Battery cell overheating breaker structure

Abstract

The utility model relates to the technical field of battery cell safety protection, in particular to a battery cell overheating breaker structure. According to the overheat breaker structure of the battery cell, the breaking unit with the fusible alloy is arranged at the pole position of the battery cell as a part of the pole, or is arranged at the connection position between the tab and the pole, so that the battery cell with overheat protection and overcurrent protection functions is obtained. When a single battery cell or a module breaks down to cause abnormal temperature rise, heat can be quickly transferred to the fusible alloy in the battery cell overheating breaker structure, and the alloy is fused after the temperature reaches the melting point of the fusible alloy, so that an electrical node at the position is broken, an internal loop of the faulted battery cell can be quickly cut off, a heat conduction path is blocked, and the service life of the battery cell is prolonged. And the occurrence of thermal runaway between single battery cells or modules is effectively reduced.

Description

Technical Field

[0001] This utility model relates to the field of battery cell safety protection technology, and in particular to a battery cell overheating disconnector structure. Background Technology

[0002] Misuse of battery cells can lead to thermal runaway of a single battery cell. When the temperature of a single thermal runaway battery cell rises uncontrollably, it can easily trigger a fire in adjacent battery cells or modules, causing the fire to spread and resulting in fires in energy storage systems and electric vehicle battery cells, which in turn can lead to large-scale fire accidents.

[0003] In electric vehicle fires, the internal terminals of the original square battery cells are mainly made of materials such as aluminum busbars or copper busbars. When a single battery cell or module experiences thermal runaway, the high melting points of aluminum and copper busbars (copper melting point 1083℃, aluminum melting point 660℃) prevent them from quickly cutting off the battery cell circuit in the initial stage of thermal runaway, thus causing a fire in a single battery cell or module. Utility Model Content

[0004] To address the problems mentioned in the background section, this utility model provides a battery cell overheating circuit breaker structure, the technical solution of which is as follows:

[0005] The battery cell overheating interrupter structure provided in this application includes a battery cell tab, a battery cell post, and an interruption unit; the interruption unit includes a fusible alloy; the post includes a busbar and a post body, and the top of the busbar is used to connect to the tab.

[0006] Wherein, the fusible alloy is connected in series between the top of the pole post and the bottom of the busbar to form a disconnectable electrical node; and / or, the fusible alloy is connected in series between the top of the busbar and the tab to form a disconnectable electrical node, so that the top of the busbar is connected to the tab through the fusible alloy.

[0007] In some embodiments, the pole post further includes a connecting block; the connecting block includes a first connecting block and a second connecting block; the first end of the first connecting block and the first end of the second connecting block are respectively connected to the top end of the pole post body and the bottom end of the busbar, and the tail end of the first connecting block and the tail end of the second connecting block are respectively connected to both ends of the fusible alloy, so that the bottom end of the busbar is connected to the top end of the pole post body through the fusible alloy.

[0008] In some embodiments, the connecting block is provided with slots on both the left and right sides; the splitting unit further includes a housing, and the fusible alloy is encapsulated in the housing; the upper and lower ends of the housing are respectively provided with insertion ports for the two connecting blocks to extend out of their inner cavities, and the inner walls on both the left and right sides are provided with locking blocks that match the slots, so that the two connecting blocks are encapsulated in the inner cavity of the housing, and the locking blocks are engaged in the slots.

[0009] In some embodiments, the outer casing includes a box body with a top opening and an inner cavity, and a cover plate that covers the box opening; the connecting block includes a protrusion and an encapsulation part in sequence from its first end to its last end; the protrusion matches the socket, and the left and right sides of the encapsulation part are provided with outwardly protruding protrusions, so that the width of the encapsulation part is greater than the width of the protrusion and the width of the socket, so that the encapsulation part is encapsulated in the inner cavity of the box body, its first end abuts against the inner wall surfaces of the upper and lower ends of the box body, and the protrusion passes through the socket and extends out of the box body.

[0010] In some embodiments, the slot is disposed on the outside of the protrusion; the upper surface of the encapsulation part is provided with a downwardly recessed isolation groove; the isolation groove extends along the left and right sides and is located between the first end of the encapsulation part and the slot.

[0011] In some embodiments, the encapsulation portion has at least one partition groove in the middle to divide the encapsulation portion into at least two connection positions for connection with the fusible alloy; the lower surface of the cover plate has a downwardly protruding first partition block, and / or the bottom inner wall surface of the box body has an upwardly protruding second partition block; the first partition block and the second partition block match the partition groove so that the connection positions are located on both sides of the first partition block and the second partition block respectively, and the first partition block is fitted into the partition groove.

[0012] In some embodiments, the top of the busbar is provided with a first connecting plate, and the first connecting plate has a first mounting hole in the middle; a connector is installed on the first mounting hole, and the top of the connector is connected to the electrode tab, so that the top of the busbar is connected to the electrode tab through the connector, and the bottom of the busbar is connected to the top of the electrode post through a fusible alloy.

[0013] In some embodiments, when the fusible alloy is connected in series between the electrode post and the busbar, the cell overheating circuit breaker structure further includes a current fuse; one end of the current fuse is connected to the electrode post and the other end is connected to the busbar, so that the current fuse and the fusible alloy are connected in parallel, and a disconnectable electrical node is formed at the current fuse.

