Battery

Abstract

The battery comprises a shell and an electrode assembly, the shell comprises a shell body and a conductive cover plate, the shell body is provided with a containing cavity, and the conductive cover plate is connected with the shell body and used for sealing the containing cavity; the electrode assembly is arranged in the accommodating cavity and comprises a core body and a first tab which are connected with each other; wherein the conductive cover plate comprises a main body part and a weak part which are connected with each other, the main body part is electrically connected with the first tab, and a connecting end for electric connection is arranged on the weak part. When the battery is used, the electric conduction between the battery and the outside is realized through the weak part, and when the battery is in thermal runaway, high-temperature and high-pressure gas bursts through the weak part, so that the weak part is separated from the main body part, the electric connection between the weak part and the main body part is disconnected, the electric conduction between the first tab and the outside is interrupted, and a circuit break protection function is realized; and the heat spreading influence of the battery on other external batteries or parts is reduced, so that the safety performance of the battery is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more particularly to a battery. Background Technology

[0002] With the rapid development of new energy technologies, batteries, as a core component of these technologies, are also developing rapidly. Battery safety performance is one of the important factors to consider when evaluating the overall performance of a battery.

[0003] When a battery experiences thermal runaway, fire and high-temperature gases may ignite inside the battery casing. A common safety measure is to install an explosion-proof valve on the battery casing to allow the high-temperature gases to escape quickly.

[0004] However, the tabs and electrode terminals are still electrically connected, which could allow thermal runaway of a single battery cell to spread to other battery cells or components, thereby exacerbating the dangerous situation of the battery pack. Utility Model Content

[0005] This application provides a battery that effectively reduces the propagation of battery thermal runaway and improves battery safety performance.

[0006] A battery includes: a casing, comprising a housing and a conductive cover plate, the housing having an open receiving cavity, the conductive cover plate sealing the open portion; an electrode assembly disposed in the receiving cavity, comprising a core and a first electrode tab connected to each other; wherein the conductive cover plate comprises a main body portion and a weak portion connected to each other, the main body portion being electrically connected to the first electrode tab, and the weak portion having a connection terminal for electrical connection.

[0007] To achieve the above technical solution, during battery use, electrical conduction between the battery and the external environment is achieved through the weak point. The current flow path is: first tab, main body, weak point, and external environment. When the battery experiences thermal runaway, high-pressure gas rapidly accumulates within the containment cavity, forcing open the weak point. This causes the weak point to detach from the main body, breaking the electrical connection between them. Consequently, electrical conduction between the first tab and the external environment is interrupted. This achieves both pressure relief and circuit breaking protection, reducing the thermal spread of the battery to other batteries or components, thereby improving battery safety. Furthermore, because the weak point is used as the connection point to the external environment, the first tab does not need to be connected to the external environment via battery terminals as in traditional technologies. This reduces the need for terminal design and the associated riveted aluminum blocks and plastic coatings, lowering production costs.

[0008] As one of the optional embodiments of this solution, the first electrode is disposed at the end of the core facing the conductive cover plate, one end of the first electrode is connected to the core, and the other end of the first electrode is connected to the main body.

[0009] As one of the optional embodiments of this solution, the first electrode includes a base and a bent portion that are connected to each other. One end of the base is connected to the core, and the end of the base away from the core is connected to the bent portion. The bent portion is connected to the main body.

[0010] As one of the optional embodiments of this solution, the conductive cover plate has an outer surface that is away from the accommodating cavity, and the orthographic projection of the bent portion on the outer surface does not overlap with the orthographic projection of the weak portion on the outer surface.

[0011] To achieve the above technical solution, the first tab is connected to the main body, which can be selected as a welding connection. This reduces the internal resistance of the battery, ensures the stability of the connection between the first tab and the main body, and ensures the smooth flow of current. Furthermore, the setting that the orthographic projection of the bent part on the outer surface and the orthographic projection of the weak part on the outer surface do not overlap can ensure that the gas flows smoothly to the weak part and pushes it open. It is understandable that if the bent part of the first tab is welded to the main body, and the other parts are piled up in the area directly below the weak part near the core, when the battery thermally runs away, the high-temperature gas will be blocked by the first tab when it flows to the area below the weak part. This will make it difficult for the gas to push the weak part open smoothly, which may result in the circuit breaker protection function not being implemented smoothly.

