Battery protection structure and battery

Abstract

The utility model relates to a battery protection structure and a battery, and relates to the technical field of batteries. The battery protection structure is arranged between a roll core and a pole of the battery, and comprises a collector plate and an overturning piece, the collector plate is arranged at the end of the roll core and comprises a plate body and a separation part, the separation part is arranged in the middle of the plate body and connected with the plate body, and the plate body is connected with the roll core. The turnover piece is connected between the pole and the collector plate, the turnover piece comprises a connecting part and a welding part, the connecting part is connected with the welding part, the connecting part is connected to the pole, and the welding part is connected to the separation part. Wherein the separating part can be separated from the disc body and disconnected with the disc body along with the welding part when the separating part bears pressure in the winding core direction and reaches a pressure threshold value. According to the battery protection structure provided by the invention, the problem that the thermal runaway condition is aggravated due to continuous internal electrochemical reaction in the thermal runaway process of the battery cell in the prior art can be solved.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a battery protection structure and a battery. Background Technology

[0002] When a power battery is in use, external impacts and unstable charging voltage can cause the battery cells to overheat abnormally. In severe cases, this can lead to thermal runaway or even combustion and explosion, resulting in serious safety issues.

[0003] In the existing technology, taking cylindrical batteries as an example, in order to ensure safety during use, an explosion-proof valve is usually installed on the battery cover, so that the explosion-proof valve can be opened to release pressure when the internal pressure of the battery cell reaches the pressure threshold of the explosion-proof valve.

[0004] However, in actual use, the explosion-proof valve and other protective structures mentioned above can only serve as a last resort to relieve pressure before the battery completely thermally runs away. Before that, the continuous electrochemical reaction inside the cell will further accelerate the thermal runaway of the cell, causing the explosion-proof valve to fail to open in time and resulting in a fire and explosion.

[0005] Therefore, there is an urgent need to provide a battery protection structure that can delay or interrupt the electrochemical reaction inside the cell during thermal runaway, so as to avoid aggravating the thermal runaway and thus improve the safety of the battery during use. Utility Model Content

[0006] The purpose of this application is to provide a battery protection structure and a battery that can solve the problem in the prior art where the continued internal electrochemical reaction during the thermal runaway of the battery cell exacerbates the thermal runaway.

[0007] To achieve the above objectives, in a first aspect, this application provides a battery protection structure disposed between the battery core and the terminal post. The battery protection structure includes a current collector and a flipping member. The current collector is disposed at the end of the core and includes a disc body and a detachment portion. The detachment portion is disposed in the middle of the disc body and is connected to the disc body, which is in turn connected to the core. The flipping member is connected between the terminal post and the current collector and includes a connecting portion and a welding portion. The connecting portion and the welding portion are connected, and the connecting portion is connected to the terminal post, while the welding portion is connected to the detachment portion. The detachment portion, when subjected to pressure in the direction of the core and reaching a pressure threshold, can detach from the disc body and disconnect from it.

[0008] Based on the embodiments described above, when the battery is in use, the current collector and the flipping component together serve as the conductive structure between the battery core and the terminals. The core is connected to the terminals sequentially via the current collector and the flipping component, and then connected to the outside of the battery via the terminals, enabling the input and output of battery current. When thermal runaway begins inside the battery, the internal temperature rises while the pressure gradually increases. At this time, the detachment part is subjected to pressure in the direction of the core. When the pressure reaches a pressure threshold, the detachment part is separated from the plate, causing the connection between the detachment part and the plate to break. This disconnects the connection between the battery core and the terminals, and disconnects the battery's input and output circuits. This weakens or even completely stops the electrochemical reaction inside the battery, thereby solving the problem of the internal electrochemical reaction exacerbating battery thermal runaway during the process, and thus improving battery safety.

[0009] In some embodiments, the flipping member further includes a folding portion connected between the connecting portion and the welding portion, and the folding portion is arranged at an angle to the axial direction of the core.

[0010] Based on the above embodiments of this application, when thermal runaway occurs inside the battery, the pressure inside the battery is transmitted to the flipping component through the current collector. At this time, the pressure direction is from the core direction to the current collector direction, that is, the axial direction of the core. By providing a folding part, and the setting direction of the folding part is at an angle to the axial direction of the core, there is an angle between the force on the folding part and the angle of the folding part itself. This makes it easier for the folding part to fold and deform to the side when subjected to pressure in the core direction, thereby driving the welded part to move towards the connecting part, causing the detachment part to detach from the disc body, realizing the disconnection between the detachment part and the disc body, thereby disconnecting the battery input and output lines, thereby weakening or even stopping the electrochemical reaction inside the battery.