[0014] In some embodiments, the breaking unit further includes a housing, and the fusible alloy is encapsulated within the housing; the housing includes a shell and two electrode covers; the top and bottom of the shell are respectively provided with openings, and the interior of the shell is provided with a receiving cavity for accommodating the fusible alloy, the two electrode covers respectively cover the openings at both ends, and the receiving cavity extends through the openings at both ends, so that the two ends of the fusible alloy are respectively connected to the two electrode covers; wherein, the electrode cover at the top of the shell is connected to the tab, and the electrode cover at the bottom of the shell is connected to the busbar, so that the fusible alloy is connected in series between the busbar and the tab.

[0015] In some embodiments, when the fusible alloy is connected in series between the busbar and the tab, the cell overheating circuit breaker structure further includes a current fuse; one end of the current fuse is connected to the terminal post and the other end is connected to the tab, so that the current fuse and the fusible alloy are connected in parallel, and a disconnectable electrical node is formed at the current fuse.

[0016] In some embodiments, when the fusible alloy is connected in series between the busbar and the tab, the cell overheating interrupter structure further includes a current fuse; the two ends of the current fuse are respectively connected to two electrode covers, so that the current fuse and the fusible alloy are arranged in parallel, and a disconnectable electrical node is formed at the current fuse.

[0017] In some embodiments, the housing further includes an electrode plate disposed between the opening and the electrode cover; wherein the electrode plate has a through hole communicating with the accommodating cavity, and the outer periphery of the through hole has an annular boss protruding toward the electrode cover; the through hole matches the fusible alloy so that the end of the fusible alloy can pass through the through hole and connect with the electrode cover.

[0018] In some embodiments, the opening has a first step protruding towards the electrode cover on both the front and rear sides, and a second step protruding towards the electrode cover on both the left and right sides, with the height of the first step being lower than that of the second step; the electrode sheet has an upwardly bent L-shaped surface on both the front and rear sides; the first step matches the L-shaped surface so that the electrode sheet abuts against the opening, the L-shaped surface is in contact with the first step, and the left and right sides of the L-shaped surface abut against the inner sidewall of the second step.

[0019] In some embodiments, the electrode sheet has a pouring port for pouring flux, and the pouring port is connected to the receiving cavity.

[0020] In some embodiments, the busbar has a second mounting hole for mounting the disconnecting unit, and the tab has a third mounting hole for mounting the disconnecting unit; wherein the second mounting hole and the third mounting hole are both adapted to the housing, the electrode cover at the bottom of the housing is connected to the second mounting hole so as to connect it to the busbar, the housing is embedded in the third mounting hole, and the electrode cover at the top of the housing is connected to the tab.

[0021] The battery cell overheating circuit breaker structure provided by this utility model has the following beneficial effects:

[0022] The battery cell overheating interrupter structure provided by this utility model sets the interrupting unit with fusible alloy at the terminal position of the battery cell as part of the terminal, or at the connection position between the tab and the terminal, thereby obtaining a battery cell with overheat protection and overcurrent protection functions. When a single battery cell or module fails and causes abnormal temperature rise, using this battery cell overheating interrupter structure, heat can be quickly transferred to the fusible alloy inside. After the temperature reaches the melting point of the fusible alloy, the alloy melts and breaks, causing the electrical node at that point to break. This can quickly cut off the internal circuit of the faulty battery cell, block the heat conduction path, and effectively reduce the occurrence of thermal runaway between a single battery cell or module.

[0023] Other features and beneficial effects of this invention will be set forth in the following description, and some of the technical features and beneficial effects may be apparent from the description or learned by practicing this invention. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, some of the drawings in the following description are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of the battery cell overheating interrupter provided in Embodiment 1 of this utility model when applied to the battery cell electrode plate component;

[0026] Figure 2 for Figure 1 A partial structural breakdown diagram;

[0027] Figure 3 for Figure 1 A structural breakdown diagram of the overheating circuit breaker structure of Zhongdianxin;

[0028] Figure 4 for Figure 3Schematic diagram of the positive terminal column of the overheating circuit breaker for battery cells Figure 1 ;

[0029] Figure 5 for Figure 3 Schematic diagram of the positive terminal column of the overheating circuit breaker for battery cells Figure 2 ;

[0030] Figure 6 for Figure 3 Schematic diagram of the positive busbar structure of the overheating circuit breaker for battery cells Figure 1 ;

[0031] Figure 7 for Figure 3 Schematic diagram of the positive busbar structure of the overheating circuit breaker for battery cells Figure 2 ;

[0032] Figure 8 for Figure 1 A schematic diagram of the internal structure of the Zhongdianxin overheating circuit breaker;

[0033] Figure 9 for Figure 1 A side view of the structure of the Zhongdianxin overheating circuit breaker;

[0034] Figure 10 for Figure 9 AA cross-section view;

[0035] Figure 11 for Figure 10 A cross-sectional view of the box in the middle;

[0036] Figure 12 for Figure 3 A schematic diagram of the box structure;

[0037] Figure 13 for Figure 3 A schematic diagram of the bottom structure of the cover plate;

[0038] Figure 14 This is a schematic diagram of the structure of the battery cell overheating interrupter provided in Embodiment 2 of this utility model when applied to the battery cell electrode plate component;

[0039] Figure 15 for Figure 14 A partial structural breakdown diagram;

[0040] Figure 16 for Figure 15 A structural breakdown diagram of the disconnection unit in the overheating disconnector structure of the Zhongdianxin;

[0041] Figure 17 for Figure 16 Schematic diagram of the structure of the intermediate electrode plate;

[0042] Figure 18 for Figure 16 Schematic diagram of the middle shell structure;

[0043] Figure 19 for Figure 15 Schematic diagram of the positive electrode post;

[0044] Figure 20 This is a structural breakdown diagram of the overheating circuit breaker structure with a current fuse connected in parallel in Example 3 when applied to the battery cell electrode plate component;

[0045] Figure 21 This is a structural breakdown diagram of the overheating circuit breaker structure with a current fuse connected in parallel in Example 4 when applied to the cell electrode plate component;

[0046] Figure 22 This is a structural breakdown diagram of the overheating circuit breaker structure with a current fuse connected in parallel in Example 5 when applied to the battery cell electrode plate component;

[0047] Figure 23 This is a schematic diagram illustrating the parallel connection principle of the current fuse and the fusible alloy in Examples 3-4.

