Top cover assembly of battery and battery structure

Abstract

The invention provides a top cover assembly of a battery and a battery structure, the top cover assembly comprises a cover plate, a connecting sheet and a stress piece, the cover plate is provided with a pole, the connecting sheet is connected with the pole, the stress piece can bear force and is arranged between the cover plate and the connecting sheet in an abutting mode, and the connecting sheet is connected with the stress 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 invention, 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 is heated to deform, 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 present invention relates to the technical field of batteries, and in particular to a battery top cover assembly and a battery structure. Background Art

[0002] In the prior art, people are paying more and more attention to the safety of batteries. For example, as the requirements for the charging and discharging performance of secondary batteries increase, the internal resistance of secondary batteries is getting smaller and smaller; when a high short-circuit current is connected, the temperature of the connection between the metal connecting piece and the pole in the secondary battery will rise sharply. As the temperature rises, the rubber sealing ring on the pole may become loose and the electrolyte may leak. In addition, the temperature at the pole is high, which may easily cause a series of safety hazards such as battery fire or explosion.

[0003] At present, a common way to protect batteries is to add a pressure relief valve to the top cover assembly of the battery. When the gas inside the battery expands, the pressure relief valve breaks to release the internal gas pressure of the battery, thereby preventing the entire battery from exploding. However, the pressure relief valve will only break when the gas pressure inside the battery accumulates to a certain level, resulting in certain limitations in its role in protecting the battery. Summary of the invention

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

[0005] A top cover assembly of a battery 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 a 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, the elastic member 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, the spring is compressed and pressed tightly between the cover plate and the connecting piece, and the connecting piece is used to be broken by the reaction force of the spring when it is deformed by heat.

[0009] In one embodiment, the elastic member is a 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 arranged 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 of the embodiments, 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 of the embodiments, the connecting piece includes a pole connecting portion and at least two pole lug connecting arms, the pole connecting portion is used to be connected to the pole, and the force-bearing member is arranged on the pole lug 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 arranged between the cover plate and the connecting piece, when the battery is overcharged or short-circuited, when the connecting piece is deformed by heat, it 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 is a graph showing the relationship between short-circuit current and time of Comparative Example 1 in a battery short-circuit test in an 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] Fig. 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] Fig.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] Fig.11 is a graph showing the relationship between short-circuit current and time of Comparative Example 2 in a battery short-circuit test in an embodiment;

[0030] Fig.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] Fig.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] Fig.14 This is a graph showing the relationship between the short-circuit current and time of Example 6 in a battery short-circuit test.

[0033] Description of labels:

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

[0035] In order to facilitate the understanding of the present application, in order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application, and the preferred implementation methods of the present application are given in the accompanying drawings. However, the present application can be implemented in many different forms and is not limited to the implementation methods described herein. On the contrary, the purpose of providing these implementation methods is to make the disclosure of the present application more thoroughly and comprehensively understood. The present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited to the specific embodiments disclosed below. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In the description of the present application, the meaning of "several" is at least one, such as one, two, etc., unless otherwise clearly and 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 a centered element. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be a centered element 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 those commonly understood by technicians in the technical field of this application. The terms used herein are only for the purpose of describing specific implementation methods 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] Embodiment 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 can bear force and is tightly arranged between the cover plate 110 and the connecting piece 120, and the force-bearing member 130 is located on a 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, a pole hole is formed on the cover plate 110, and the pole 111 is installed in the pole hole. The pole 111 is installed in the pole hole in a manner including but not limited to injection molding, riveting, welding, or fixing through an installation structure.

[0039] The connecting piece 120 is a bridge connecting the pole and the current collector at the top cover of the battery. In one embodiment, the pole 111 and the connecting piece 120 can be connected in such a way that a mounting hole penetrating the pole 111 is provided inside the pole 111, and the connecting piece 120 is provided with a stamping boss, which extends into and is welded to the side wall of the mounting hole to achieve the connection between the connecting piece and the pole 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 tightly arranged 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 accelerated to fracture by the reaction force of the force-bearing member 130.

[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 timeliness of the breaking 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 breaking 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 , and the spring 131 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 plate 120 is adaptively adjusted according to the force applied to the connecting plate 120 to avoid affecting the welding of the connecting plate 120 and the pole 110, and the height of the springs 131 arranged between the cover plate 110 and the connecting plate 120 is related to the gap between the connecting plate 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. Correspondingly, 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 state when it is not compressed 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 the fracture.

[0051] In one embodiment, the elastic member is a 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, and the specific temperature resistance range varies depending on the type of material and the manufacturing process. For example, the maximum operating temperature of some fireproof and high temperature resistant foams can reach 800°C, and can even maintain high high temperature resistance in a high temperature environment 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 , and the boss 132 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 formed by stamping on the cover plate 110, and the boss 132 is arranged on the side of the cover plate 110 facing the connecting piece 120. Similarly, when the connecting piece 120 and the pole 111 are welded, a pressing force will be applied to the two to prevent the problem of cold welding, and the pressing force on the connecting piece will cause 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 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.