[0011] In some embodiments, the thickness of the folded portion is H1, the thickness of the welded portion is H2, and 0.4H2≤H1≤0.8H2.

[0012] Based on the embodiments described above, by limiting the thickness of the folded portion relative to the welded portion, on the one hand, the strength of the folded portion itself can be weakened, making it easier for the folded portion to deform, thereby driving the welded portion to move and causing the detachment portion to detach from the disc body. On the other hand, by making the strength of the folded portion lower than that of the welded portion, the connection strength at the connection point between the welded portion and the detachment portion can be improved. At the same time, when the flipped part is subjected to pressure, the folded portion can deform preferentially, and the strength at the connection point between the welded portion and the detachment portion can also be improved.

[0013] In some embodiments, the connecting portion is provided with a flange, the flange being perpendicular to the axial direction of the core, and the flange being fixedly connected to the pole post.

[0014] Based on the above embodiments of this application, by setting the flange, the connection area between the connecting part and the terminal post can be increased without affecting the axial dimension of the battery, thereby enhancing the connection strength between the connecting part and the terminal post, so that the flipping part can stably maintain the connection with the terminal post when subjected to force.

[0015] In some embodiments, the welding part is configured as a disc structure, and the diameter of the welding part is D1, where D1 ≥ 4 mm.

[0016] Based on the above embodiments of this application, when the battery is in use, the flip-up component and the current collector are connected as a conductive component between the core and the terminal post, specifically through the connection between the welded part and the detachment part. Therefore, when the welded part is set as a disc structure, by limiting the diameter of the welded part, the flow area between the flip-up component and the current collector can be guaranteed, thereby ensuring the flow capacity at the connection point between the two and meeting the input and output requirements when the battery is in use.

[0017] In some embodiments, a break-through hole is provided at the junction of the disc body and the detachment part to reduce the connection strength at the junction of the disc body and the detachment part.

[0018] Based on the above embodiments of this application, by setting the auxiliary break hole, the connection strength between the disc body and the detachment part is reduced, thereby facilitating the detachment part to detach from the disc body when subjected to pressure.

[0019] In some embodiments, the thickness of the detachment portion is H3, and the thickness of the disc body is H4, where 0.1H4≤H3≤0.6H4.

[0020] Based on the above embodiments of this application, by limiting the thickness of the detachment portion relative to the disc body, it is possible to make the junction between the disc body and the detachment portion have a significant strength difference compared to other areas, thereby facilitating the detachment portion to separate from the disc body when under pressure.

[0021] According to a second aspect of this application, a battery is provided, comprising a casing, a winding core, terminals, and the aforementioned battery protection structure. One end of the casing is open and forms a receiving cavity, the winding core is disposed within the receiving cavity, and the terminals are disposed at the open end of the casing. A disc is connected to the winding core, and a detachment portion is indirectly connected to the terminals via a flipping member.

[0022] Based on the above embodiments of this application, the battery provided by this application includes the aforementioned battery protection structure. Through this battery protection structure, during battery use, when thermal runaway occurs inside the battery, the internal pressure directly acts on the current collector and is transmitted to the flipping component through the current collector. As the internal pressure of the battery increases, when the pressure reaches a pressure threshold, the flipping component deforms and causes the detachment part to detach from the disk, thus disconnecting the connection between the battery core and the terminal post. This weakens or even stops the electrochemical reaction inside the battery, reducing the exacerbation of the battery's thermal runaway process by the internal electrochemical reaction, thereby improving battery safety.

[0023] In some embodiments, the battery further includes an insulating element disposed at the opening end of the housing for insulating protection between the housing and the terminals and between the housing and the winding core.

[0024] Based on the above embodiments of this application, by setting the insulating component, insulation protection can be provided between the casing and the terminal post and between the casing and the winding core, so as to avoid problems such as short circuits inside the battery.

[0025] In some embodiments, a needle winding cavity is provided in the middle of the core, with one end of the needle winding cavity facing the release portion.

[0026] Based on the above embodiments of this application, by setting the needle winding cavity, high-temperature flue gas can be concentrated in the needle winding cavity when thermal runaway occurs inside the battery, thereby concentrating the pressure inside the cell onto the detachment part located at one end of the needle winding cavity, thereby improving the sensitivity of the protection structure composed of the detachment part and the flipping part to the internal pressure of the battery, and further improving the safety of the battery.

[0027] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0028] The accompanying drawings are provided to further illustrate the present application and form part of the specification. They are used together with the following detailed description to explain the present application, but do not constitute a limitation thereof. In the drawings:

[0029] Figure 1 This is a schematic diagram of the battery structure provided in the embodiments of this application.

[0030] Figure 2 This is a cross-sectional schematic diagram of the battery provided in an embodiment of this application.