[0048] Figure label:

[0049] 100. Overheat circuit breaker; 200. Positive electrode connector; 300. Insulating plate; 400. Base plate of electrode post; 500. Insulating pad; 600. Positive electrode tab; 700. Negative electrode tab; 800. Negative electrode connector; 900. Negative electrode post; 1000. Current fuse;

[0050] 110. Positive electrode post; 101. Positive electrode post body; 102. Positive busbar; 104. Fusible alloy; 1011a. First connection position; 1012a. Second connection position; 1013a. First slot; 1014a. First isolation groove; 1016a. First partition groove; 1017a. First protrusion; 1018a. First encapsulation part; 1021a. Third connection position; 1022a. Fourth connection position; 1023a. Second slot; 1024a. Second isolation groove; 1025a. First mounting hole; 1026a. Second partition groove; 1027a. Second protrusion; 1028a, Second encapsulation part; 103a, Cover plate; 105a, Box body; 1031a, First partition block; 1051a, First locking block; 1052a, Second locking block; 1053a, Second partition block; 1054a, Insertion port; 101b, Electrode cover plate; 102b, Electrode plate; 103b, Housing; 1021b, Through hole; 1022b, Annular boss; 1023b, Casting gate; 1024b, L-shaped bent surface; 1031b, Receiving cavity; 1032b, First step; 1033b, Second step; 1021c, Second mounting hole; 601b, Third mounting hole. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The technical features designed in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the protection scope of this utility model.

[0052] In the description of this utility model, it should be understood that the terms "center," "lateral," "upper," "lower," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more. Additionally, the term "comprising" and any variations thereof mean "at least comprising."

[0053] This utility model provides, for example Figure 1-13 Example 1, such as Figure 14-19 The cell overheating circuit breaker structure 100 shown in Example 2:

[0054] Example 1

[0055] This utility model provides, for example Figure 1-13 The overheating circuit breaker structure 100 shown in Embodiment 1 is applied to the interior of a traditional square battery cell; wherein, the vertical orientation of Embodiment 1 is based on... Figure 1 With the center position as the reference, the positive busbar 102 and the positive electrode post 101 are designed to be positioned relative to each other in the vertical direction. Figure 11 The two sides of a certain connecting block are the left and right sides, and the direction of the connecting block from its first end to its last end is the direction closest to the fusible alloy 104:

[0056] The battery cell overheating interrupter structure 100 includes a positive terminal 110 of the battery cell, a interrupting unit, and a positive electrode tab 600. The interrupting unit includes a fusible alloy 104. The positive terminal 110 includes two parts: a positive busbar 102 and a positive terminal body 101. The top end of the positive busbar 102 is used to connect to the positive electrode tab 600 of the battery cell. The fusible alloy 104 is connected in series between the top end of the positive terminal body 101 and the bottom end of the positive busbar 102, forming a disconnectable electrical node.

[0057] Specifically, such as Figure 2-3As shown, in Embodiment 1, the breaking unit with fusible alloy 104 serves as a connector between the positive busbar 102 and the positive terminal post 101. The components consisting of the breaking unit, the positive busbar 102, and the positive terminal post 101 are equivalent to those used in a conventional positive terminal post 110. The difference lies in that Embodiment 1 introduces the breaking unit as part of the positive terminal post 110, thereby forming a cell overheating breaker structure 100 with over-temperature protection and over-current protection functions.

[0058] like Figure 2-3 , Figure 8 As shown, the fusible alloy 104 is connected in series between the positive busbar 102 (also commonly referred to as the first copper busbar of the positive terminal 110) and the positive terminal body 101 (also commonly referred to as the second copper busbar of the positive terminal 110), and the fusible alloy 104 is encapsulated in a casing to form a cell overheating interrupter structure, thereby obtaining a cell with thermal protection. The specific operational process is as follows:

[0059] When a single thermally protected cell or module malfunctions (internal short circuit, thermal abuse, mechanical abuse, etc.) leading to abnormal temperature rise, heat can be rapidly transferred through the positive terminal post 101 and positive bus 102 of the positive terminal post 110 to the fusible alloy 104 inside. Once the temperature reaches the melting point of the fusible alloy 104, the alloy melts, causing the electrical node at that point to break. This quickly cuts off the internal circuit of the faulty cell, blocking the heat conduction path and effectively reducing the occurrence of thermal runaway between single cells or modules. In this embodiment, the overheating interrupter is located in the positive terminal post 110. After the positive terminal post 110 is placed inside the battery, the overheating interrupter can quickly absorb heat and rapidly disconnect the circuit when a fault occurs.

[0060] Optionally, the upper surface of the fusible alloy 104 is coated with a fusing agent.

[0061] Applying a fluxing agent facilitates the rapid melting of fusible alloy 104 and improves the breaking response speed.

