Battery cell structure and cylindrical battery

Abstract

The utility model provides a battery cell structure and a cylindrical battery. The battery cell structure comprises a positive electrode lead, a positive electrode end cover and a moving part, wherein the moving part is movably arranged between the positive electrode lead and the positive electrode end cover in an operable manner, so that conduction or disconnection of current between the positive electrode lead and the positive electrode end cover is realized. The protective structure has the advantages of convenience in operation and high electrical safety, and can eliminate the potential safety hazard of thermal runaway caused by failure of the protective structure after a conventional cylindrical battery is subjected to a destructive test.

Description

Technical Field

[0001] The utility model relates to the technical field of cylindrical battery cells, and in particular to a cell structure. The utility model also relates to a cylindrical battery comprising the cell structure. Background Art

[0002] Cylindrical batteries are a general term for battery products with a cylindrical appearance. They are usually composed of a positive electrode, a negative electrode, a diaphragm, an electrolyte, a safety valve, an overcurrent protection device, an insulating part, etc. These components are precisely wound or stacked together and encapsulated in a cylindrical metal casing. Cylindrical batteries are easy to automate due to their standardized sizes (such as the common 18650, 21700 and other models), which reduces manufacturing costs and is also convenient for replacement and maintenance. In addition, its cylindrical shape and structural design is conducive to the uniform distribution and dissipation of heat, which helps to improve the safety of the battery and extend its service life. Therefore, it is widely used in new energy vehicles, precision electronic equipment, power tools, drones and other technical fields, and is an extremely important type of product in the current battery market.

[0003] The testing of cylindrical battery cells is an important part of ensuring battery performance, safety and consistency, and involves the entire process of battery production to application. The test content covers multiple dimensions such as electrical performance, safety performance, mechanical performance and durability to ensure that the battery cells can perform their expected functions under different conditions of use. In addition to internal resistance, capacity, cycle life and self-discharge rate, specific test items also include safety-related tests such as overcharge, over-discharge, short circuit, extrusion, puncture, vibration, and thermal stability. However, since the tested cylindrical battery cells have been subjected to destructive operations, the protective structure that they were designed with may face the risk of failure, and therefore there is a safety hazard of thermal runaway.

[0004] From the above technical content, we can know that after destructive testing, existing cylindrical batteries have certain safety hazards and are prone to thermal runaway and other phenomena. Utility Model Content

[0005] In view of this, the utility model aims to propose a battery cell structure that can eliminate the potential safety hazard of thermal runaway of the battery cell caused by failure of the cylindrical battery protection structure due to destructive testing, thereby improving the electrical safety of the cylindrical battery.

[0006] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0007] The utility model provides a battery core structure, including a positive electrode lead and a positive terminal cover, and in addition, further comprising:

[0008] A moving member is operably disposed between the positive electrode lead and the positive terminal cap to achieve conduction or disconnection of current between the positive electrode lead and the positive terminal cap.

[0009] Furthermore, a traction portion is provided on the moving member, and the moving member moves due to the traction effect of the traction portion.

[0010] Furthermore, a vent hole is provided on the positive terminal cover; the traction part is constructed as a flexible rope with one end fixed to the moving part, and the other end of the traction part is passed through the vent hole and extends to the outside of the positive terminal cover.

[0011] Furthermore, the diameter of the vent hole is larger than the outer diameter of the traction portion.

[0012] Furthermore, the battery cell structure also includes:

[0013] A first elastic member acts on the moving member to make the moving member abut against the positive electrode lead; or

[0014] causing the moving member to abut against the positive terminal cover;

[0015] So that the positive electrode lead and the positive terminal cap maintain a state of current conduction.

[0016] Furthermore, the battery cell structure also includes:

[0017] a limiting assembly, used to overcome the elastic force of the first elastic member and keep the position of the moving member at a position not in contact with the positive lead; or,

[0018] The position of the moving member is maintained at a position not in contact with the positive terminal cover.

