different. When the materials are different, the base 125 can be made of copper and the column 126 can be made of aluminum; or the base 125 can be made of aluminum and the column 126 can be made of copper.

[0086] In this embodiment, the base 125 and the column 126 of the split structure can be fixed by friction welding (i.e., the column 126 and the base 125 are fixed by friction welding) or by riveting. Of course, other methods can also be used for fixing, but this embodiment does not limit this.

[0087] from Figure 2 and Figure 3 As can be seen from the figure, in this embodiment, a through hole 16 is formed on the insulating plate 113. The through hole 16 penetrates the insulating plate 113 in the thickness direction and is located directly above the polarity terminal 12 limiting part 123.

[0088] In this embodiment, there are 4 through holes 16. In some other embodiments, the number of through holes 16 can be adjusted.

[0089] like Figure 4As shown, in the battery module, when a single cell 2 experiences thermal runaway, the temperature of the connecting plate 112 in the upper cover unit 1 of the single cell 2 rises to or exceeds a set threshold temperature, causing the connecting plate 112 to become molten. Under the action of gravity, the molten connecting plate 112 flows into the through hole 16 and is connected between the upper cover plate 111 and the polarity terminal 12 limiting part 123 through the through hole 16. This achieves the electrical connection between the upper cover plate 111 and the polarity terminal 12, making the single cell 2 a resistor in the circuit of the entire battery module. At least a portion of the discharge current of the single cell 2 that has not experienced thermal runaway flows through the upper cover assembly 11 of the single cell 2 to continue to supply power to the load.

[0090] It should be noted that the molten connecting plate 112 may also flow into the first annular gap 19, connecting the electrical connection area of ​​the polarity terminal located in the mounting hole to the upper cover plate, thereby achieving electrical connection between the upper cover plate 111 and the polarity terminal 12.

[0091] In other embodiments, the connecting plate 112 may also take other structural forms, for example, such as Figure 5 and Figure 6 As shown, it can be a rectangular plate or a circular plate sandwiched between the upper cover plate 111 and the insulating plate 113; multiple through holes 16 are opened at the positions corresponding to the insulating plate. When the temperature of the connecting plate 112 in the upper cover unit 1 of the single cell 2 rises to or exceeds the set threshold temperature, the connecting plate 112 becomes molten. Under the action of gravity, the molten connecting plate 112 flows into the through holes 16 and is connected between the upper cover plate 111 and the polar terminal 12 limiting part 123 through the through holes 16. This also realizes the electrical connection between the upper cover plate 111 and the polar terminal 12, so that the single cell 2 becomes a resistor in the circuit of the entire battery module. At least a part of the discharge current of the single cell 2 that has not experienced thermal runaway in the entire battery module flows through the upper cover assembly 11 of the single cell 2 to continue to supply power to the load.

[0092] In some other embodiments, when the connecting plate is a thermally expandable temperature-sensitive conductor, the temperature of the connecting plate 112 in the cover unit 1 of the single cell 2 rises to or exceeds a set threshold temperature, causing the connecting plate 112 to expand due to heat. The expanded part passes through the through hole 16 or the first annular gap 19 and connects between the cover plate 111 and the polarity terminal 12 limiting part 123. This can also realize the electrical connection between the cover plate 111 and the polarity terminal 12, so that the single cell 2 becomes a resistor in the circuit of the entire battery module. At least a portion of the discharge current of the single cell 2 that has not experienced thermal runaway in the entire battery module flows through the cover assembly 11 of the single cell 2 to continue to supply power to the load.

[0093] In this embodiment, a first opening element can also be provided on the top cover assembly 11, which is located between the two polar terminals 12. Under the action of external force or electrolyte, the first opening element can detach from the top cover assembly 11 of the single cell 2 and form a through hole 16 in the top cover assembly 11 that penetrates the inner cavity of the outer shell. The first opening element adopts an existing structure, such as the first opening element disclosed in Chinese Patent CN221327991 U, the sealing device disclosed in Chinese Patent CN117476997A, and the opening device disclosed in CN117477117A.

[0094] Example 2

[0095] This embodiment also describes a top cover unit 1 for a single battery cell 2, the structure of which is as follows: Figure 7 As shown; unlike Embodiment 1, in this embodiment, the diameter of the second mounting hole 14 on the insulating plate 113 is larger than the diameter of the first mounting hole 13 on the upper cover plate 111; after the polar terminal 12 electrical connection portion 124 passes through the second mounting hole 14, there is a second annular gap 17 between it and the insulating plate 113.