[0031] Figure 3 yes Figure 2 A schematic diagram of the structure of region A in the middle.

[0032] Figure 4 yes Figure 2A schematic diagram of the structure after the detachment part in region A is detached.

[0033] Figure 5 This is a schematic diagram of the flipping component in a battery protection structure provided in another embodiment of this application.

[0034] Figure 6 This is a schematic diagram of the flipping component in the battery protection structure provided in the third embodiment of this application.

[0035] Figure 7 This is a schematic diagram of the flipping component in the battery protection structure provided in the fourth embodiment of this application.

[0036] Figure 8 This is a schematic diagram of the current collector in the battery protection structure provided in the embodiments of this application.

[0037] Explanation of reference numerals in the attached figures

[0038] 1. Core; 11. Needle winding chamber; 2. Pole post; 3. Collector plate; 31. Plate body; 32. Separation part; 33. Auxiliary break hole; 4. Flipping part; 41. Connecting part; 42. Welding part; 43. Folding part; 44. Flanged edge; 45. Vulnerable structure; 5. Housing; 6. Insulating part; 7. Sealing part; 8. Explosion-proof valve. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, 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 some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0041] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0042] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0043] In the description of this application, it should be noted that, unless otherwise stated, the terms "inner," "outer," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0044] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "setup" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0045] In the prior art, a pressure relief valve needs to be installed in the battery during use to deal with the situation of thermal runaway. When the battery thermal runaway is accompanied by the generation of high temperature flue gas, the temperature and pressure inside the battery will increase. The pressure relief valve can open to release pressure when the pressure threshold is reached.

[0046] However, when configuring the aforementioned pressure relief valve, it's important to consider that batteries generate heat during normal use, leading to an increase in internal pressure. Therefore, to prevent accidental opening of the pressure relief valve during normal operation, the pressure threshold is typically set relatively high. During battery thermal runaway, as the battery's input and output processes continue, internal electrochemical reactions also occur, further exacerbating the thermal runaway. In this situation, the battery may catch fire and explode before the pressure relief valve can open, posing a serious safety hazard.

[0047] To address the aforementioned problems in the prior art, reference is made to... Figures 1 to 3As shown, according to a first aspect of this application, an embodiment of this application provides a battery protection structure. The battery protection structure is disposed between the battery core 1 and the terminal post 2. The battery protection structure includes a current collector 3 and a flipping member 4. The current collector 3 is disposed at the end of the core 1 and includes a disc body 31 and a detachment portion 32. The detachment portion 32 is disposed in the middle of the disc body 31 and is connected to the disc body 31. The disc body 31 is connected to the core 1. The flipping member 4 is connected between the terminal post 2 and the current collector 3. The flipping member 4 includes a connecting portion 41 and a welding portion 42. The connecting portion 41 and the welding portion 42 are connected, and the connecting portion 41 is connected to the terminal post 2. The welding portion 42 is connected to the detachment portion 32. When the detachment portion 32 is subjected to pressure in the direction of the core 1 and reaches a pressure threshold, it can detach from the disc body 31 along with the welding portion 42 and disconnect from the disc body 31.

[0048] Furthermore, it should be noted that the battery protection structure described in this application is not only applicable to cylindrical batteries. After adaptive adjustments, the battery protection structure can also be applied to prismatic batteries and other irregularly shaped battery structures. Based on this, the shape of the current collector 3 can be set to a suitable shape, such as circular, square, or other irregular shapes, specifically according to the battery assembly requirements. This application does not impose any specific limitations on this.

[0049] Based on the above embodiments of this application, when the battery is in use, the current collector 3 and the flipper 4 together serve as the conductive structure between the battery core 1 and the terminal post 2, so that the core 1 is connected to the terminal post 2 in sequence through the current collector 3 and the flipper 4, and is connected to the outside of the battery through the terminal post 2 to realize the input and output of battery current. When thermal runaway begins to occur inside the battery, the internal temperature of the battery rises and the pressure gradually increases. At this time, the detachment part 32 is subjected to pressure in the direction of the core 1. When the pressure reaches the pressure threshold, the detachment part 32 is pressed and separates from the disc body 31, so that the connection between the detachment part 32 and the disc body 31 is broken, thereby realizing the disconnection between the battery core 1 and the terminal post 2, and the disconnection of the battery's input and output circuits. This can weaken or even completely stop the electrochemical reaction inside the battery, thereby solving the problem that the internal electrochemical reaction of the battery exacerbates the thermal runaway during the battery thermal runaway process, and thus improving the safety of the battery.

[0050] Meanwhile, compared to cutting off the battery input and output lines through control modules such as the external Battery Management System (BMS), the battery protection structure in this application can physically disconnect the battery input and output lines when necessary, thus providing higher reliability in the event of thermal runaway inside the battery.