[0019] Furthermore, a card slot is provided on the moving member;

[0020] The limiting assembly includes a clamping block and a second elastic member;

[0021] The second elastic member acts on the clamping block to cause the clamping block to have a tendency to move into the clamping slot. When the clamping block is located in the clamping slot, the position of the moving member is maintained.

[0022] Furthermore, the card block has an insulating material layer.

[0023] Furthermore, a slide groove is provided on the positive terminal cover along the compression direction of the second elastic member, and the clamping block is slidably arranged in the slide groove.

[0024] Compared with the prior art, the utility model has the following advantages:

[0025] The battery cell structure described in the utility model, wherein the positive lead serves as the connection terminal of the positive electrode, is the conductor part connecting the positive electrode material inside the cylindrical battery with the external circuit, can conduct the current generated by the positive electrode inside the cylindrical battery to the external circuit, is the channel for the battery to output electric energy, so that the cylindrical battery can power an external device or system, and at the same time plays a certain structural support role for the cylindrical battery itself. The positive terminal cap serves as the positive output terminal of the cylindrical battery, allowing current to flow out of the battery to power an external device, and at the same time plays a role of structural support and insulation sealing for the cylindrical battery. The moving part serves as a bridge connecting the positive lead and the positive terminal cap. When the position of the moving part is maintained at the position where the positive lead and the positive terminal cap are current-conductive, the cylindrical battery can achieve normal charging and discharging functions. When the position of the moving part is moved to the position where the positive lead and the positive terminal cap are not current-conductive due to operation, the charging and discharging functions of the cylindrical battery fail because the outside world cannot achieve current conduction with the positive lead. Even if the protective structure of the cylindrical battery itself loses its protective function due to destructive testing, the cylindrical battery cannot form a circuit when the positive terminal cap and the positive lead are disconnected, fundamentally avoiding the safety hazard of thermal runaway of the cylindrical battery.

[0026] In addition, by providing a traction portion on the moving part, the process of operating the moving part can be further simplified, so that the operator can easily change the position of the moving part, thereby achieving the switching of the on and off state between the positive terminal cover and the positive lead.

[0027] Secondly, by opening a vent hole on the positive terminal cover, a position can be reserved for the setting of the traction part, so that the traction part can extend to the outside of the positive terminal cover, so that the operator can operate the traction part without the help of tools or opening the cylindrical battery. By setting the traction part as a flexible rope, the impact of bumps or accidental touches is avoided to a certain extent, and the stability of the cylindrical battery is improved. By setting the diameter of the vent hole to a through hole larger than the outer diameter of the traction part, the vent hole has an exhaust function, which can play a role in exhausting and relieving pressure when the battery cell is overheated or in other abnormal conditions.

[0028] Furthermore, by acting on the first elastic member on the moving member, the moving member is pressed against the positive lead or the positive terminal cap, thereby maintaining the current conduction state with the positive terminal cap or the positive lead. The first elastic member acts as a limiter on the moving member, preventing the moving member from being dislocated due to impact or vibration, thereby causing the positive terminal cap to be disconnected from the positive lead.

[0029] Secondly, by setting a limit assembly, the position of the moving part can be limited. The setting of the limit assembly can keep the limiter in a position where it does not contact the positive terminal cover or the positive lead after operation. It can prevent the limiter from being affected by vibration, impact or other factors, and return to the initial position after operation, so that the positive lead is reconnected with the positive terminal cover.

[0030] By setting the limit assembly as a combination of a card block and a second elastic member, and providing a card slot at a position corresponding to the moving member, after the moving member is moved to a certain position through operation, the card block can enter the card slot under the action of the second elastic member, thereby achieving locking of the position of the moving member. By providing a slide slot on the positive terminal cover, the movement process of the card block can be limited, ensuring the smoothness of the process of the card block sliding into the card slot. By providing an insulating material layer on the card block, insulation between the card block and the moving member can be achieved, thereby further improving the insulation protection performance and electrical safety of the present application.