[0062] Optionally, the positive electrode post 110 further includes a connecting block; the connecting block includes a first connecting block and a second connecting block; the first end of the first connecting block and the first end of the second connecting block are respectively connected to the top end of the positive electrode post body 101 and the bottom end of the positive electrode busbar 102, and the tail ends of the first connecting block and the tail ends of the second connecting block are respectively connected to the two ends of the fusible alloy 104, so that the bottom end of the positive electrode busbar 102 is connected to the top end of the positive electrode post body 101 through the fusible alloy 104; wherein, the left and right sides of the connecting block are provided with slots; the disconnecting unit also includes a housing, the fusible alloy 104 is encapsulated in the housing, the upper and lower ends of the housing are respectively provided with insertion ports 1054a for the two connecting blocks to extend out of their inner cavities, and the inner walls on the left and right sides are provided with locking blocks that match the slots, so that the two connecting blocks are encapsulated in the inner cavity of the housing, and the locking blocks are embedded in the slots.

[0063] In this embodiment 1, the first connecting block has a first slot 1013a on both sides, and the second connecting block has a second slot 1023a on both sides. During packaging, an outer shell is formed by injection molding. The left and right inner sidewalls of the outer shell form a first locking block 1051a and a second locking block 1052a that match the first slot 1013a and the second slot 1023a, so that the first locking block 1051a and the second locking block 1052a are respectively embedded in the first slot 1013a and the second slot 1023a. The overall strength of the product is increased by using this slot injection molding method.

[0064] It should be noted that the first card slot 1013a and the second card slot 1023a include, but are not limited to, U-shaped or other irregularly shaped slots, and the shapes and structures of the first card block 1051a and the second card block 1052a are adapted to them.

[0065] Optionally, the outer shell includes a box body 105a with a box opening at the top and an inner cavity inside, and a cover plate 103a that covers the box opening; the connecting block includes a protrusion and an encapsulation part in sequence from its first end to its last end; the protrusion matches the socket 1054a, and the left and right sides of the encapsulation part are provided with outward protrusions, so that the width of the encapsulation part is greater than the width of the protrusion and the width of the socket 1054a, so that the encapsulation part is encapsulated in the inner cavity of the box body 105a, its first end abuts against the inner wall surface of the upper and lower ends of the box body 105a, and the protrusion passes through the socket 1054a and extends out of the box body 105a.

[0066] In this embodiment 1, the first connecting block sequentially includes a first protrusion 1017a and a first encapsulation part 1018a, and the second connecting block sequentially includes a second protrusion 1027a and a second encapsulation part 1028a. Through the specific size design of the encapsulation part and the protrusion part, when the encapsulation is injection molded to form the outer shell, the encapsulation part is encapsulated in the inner cavity of the box body 105a, and its movement is blocked because its head end abuts against the inner wall surfaces of the upper and lower ends of the box body 105a. This design is beneficial to improving the overall installation and connection stability of the splitting unit.

[0067] Optionally, the card slot is located on the outside of the protrusion; the upper surface of the encapsulation part is provided with a downwardly recessed isolation groove, which extends along the left and right sides and is located between the first end of the encapsulation part and the card slot.

[0068] In this embodiment 1, the first connecting block is provided with a first isolation groove 1014a, and the second connecting block is provided with a second isolation groove 1024a. Through the isolation groove design, the overall airtightness of the split unit in the product can be improved after the injection molding shell.

[0069] Optionally, at least one partition groove is provided in the middle of the encapsulation part to divide the encapsulation part into at least two connection positions for connection with the fusible alloy 104; the lower surface of the cover plate 103a is provided with a downwardly protruding first partition block 1031a, and / or the bottom inner wall surface of the box body 105a is provided with an upwardly protruding second partition block 1053a; the first partition block 1031a and the second partition block 1053a match the partition groove so that the connection positions are located on both sides of the first partition block 1031a and the second partition block 1053a respectively, and the first partition block 1031a is fitted into the partition groove.

[0070] In practice, multiple connection positions are formed by the design of the dividing slot, which facilitates the connection of multiple fusible alloys 104 at the connection positions. Furthermore, the design of the first dividing block 1031a and the second dividing block 1053a helps to separate the fusible alloys 104 and prevent the alloys from accumulating after melting.

[0071] In this embodiment 1, each encapsulation part is designed with a partition groove to form two connection positions. The first connecting block is designed with a first partition groove 1016a to form two connection positions (first connection position 1011a and second connection position 1012a), and the second connecting block is designed with a second partition groove 1026a to form two connection positions (third connection position 1021a and fourth connection position 1022a). A first partition block 1031a and a second partition block 1053a are also provided.

[0072] It should be noted that the design of the number and position of the dividing slots and the corresponding first dividing block 1031a and second dividing block 1053a can be adaptively adjusted according to the number of fusible alloys 104 connected as needed, including but not limited to the scheme of Example 1.

[0073] Optionally, the cover plate 103a and the box body 105a can be welded or sealed to form a closed shell.

[0074] Optionally, the top of the positive busbar 102 is provided with a first connecting plate, and the middle of the first connecting plate is provided with a first mounting hole 1025a; a positive connector 200 is installed on the first mounting hole 1025a, and the top of the positive connector 200 is connected to the positive electrode tab 600, so that the top of the positive busbar 102 is connected to the positive electrode tab 600 through the positive connector 200, and the bottom of the positive busbar 102 is connected to the top of the positive electrode post 101 through a fusible alloy 104.

[0075] The design employs a first mounting hole 1025a to facilitate the installation and connection of the positive electrode connector 200 and the positive electrode busbar 102. Optionally, the first mounting hole 1025a and the positive electrode connector 200 are assembled by welding.

[0076] Optionally, a "+" mark may be provided on the top of the positive electrode connector 200 to facilitate the assembly of the positive electrode connector 200.