[0096] like Figure 8 As shown, in the battery module, when a single cell 2 experiences thermal runaway, the temperature of the connecting plate 112 in the upper cover unit 1 of the single cell 2 rises to or exceeds a set threshold temperature, causing the connecting plate 112 to become molten. Under the action of gravity, the molten connecting plate 112 flows into the second annular gap 17 and is connected between the upper cover plate 111 and the polar terminal 12 limiting part 123 through the second annular gap 17. This achieves the electrical connection between the upper cover plate 111 and the polar terminal 12, making the single cell 2 a resistor in the circuit of the entire battery module. At least a portion of the discharge current of the single cell 2 that has not experienced thermal runaway flows through the upper cover assembly 11 of the single cell 2 to continue supplying power to the load.

[0097] It should be noted that the molten connecting plate 112 may also contact the electrical connection portion 124 area located in the mounting hole within the second annular gap 17, thereby enabling the electrical connection between the upper cover plate 111 and the polarity terminal 12.

[0098] Example 3

[0099] This embodiment is also a top cover unit for a single battery cell, and its structure is as follows: Figure 9 and Figure 10 As shown, unlike the above embodiments, this embodiment adds an insulating sealing ring 18 between the upper cover plate 111 and the polarity terminal 12 limiting part 123.

[0100] like Figure 9 As shown, taking the addition of an insulating sealing ring 18 to the upper cover unit 1 of Embodiment 1 as an example;

[0101] Based on Embodiment 1, this embodiment adjusts the diameter of the second mounting hole 14 to make it larger than the diameter of the first mounting hole 13; the annular gap between the polar terminal 12 electrical connection portion 124, which passes through the second mounting hole 14, and the insulating plate 113 serves as the installation space for the insulating sealing ring.

[0102] An insulating sealing ring 18 is fitted onto the polar terminal 12. The outer ring surface of the insulating sealing ring 18 is in close contact with the wall of the second mounting hole 14. The top and bottom surfaces of the insulating sealing ring 18 abut against the upper cover plate 111 and the limiting part 123 of the polar terminal 12, respectively, thereby clamping the insulating sealing ring 18 between the upper cover plate 111 and the limiting part 123 of the polar terminal 12. In this way, the sealing performance between the polar terminal 12 and the upper cover plate 111 can be further improved.

[0103] like Figure 10 As shown, taking the addition of an insulating sealing ring 18 to the upper cover unit 1 of Embodiment 2 as an example;

[0104] An insulating sealing ring 18 is fitted onto the polar terminal 12, with a gap reserved between the outer ring surface of the insulating sealing ring 18 and the wall of the second mounting hole 14, so that the molten connecting plate 112 can flow into the gap and realize the electrical connection between the upper cover plate 111 and the polar terminal 12. The top and bottom surfaces of the insulating sealing ring 18 abut against the upper cover plate 111 and the limiting part 123 of the polar terminal 12, respectively, thereby clamping the insulating sealing ring 18 between the upper cover plate 111 and the limiting part 123 of the polar terminal 12. In this way, the sealing performance between the polar terminal 12 and the upper cover plate 111 can be further improved.

[0105] In addition, under normal operating conditions of the single cell 2, the above-mentioned insulating sealing ring 18 can further improve the insulation performance between the upper cover plate 111, the connecting plate 112 and the polar terminal 12.

[0106] Example 4

[0107] This embodiment is a single-cell battery, the structure of which is as follows: Figure 11 As shown, the device includes an outer shell and an electrode assembly and electrolyte located within the outer shell; wherein the outer shell is formed by an outer cylinder, a lower cover assembly, and an upper cover unit 1 as described in the above embodiment. The first polarity terminal 121 and the second polarity terminal 122 on the upper cover assembly 11 are electrically connected to the positive and negative electrodes of the electrode assembly, respectively.

[0108] In this embodiment, the lower cover assembly includes a lower cover plate 21, and a second opening member 22 may be provided on the lower cover plate 21. This second opening member 22 can detach from the lower cover plate 21 of the individual battery 2 under external force or electrolyte action, and forms a through hole in the lower cover plate 21 that penetrates the inner cavity of the outer casing. The second opening member 22 can also be a conventional structure, such as the opening member disclosed in Chinese Patent CN221327991 U, the sealing device disclosed in Chinese Patent CN117476997A, and the opening device disclosed in CN117477117A. The structure of the second opening member 22 can be the same as or different from the first opening member.

[0109] Example 5

[0110] like Figure 12 As shown, this embodiment is a battery module, including 12 individual battery cells 2 arranged in the same direction as in embodiment 4. In some other embodiments, the number of individual battery cells 2 can be adjusted according to actual needs. The 12 individual battery cells 2 are electrically connected based on polarity terminals 12, and this electrical connection can be parallel, series, or a combination of both.