[0031] In addition, the utility model also proposes a cylindrical battery provided with the above-mentioned battery core structure.

[0032] The cylindrical battery described in the present invention has the same beneficial effects as the battery cell structure described above relative to the prior art, and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0034] Figure 1 This is a schematic diagram of the structure of the battery cell in the embodiment of the present application;

[0035] Figure 2 It is a structural schematic diagram of the disconnected state of the battery cell structure in an embodiment of the present application.

[0036] Description of reference numerals:

[0037] 1. Positive lead;

[0038] 2. Positive terminal cap;

[0039] 201, vent hole; 202, slide groove;

[0040] 3. Moving parts;

[0041] 301, traction unit; 302, card slot;

[0042] 4. a first elastic member;

[0043] 5. Limiting components;

[0044] 501, a clamping block; 502, a second elastic member. DETAILED DESCRIPTION

[0045] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0046] In the description of the present invention, it should be noted that if there are terms such as "upper", "lower", "inner", "outer" and the like indicating orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, if there are terms such as "first" and "second", they are also used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0047] Taking a cell structure and cylindrical battery described in the present invention as an example, the directional words used in the embodiments, such as "up, down, left, right, front, back", are defined based on the up and down direction (also known as the height direction, or the Z direction of the battery pack), the left and right direction (also known as the width direction, or the Y direction of the battery pack), and the front and back direction (also known as the length direction, or the X direction of the battery pack). "Inside and outside" are defined based on the contour of the corresponding parts. For example, "inside" and "outside" are defined based on the contour of the battery pack, and the side of the battery pack contour close to the middle of the battery pack is "inside", and the opposite is "outside".

[0048] In addition, in the description of the present invention, unless otherwise clearly defined, the terms "installation", "connection", "connection" and "connector" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood in combination with specific circumstances.

[0049] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0050] Embodiment 1

[0051] This embodiment relates to a battery cell structure, which achieves the purpose of changing the on-off state of the current between the positive lead and the positive end cap by setting a movable part that can change its position between the positive lead and the positive end cap. After the destructive test of the cylindrical battery, when the cylindrical battery needs to be scrapped, the position of the movable part is changed by operation to disconnect the connection between the positive lead and the positive end cap, thereby ensuring the electrical safety of the cylindrical battery and avoiding the phenomenon of thermal runaway.

[0052] In terms of overall structure, refer to Figure 1 and Figure 2 The cell structure of this embodiment includes a positive lead 1, a positive terminal cover 2 and a moving member 3. The moving member 3 is operably arranged between the positive lead 1 and the positive terminal cover 2. Under normal conditions, the positive lead 1 and the positive terminal cover 2 are electrically connected, and the charge and discharge circuit of the cylindrical battery is turned on, so that the charge and discharge functions can be realized.

[0053] As set above, when the cylindrical battery needs to be scrapped after the destructive test, it only needs to operate the moving part 3 to disconnect the connection between the positive lead 1 and the positive terminal cap 2. The cylindrical battery cannot be charged or discharged in the state where the connection between the positive lead 1 and the positive terminal cap 2 is disconnected, thereby fundamentally avoiding the possibility of thermal runaway of the cylindrical battery and achieving the purpose of improving the electrical safety of the cylindrical battery.

[0054] Based on the above design concept, specifically, in this embodiment, refer to Figure 1 and Figure 2 , the positive lead 1 is constructed as a metal cylinder with good conductivity. The positive lead 1 is connected to the positive electrode material inside the cylindrical battery and realizes electrical connection. The positive lead 1 can be made of copper or nickel-plated copper. The positive lead 1 can conduct the current generated by the positive electrode inside the battery to external electrical equipment or circuits. The positive lead 1 can be connected to the positive electrode material inside the battery by welding, bolting or spring compression. The positive lead 1 can also be integrated with protection elements such as fuses or PTC (positive temperature coefficient thermistor), which automatically disconnect or increase resistance when the current is too large or the temperature is too high, thereby playing a role of overcurrent protection.