[0051] Specifically, taking a cylindrical wound cell as an example, during battery assembly, the current collector 3 is located at the end of the wound cell 1, and the current collector 3 and the wound cell 1 are connected and conductive. Specifically, the wound cell 1 is partially connected and conductive to the disc body 31 of the current collector 3, and then the disc body 31 is connected to the detachment part 32, and then connected to the terminal post 2 in sequence through the welding part 42 and the connecting part 41. Finally, the connection between the wound cell 1 and the outside of the battery is realized through the terminal post 2, realizing the input and output of the battery.

[0052] When thermal runaway occurs inside the battery, a large amount of high-temperature fumes are generated, causing the internal temperature and pressure to rise. At this time, the current collector 3 is subjected to pressure from the direction of the winding core 1. The pressure on the detachment part 32 is transmitted to the flipping part 4 through the connection between the detachment part 32 and the welding part 42. When the pressure reaches the pressure threshold, the flipping part 4 deforms, and the detachment part 32 detaches from the disk body 31, completely breaking the connection between the detachment part 32 and the disk body 31. This disconnects the input and output lines between the winding core 1 and the outside world. Under these circumstances, the electrochemical reaction inside the battery will weaken and gradually stop, thus solving the problem of the internal electrochemical reaction exacerbating the battery's thermal runaway process and improving the safety of the battery during use.

[0053] Furthermore, it should be noted that the electrochemical reactions inside a battery typically refer to the oxidation and reduction reactions that occur during the battery's charging and discharging process. During charging and discharging, an electromotive force is generated between the positive and negative electrodes, which drives the movement of electrons within the battery, causing an electrochemical reaction between the positive and negative electrodes. With the aforementioned configuration of this application, when the battery protection structure reaches the pressure threshold and triggers the disconnection of the battery's input and output circuits, the electromotive force between the positive and negative electrodes disappears, thereby stopping the electrochemical reaction process driven by electron movement. This reduces or even eliminates the impact of the internal electrochemical reactions on the battery's thermal runaway process.

[0054] Furthermore, the pressure threshold mentioned above in this application refers to the pressure value that enables the disengagement part 32 to detach from the disc body 21 and completely disconnect from the disc body 21. Specifically, refer to... Figure 3 and Figure 4As shown, when the flipper 4 and the collector plate 3 are in use, the flipper 4 is connected to the pole post 2 via the connecting part 41, and then connected to the detachment part 32 via the welding part 42. The detachment part 32 is then connected to the plate body 31. During this process, the detachment part 32 is supported by the connection force of the plate body 21, and also by the support force of the welding part 42 and the flipper 4 as a whole. Therefore, as the detachment part 32 is subjected to pressure from the direction of the core 1 and the pressure gradually increases, the pressure needs to overcome the support force of the plate body 31 on the detachment part 32, and also needs to overcome the support force of the flipper 4 on the detachment part 32, causing the flipper 4 itself to deform.

[0055] In summary, when specifically setting the battery protection structure, the pressure threshold is related to the strength of the flipping component 4 itself and the connection strength between the detachment part 32 and the disc body 31. Therefore, when specifically setting it, the material structure of the flipping component 4 and the connection structure between the detachment part 32 and the disc body 31 can be set according to the required trigger pressure range to meet the above pressure threshold requirements. The specific settings can be made according to the actual situation, and this application does not impose any specific restrictions on this.

[0056] In this application, the specific structure of the flipper 4 can be any suitable structure.

[0057] refer to Figures 3 to 7 As shown in the exemplary embodiment provided in this application, the flipping member 4 may further include a folding portion 43, which is connected between the connecting portion 41 and the welding portion 42, and the setting direction of the folding portion 43 is set at an angle to the axial direction of the core 1.

[0058] Based on the above embodiments of this application, when thermal runaway occurs inside the battery, the pressure inside the battery is transmitted to the flipping member 4 through the current collector 3. At this time, the pressure direction is from the direction of the core 1 to the direction of the current collector 3, that is, the axial direction of the core 1. By providing the folding part 43, and the setting direction of the folding part 43 is set at an angle to the axial direction of the core 1, there is an angle between the force on the folding part 43 and the angle of the folding part 43 itself. This makes it easier for the folding part 43 to fold and deform to the side when subjected to pressure in the direction of the core 1, thereby driving the welding part 42 to move towards the connecting part 41, so that the detachment part 32 detaches from the disc body 31, realizing the disconnection between the detachment part 32 and the disc body 31, thereby realizing the disconnection of the battery input and output lines, thereby weakening or even stopping the electrochemical reaction inside the battery.

