Top cover assembly of battery and battery structure

Abstract

The utility model provides a top cover assembly of battery and battery structure, the top cover assembly includes cover plate, connecting piece and bearing piece, said cover plate is equipped with the pole, said connecting piece with said pole is connected, said bearing piece can bear the force and is pressed tightly between said cover plate and said connecting piece, said connecting piece is pressed tightly between said cover plate and said connecting piece, said bearing piece is pressed tightly between said connecting piece and said cover plate, said connecting piece is pressed tightly between said cover plate and said connecting piece. The stress piece is located on one side, far away from the pole, of the connecting piece, and the connecting piece is constructed to be capable of being broken under the counter-acting force of the stress piece when the connecting piece is heated to deform. According to the utility model, the stress piece is arranged between the cover plate and the connecting piece, so that when the battery is overcharged or short-circuited and the connecting piece deforms due to heating, the connecting piece is subjected to the counter-acting force of the stress piece at the same time, the connecting piece is broken along a certain direction, and the internal circuit of the battery is disconnected due to the breakage of the connecting piece so as to cut off the current; therefore, the effect of protecting the battery is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery top cover assembly and a battery structure. Background Art

[0002] In the existing technology, people are increasingly concerned about battery safety issues. For example, as the charge and discharge performance requirements of secondary batteries increase, the internal resistance of secondary batteries is becoming smaller and smaller. When high short-circuit current is connected, the temperature at the connection between the metal connecting plate and the terminal in the secondary battery will rise sharply. As the temperature rises, the rubber sealing ring on the terminal may become loose and fuse, causing electrolyte leakage. In addition, the high temperature at the terminal can easily lead to a series of safety hazards such as battery fire or explosion.

[0003] Currently, a common battery protection method is to add a pressure relief valve to the battery's top cover assembly. When the gas inside the battery expands, the pressure relief valve ruptures to release the internal battery pressure, thereby preventing the entire battery from exploding. However, the pressure relief valve only ruptures when the internal pressure accumulates to a certain level, resulting in certain limitations in its safety protection for the battery. Utility Model Content

[0004] Based on this, it is necessary to provide a battery top cover assembly and a battery structure to address the above technical problems.

[0005] A top cover assembly of a battery includes a cover plate, a connecting piece, and a force-bearing member, wherein a pole is mounted on the cover plate, the connecting piece is connected to the pole, the force-bearing member is capable of bearing force and is tightly arranged between the cover plate and the connecting piece, and the force-bearing member is located on the side of the connecting piece away from the pole, and the connecting piece is constructed so that it can break under the reaction force of the force-bearing member when it is deformed by heat.

[0006] In one embodiment, there are multiple force-bearing members, and the multiple force-bearing members are evenly distributed on a parallel line parallel to the width direction of the cover plate.

[0007] In one embodiment, the force-bearing member is an elastic member, which is compressed by force and is tightly arranged between the cover plate and the connecting piece.

[0008] In one embodiment, the elastic member is a spring, which is compressed and pressed tightly between the cover plate and the connecting piece. The connecting piece is configured to break due to the reaction force of the spring when deformed by heat.

[0009] In one embodiment, the elastic member is made of high-temperature elastic insulating material.

[0010] In one embodiment, the force-bearing member is a boss, and the boss is configured as:

[0011] The boss is integrally formed with the cover plate, and the boss is provided on a side of the cover plate facing the connecting piece;

[0012] or,

[0013] The boss is integrally formed with the connecting piece, and the boss is arranged on a side of the connecting piece facing the cover plate.

[0014] In one embodiment, the boss is formed by stamping.

[0015] In one embodiment, a fractured weak region is provided at one end of the connecting piece away from the pole, and the structural strength of the fractured weak region is lower than the structural strength of the non-fractured weak region of the connecting piece.

[0016] In one embodiment, the connecting piece includes a pole connecting portion and at least two tab connecting arms, the pole connecting portion is used to be connected to the pole, and the force-bearing member is provided on the tab connecting arms.

[0017] A battery structure comprises: a shell, a plurality of battery cells and a top cover assembly as described above, wherein the shell has an opening, the plurality of battery cells are installed in the shell, and the top cover assembly is sealed and installed at the opening of the shell.