[0077] It should be noted that:

[0078] The structure of the cell overheating interrupter structure 100 when applied to the cell electrode plate component is as follows: Figure 1 As shown, the battery cell terminal plate assembly includes components such as a positive electrode connector 200, an insulating plate 300, a terminal plate 400, an insulating pad 500, a positive electrode tab 600, a negative electrode tab 700, a negative electrode connector 800, and a negative electrode post 900. The top of the positive electrode connector 200 (marked with a "+") passes sequentially through the insulating plate 300, the terminal plate 400, and the insulating pad 500, and is assembled and welded to the positive electrode tab 600. The design of the insulating pad 500 and the insulating plate 300 prevents short circuits between the positive and negative electrodes of the battery cell terminal plate assembly. The specific construction of the aforementioned components, the connection structure of these components, and the design of the insulating components to prevent short circuits are all existing technologies and will not be elaborated here. The design concept for achieving overheat protection and overcurrent protection in this embodiment 1 lies in designing a breaking unit with a fusible alloy 104 at the position of the positive electrode post 110 of the battery cell as part of the positive electrode post 110. Similarly, this design can also be applied to the negative terminal 900, with fusible alloy 104 connected in series in the negative terminal 900 of the cell as part of the negative terminal 900.

[0079] Example 2:

[0080] This utility model provides, for example Figure 14-19 The overheating circuit breaker structure 100 shown in Embodiment 2 is an implementation method applied inside the original square battery cell, wherein the vertical orientation of Embodiment 1 is as follows: Figure 14 With the center position as the reference, the positive busbar 102 and the positive electrode post 101 are designed to be positioned relative to each other in the vertical direction. Figure 16 The middle electrode sheet 102b has an L-shaped bending surface 1024b with front and rear sides on both sides, and the side perpendicular to the left and right direction is the left and right direction:

[0081] The battery cell overheating interrupter structure 100 includes a positive terminal post 110 and a positive terminal tab 600 of the battery cell, and an interruption unit. The interruption unit includes a fusible alloy 104. The positive terminal post 110 includes two parts: a positive busbar 102 and a positive terminal post body 101. The top end of the positive busbar 102 is connected to the positive terminal tab 600 of the battery cell through the fusible alloy 104, so that the fusible alloy 104 is connected in series between the positive busbar 102 and the positive terminal tab 600 to form a disconnectable electrical node.

[0082] Specifically, such as Figure 14-15As shown, in Example 1, the breaking unit with fusible alloy 104 serves as the connector between the positive electrode post 110 and the positive electrode tab 600. The breaking unit is equivalent to a traditional electrode connection block, except that it also has an overheating fuse function, thus forming a cell overheating breaker structure 100 with over-temperature protection and over-current protection functions: as shown Figure 15 As shown, the fusible alloy 104 in the breaking unit is connected in series between the positive terminal 110 and the positive terminal tab 600, and the fusible alloy 104 is encapsulated in the shell to form a cell overheating breaking device structure, thereby obtaining a cell with thermal protection. The specific working process is as follows:

[0083] When a single thermally protected cell or module malfunctions (internal short circuit, thermal abuse, mechanical abuse, etc.) and causes abnormal temperature rise, the heat is rapidly transferred through the positive electrode post 110 to the fusible alloy 104 at its top. When the temperature reaches the melting point of the fusible alloy 104, the alloy melts and breaks, causing the electrical node at that point to disconnect. This can quickly cut off the internal circuit of the faulty cell, block the heat conduction path, and effectively reduce the occurrence of thermal runaway between a single cell or module.

[0084] It should be noted that the positive electrode post 110 in this article consists of two parts from top to bottom: the positive electrode bus 102 and the positive electrode post body 101. When the fusible alloy 104 is not connected to the positive electrode post 110, the positive electrode post 110 is generally made as one piece. However, its parts can also be made separately. This article does not restrict this.

[0085] Optionally, the upper surface of the fusible alloy 104 is coated with a fusing agent.

[0086] Applying a fluxing agent facilitates the rapid melting of fusible alloy 104 and improves the breaking response speed.

[0087] Optionally, the disconnecting unit also includes a housing, in which the fusible alloy 104 is encapsulated. The housing includes a shell 103b and two electrode covers 101b. The top and bottom of the shell 103b are respectively provided with openings, and its interior is provided with a receiving cavity 1031b for accommodating the fusible alloy 104. The two electrode covers 101b respectively cover the openings at both ends, and the receiving cavity 1031b extends to the openings at both ends, so that the two ends of the fusible alloy 104 are respectively connected to the two electrode covers 101b. The electrode cover 101b at the top of the shell 103b is connected to the positive electrode tab 600, and the electrode cover 101b at the bottom of the shell 103b is connected to the positive busbar 102, so that the fusible alloy 104 is connected in series between the positive busbar 102 and the positive electrode tab 600.

[0088] Optionally, the housing also includes an electrode plate 102b disposed between the opening and the electrode cover plate 101b; wherein, the electrode plate 102b has a through hole 1021b communicating with the accommodating cavity 1031b, and the outer periphery of the through hole 1021b has an annular boss 1022b protruding towards the electrode cover plate 101b; the through hole 1021b matches the fusible alloy 104 so that the end of the fusible alloy 104 can pass through the through hole 1021b and connect with the electrode cover plate 101b.

[0089] During the installation of the disconnecting unit, the fusible alloy 104 is inserted into the receiving cavity 1031b through the through hole 1021b. The welding point between the fusible alloy 104 and the electrode plate 102b is located at the position of the annular boss 1022b. The design of the annular boss 1022b structure can increase the welding area of ​​the fusible alloy 104, reduce incomplete welding, and avoid insufficient current carrying capacity.