[0059] Meanwhile, the folding part 43 allows the flipping part 4 to deform more stably around the folding part 43 when it deforms, making the deformation process more stable and controllable, thereby improving the stability of the battery protection structure during use and further enhancing the overall safety of the battery.

[0060] Specifically, when the battery is configured as a cylindrical wound core battery, in the event of thermal runaway inside the battery, the internal pressure will act on the current collector 3. Since the current collector 3 is located at the end of the cylindrical battery, the direction of the pressure on the current collector 3 is consistent with the axial direction of the cylindrical battery. The flipping component 4 is configured as a U-shaped structure, which forms a cavity structure, thus providing space for the flipping deformation of the flipping component 4. In order to ensure the connection between the welding part 42 and the detachment part 32, the welding part 42 is configured to be in contact with the surface of the detachment part 32, that is, the welding part 42 is configured to be parallel to the plane of the detachment part 32. When the folding part 43 is configured in the same direction as the axial direction of the wound core 1, the pressure direction is consistent with the orientation of the folding part 43 itself. Therefore, the folding part 43 is more likely to undergo compressive deformation under stress rather than lateral flipping deformation. Due to the rigidity of the folding part 43 itself, the amount of compressive deformation is usually small.

[0061] When the folding section 43 is set at an angle to the axial direction of the core 1, for example, referring to... Figure 3 and Figure 4 As shown, when the folding part 43 folds inward relative to the axial direction of the core 1, the folding part 43 is prone to inward overturning deformation when subjected to pressure along the axial direction of the core 1. At this time, the overturning deformation is greater than the compression deformation, making it easier to drive the detachment part 32 to detach from the disc body 31.

[0062] For example, refer to Figure 5 As shown, when the folding portion 43 folds outward relative to the axial direction of the winding core 1, it is prone to outward deformation under pressure in the axial direction of the winding core 1, thereby causing the detachment portion 32 to detach from the disc body 31. However, compared to when the folding portion 43 folds inward, the overall space occupied by the flipping member 4 is larger, which may affect the internal space occupancy and energy density of the battery.

[0063] Further, refer to Figure 6 and Figure 7 As shown, in some other embodiments of this application, the folded portion 43 may also be provided with a weak structure 45, for example, a groove or a bending structure. This weakens the strength at a specific location on the folded portion 43, allowing it to deform preferentially at that location when subjected to force. This reduces the strength of the folded portion 43 without affecting the strength of other locations on the flipper 4, and also makes the deformation location on the folded portion 43 more stable and controllable.

[0064] In some embodiments of this application, the thickness of the folded portion 43 is H1 and the thickness of the welded portion 42 is H2. The specific thickness ratio of the folded portion 43 to the welded portion 42 can be set to 0.4H2≤H1≤0.8H2.

[0065] Based on the above embodiments of this application, by limiting the thickness of the folded portion 43 relative to the welded portion 42, on the one hand, the strength of the folded portion 43 itself can be weakened, making the folded portion 43 more prone to deformation, thereby driving the welded portion 42 to move and causing the detachment portion 32 to detach from the disc body 31. On the other hand, the strength of the folded portion 43 is lower than that of the welded portion 42, which can improve the connection strength at the connection position between the welded portion 42 and the detachment portion 32. At the same time, when the flipping member 4 is subjected to pressure, the folded portion 43 can deform preferentially.

[0066] Specifically, as described in the above embodiments of this application, the pressure threshold of the battery protection structure is related to the strength of the flipping member 4 itself. When the flipping member 43 is provided, it will preferentially deform at the folding part 43 when deformation occurs. Therefore, the strength of the folding part 43 directly affects the pressure threshold of the battery protection structure. Thus, by limiting the thickness of the folding part 43, its strength is reduced, allowing the battery protection structure to be triggered at lower pressures, improving the sensitivity of the triggering mechanism, and thereby enhancing battery safety during use. In actual production, the thickness of the folding part 43 can be set to multiple specific proportions such as 40%, 50%, 60%, 70%, and 80% of the thickness of the welding part 42. The specific thickness of the welding part 42 can be set according to factors such as connection strength requirements and current flow requirements between the welding part 42 and the current collector 3. This application does not impose specific limitations on this.

[0067] refer to Figures 3 to 7 As shown in some embodiments of this application, the connecting part 41 may be provided with a flange 44, the flange 44 being provided in a direction perpendicular to the axial direction of the core 1, and the flange 44 being fixedly connected to the pole post 2.

[0068] Based on the above embodiments of this application, by setting the flange 44, the connection area between the connecting part 41 and the terminal post 2 can be increased without affecting the axial dimension of the battery, thereby enhancing the connection strength between the connecting part 41 and the terminal post 2, so that the flipping part 4 can stably maintain the connection with the terminal post 2 when subjected to force.