[0012] As one of the optional embodiments of this solution, it also includes an electrode post that penetrates through a conductive cover plate and is insulated from the conductive cover plate; the electrode assembly also includes a second electrode tab that has the opposite polarity to the first electrode tab, the second electrode tab is connected to the end of the core near the conductive cover plate, and the end of the second electrode tab away from the core is electrically connected to the electrode post.

[0013] As one of the optional embodiments of this solution, it also includes an outer insulating component, which is sleeved on the outer periphery of the electrode post and disposed between the electrode post and the conductive cover plate for insulation between the two.

[0014] To achieve the above technical solution, the first tab, the main body, and the weak point form a circuit with one polarity connected to the outside world, while the second tab and the terminal form a circuit with the opposite polarity connected to the outside world, thereby realizing the cyclic circuit connection between the battery and the outside world. It is understood that there are two paths of electrical conduction between the battery and the outside world, one positive and one negative. In this embodiment, the circuit breaking design of the first tab can achieve the overall circuit breaking protection function of the battery, requiring minimal changes to the battery structure and correspondingly minimal adjustments to the production line, making it more suitable from a production perspective.

[0015] As one of the optional embodiments of this solution, it also includes an inner insulating component, which is disposed on the side of the conductive cover plate near the core. The inner insulating component has a first through hole, and the first electrode tab passes through the first through hole and is electrically connected to the main body.

[0016] As one of the optional embodiments of this solution, a second through hole is provided on the inner insulating component, and the pole post passes through the second through hole and is electrically connected to the second pole ear.

[0017] As one of the optional embodiments of this solution, the inner insulating component includes a plate portion and an abutting portion that are connected to each other. The plate portion is connected to the conductive cover plate, and the abutting portion protrudes from one side of the plate portion away from the conductive cover plate. The abutting portion abuts against one end of the core near the conductive cover plate.

[0018] To achieve the above technical solution, since the first electrode and the second electrode are located at the same end of the core in this embodiment, the insulation between the first electrode and the second electrode is important. Therefore, a first through hole is opened on the inner insulating member to better constrain the first electrode and reduce the movement of the first electrode, reduce short-circuit contact, and the structural design of the inner insulating member enables the abutting part to abut against the core, thereby ensuring the stability of the core and further reducing the movement of the electrode assembly and improving the stability of the battery.

[0019] As one of the optional embodiments of this solution, the casing has a second cover facing the conductive cover plate, the battery also includes a terminal post that penetrates through the second cover and is insulated from the second cover; the electrode assembly also includes a second tab that has the opposite polarity to the first tab, the second tab is disposed at the end of the core facing the second cover, and the second tab is electrically connected to the terminal post.

[0020] To achieve the above technical solution, another electrode structure design is proposed. In this embodiment, the electrode and the conductive cover are positioned on opposite sides, effectively isolating the first and second electrodes. No short circuit will occur between the first and second electrodes, ensuring battery safety. Disconnecting the electrical connection between the first electrode and the outside world smoothly achieves the circuit breaker protection function. In other alternative embodiments, it is possible that the second electrode is electrically connected to the outside world using the same principle as the first electrode.

[0021] One of the above technical solutions has the following advantages or beneficial effects: During battery use, electrical conduction between the battery and the outside world is achieved through a weak point. For example, when the first tab is the positive tab, the current flow path during discharge is the first tab, the main body, the weak point, and the outside world. When the battery experiences thermal runaway, the high-temperature, high-pressure gas forces open the weak point, causing it to detach from the main body. This disconnects the electrical connection between the weak point and the main body, thus interrupting electrical conduction between the first tab and the outside world. This achieves circuit breaker protection while simultaneously releasing pressure, reducing the thermal spread of the battery to other batteries or components, thereby improving battery safety. Furthermore, because the weak point is used as the connection point to the outside world, the first tab does not need to be connected to the outside world via a battery terminal as in traditional technologies. This reduces the need for terminal design and the associated riveted aluminum blocks, plastic coatings, and other structural designs, lowering production costs. Attached Figure Description

[0022] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0023] Figure 1 This is an overall structural diagram of the battery provided in the embodiments of this application;

[0024] Figure 2 This is an exploded structural diagram of the battery provided in an embodiment of this application;

[0025] Figure 3 This is a cross-sectional view of the battery along section AA provided in the embodiment of this application;

[0026] Figure 4 This is a cross-sectional view of the battery along the BB section provided in the embodiment of this application;

[0027] Figure 5 This is an exploded structural diagram showing the electrical connection between the first electrode tab and the main body, provided in an embodiment of this application.