[0090] Optionally, the housing 103b is divided into several accommodating cavities 1031b, and the through hole 1021b matches the accommodating cavity 1031b and the fusible alloy 104.

[0091] It should be noted that in this embodiment 2, the housing 103b is divided into two accommodating cavities 1031b, which are matched with two fusible alloys 104, and the electrode plate 102b is matched with two through holes 1021b. It should be noted that the number and position design of the accommodating cavities 1031b and the corresponding through holes 1021b can be adaptively adjusted according to the number of fusible alloys 104 to be connected, including but not limited to the scheme of embodiment 2.

[0092] Optionally, the front and rear sides of the opening are provided with a first step 1032b protruding towards the electrode cover 101b, and the left and right sides of the opening are provided with a second step 1033b protruding towards the electrode cover 101b, and the height of the first step 1032b is lower than that of the second step 1033b; the front and rear sides of the electrode sheet 102b are provided with an upwardly bent L-shaped bending surface 1024b; the first step 1032b and the L-shaped bending surface 1024b are matched so that the electrode sheet 102b abuts against the opening, the L-shaped bending surface 1024b and the first step 1032b are in close contact, and the left and right sides of the L-shaped bending surface 1024b abut against the inner sidewall of the second step 1033b.

[0093] With the above design, during installation, the upper and lower electrode plates 102b are pre-assembled onto the upper and lower openings of the housing 103b. Specifically, the L-shaped bending surface 1024b is fitted into the first step 1032b. Then, the electrode plates 102b are welded to the housing 103b and the fusible alloy 104. Finally, the electrode cover plate 101b is welded to the second step 1033b and the L-shaped bending surface 1024b of the electrode plate 102b to close and form a closed shell.

[0094] The matching design of the first step 1032b and the second step 1033b with the two electrode plates 102b (especially their L-shaped bending surface 1024b) creates a locking effect, thereby increasing the installation stability and overall strength of the splitting unit.

[0095] Optionally, the electrode sheet 102b is provided with a pouring port 1023b for pouring flux, and the pouring port 1023b is connected to the receiving cavity 1031b.

[0096] The pouring port 1023b is designed to facilitate the pouring of fluxing agent. In this embodiment 2, the pouring port 1023b is designed in the middle of the two through holes 1021b so that the fluxing agent can flow to multiple accommodating cavities 1031b and reach the fusible alloy 104 part.

[0097] Optionally, the positive busbar 102 is provided with a second mounting hole 1021c for installing the disconnecting unit, and the positive electrode tab 600 is provided with a third mounting hole 601b for installing the disconnecting unit; wherein, the second mounting hole 1021c and the third mounting hole 601b are both adapted to the outer shell, the electrode cover 101b at the bottom of the shell 103b is connected to the second mounting hole 1021c so that it is connected to the positive busbar 102, the outer shell is embedded in the third mounting hole 601b, and the electrode cover 101b at the top of the shell 103b is connected to the positive electrode tab 600.

[0098] The second mounting hole 1021c and the third mounting hole 601b are designed to facilitate the assembly and connection of the entire disconnecting unit with the positive electrode tab 600 and the positive electrode post 110.

[0099] Optionally, a "+" mark is provided on the top of the breaking unit (i.e., the upper surface of the electrode cover 101b located at the upper opening) to facilitate the assembly of the breaking unit.

[0100] It should be noted that:

[0101] The structure of the cell overheating interrupter structure 100 when applied to the cell electrode plate component is as follows: Figure 14-15As shown, the battery cell terminal plate assembly includes components such as an insulating plate 300, a terminal base plate 400, an insulating pad 500, a positive electrode tab 600, a negative electrode tab 700, a negative electrode connector 800, and a negative electrode post 900. The top of the disconnecting unit (marked with a "+") passes sequentially through openings in the insulating plate 300, the terminal base plate 400, and the insulating pad 500, and is assembled and welded to the positive electrode tab 600. The design of the insulating pad 500 and the insulating plate 300 prevents short circuits between the positive and negative electrodes of the battery cell terminal plate assembly. The specific construction of the aforementioned components, their connection structure, and the design of the insulating components to prevent short circuits are all existing technologies and will not be elaborated upon here. The design concept for achieving overheat protection and overcurrent protection in this embodiment 2 is as follows: the breaking unit with fusible alloy 104 is used as the connector between the positive terminal 110 and the positive terminal tab 600 (the position of the breaking unit is equivalent to that of a traditional terminal connector block), and the fusible alloy 104 in the breaking unit is connected in series between the positive terminal 110 and the positive terminal tab 600. Similarly, this design can also be applied to the negative terminal 900, using fusible alloy 104 as a connector, connected in series between the negative terminal 900 and the positive terminal tab 700 of the battery cell.

[0102] It should be noted that:

[0103] The design concept of this application is to connect fusible alloy 104 in series with the terminal of the battery cell as part of the terminal, or to connect fusible alloy 104 as a connector between the terminal and the tab of the battery cell, thereby obtaining a battery cell with overheat protection and current protection functions. Since lithium batteries undergo several critical stages under fault conditions, especially when thermal runaway occurs, including the early stage of thermal runaway, the battery bulging stage, and the fire and explosion stage, the internal chemical reactions of the battery cause the temperature to rise. Since the chemical reactivity of the positive electrode material is usually higher than that of the negative electrode material, the positive electrode temperature is more likely to rise. Setting the thermal protection node at the positive electrode is the preferred solution, but the disconnection unit can also be set at the negative electrode. In specific implementations of this application, the schemes of Examples 1-2 are not limited to these examples; Examples 1-2 are merely illustrative.