[0069] Specifically, the flip-up component 4 is disposed between the terminal post 2 and the current collector 3 for connection and conduction between the two. In a specific configuration, the connecting part 41 and the flange 44 can be directly welded to the terminal post 2, while the welding part 42 is welded to the detachment part 32 in the current collector 3. When the battery protection structure triggers protection, the connecting part 41 and the flange 44 remain stably connected to the terminal post 2, while the flip-up component 4 deforms itself, causing the detachment part 32 to detach from the disk body 31.

[0070] In this application, when the battery is in normal use, the flip-up component 4 is connected to the current collector 3 as a conductive element between the winding core 1 and the terminal post 2. Therefore, to ensure the input and output power of the battery, it is necessary to ensure the current-carrying capacity at the connection point between the flip-up component 4 and the current collector 3. (Reference) Figure 3 As shown, in some embodiments of this application, the welding part 42 can be configured as a disc structure, and the diameter of the welding part 42 is D1. In this case, the specific size of the welding part 42 can be set to D1≥4mm.

[0071] Based on the above embodiments of this application, the connection between the flip-over part 4 and the current collector 3 is specifically achieved through the communication between the welding part 42 and the detachment part 32. Therefore, when the welding part 42 is configured as a disc structure, by limiting the diameter of the welding part 42, the flow area between the flip-over part 4 and the current collector 3 can be guaranteed, thereby ensuring the flow capacity at the connection point and meeting the input and output requirements during battery use. Furthermore, by limiting the size of the welding part 42, that is, by limiting the size of the folding part 43, when the size of the folding part 43 is small, the overall strength of the folding part 43 is approximately that of a columnar structure, so it is not easy to deform under pressure. Limiting the size of the folding part 43 can also improve the deformation performance of the folding part 43.

[0072] In actual use, the diameter of the welding part 42 can be set to a number of specific values ​​such as 4mm, 5mm, 6mm and 7mm. This application does not impose any specific restrictions on this.

[0073] Meanwhile, when the welding part 42 is set to other shapes, such as rectangles or triangles, the flow capacity between the flipping part 4 and the collector plate 3 can also be guaranteed by limiting the area of ​​the welding part 42.

[0074] Furthermore, while limiting the size of the welding part 42 itself, it is also necessary to ensure the area of ​​the joint area between the welding part 42 and the detachment part 32 so as to ensure that there is sufficient flow area between the two.

[0075] refer to Figure 8 As shown in some embodiments of this application, a break hole 33 may be provided at the junction of the disc body 31 and the detachment part 32 to reduce the connection strength at the junction of the disc body 31 and the detachment part 32.

[0076] Based on the above embodiments of this application, by providing the auxiliary break hole 33, the connection strength between the disc body 31 and the detachment part 32 is reduced, thereby facilitating the detachment part 32 to detach from the disc body 31 when subjected to pressure.

[0077] Specifically, when the current collector 3 is set up, it must ensure that the current can be stably conducted between the disk body 31 and the disconnection part 32 when the battery is in normal use, and it must also ensure that the disk body 31 and the disconnection part 32 can be quickly and stably disconnected when the battery protection structure triggers protection.

[0078] Based on this, in actual production and processing, when the collector plate 3 is set as a disc structure, a receiving hole can be opened in the middle of the disc body 31. The detachment part 32 is set as a disc structure with a diameter slightly smaller than the receiving hole and is placed in the receiving hole. The detachment part 32 is fixed to the disc body 31 by means of welding with connecting strips. Subsequently, the connection strength between the disc body 31 and the detachment part 32 is further reduced by opening a break-off hole 33 at the connection position, so that the connection position can be quickly and stably disconnected when the pressure threshold is reached.

[0079] Alternatively, in some other embodiments of this application, when the current collector 3 is configured as a disc structure, the current collector 3 can be integrally formed by stamping or other methods, and then a circular groove structure is formed in the middle of the current collector 3 to separate the disc body 31 and the detachment part 32. When the internal pressure of the battery reaches the pressure threshold, the detachment part 32 and the disc body 31 can be separated from each other by the groove structure.

[0080] Furthermore, in some embodiments of this application, the thickness of the detachment portion 32 is H3, the thickness of the disk body 31 is H4, and the thickness relationship between the disk body 31 and the detachment portion 32 can be specifically set as 0.1H4≤H3≤0.6H4.

[0081] Based on the above embodiments of this application, by limiting the thickness of the detachment portion 32 relative to the disc body 31, the junction of the disc body 31 and the detachment portion 32 can have a significant thickness difference compared to other areas, making the connection between the two more prone to breakage when subjected to pressure, thereby facilitating the detachment portion 32 to detach from the disc body 31 when subjected to pressure.