[0055] In this embodiment, refer to Figure 1 and Figure 2 , the positive terminal cap 2 is installed on the top of the cylindrical battery. The positive terminal cap 2 can be constructed as a disc-shaped metal made of nickel-plated steel or aluminum alloy, and is made in an integrated stamping method. The edge of the positive terminal cap 2 is clamped in the insulating gasket on the top of the cylindrical battery. The side of the positive terminal cap 2 close to the inside of the cylindrical battery extends into the inside of the cylindrical battery.

[0056] Reference Figure 1 and Figure 2, for the purpose of improving the electrical safety of the cylindrical battery, in this embodiment, a moving part 3 is also included. The moving part 3 can be a metal block with good conductivity. The moving part 3 is operably arranged between the positive terminal cover 2 and the positive lead 1. Under normal circumstances, the moving part 3 contacts the positive lead 1 and the positive terminal cover 2 respectively, thereby realizing the electrical connection between the positive lead 1 and the positive terminal cover 2. After the performance test of the cylindrical battery is completed, for safety reasons, the moving part 3 can be moved to another position to disconnect the connection between the positive lead 1 and the positive terminal cover 2, thereby avoiding the occurrence of thermal runaway of the battery cell.

[0057] Reference Figure 1 and Figure 2 In order to facilitate the operation of the moving part 3, in the present embodiment, a traction member is provided on the moving part 3. A vent 201 is provided on the positive terminal cover 2, one end of the traction member is fixedly connected to the moving part 3, and the other end passes through the vent 201 and extends to the outside of the positive terminal cover 2. The operator can change the position of the moving part 3 by operating the traction member to extend to one end of the outside of the positive terminal cover 2 without using other tools and without destroying the cylindrical battery shell structure. In order to avoid the impact caused by collision or misoperation, the traction member is set as a flexible rope in the present embodiment. In addition, the vent 201 is opened along the thickness direction of the positive terminal cover 2, and is constructed as a circular through hole with a diameter greater than the outer diameter of the traction member. The vent 201 can discharge the gas generated by overheating of the battery cell to the outside, thereby realizing the function of voltage reduction protection.

[0058] Reference Figure 1 and Figure 2 In order to avoid the influence of collision or vibration on the position of the moving part 3, the battery cell structure in this embodiment further includes a first elastic member 4. The first elastic member 4 is arranged inside the cylindrical battery, and the first elastic member 4 acts on the moving part 3 to keep good contact between the moving part 3 and the positive lead 1.

[0059] It should be noted that in the present embodiment, the movable member 3 is configured to be disconnected from the positive lead 1 after movement. The moving direction of the movable member 3 is the direction of approaching or moving away from the positive lead 1. The structure adopted in the present embodiment does not constitute a limitation on the actual setting form of the movable member 3. The movable member 3 can also be configured to be disconnected from the positive terminal cover 2 after movement. In this case, the moving direction of the movable member 3 is the direction of approaching or moving away from the positive terminal cover 2. In the above case, the setting of the first elastic member 4 will keep the movable member 3 in a position where it maintains good contact with the positive terminal cover 2.

[0060] Reference Figure 1 and Figure 2In order to avoid the influence of collision or vibration on the position of the moving part 3 after operation, the cell structure in this embodiment further includes a limit assembly 5. The limit assembly 5 can maintain the position of the moving part 3 after the moving part 3 moves and is disconnected from the positive lead 1, so that it will not return to the original position due to unexpected situations such as collision or vibration, thereby further improving the electrical safety of the present application.

[0061] It should be noted that in the present embodiment, the movable member 3 is configured to be disconnected from the positive lead 1 after movement. The moving direction of the movable member 3 is the direction of approaching or moving away from the positive lead 1. The structure adopted in the present embodiment does not constitute a limitation on the actual setting form of the movable member 3. The movable member 3 can also be configured to be disconnected from the positive terminal cover 2 after movement. In this case, the moving direction of the movable member 3 is the direction of approaching or moving away from the positive terminal cover 2. In the above case, the setting of the limit assembly 5 can maintain the position of the movable member 3 after the movable member 3 moves and is disconnected from the positive terminal cover 2, so that it will not return to the original position due to unexpected situations such as collision or vibration.