[0111] When each individual battery cell 2 has a second opening part 22 on its lower cover plate 21, the second opening part 22 of each individual battery cell 2 can be opened, and a hollow component can be used to connect the inner cavities of all individual batteries 2 to achieve electrolyte sharing, reduce the differences between individual batteries 2, and optimize the cycle performance of the battery module. It should be noted that when each individual battery cell 2 achieves electrolyte sharing, the individual batteries 2 are preferably connected in parallel.

[0112] When each individual battery cell 2 has a cover assembly 11 with a first opening piece, the first opening piece of each individual battery cell 2 cover assembly 11 can be opened, and another hollow component can be used to connect the inner cavities of all individual batteries 2 to achieve gas sharing, gas balance, and further optimize the cycle performance of the battery module.

[0113] In the event of thermal runaway of any single cell 2 in the battery module, the temperature of the connecting plate 112 of the single cell 2 rises to or exceeds a set threshold temperature, causing the connecting plate 112 to be heated and become molten. The molten material flows through the through hole 16 or the second annular gap 17 to the polar terminal 12, connecting the upper cover assembly 11 and the polar terminal 12. This achieves the electrical connection between the upper cover assembly 11 and the polar terminal 12, making the single cell 2 a resistor in the circuit of the entire battery module. At least a portion of the discharge current of the single cell 2 that has not experienced thermal runaway flows through the upper cover assembly 11 of the single cell 2 to continue supplying power to the load.

[0114] Example 6

[0115] This embodiment presents another type of battery module. Its structure differs from that of Embodiment 5 in that the battery module in this embodiment also includes a housing 3, the specific structure of which is as follows: Figure 13 , Figure 14 and Figure 15 As shown.

[0116] Figure 13 and Figure 14 In Figure 12 Taking the battery module shown as an example, an outer casing 3 is added.

[0117] from Figures 13 to 15 As can be seen from this, this embodiment is in Figure 12 A housing 3 is added to the battery module shown, and the individual battery cells 2 are arranged inside the housing 3. A clearance hole 32 is provided on the top plate 31 of the housing to allow the polarity terminals 12 of each individual battery cell 2 to extend. The polarity terminals 12 of each individual battery cell 2 extend out of the corresponding clearance hole 32, and the area of ​​the top plate 31 corresponding to the clearance hole 32 is fixedly sealed to the upper cover plate 111 of the individual battery cell 2. In this embodiment, a sealing connector 37 is used to achieve the fixed seal between the area of ​​the top plate 31 corresponding to the clearance hole 32 and the upper cover plate 111 of the individual battery cell 2; specifically as follows... Figure 15 As shown, in this embodiment, the sealing connector 37 is a hollow tube with an annular plate on the inner side of the bottom end of the hollow tube. The annular plate and the area of ​​the cover plate 111 of the single cell 2 around the insulating component 15 are fixed. The hollow tube extends into the clearance hole 32, and the outer wall and the hole wall of the clearance hole 32 are sealed together.

[0118] A support member 34 extending in the x-direction is provided between the bottom plate 33 of the outer casing and each individual battery cell 2 to form a liquid channel, serving as an electrolyte sharing chamber 35. When the lower cover plate 21 of each individual battery cell 2 has a second opening part 22, the second opening part 22 of the lower cover plate 21 of each individual battery cell 2 can be opened, and the inner cavities of all individual battery cells 2 can be connected based on the electrolyte sharing chamber 35 to realize electrolyte sharing, reduce the differences between individual battery cells 2, and optimize the cycle performance of the battery module. It should be noted that when the individual battery cells 2 realize electrolyte sharing, the individual battery cells 2 are preferably connected in parallel.

[0119] Figure 13 and Figure 14 In the case, a boss extending in the x-direction is provided on the top plate 31 of the outer casing. A gas channel is opened on the boss. The gas channel is connected to the inner cavity of the outer casing 3 and serves as a gas sharing chamber 36, which is connected to the gas area of ​​the inner cavity of each individual battery cell 2. When gas is generated in the inner cavity of the individual battery cell 2, the inner cavity of the gas channel can also serve as a gas containing cavity to alleviate the problem of the outer casing 3 bulging caused by gas generation.