[0028] Figure 6 This is an exploded structural diagram of the battery conductive cover and inner insulating component provided in the embodiments of this application;

[0029] Figure 7 This is an exploded structural diagram provided in an embodiment of this application to illustrate the pole structure;

[0030] Figure 8 This is a structural diagram of the pole column in another embodiment provided in this application.

[0031] Reference numerals: 1. Outer shell; 10. Receiving cavity; 11. Housing; 12. Conductive cover plate; 120. Outer surface; 121. Main body; 122. Weak part;

[0032] 2. Electrode assembly; 21. Core; 22. First tab; 221. Base; 222. Bending portion; 23. Second tab;

[0033] 3. Pole post;

[0034] 4. External insulation components;

[0035] 5. Inner insulation component; 5a. First through hole; 5b. Second through hole; 51. Plate body; 52. Abutment part;

[0036] 6. Explosion-proof valve;

[0037] 7. Second capping. Detailed Implementation

[0038] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0039] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the term "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Furthermore, the character " / " in this document, unless otherwise specified, generally indicates that the preceding and following related objects have an "or" relationship.

[0040] The following is in conjunction with the appendix Figure 1-8 This application will be further described below.

[0041] Reference Figure 1 and Figure 2 The present application discloses a battery comprising a housing 1 having a receiving cavity 10 and an electrode assembly 2 disposed within the receiving cavity 10.

[0042] The outer casing 1 includes a housing 11 and a conductive cover plate 12. The housing 11 is square and has an open accommodating cavity 10. The conductive cover plate 12 covers the open cavity. Specifically, the conductive cover plate 12 is welded to the periphery of the open cavity to achieve a seal. In one example, the conductive cover plate 12 is made of aluminum.

[0043] Reference Figure 3 and Figure 4 The electrode assembly 2 includes a core 21 and a first electrode tab 22 that are connected to each other. The conductive cover plate 12 includes a main body 121 and a weak part 122 that are connected to each other. The main body 121 is electrically connected to the first electrode tab 22, and the weak part 122 is provided with a connection terminal for electrical connection.

[0044] It should be noted that, in this embodiment, the electrode assembly 2 is provided in two sets, each set of electrode assembly 2 including a core 21 and a first tab 22. After the two electrode assemblies 2 are joined together, they are placed into the receiving cavity 10. In this embodiment, the first tab 22 is a positive tab. The core 21 includes a positive electrode sheet, a negative electrode sheet, and a separator formed by winding or stacking processes. It is not excluded that in optional embodiments, there may be only one set or more than two sets of electrode assemblies 2.

[0045] It is understandable that the weak part 122 refers to the reduced connection strength between the weak part 122 and the main body 121. In one example, a recessed groove is made at the connection between the weak part 122 and the main body 121, which allows the internal gas to blow the weak part 122 apart during battery thermal runaway, thereby causing the weak part 122 to detach from the main body 121.

[0046] It should be noted that the connection terminal on the weak part 122 for electrical connection refers to the fact that, in the battery's operating state, the weak part 122 will be connected to the connection terminal to achieve electrical connection with the outside world, thereby enabling current conduction between the battery and external electrical equipment or other external single-cell batteries. In other words, when a single-cell battery needs to be connected in series or parallel with other single-cell batteries via a connecting plate, the connecting plate is directly electrically connected to the weak part 122; this connecting plate can be called the connection terminal. Alternatively, when a single-cell battery needs to be used with an electrical device, the electrical connector of the device is directly electrically connected to the weak part 122; this electrical connector is the connection terminal. In this way, current conduction between the single-cell battery and the outside world is achieved.