[0082] In the specific production and processing process, the thickness of the detachment part 32 can be set to multiple thickness ranges such as 10%, 20%, 30%, 40%, 50%, and 60% of the thickness of the disc body 31, depending on factors such as processing method and pressure threshold requirements.

[0083] Based on the above technical solution, according to the second aspect of this application, a battery is provided, with reference to... Figure 1 and Figure 2As shown, the battery includes a casing 5, a winding core 1, terminals 2, and the aforementioned battery protection structure. One end of the casing 5 is open and forms a receiving cavity, within which the winding core 1 is disposed. The terminals 2 are disposed at the open end of the casing 5. A disc body 31 is connected to the winding core 1, and a detachment portion 32 is indirectly connected to the terminals 2 via a flipping member 4.

[0084] Based on the above embodiments of this application, the battery provided by this application includes the aforementioned battery protection structure. Through this battery protection structure, during battery use, when thermal runaway occurs inside the battery, the internal pressure directly acts on the current collector 3 and is transmitted to the flipping member 4 via the current collector 3. As the internal pressure of the battery increases, when the pressure reaches a pressure threshold, the flipping member 4 deforms and causes the detachment part 32 to detach from the disc body 31, thereby disconnecting the connection between the battery core 1 and the terminal post 2. This weakens or even stops the electrochemical reaction inside the battery, reducing the exacerbation of the battery thermal runaway process by the internal electrochemical reaction, and thus improving battery safety.

[0085] Specifically, when the battery is configured as a cylindrical battery, the casing 5 is a cylindrical structure with closed ends, and one end of the casing 5 is open to allow the terminal post 2 to pass through. The core 1 is disposed inside the casing 5 and is connected to the terminal post 2 through the current collector 3 and the flipping component 4. At this time, the casing 5 carries a negative charge and the terminal post 2 carries a positive charge, thus forming a complete battery structure. Subsequently, the battery protection structure formed by the flipping component 4 and the current collector 3 cuts off the input and output lines connecting the battery to the outside when thermal runaway occurs, thereby weakening or even stopping the electrochemical reaction inside the battery.

[0086] Furthermore, the battery in this application is not limited to the above structure. In specific use, any suitable structure can be set according to the usage requirements. For example, when the core 1 is connected to the disk body 31 of the current collector 3, a tab can also be provided between the core 1 and the disk body 31. By providing the tab, the current generated by the core 1 can be collected, which facilitates the connection and conduction between the core 1 and the disk body 31.

[0087] refer to Figure 3 and Figure 4 As shown in some embodiments of this application, the battery may further include an insulating member 6, which is disposed at the open end of the housing 5 to provide insulation protection between the housing 5 and the terminal post 2 and between the housing 5 and the winding core 1.

[0088] Based on the above embodiments of this application, by providing the insulating member 6, insulation protection can be provided between the housing 5 and the electrode post 2, and between the housing 5 and the winding core 1, so as to avoid problems such as short circuits inside the battery.

[0089] Specifically, during assembly, the terminal post 2 of the battery structure is positioned at the open end of the housing 5 and connected to the winding core 1 via the flipping component 4 and the current collector 3. Since the housing 5 and the terminal post 2 carry different charges, insulating structures are required to separate the housing 5 from the terminal post 2 and from the winding core 1. The insulating component 6 can be configured according to the shape of the gap between the housing 5 and the terminal post 2 and between the housing 5 and the winding core 1; this application does not impose specific limitations on this.

[0090] refer to Figure 3 and Figure 4 As shown in some embodiments of this application, the battery may also include a seal 7, which is disposed at the open end of the housing 5 and is used to seal the gap between the housing 5 and the terminal post 2.

[0091] Based on the above embodiments of this application, the sealing effect of the battery as a whole can be enhanced by the setting of the sealing member 7, thereby avoiding problems such as electrolyte leakage from the terminal post 2 at the opening end of the casing 5, and improving the safety and service life of the battery during use.

[0092] refer to Figure 2 As shown in some embodiments of this application, a needle winding cavity 11 may be provided in the middle of the core 1, with one end of the needle winding cavity 11 facing the release part 32.

[0093] Based on the above embodiments of this application, by setting the winding needle cavity 11, when thermal runaway occurs inside the battery, the high-temperature flue gas can be concentrated in the winding needle cavity 11, thereby allowing the pressure inside the cell to be concentrated on the detachment part 32 located at one end of the winding needle cavity 11, thereby improving the sensitivity of the protection structure composed of the detachment part 32 and the flipping member 4 to the internal pressure of the battery, and further improving the safety of the battery.