[0120] In some other embodiments, only an electrolyte-sharing chamber 35 or a gas-sharing chamber 36 may be provided. For example... Figure 16As shown, in the battery module, if any single cell 2 experiences thermal runaway, the temperature of the connecting plate 112 of that single cell 2 rises to or exceeds a set threshold temperature, causing the connecting plate 112 to become heated and melt, which then flows through the through hole 16 ( Figure 15 and Figure 16 Taking the through hole 16 as an example, the current flows to the polarity terminal 12 limiting part 123 and is connected between the upper cover plate 111 and the polarity terminal 12. This realizes the electrical connection between the upper cover assembly 11 and the polarity terminal 12, so that the single cell 2 becomes a resistor in the circuit of the entire battery module. At least a part of the discharge current of the single cell 2 that has not experienced thermal runaway flows through the upper cover assembly 11 of the single cell 2 to continue to supply power to the load.

Claims

1. A cover unit for a single battery cell, comprising a cover assembly and polarity terminals fixed on the cover assembly; characterized in that: The top cover assembly includes a top cover plate, a connecting plate, and an insulating plate stacked sequentially; in the stacking direction, the top cover plate and the insulating plate have through mounting holes. The polarity terminal passes through the mounting hole and is fixedly sealed between the upper cover plate; Both the top cover and the connecting plate are electrical conductors, while the insulating plate is an electrical insulator. The top cover is insulated from the polarity terminals, and a channel is provided between the connecting plate and the polarity terminals; When the temperature reaches the set threshold temperature, the connecting plate deforms due to heat, and part of the structure fills the channel, realizing electrical conduction between the top cover and the polarity terminal.

2. The top cover unit for a single battery according to claim 1, characterized in that: The polarity terminal includes a limiting part and an electrical connection part; the electrical connection part of the polarity terminal passes through the mounting hole and is fixedly sealed between the terminal and the upper cover plate, and the electrical connection part is located on the side of the upper cover plate, while the limiting part is limited on the side of the insulating plate.

3. The top cover unit for a single battery according to claim 2, characterized in that: The channel is at least one through hole formed on the insulating plate, the through hole penetrating the insulating plate along the thickness direction of the insulating plate; and the through hole is located directly above the polarity terminal limiting part; When the temperature reaches the set threshold temperature, the connecting plate deforms, and part of the structure fills the through hole, connecting between the polarity terminal limiting part and the upper cover plate, so as to realize the electrical conduction between the upper cover plate and the polarity terminal.

4. The top cover unit for a single battery according to claim 2, characterized in that: The diameter of the mounting holes on the insulating plate is larger than the diameter of the mounting holes on the upper cover plate; The channel is the second annular gap formed between the polar terminal through the mounting hole and the insulating plate; When the temperature reaches the set threshold temperature, the connecting plate deforms, and part of the structure fills the second annular gap, connecting between the polar terminal and the upper cover plate, thereby achieving electrical conductivity between the upper cover plate and the polar terminal.

5. The cover unit for a single battery cell according to any one of claims 1 to 4, characterized in that: The connecting plate is a metal plate; the melting point of the metal plate is less than or equal to a set threshold temperature.

6. The top cover unit for a single battery according to claim 5, characterized in that: The metal plate is an annular metal plate; the polar terminal passes through the inner hole of the annular metal plate and has a gap between it and the inner hole.

7. The top cover unit for a single battery according to claim 6, characterized in that: It also includes an insulating sealing ring; the insulating sealing ring is sleeved on the polar terminal and clamped between the upper cover plate and the polar terminal limiting part.

8. The top cover unit for a single battery according to claim 1, characterized in that: The top cover assembly has a first opening component.

9. A single-cell battery, comprising an outer cylinder, an upper cover assembly, a lower cover assembly, and an electrode assembly; the outer cylinder, the upper cover assembly, and the lower cover assembly enclose a single-cell battery casing, and the electrode assembly is located within the casing; characterized in that: The top cover assembly adopts the top cover unit for a single battery as described in any one of claims 1-8, and the polarity terminal is electrically connected to the tab of the electrode assembly.

10. The single-cell battery according to claim 9, characterized in that: The lower cover assembly includes a lower cover plate and a second opening component disposed on the lower cover plate.

11. A battery module, characterized in that: It includes n individual cells arranged in the same direction; wherein the individual cells are the individual cells as described in claim 9 or 10; and n is an integer greater than 1.

12. The battery module according to claim 11, characterized in that: It also includes a housing; n individual cells are arranged in the same direction in the inner cavity of the housing, the housing has at least one shared chamber, the inner cavity of the shared chamber is in communication with the inner cavities of all individual cells; the top plate of the housing has clearance holes corresponding to the polarity terminals of each individual cell; the polarity terminals of each individual cell extend out of the clearance holes, and the area of ​​the top plate of the housing corresponding to the clearance holes is fixedly sealed to the housing body of the individual cells.

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