[0104] Examples 3-5

[0105] Based on Examples 1-2, this application also adds a current fuse 1000 connected in parallel with the fusible alloy 104, forming Examples 3-5. Adding a current fuse 1000 to Example 1 forms Example 3, and adding a current fuse 1000 to Example 2 forms Examples 4-5. The specific schemes of Examples 3-5 are as follows:

[0106] 1. Example 3

[0107] like Figure 20As shown in Example 3, based on Example 1, a current fuse 1000 is designed according to the scheme of Example 1:

[0108] When the fusible alloy 104 is connected in series between the positive terminal post 101 and the positive busbar 102, the cell overheating circuit breaker structure also includes a current fuse 1000; one end of the current fuse 1000 is connected to the positive terminal post 101, and the other end is connected to the positive busbar 102, so that the current fuse 1000 and the fusible alloy 104 are connected in parallel, and a disconnectable electrical node is formed at the current fuse 1000.

[0109] 2. Example 4

[0110] like Figure 21 As shown in Example 4, based on Example 2, a current fuse 1000 is designed according to the scheme of Example 2:

[0111] When the fusible alloy 104 is connected in series between the positive busbar 102 and the positive electrode tab 600, the overheating circuit breaker structure also includes a current fuse 1000; one end of the current fuse 1000 is connected to the positive electrode post 110 (which can be either the positive busbar 102 or a part of the positive electrode post body 101), and the other end is connected to the positive electrode tab 600, so that the current fuse 1000 and the fusible alloy 104 are connected in parallel, and a disconnectable electrical node is formed at the current fuse 1000.

[0112] 3. Example 5

[0113] like Figure 22 As shown in Example 5, based on Example 2, a current fuse 1000 is designed according to the scheme of Example 2:

[0114] When the fusible alloy 104 is connected in series between the positive busbar 102 and the positive electrode tab 600, the cell overheating interrupter structure also includes a current fuse 1000; the two ends of the current fuse 1000 are respectively connected to two electrode covers (101b) so that the current fuse 1000 and the fusible alloy 104 are connected in parallel, and a disconnectable electrical node is formed at the current fuse 1000.

[0115] The function of Examples 3-5 is as follows: parallel connection Figure 23 As shown, by using a parallel design of current fuse 1000 and fusible alloy 104, the breaking performance of the cell overheating circuit breaker structure can be further improved. The FUSE, commonly known as current fuse 1000, functions to melt during overcurrent and is ineffective against overtemperature. In certain applications where high breaking performance is required, a parallel alloy FUSE can be used to ensure the FUSE performs the final cut-off.

[0116] It should be noted that:

[0117] The design concept of Examples 3-5 involves connecting the current fuse 1000 and the fusible alloy 104 in parallel for final disconnection. Based on this design concept, the connection positions at both ends of the current fuse 1000 can be adaptively adjusted according to the position of the fusible alloy 104, including but not limited to the schemes of Examples 3-5. For example:

[0118] When the fusible alloy 104 is connected in series in the negative terminal 900 of the battery cell as part of the negative terminal 900, or when the fusible alloy 104 is connected in series between the negative terminal 900 and the positive terminal tab 700 of the battery cell as a connector, the parallel current fuse 1000 design of Examples 3-5 can also be applied to the negative terminal 900.

[0119] The role of the fluxing agent in this article is to help the alloy to be quickly cut after melting. The fluxing agent is an existing material. Based on the design concept of this application, those skilled in the art can make an appropriate selection according to their needs.

[0120] Fusible alloy 104 is an existing material, and those skilled in the art can adaptively select from existing materials according to the predetermined melting temperature requirements.

[0121] Furthermore, those skilled in the art should understand that although many problems exist in the prior art, each embodiment or technical solution of this utility model can be improved in only one or a few aspects, without necessarily solving all the technical problems listed in the prior art or background art simultaneously. Those skilled in the art should understand that any content not mentioned in a claim should not be construed as a limitation on that claim.

[0122] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A cell overheating circuit breaker structure, characterized in that: This includes the battery cell's tabs, battery cell terminals, and disconnection unit; The breaking unit includes a fusible alloy (104); the pole includes a busbar and a pole body, and the top of the busbar is used to connect to the tab; Wherein, the fusible alloy (104) is connected in series between the top end of the pole post and the bottom end of the busbar to form a disconnectable electrical node; and / or, the fusible alloy (104) is connected in series between the top end of the busbar and the tab to form a disconnectable electrical node, so that the top end of the busbar is connected to the tab through the fusible alloy (104).

2. The cell overheating circuit breaker structure according to claim 1, characterized in that: The pole post further includes a connecting block; the connecting block includes a first connecting block and a second connecting block; The first end of the first connecting block and the first end of the second connecting block are respectively connected to the top end of the pole post and the bottom end of the busbar, and the tail end of the first connecting block and the tail end of the second connecting block are respectively connected to both ends of the fusible alloy (104), so that the bottom end of the busbar is connected to the top end of the pole post through the fusible alloy (104).

3. The cell overheating circuit breaker structure according to claim 2, characterized in that: The connecting block has slots on both the left and right sides; the splitting unit also includes a shell, and the fusible alloy (104) is encapsulated in the shell; The upper and lower ends of the outer shell are respectively provided with an insertion port (1054a) for the two connecting blocks to extend out of their inner cavity, and the inner walls on the left and right sides are provided with a card block that matches the card slot, so that the two connecting blocks are encapsulated in the inner cavity of the outer shell, and the card block is inserted into the card slot.