[0018] The top cover assembly and battery structure of the above-mentioned battery, through the force-bearing member provided between the cover plate and the connecting piece, ensure that when the battery is overcharged or short-circuited, the connecting piece is deformed by heat and is simultaneously subjected to the reaction force of the force-bearing member, causing the connecting piece to break in a certain direction. Due to the breakage of the connecting piece, the internal circuit of the battery is disconnected to cut off the current, thereby protecting the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a bottom view of a top cover assembly of a battery in one embodiment;

[0020] Figure 2 is a top view of a top cover assembly of a battery in one embodiment;

[0021] Figure 3 is an exploded schematic diagram of a top cover assembly of a battery in one embodiment;

[0022] Figure 4 is a cross-sectional view of a top cover assembly of a battery in one embodiment;

[0023] Figure 5 is an exploded schematic diagram of a top cover assembly of a battery in one embodiment;

[0024] Figure 6 is an exploded schematic diagram of a top cover assembly of a battery in one embodiment;

[0025] Figure 7 1 is a graph showing the relationship between short-circuit current and time in a battery short-circuit test of Comparative Example 1 in one embodiment;

[0026] Figure 8 is a graph showing the relationship between short-circuit current and time in a battery short-circuit test of Example 1 in one embodiment;

[0027] Figure 9 is a graph showing the relationship between short-circuit current and time in a battery short-circuit test of Example 2 in one embodiment;

[0028] Figure 10 is a graph showing the relationship between short-circuit current and time in a battery short-circuit test of Example 3 in one embodiment;

[0029] Figure 11 1 is a graph showing the relationship between short-circuit current and time in a battery short-circuit test of Comparative Example 2 in one embodiment;

[0030] Figure 12 is a graph showing the relationship between short-circuit current and time in a battery short-circuit test of Example 4 in one embodiment;

[0031] Figure 13 is a graph showing the relationship between short-circuit current and time in a battery short-circuit test of Example 5 in one embodiment;

[0032] Figure 14 FIG. 1 is a diagram showing the relationship between the short-circuit current and time in a battery short-circuit test of Example 6 in one embodiment.

[0033] Description of labels:

[0034] 100-top cover assembly; 110-cover plate; 120-connecting piece; 111-pole; 130-stress member; 131-spring; 132-boss; 121-pole connecting part; 122-pole ear connecting arm. DETAILED DESCRIPTION

[0035] To facilitate understanding of this application and to make the above-mentioned objectives, features, and advantages of this application more readily apparent, the following detailed description of specific embodiments of this application is provided in conjunction with the accompanying drawings. The following description sets forth numerous specific details to facilitate a full understanding of this application, and the accompanying drawings illustrate preferred embodiments of this application. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of this application. This application can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of this application. Therefore, this application is not limited to the specific embodiments disclosed below. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed to indicate or imply relative importance or to implicitly specify the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout this description, "a plurality" means at least two, such as two or three, unless otherwise specifically defined. Throughout this description, "several" means at least one, such as one or two, unless otherwise specifically defined. It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may also be an element centered. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be an element centered at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. The terms used herein are for the purpose of describing specific implementation methods only and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0036] Example 1

[0037] In this embodiment, Figures 1 to 6 As shown, a top cover assembly 100 of a battery is provided, comprising a cover plate 110, a connecting piece 120 and a force-bearing member 130, wherein a pole 111 is mounted on the cover plate 110, the connecting piece 120 is connected to the pole 111, the force-bearing member 130 is capable of bearing force and is tightly arranged between the cover plate 110 and the connecting piece 120, and the force-bearing member 130 is located on the side of the connecting piece 120 away from the pole 111, and the connecting piece 120 is constructed so that it can break under the reaction force of the force-bearing member 130 when it is deformed by heat.

[0038] In one embodiment, the cover plate 110 is provided with a pole hole, and the pole 111 is installed in the pole hole. The pole 111 may be installed in the pole hole in a manner including, but not limited to, injection molding, riveting, welding, or fixing via a mounting structure.

[0039] The connecting piece 120 is a bridge connecting the terminal and the current collector at the top cover of the battery. In one embodiment, the terminal 111 and the connecting piece 120 can be connected by defining a mounting hole extending through the terminal 111, and the connecting piece 120 is provided with a stamped boss that extends into and is welded to the side wall of the mounting hole to achieve the connection between the connecting piece and the terminal 111.