[0047] Reference Figure 3 and Figure 4 During battery use, electrical conduction between the battery and the external environment is achieved through the weak point 122. For example, during discharge, the current flow path is: first tab 22, main body 121, weak point 122, and external environment. When the battery experiences thermal runaway, the high-temperature, high-pressure gas forces open the weak point 122, causing it to detach from the main body 121. This disconnects the electrical connection between the weak point 122 and the main body 121, thus interrupting electrical conduction between the first tab 22 and the external environment. This achieves both pressure relief and circuit breaking protection, reducing the thermal spread of the battery to other batteries or components, thereby improving battery safety. Furthermore, since the weak point 122 is used as the connection point for electrical connection to the external environment, the first tab 22 does not need to be connected to the external environment via battery terminals as in traditional technologies. This reduces the need for terminal design and the associated riveted aluminum blocks and plastic coatings, lowering production costs.

[0048] Reference Figure 3 and Figure 4 As one of the optional embodiments of this solution, the first electrode 22 is disposed at one end of the core 21 facing the conductive cover plate 12. One end of the first electrode 22 is integrally connected to the core 21, and the other end of the first electrode 22 is electrically connected to the main body 121. In an optional example, the first electrode 22 is welded to the main body 121.

[0049] It is understandable that the first electrode 22 can also be located at the end of the core 21 away from the conductive cover plate 12. In this case, the electrical connection between the first electrode 22 and the main body 121 can be connected by an adapter piece. At this time, the function of circuit breaking protection can still be achieved. That is, when the weak part 122 is broken, the electrical connection between the weak part 122 and the main body 121 is broken, thereby causing the electrical connection between the first electrode 22 and the weak part 122 to be broken through the adapter piece.

[0050] Reference Figure 4 and Figure 5 As one optional embodiment of this solution, the first electrode 22 includes a base 221 and a bent portion 222 connected to each other. One end of the base 221 is connected to the core 21, and the end of the base 221 away from the core 21 is connected to the bent portion 222. The bent portion 222 is electrically connected to the main body 121. In an optional example, the bent portion 222 is welded to the main body 121. The conductive cover plate 12 has an outer surface 120 facing away from the accommodating cavity 10. The orthographic projection of the bent portion 222 on the outer surface 120 does not overlap with the orthographic projection of the weak portion 122 on the outer surface 120.

[0051] In this case, the first tab 22 is a positive tab, and the base 221 is formed by stacking positive tabs on multiple positive electrode plates. The base 221 gradually extends toward the conductive cover plate 12, and the bend 222 forms a turn relative to the base 221. In one example, the bend 222 is parallel to one side of the conductive cover plate 12 near the core 21.

[0052] To achieve the above technical solution, the first tab 22 is welded to the main body 121, reducing the internal resistance of the battery, ensuring the stability of the connection between the first tab 22 and the main body 121, ensuring smooth current flow, and the setting that the orthographic projection of the bent portion 222 on the outer surface 120 and the orthographic projection of the weak portion 122 on the outer surface 120 do not overlap can ensure that the gas flows smoothly to the weak portion 122 and pushes it open. It can be understood that if the bent portion 222 of the first tab 22 is partially welded to the main body 121, and the other parts accumulate in the area directly below the weak portion 122 near the core 21, when the battery thermally runs away, the high-temperature gas will be blocked by the first tab 22 when it flows to the area below the weak portion 122. This will make it difficult for the gas to push the weak portion 122 open smoothly, which may result in the circuit breaker protection function not being implemented smoothly.

[0053] The above mainly describes the electrical conduction between the first electrode 22 with one polarity and the outside world. The design of the second electrode 23 with the opposite polarity is described below.

[0054] Reference Figure 3 , Figure 4 , Figure 6 and Figure 7As one of the optional embodiments of this solution, it also includes an electrode post 3, which penetrates the conductive cover plate 12 and is insulated from the conductive cover plate 12; the electrode assembly 2 also includes a second electrode tab 23, which has the opposite polarity to the first electrode tab 22. The second electrode tab 23 is connected to the end of the core 21 near the conductive cover plate 12, and the end of the second electrode tab 23 away from the core 21 is electrically connected to the electrode post 3.