4. The cell overheating circuit breaker structure according to claim 3, characterized in that: The outer casing includes a box body (105a) with a box opening at the top and an inner cavity inside, and a cover plate (103a) that covers the box opening. The connecting block includes, in sequence from its first end to its last end, a protruding part and a sealing part; The protrusion matches the socket (1054a). The left and right sides of the encapsulation part are provided with outward protrusions, so that the width of the encapsulation part is greater than the width of the protrusion and the width of the socket (1054a), so that the encapsulation part is encapsulated in the inner cavity of the box (105a), and its head end abuts against the inner wall surface of the upper and lower ends of the box (105a), and the protrusion passes through the socket (1054a) and extends out of the box (105a).

5. The cell overheating circuit breaker structure according to claim 4, characterized in that: The slot is located on the outside of the protrusion; The upper surface of the encapsulation part is provided with a downwardly recessed isolation groove; the isolation groove extends along the left and right sides and is located between the first end of the encapsulation part and the card slot.

6. The cell overheating circuit breaker structure according to claim 5, characterized in that: The encapsulation part has at least one partition groove in the middle to divide the encapsulation part into at least two connection positions for connecting with the fusible alloy (104); the lower surface of the cover plate (103a) has a downwardly protruding first partition block (1031a), and / or the bottom inner wall surface of the box body (105a) has an upwardly protruding second partition block (1053a); the first partition block (1031a) and the second partition block (1053a) match the partition groove so that the connection positions are located on both sides of the first partition block (1031a) and the second partition block (1053a) respectively, and the first partition block (1031a) is fitted into the partition groove; And / or, the top of the busbar is provided with a first connecting plate, and the first connecting plate has a first mounting hole (1025a) in the middle; a connector is installed on the first mounting hole (1025a), the top of the connector is connected to the tab, so that the top of the busbar is connected to the tab through the connector, and the bottom of the busbar is connected to the top of the pole body through a fusible alloy (104).

7. The cell overheating circuit breaker structure according to claim 1, characterized in that: When the fusible alloy (104) is connected in series between the electrode post and the busbar, the cell overheating circuit breaker structure also includes a current fuse (1000). One end of the current fuse (1000) is connected to the pole body, and the other end is connected to the busbar, so that the current fuse (1000) and the fusible alloy (104) are connected in parallel, and a disconnectable electrical node is formed at the current fuse (1000).

8. The cell overheating circuit breaker structure according to claim 1, characterized in that: The breaking unit also includes a housing, and the fusible alloy (104) is encapsulated within the housing; The outer casing includes a housing (103b) and two electrode covers (101b). The housing (103b) has openings at the top and bottom, and an internal cavity (1031b) for accommodating the fusible alloy (104). Two electrode covers (101b) cover the openings at both ends, and the cavity (1031b) extends through the openings at both ends, so that the two ends of the fusible alloy (104) are connected to the two electrode covers (101b). The electrode cover (101b) at the top of the housing (103b) is connected to the tab, and the electrode cover (101b) at the bottom of the housing (103b) is connected to the busbar, so that the fusible alloy (104) is connected in series between the busbar and the tab.

9. The cell overheating circuit breaker structure according to claim 8, characterized in that: When the fusible alloy (104) is connected in series between the busbar and the tab, the overheating circuit breaker structure of the battery cell also includes a current fuse (1000); one end of the current fuse (1000) is connected to the pole and the other end is connected to the tab, so that the current fuse (1000) and the fusible alloy (104) are connected in parallel, and a disconnectable electrical node is formed at the current fuse (1000); And / or, when the fusible alloy (104) is connected in series between the busbar and the tab, the cell overheating interrupter structure further includes a current fuse (1000); the two ends of the current fuse (1000) are respectively connected to two electrode covers, so that the current fuse (1000) and the fusible alloy (104) are connected in parallel, and a disconnectable electrical node is formed at the current fuse (1000); And / or, the housing further includes an electrode plate (102b) disposed between the opening and the electrode cover plate (101b); wherein, the electrode plate (102b) has a through hole (1021b) communicating with the accommodating cavity (1031b), and the outer periphery of the through hole (1021b) has an annular boss (1022b) protruding towards the electrode cover plate (101b); the through hole (1021b) matches the fusible alloy (104) so ​​that the end of the fusible alloy (104) can pass through the through hole (1021b) and connect with the electrode cover plate (101b); And / or, The opening has a first step (1032b) protruding towards the electrode cover (101b) on both the front and rear sides, and a second step (1033b) protruding towards the electrode cover (101b) on both the left and right sides, with the height of the first step (1032b) being lower than that of the second step (1033b). The electrode sheet (102b) has an upwardly bent L-shaped surface (1024b) on both the front and rear sides. The first step (1032b) matches the L-shaped surface (1024b) so that the electrode sheet (102b) abuts against the opening, the L-shaped surface (1024b) is in close contact with the first step (1032b), and the left and right sides of the L-shaped surface (1024b) abut against the inner wall of the second step (1033b).

10. The cell overheating circuit breaker structure according to claim 9, characterized in that: The electrode sheet (102b) is provided with a pouring port (1023b) for pouring flux, and the pouring port (1023b) is connected to the receiving cavity (1031b). And / or, The busbar has a second mounting hole (1021c) for mounting the disconnecting unit, and the tab has a third mounting hole (601b) for mounting the disconnecting unit. The second mounting hole (1021c) and the third mounting hole (601b) are both adapted to the housing. The electrode cover (101b) at the bottom of the housing (103b) is connected to the second mounting hole (1021c) so that it is connected to the busbar. The housing is embedded in the third mounting hole (601b), and the electrode cover (101b) at the top of the housing (103b) is connected to the tab.

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