[0040] Furthermore, in order to ensure the stability of the connection between the connecting piece 120 and the pole 111, a pressing force is applied to the connecting piece 120 and the pole 111 during the welding process to prevent the problem of cold welding. The pressing force on the connecting piece enables the force-bearing member 130 to be stressed and pressed tightly between the cover plate 110 and the connecting piece 120, and the force-bearing member 130 will form a reaction force on the connecting piece 120. In this way, when the battery short circuit causes the internal temperature of the battery to rise sharply and the connecting piece 120 is deformed by heat, the connecting piece 120 is subjected to the reaction force of the force-bearing member 130, which will cause the connecting piece 120 to break in a certain direction. Due to the breakage of the connecting piece, the internal circuit of the battery is disconnected to cut off the current, thereby protecting the battery.

[0041] Among them, the fracture position of the connecting piece 120 is mostly located on the side of the connecting piece 120 away from the pole 111. Therefore, the force-bearing member 130 is located on the side of the connecting piece 120 away from the pole 111, so that when the connecting piece 120 is deformed by heat, it is subjected to the reaction force of the force-bearing member 130 and accelerates the fracture.

[0042] In one embodiment, there are multiple force-bearing members 130 , and the multiple force-bearing members 130 are evenly distributed on a parallel line parallel to the width direction of the cover plate 110 .

[0043] In order to ensure the timely rupture of the connecting piece 120, a plurality of force-bearing members 130 are provided, and the plurality of force-bearing members 130 are evenly distributed on a parallel line parallel to the width direction of the cover plate 110, that is, the connecting line between the plurality of force-bearing members 130 is parallel to the width direction of the cover plate 110. In this way, the consistency of the direction of the reaction force of the force-bearing members 130 on the connecting piece 110 is ensured, and the rupture of the connecting piece 120 is accelerated when the connecting piece 120 is deformed by heat.

[0044] In one embodiment, the number of the force-bearing members 130 is set to two, and the two force-bearing members are symmetrically distributed on both sides of the cover plate 110 in the width direction along the central axis of the cover plate 110 .

[0045] In this embodiment, the number of the force-bearing members 130 is adaptively adjusted according to the capacity of the battery, wherein the sum of the reaction forces generated by all the force-bearing members 130 on the connecting piece 120 does not affect the welding of the connecting piece 120 and the pole 111 .

[0046] In one embodiment, see Figure 3 and Figure 4 As shown, the force-bearing member 130 is an elastic member, which is compressed by force and is tightly arranged between the cover plate 110 and the connecting piece 120 .

[0047] In this embodiment, the force-bearing member 130 is an elastic member. During the connection process between the connecting piece 120 and the pole 111, the force-bearing member 130 is compressed by the pressing force and is tightly arranged between the cover plate 110 and the connecting piece 120. When the battery short circuit causes the internal temperature of the battery to rise sharply and the connecting piece 120 is deformed by heat, the connecting piece 120 is subjected to the reaction force of the force-bearing member 130, which will cause the connecting piece 120 to break in a certain direction. Due to the breakage of the connecting piece 120, the internal circuit of the battery is disconnected to cut off the current, thereby protecting the battery.

[0048] In one embodiment, continue to refer to Figure 3 and Figure 4 As shown, the elastic member is a spring 131 , which is compressed and pressed tightly between the cover plate 110 and the connecting piece 120 . The connecting piece 120 is constructed so that it can be broken by the reaction force of the spring 131 when it is deformed by heat.

[0049] In one embodiment, the number of springs 131 arranged between the cover plate 110 and the connecting piece 120 is adaptively adjusted according to the force applied to the connecting piece 120 to avoid affecting the welding of the connecting piece 120 and the pole 110, and the height of the springs 131 arranged between the cover plate 110 and the connecting piece 120 is related to the gap between the connecting piece 120 and the cover plate 110.

[0050] In one embodiment, the design gap between the cover plate 110 and the connecting piece 120 is 1 mm. Accordingly, the height of the spring 131 in the compressed state when it is pressed tightly between the cover plate 110 and the connecting piece 120 is 1 mm, and the height of the spring 131 in the original uncompressed state is 3 mm. This ensures that the welding between the connecting piece 120 and the pole 110 is not affected, and when the connecting piece 120 is deformed by heat, the reaction force of the spring 131 can accelerate its fracture.