[0055] The insulation between the electrode post 3 and the conductive cover plate 12 is achieved through an outer insulating member 4. The outer insulating member 4 is sleeved on the outer periphery of the electrode post 3 and is disposed between the electrode post 3 and the conductive cover plate 12 for insulation between the two. In one example, the outer insulating member 4 is made of plastic. Since the conductive cover plate 12 needs to have an opening for the electrode post 3 to pass through, the outer insulating member 4, sleeved on the outside of the electrode post 3, also serves as a seal.

[0056] To achieve the above technical solution, the first tab 22, the main body 121, and the weak point 122 form a circuit with one polarity connected to the outside world, while the second tab 23 and the terminal 3 form a circuit with the opposite polarity connected to the outside world, thereby realizing the circulating circuit connection between the battery and the outside world. It is understood that there are two paths of electrical conduction between the battery and the outside world, one positive and one negative. In this embodiment, the circuit breaking design of the first tab 22 can achieve the overall circuit breaking protection function of the battery, requiring minimal changes to the battery structure and correspondingly minimal adjustments to the production line, making it more suitable from a production perspective.

[0057] Reference Figure 6 and Figure 7 As one optional embodiment of this solution, it also includes an inner insulating member 5, which is disposed on the side of the conductive cover plate 12 near the core 21. The inner insulating member 5 has a first through hole 5a, through which the first electrode tab 22 passes and is electrically connected to the main body 121. The inner insulating member 5 has a second through hole 5b, through which the electrode post 3 passes and is electrically connected to the second electrode tab 23.

[0058] In this embodiment, the first tab 22 and the second tab 23 are located at the same end of the core 21. Therefore, the insulation between the first tab 22 and the second tab 23 is important. For this reason, a first through hole 5a is opened on the inner insulating member 5 to better constrain the first tab 22, reduce the movement of the first tab 22, and reduce short circuit contact.

[0059] Reference Figure 3 and Figure 6 More specifically, the inner insulating member 5 includes a plate portion 51 and an abutting portion 52 connected to each other. The plate portion 51 is connected to the conductive cover plate 12, and the abutting portion 52 protrudes from the side of the plate portion 51 away from the conductive cover plate 12. The abutting portion 52 abuts against the end of the core 21 near the conductive cover plate 12.

[0060] To achieve the above technical solution, after the inner insulating component 5 is installed in the accommodating cavity 10, the plate body 51 abuts against the conductive cover plate 12, and the abutting part 52 abuts against the core 21, thereby providing a stable limit for the core 21 and ensuring the stability of the core 21, so as to further reduce the movement of the electrode assembly 2 and improve the stability of the battery.

[0061] Reference Figure 3 As one optional embodiment of this solution, an explosion-proof valve 6 is also included, which is disposed on the housing 11. Specifically, the explosion-proof valve 6 is disposed on the side plate of the housing 11 opposite to the conductive cover plate 12.

[0062] Reference Figure 8 As one of the optional embodiments of this solution, the housing 11 has a second cover 7 facing the conductive cover plate 12, and the battery also includes a terminal post 3, which is disposed through the second cover 7 and is insulated from the second cover 7; the electrode assembly 2 also includes a second tab 23, which has the opposite polarity to the first tab 22, and is disposed at one end of the core 21 facing the second cover 7, and is electrically connected to the terminal post 3.

[0063] To achieve the above technical solution, another design scheme for the electrode post 3 structure is proposed. In this embodiment, the electrode post 3 and the conductive cover plate 12 are arranged on opposite sides, effectively isolating the first electrode tab 22 and the second electrode tab 23. No short circuit will occur between the first electrode tab 22 and the second electrode tab 23, ensuring the battery's safety performance. Disconnecting the electrical connection path between the first electrode tab 22 and the outside world smoothly achieves the circuit breaker protection function.

[0064] Furthermore, in other alternative embodiments, it is possible that the second electrode 23 is electrically connected to the outside world through the same principle as the first electrode 22. For example, in existing... Figure 7 In this design, the second cover 7 is made of a conductive material, and the second cover 7 has the same structural design as the conductive cover plate 12. The second tab 23 is connected to the non-weak structure on the second cover 7, while the weak structure is electrically connected to the outside. Therefore, when the battery experiences thermal runaway, the circuit breaker function can be achieved if either the second cover 7 or the conductive cover plate 12 is breached.