[0056] In one embodiment, the force-bearing member 130 is a boss 132 , and 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 formed by stamping on the connecting piece 120, and the boss 132 is arranged on the side of the connecting piece 120 facing the cover plate 110. Similarly, when the connecting piece 120 and the pole 111 are welded, a pressing force will be applied to the two to prevent the problem of cold welding, and the pressing force on the connecting piece will cause 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 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.

[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 fractured weak region 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 fractured weak region of the connecting piece 120 can be fractured more quickly.

[0061] In one embodiment, the fractured weak region of the connecting sheet 120 may be configured to have a smaller thickness 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 sheet 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 pole tab connecting arms 122 . The pole connecting portion 121 is used to connect to the pole 111 , and the force bearing member 130 is disposed on the pole 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 lug connecting arms 122, and the force-bearing member 130 is arranged on the pole lug connecting arm 122, that is, the pole lug 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 lug connecting arm 122 is smaller and can break faster.

[0065] Embodiment 2

[0066] In this embodiment, multiple types of batteries are provided for short-circuit performance testing to obtain the connecting piece rupture time and the connecting piece rupture current of each battery, wherein the capacity of each battery is the same but the top cover assembly of each battery is different.

[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, a pole is mounted on the cover plate, and 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 as shown in FIG. 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, the elastic member can be stressed and is tightly arranged 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 in 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 according to the force acting on the connecting piece to avoid affecting the welding of the connecting piece and the pole, and the height of the elastic member arranged between the cover plate and the connecting piece is related to the gap between the connecting piece and the cover plate. Specifically, if the design gap between the cover plate and the connecting piece is 1mm, then the height of the elastic member in the compressed state where it is pressed tightly between the cover plate and the connecting piece is 1mm, and the height of the elastic member in the original state where it is not compressed is 3mm, so as to ensure that the welding of the connecting piece and the pole is not affected, and when the connecting piece is deformed by heat, the reaction force of the elastic member can accelerate the fracture.

[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 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, 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 2 in the battery short-circuit test is shown in the figure below. Fig. 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 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, the boss and the connecting piece 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 1.1mm, 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. Fig.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 rupture time of the connecting piece of each battery and the current of the ruptured connecting piece, 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 in Examples 1, 2 and 3 breaks is faster than the time when the connecting piece of the battery in Comparative Example 1 breaks. It can be seen that the importance of providing stress-bearing parts on the cover plate and the connecting piece of the battery top cover assembly is beneficial to shortening 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] Embodiment 3

[0077] In this embodiment, multiple types of batteries are provided for short-circuit performance testing to obtain the connecting piece rupture time and the connecting piece rupture current of each battery, wherein the capacity of each battery is the same but the top cover assembly of each battery is different.

[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, a pole is mounted on the cover plate, and 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 as shown in FIG. Fig.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, the connecting piece is connected to the pole, wherein the connecting piece and the pole are connected by welding, 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: Fig.12 shown.

[0080] Furthermore, the number of elastic members is adaptively adjusted according to the force acting on the connecting piece to avoid affecting the welding of the connecting piece and the pole, and the height of the elastic member arranged between the cover plate and the connecting piece is related to the gap between the connecting piece and the cover plate. Specifically, if the design gap between the cover plate and the connecting piece is 1mm, then the height of the elastic member in the compressed state where it is pressed tightly between the cover plate and the connecting piece is 1mm, and the height of the elastic member in the original state where it is not compressed is 3mm, so as to ensure that the welding of the connecting piece and the pole is not affected, and when the connecting piece is deformed by heat, the reaction force of the elastic member can accelerate the fracture.

[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. Fig.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 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 6 in the battery short-circuit test is shown in the figure below. Fig.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 rupture time of the connecting piece of each battery and the current of the ruptured connecting piece, 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 in Examples 4, 5 and 6 breaks is faster than the time when the connecting piece of the battery in Comparative Example 2 breaks. It can be seen that the top cover assembly of the battery is important to provide a force-bearing member on the cover plate and the connecting piece, 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] Embodiment 4

[0088] In this embodiment, a battery structure is provided, including: a shell, a plurality of battery cells and a top cover assembly as 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, by providing a force-bearing member 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 technical features of the above-described embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above-described embodiments are not 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 the present application, rather than to limit the present application. The above-described embodiments only express several implementation methods of the present application, and the description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the patent application. It should be pointed out that for a person of ordinary skill in the art, without departing from the concept of the present application, several variations and improvements can also be made, which all belong to the scope of protection of the present application. Therefore, the scope of protection of the patent in this application shall be subject to the attached claims.

Claims

1. A top cover assembly of a battery, characterized in that: It 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 can bear force and is tightly arranged between the cover plate and the connecting piece, and the force-bearing member is located on a 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 sheet.

4. The top cover assembly of the battery according to claim 3, characterized in that: The elastic member is a spring, and the spring 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 arranged 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 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.

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