[0051] In one embodiment, the elastic member is made of high-temperature elastic insulating material.

[0052] In one embodiment, the high-temperature elastic insulating material is a high-temperature resistant foam. High-temperature resistant foam, also known as high-temperature insulation foam, has the main characteristic of being able to withstand high-temperature environments. The specific temperature resistance range varies depending on the type of material and the manufacturing process. For example, the maximum operating temperature of certain fire-resistant and high-temperature resistant foams can reach 800°C, and can even maintain high high-temperature resistance in high-temperature environments for a long time. Furthermore, the main components of high-temperature resistant foams include glass fiber, ceramic composite materials, aluminum silicate fiber, and silicone materials.

[0053] In one embodiment, see Figure 5 and Figure 6 As shown, the force-bearing member 130 is a boss 132 , which is integrally formed with the cover plate 110 . The boss 132 is disposed on a side of the cover plate 110 facing the connecting piece 120 .

[0054] In one embodiment, the cover plate 110 and the boss 132 are formed by stamping.

[0055] In this embodiment, refer to Figure 5 As shown, the force-bearing member is a boss 132 stamped on the cover plate 110, and the boss 132 is provided on the side of the cover plate 110 facing the connecting piece 120. Similarly, when welding the connecting piece 120 and the terminal 111, a pressing force is applied to both to prevent the problem of cold welding. The pressing force on the connecting piece causes the boss 132 to generate a reaction force on the connecting piece 120. When the battery short circuit causes the internal temperature of the battery to rise sharply and the connecting piece 120 is deformed by heat, the connecting piece 120 is subjected to the reaction force of the boss 132, which causes the connecting piece 120 to break in a certain direction. Due to the breakage of the connecting piece 120, the internal circuit of the battery is disconnected, thereby cutting off the current, thereby protecting the battery.

[0056] In one embodiment, the force-bearing member 130 is a boss 132 . The boss 132 is integrally formed with the connecting piece 120 . The boss 132 is disposed on a side of the connecting piece 120 facing the cover plate 110 .

[0057] In one embodiment, the connecting piece 120 and the boss 132 are formed by stamping.

[0058] In this embodiment, refer to Figure 6As shown, the force-bearing member 130 is a boss 132 stamped on the connecting piece 120, and the boss 132 is provided on the side of the connecting piece 120 facing the cover plate 110. Similarly, when welding the connecting piece 120 and the terminal 111, a pressing force is applied to both to prevent the problem of cold welding. The pressing force on the connecting piece causes the boss 132 to generate a reaction force on the connecting piece 120. When the battery short circuit causes the internal temperature of the battery to rise sharply, and the connecting piece 120 is deformed by heat, the connecting piece 120 is subjected to the reaction force of the boss 132, which causes the connecting piece 120 to break in a certain direction. Due to the breakage of the connecting piece 120, the internal circuit of the battery is disconnected, thereby cutting off the current, thereby protecting the battery.

[0059] In one embodiment, a fractured weak region is provided at one end of the connecting piece 120 away from the pole 111 , and the structural strength of the fractured weak region is lower than the structural strength of the non-fractured weak region of the connecting piece 120 .

[0060] In this embodiment, a fracture weak area is provided on one end of the connecting piece 120 away from the pole 111 , so that when the connecting piece 120 is deformed by heat, the fracture weak area of ​​the connecting piece 120 can fracture faster.

[0061] In one embodiment, the fractured weak region of the connecting piece 120 may be configured to have a smaller thickness therein, so that the structural strength of the fractured weak region is lower than the structural strength of the non-fractured weak region of the connecting piece 120 .

[0062] In one embodiment, the fractured weak region of the connecting piece 120 may be set to have a shorter length there, so that the structural strength of the fractured weak region is lower than the structural strength of the non-fractured weak region of the connecting piece 120 .

[0063] In one embodiment, see Figure 3 As shown, the connecting piece 120 includes a pole connecting portion 121 and at least two tab connecting arms 122 . The pole connecting portion 121 is used to connect to the pole 111 , and the force-bearing member 130 is provided on the tab connecting arms 122 .

[0064] In this embodiment, the connecting piece 120 is a U-shaped structure, including a pole connecting portion 121 and two pole tab connecting arms 122, and the force-bearing member 130 is arranged on the pole tab connecting arm 122, that is, the pole tab connecting arm 122 is a weak area of ​​the connecting piece 120 that is prone to breaking, so that when the connecting piece 120 is deformed by heat, the structural strength at the pole tab connecting arm 122 is smaller and can break faster.