[0094] Specifically, in the production and processing of a wound-core battery, the electrode sheets need to be wound onto a winding needle to form the wound core 1, and then the winding needle is pulled out. Therefore, the winding needle cavity 11 is formed during the wound core production and processing, and does not need to be opened separately, thereby simplifying the processing steps and reducing production and processing costs.

[0095] Furthermore, in some other embodiments of this application, an explosion-proof valve 8 may also be provided on the battery housing 5. The explosion-proof valve 8 is disposed opposite to the terminal post 2 at the other end of the opening end of the battery housing 5, and the other end of the needle winding cavity 11 is disposed opposite to the explosion-proof valve 8.

[0096] Based on the above embodiments of this application, when the battery experiences thermal runaway, the aforementioned battery protection structure triggers protection and weakens or even stops the electrochemical reaction inside the battery, thereby reducing the impact of the internal electrochemical reaction on the thermal runaway process. If the thermal runaway process continues, when the internal pressure of the battery reaches the pressure threshold of the explosion-proof valve 8, the explosion-proof valve 8 bursts to release pressure as a final protection measure to prevent the battery from exploding and burning, thus improving the safety of the battery during use. Simultaneously, by setting the explosion-proof valve 8 at the end of the battery casing 5 away from the terminal post 2, when the battery is used, taking a new energy vehicle as an example, multiple cells are grouped together, and the terminal post 2 is usually facing upwards. With the explosion-proof valve 8 facing downwards, it can release pressure away from the passenger compartment during bursting, further improving the safety of the battery in specific application environments such as new energy vehicles.

[0097] Specifically, during battery production and assembly, in order to ensure that the battery protection structure can be triggered before the explosion-proof valve 8 in the event of battery thermal runaway, thereby weakening or even stopping the electrochemical reaction inside the battery, the pressure threshold P1 for triggering the battery protection structure needs to be set to be lower than the pressure threshold P2 for opening the explosion-proof valve 8. This can be set to 0.4% P2 ≤ P1 ≤ 0.8P2. The specific pressure thresholds can be set according to the usage environment and safety requirements; this application does not impose specific restrictions on this.

[0098] The preferred embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this application, various simple modifications can be made to the technical solution of this application, and these simple modifications all fall within the protection scope of this application.

[0099] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, this application will not describe the various possible combinations separately.

[0100] Furthermore, various different implementations of this application can be combined in any way, as long as they do not violate the spirit of this application, they should also be regarded as the content disclosed in this application.

Claims

1. A battery protection structure disposed between the battery core and the terminal post, characterized in that, The battery protection structure includes: A collector plate is disposed at the end of the core. The collector plate includes a plate body and a release part. The release part is disposed in the middle of the plate body and connected to the plate body. The plate body is connected to the core. A flip-up component is connected between the pole post and the collector plate. The flip-up component includes a connecting part and a welding part. The connecting part and the welding part are connected, and the connecting part is connected to the pole post. The welding part is connected to the detachment part. When the detachment part is subjected to pressure in the direction of the winding core and reaches a pressure threshold, it can detach from the disc body and disconnect from the disc body.

2. The battery protection structure according to claim 1, characterized in that, The flipping component further includes a folding portion, which is connected between the connecting portion and the welding portion, and the folding portion is set at an angle to the axial direction of the core.

3. The battery protection structure according to claim 2, characterized in that, The thickness of the folded part is H1, and the thickness of the welded part is H2, where 0.4H2≤H1≤0.8H2.

4. The battery protection structure according to claim 1, characterized in that, The connecting part is provided with a flange, the flange is set in a direction perpendicular to the axial direction of the core, and the flange is fixedly connected to the pole post.

5. The battery protection structure according to claim 1, characterized in that, The welding part is configured as a disc structure, and the diameter of the welding part is D1, where D1 ≥ 4 mm.

6. The battery protection structure according to claim 1, characterized in that, A break-through hole is provided at the junction of the disc body and the detachment part to reduce the connection strength at the junction of the disc body and the detachment part.

7. The battery protection structure according to claim 6, characterized in that, The thickness of the detachment part is H3, and the thickness of the disc body is H4, where 0.1H4≤H3≤0.6H4.

8. A battery, characterized in that, The battery includes: The shell has an opening at one end and forms a receiving cavity; The core is disposed within the receiving cavity; An electrode post is disposed at the opening end of the housing; and, According to any one of claims 1-7, in the battery protection structure, the disc body is connected to the winding core, and the detachment portion is indirectly connected to the terminal post through the flipping member.

9. The battery according to claim 8, characterized in that, The battery also includes an insulating component disposed at the opening end of the housing to provide insulation protection between the housing and the terminal post, and between the housing and the winding core.

10. The battery according to claim 8, characterized in that, The winding core has a winding needle cavity in the middle, and one end of the winding needle cavity is positioned directly opposite the release part.

Images