[0065] The above description is only a partial implementation of the embodiments of this application and is not intended to limit the application in any way. The protection scope of the embodiments of this application is not limited thereto. Any simple modifications, equivalent changes and alterations that can be easily conceived by those skilled in the art within the technical scope disclosed in the embodiments of this application should be included within the protection scope of the embodiments of this application.

Claims

1. A battery, characterized by, The application relates to a battery, which comprises the following parts: a shell (1) comprising a casing (11) with an open accommodating cavity (10) and a conductive cover plate (12) covering the opening; an electrode assembly (2) arranged in the accommodating cavity (10) and comprising a core (21) and a first tab (22) connected to each other; wherein the conductive cover plate (12) comprises a main body part (121) and a weak part (122) connected to each other, the main body part (121) is electrically connected to the first tab (22), and the weak part (122) is provided with a connecting end for electrical connection.

2. The battery of claim 1, wherein, The first tab (22) is arranged at one end of the core (21) facing the conductive cover plate (12), one end of the first tab (22) is connected to the core (21), and the other end of the first tab (22) is connected to the main body part (121).

3. The battery of claim 2, wherein the cathode is a lithium cobalt oxide cathode. The first tab (22) comprises a base part (221) and a bending part (222) connected to each other, one end of the base part (221) is connected to the core (21), the other end of the base part (221) away from the core (21) is connected to the bending part (222), and the bending part (222) is connected to the main body part (121).

4. The battery of claim 3, wherein the cathode is a lithium cobalt oxide cathode. The conductive cover plate (12) has an outer surface (120) facing away from the accommodating cavity (10), and the outer projection of the bending part (222) on the outer surface (120) does not overlap with the outer projection of the weak part (122) on the outer surface (120).

5. The battery of any one of claims 1-4, wherein the cathode comprises a lithium metal oxide. Further comprising a pole (3) penetrating through the conductive cover plate (12), and the pole (3) and the conductive cover plate (12) are arranged in insulation with each other; The electrode assembly (2) further comprises a second tab (23) with opposite polarity to the first tab (22), the second tab (23) is connected to one end of the core (21) close to the conductive cover plate (12), and the other end of the second tab (23) away from the core (21) is electrically connected to the pole (3).

6. The battery of claim 5, wherein the cathode is a lithium cobalt oxide cathode. Further comprising an outer insulating part (4) sleeved on the outer periphery of the pole (3), the outer insulating part (4) is arranged between the pole (3) and the conductive cover plate (12) for insulation of the two.

7. The battery of claim 5, wherein the cathode comprises a lithium cobalt oxide. Further comprising an inner insulating part (5) arranged on the side of the conductive cover plate (12) close to the core (21), the inner insulating part (5) is provided with a first through hole (5a), and the first tab (22) passes through the first through hole (5a) to be electrically connected to the main body part (121).

8. The battery of claim 7, wherein the cathode comprises a lithium metal oxide. The inner insulating part (5) is provided with a second through hole (5b), and the pole (3) passes through the second through hole (5b) to be electrically connected to the second tab (23).

9. The battery of claim 8, wherein the cathode is a lithium cobalt oxide cathode. The inner insulation piece (5) comprises a plate body part (51) connected to the conductive cover plate (12) and an abutting part (52) protruding from a side of the plate body part (51) away from the conductive cover plate (12), the abutting part (52) abutting an end of the core (21) close to the conductive cover plate (12).

10. The battery of claim 2, wherein the cathode comprises a lithium cobalt oxide. The shell (11) has a second cover (7) facing the conductive cover plate (12), and the battery further comprises a pole (3) penetrating through the second cover (7), the pole (3) and the second cover (7) being insulated from each other. The electrode assembly (2) further comprises a second tab (23) opposite in polarity to the first tab (22), the second tab (23) being arranged at an end of the core (21) facing the second cover (7), and the second tab (23) being electrically connected to the pole (3).

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