[0065] Example 2

[0066] In this embodiment, multiple types of batteries are provided for short-circuit performance testing to obtain the time it takes for the connecting piece of each battery to break and the current at which the connecting piece breaks. The batteries have the same capacity but different top cover assemblies.

[0067] Specifically, the capacity of each battery is 280Ah. The battery structure of Comparative Example 1 is as follows: the top cover assembly includes a cover plate and a connection, the cover plate is mounted with a pole, the connection piece is connected to the pole, wherein the connection piece and the pole are connected by welding, and the width of the position where the connection piece and the pole are welded is 23mm; wherein, the relationship between the short-circuit current and time of the battery of Comparative Example 1 in the battery short-circuit test is shown as follows: Figure 7 shown.

[0068] The battery structure of Example 1 is: Figure 3 As shown, the top cover assembly includes a cover plate, a connecting piece and an elastic member, a pole is mounted on the cover plate, and the connecting piece is connected to the pole, wherein the connecting piece and the pole are connected by welding, and the width of the position where the connecting piece and the pole are welded is 23mm, and the elastic member can bear force and be pressed tightly between the cover plate and the connecting piece, and the elastic member is located on the side of the connecting piece away from the pole, and the connecting piece is constructed so that it can break under the reaction force of the elastic member when it is deformed by heat. Among them, the relationship between the short-circuit current and time of the battery of Example 1 in the battery short-circuit test is shown in the figure below. Figure 8 shown.

[0069] Furthermore, the number of elastic members is adaptively adjusted based on the force acting on the connecting piece to avoid affecting the welding of the connecting piece to the pole. Furthermore, the height of the elastic member disposed between the cover plate and the connecting piece is correlated with the gap between the two. Specifically, if the gap between the cover plate and the connecting piece is designed to be 1mm, then the corresponding height of the elastic member in its compressed state, pressed tightly against the cover plate and the connecting piece, is 1mm, while its height in its uncompressed state is 3mm. This ensures that the welding of the connecting piece to the pole is not affected, and that the reaction force of the elastic member accelerates the fracture of the connecting piece when the connecting piece is deformed by heat.

[0070] The battery structure of Example 2 is: Figure 5As shown, the top cover assembly includes a cover plate, a connecting piece and a boss, a pole is installed on the cover plate, and the connecting piece is connected to the pole, wherein the connecting piece and the pole are connected by welding, and the width of the position where the connecting piece and the pole are welded is 23mm, and the boss is stamped and formed with the cover plate, and the boss can bear force and be tightly arranged between the cover plate and the connecting piece, and the boss is located on the side of the connecting piece away from the pole, and the connecting piece is constructed so that it can break under the reaction force of the boss when it is deformed by heat. Furthermore, the height distance of the boss is 1.3mm, the plane width distance of the boss is 2.5mm, and the plane length distance of the boss is 5mm. Among them, the relationship between the short-circuit current and time of the battery of Example 2 in the battery short-circuit test is shown in the figure below. Figure 9 shown.

[0071] The battery structure of Example 3 is: Figure 6 As shown, the top cover assembly includes a cover plate, a connecting piece and a boss, a pole is installed on the cover plate, and the connecting piece is connected to the pole, wherein the connecting piece and the pole are connected by welding, and the width of the position where the connecting piece and the pole are welded is 23mm, and the boss and the connecting piece are stamped, and the boss can bear force and be tightly arranged between the cover plate and the connecting piece, and the boss is located on the side of the connecting piece away from the pole, and the connecting piece is constructed so that it can break under the reaction force of the boss when it is deformed by heat. Furthermore, the height distance of the boss is 1.1mm, the plane width distance of the boss is 1.5mm, and the plane length distance of the boss is 5mm. Among them, the relationship between the short-circuit current and time of the battery of Example 3 in the battery short-circuit test is shown in the figure below. Figure 10 shown.

[0072] Comparative Example 1, Example 1, Example 2 and Example 3 were placed in the same environment and short-circuited to obtain data on the time it takes for the connecting piece of each battery to break and the current at which the connecting piece breaks, as shown in Table 1 below.

[0073] Table 1 Test data of each battery in short circuit test

[0074]

[0075] It can be seen that the time when the connecting piece of the batteries of Example 1, Example 2 and Example 3 breaks is faster than the time when the connecting piece of the battery of Comparative Example 1 breaks. It can be seen that it is important to provide a force-bearing member on the cover plate and the connecting piece of the top cover assembly of the battery, which is beneficial to shorten the time when the connecting piece breaks. Due to the accelerated breakage of the connecting piece 120, the internal circuit of the battery is disconnected to cut off the current, thereby playing a role in timely protecting the battery.

[0076] Example 3

[0077] In this embodiment, multiple types of batteries are provided for short-circuit performance testing to obtain the time it takes for the connecting piece of each battery to break and the current at which the connecting piece breaks. The batteries have the same capacity but different top cover assemblies.

[0078] Specifically, the capacity of each battery is 280Ah. The battery structure of Comparative Example 2 is as follows: the top cover assembly includes a cover plate and a connection, the cover plate is mounted with a pole, the connection piece is connected to the pole, wherein the connection piece and the pole are connected by welding, and the width of the position where the connection piece and the pole are welded is 18mm; wherein, the relationship between the short-circuit current and time of the battery of Comparative Example 2 in the battery short-circuit test is shown in the figure below. Figure 11 shown.

[0079] The battery structure of Example 4 is as follows: the top cover assembly includes a cover plate, a connecting piece and an elastic member, a pole is mounted on the cover plate, and the connecting piece is connected to the pole, wherein the connecting piece and the pole are connected by welding, and the width of the position where the connecting piece and the pole are welded is 18mm, the elastic member can bear force and be pressed tightly between the cover plate and the connecting piece, and the elastic member is located on the side of the connecting piece away from the pole, and the connecting piece is constructed so that it can break under the reaction force of the elastic member when it is deformed by heat. Among them, the relationship between the short-circuit current and time of the battery of Example 4 in the battery short-circuit test is shown in the figure below: Figure 12 shown.

[0080] Furthermore, the number of elastic members is adaptively adjusted based on the force acting on the connecting piece to avoid affecting the welding of the connecting piece to the pole. Furthermore, the height of the elastic member disposed between the cover plate and the connecting piece is correlated with the gap between the two. Specifically, if the gap between the cover plate and the connecting piece is designed to be 1mm, then the corresponding height of the elastic member in its compressed state, pressed tightly against the cover plate and the connecting piece, is 1mm, while its height in its uncompressed state is 3mm. This ensures that the welding of the connecting piece to the pole is not affected, and that the reaction force of the elastic member accelerates the fracture of the connecting piece when the connecting piece is deformed by heat.

[0081] The battery structure of Example 5 is as follows: the top cover assembly includes a cover plate, a connecting piece and a boss, a pole is installed on the cover plate, and the connecting piece is connected to the pole, wherein the connecting piece and the pole are connected by welding, and the width of the position where the connecting piece and the pole are welded is 18mm, the boss and the cover plate are stamped, the boss can bear force and be tightly arranged between the cover plate and the connecting piece, and the boss is located on the side of the connecting piece away from the pole, and the connecting piece is constructed so that it can break under the reaction force of the boss when it is deformed by heat. Furthermore, the height distance of the boss is 1.3mm, the plane width distance of the boss is 2.5mm, and the plane length distance of the boss is 5mm. Among them, the relationship between the short-circuit current and time of the battery of Example 5 in the battery short-circuit test is shown in the figure below. Figure 13 shown.

[0082] The battery structure of Example 6 is as follows: the top cover assembly includes a cover plate, a connecting piece and a boss, a pole is installed on the cover plate, and the connecting piece is connected to the pole, wherein the connecting piece and the pole are connected by welding, and the width of the position where the connecting piece and the pole are welded is 18mm, the boss and the connecting piece are stamped, the boss can bear force and be pressed between the cover plate and the connecting piece, and the boss is located on the side of the connecting piece away from the pole, and the connecting piece is constructed so that it can break under the reaction force of the boss when it is deformed by heat. Furthermore, the height distance of the boss is 1.1mm, the plane width distance of the boss is 1.5mm, and the plane length distance of the boss is 5mm. Among them, the relationship between the short-circuit current and time of the battery of Example 6 in the battery short-circuit test is shown in the figure below. Figure 14 shown.

[0083] Comparative Example 2, Example 4, Example 5 and Example 6 were placed in the same environment and short-circuited to obtain data on the time it takes for the connecting piece of each battery to break and the current at which the connecting piece breaks, as shown in Table 1 below.

[0084] Table 1 Test data of each battery in short circuit test

[0085]

[0086] It can be seen that the time when the connecting piece of the batteries of Example 4, Example 5 and Example 6 breaks is faster than the time when the connecting piece of the battery of Comparative Example 2 breaks. It can be seen that it is important to provide a force-bearing member on the cover plate and the connecting piece of the top cover assembly of the battery, which is beneficial to shortening the time when the connecting piece breaks. Due to the accelerated breakage of the connecting piece, the internal circuit of the battery is disconnected to cut off the current, thereby playing a role in timely protecting the battery.

[0087] Example 4

[0088] In this embodiment, a battery structure is provided, including: a shell, a plurality of battery cells and a top cover assembly described in any of the above embodiments, the shell having an opening, the plurality of battery cells being installed in the shell, and the top cover assembly being sealed and installed at the opening of the shell.

[0089] In this embodiment, a force-bearing member is provided between the cover plate and the connecting piece. When the battery is overcharged or short-circuited, the connecting piece is deformed by heat and is simultaneously subjected to a reaction force from the force-bearing member, causing the connecting piece to break in a certain direction. Due to the breakage of the connecting piece, the internal circuit of the battery is disconnected to cut off the current, thereby protecting the battery.

[0090] The various technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the various technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. It should be noted that "in one embodiment", "for example", "for example", etc. in this application are intended to illustrate this application, rather than to limit this application. The above-mentioned embodiments only express several implementation methods of this application, and their descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that for ordinary technicians in this field, without departing from the concept of this application, several variations and improvements can be made, which all fall within the scope of protection of this application. Therefore, the scope of protection of the patent application of this application shall be based on the attached claims.

Claims

1. A top cover assembly of a battery, characterized in that: The invention comprises a cover plate, a connecting piece and a force-bearing member, wherein a pole is mounted on the cover plate, the connecting piece is connected to the pole, the force-bearing member can bear force and is tightly arranged between the cover plate and the connecting piece, and the force-bearing member is located on the side of the connecting piece away from the pole, and the connecting piece is constructed so that it can break under the reaction force of the force-bearing member when it is deformed by heat.

2. The top cover assembly of the battery according to claim 1, characterized in that: There are multiple force-bearing members, and the multiple force-bearing members are evenly distributed on a parallel line parallel to the width direction of the cover plate.

3. The top cover assembly of the battery according to claim 1, characterized in that: The force-bearing member is an elastic member, which is compressed by force and is tightly arranged between the cover plate and the connecting piece.

4. The top cover assembly of the battery according to claim 3, characterized in that: The elastic member is a spring, which is compressed and pressed tightly between the cover plate and the connecting piece. The connecting piece is used to be broken by the reaction force of the spring when it is deformed by heat.

5. The top cover assembly of the battery according to claim 3, characterized in that: The elastic member is made of high-temperature elastic insulating material.

6. The top cover assembly of the battery according to claim 1, characterized in that: The force-bearing member is a boss, and the boss is configured as: The boss is integrally formed with the cover plate, and the boss is provided on a side of the cover plate facing the connecting piece; or, The boss is integrally formed with the connecting piece, and the boss is arranged on a side of the connecting piece facing the cover plate.

7. The top cover assembly of the battery according to claim 6, characterized in that: The boss is formed by stamping.

8. The top cover assembly of the battery according to claim 1, characterized in that: A fractured weak area is provided at one end of the connecting piece away from the pole, and the structural strength of the fractured weak area is lower than the structural strength of the non-fractured weak area of ​​the connecting piece.

9. The top cover assembly of the battery according to claim 1, characterized in that: The connecting piece includes a pole connecting portion and at least two tab connecting arms. The pole connecting portion is used to be connected to the pole, and the force-bearing member is provided on the tab connecting arms.

10. A battery structure, characterized in that: include: A shell, a plurality of battery cells and a top cover assembly as described in any one of claims 1 to 9, wherein the shell has an opening, the plurality of battery cells are installed in the shell, and the top cover assembly is sealed and installed at the opening of the shell.

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