[0062] Reference Figure 1 and Figure 2 , in order to further improve the stability of the position-keeping effect of the limit assembly 5 on the moving member 3. In the present embodiment, the moving assembly includes a block 501 and a second elastic member 502. A slot 302 corresponding to the shape of the block 501 is provided at a position corresponding to the block 501 on the moving member 3. The second elastic member 502 acts on the block 501, so that the block 501 has a tendency to move toward the slot 302. When the position of the moving member 3 changes, the block 501 enters the slot 302 under the action of the second elastic member 502, thereby limiting and locking the position of the moving member 3. The portion of the positive terminal cover 2 extending into the cylindrical battery can be provided with a chute 202 along the compression direction of the second elastic member 502. The chute 202 is used to form a limit to the sliding of the block 501, thereby improving the smoothness of the movement process of the block 501. The outer surface of the block 501 can be provided with a surface material with good insulation to achieve insulation between the block 501 and the moving member 3, thereby obtaining better electrical safety.

[0063] In the above structure, the first elastic member 4 and the second elastic member 502 can be springs, elastic rods or elastic rubber blocks.

[0064] Embodiment 2

[0065] This embodiment relates to a cylindrical battery, including the battery cell structure involved in the first embodiment.

[0066] In this embodiment, the electrical safety of the cylindrical battery is ensured by adopting a battery cell structure in which the positive lead and the positive terminal cap can be disconnected. After the cylindrical battery is tested for performance, the connection between the positive lead and the positive terminal cap can be disconnected by operation, thereby fundamentally avoiding the possibility of thermal runaway of the battery cell.

[0067] It should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A battery cell structure, comprising a positive lead and a positive terminal cap, characterized in that: Also includes: A moving member is operably disposed between the positive electrode lead and the positive terminal cap to achieve conduction or disconnection of current between the positive electrode lead and the positive terminal cap.

2. The battery cell structure according to claim 1, characterized in that: The moving member is provided with a traction portion, and the moving member moves due to the traction effect of the traction portion.

3. The battery cell structure according to claim 2, characterized in that: The positive terminal cover is provided with a vent hole; The traction part is constructed as a flexible rope with one end fixed to the moving member, and the other end of the traction part is passed through the vent hole and extends to the outside of the positive terminal cover.

4. The battery cell structure according to claim 3, characterized in that: The diameter of the vent hole is greater than the outer diameter of the traction portion.

5. The battery core structure according to any one of claims 2 to 4, characterized in that: Also includes: a first elastic member, acting on the moving member to make the moving member abut against the positive electrode lead; or, causing the moving member to abut against the positive terminal cover; So that the positive electrode lead and the positive terminal cap maintain a state of current conduction.

6. The battery cell structure according to claim 5, characterized in that: Also includes: a limiting assembly, used for overcoming the elastic force of the first elastic member and maintaining the position of the moving member at a position not in contact with the positive electrode lead; or, The position of the moving member is maintained at a position not in contact with the positive terminal cover.

7. The battery cell structure according to claim 6, characterized in that: The moving part is provided with a card slot; The limiting assembly includes a clamping block and a second elastic member; The second elastic member acts on the clamping block to cause the clamping block to have a tendency to move into the clamping slot. When the clamping block is located in the clamping slot, the position of the moving member is maintained.

8. The battery cell structure according to claim 7, characterized in that: The outer surface of the card block has an insulating material layer.

9. The battery cell structure according to claim 7, characterized in that: The positive terminal cover is provided with a slide groove along the compression direction of the second elastic member, and the clamping block is slidably arranged in the slide groove.

10. A cylindrical battery, characterized in that: Comprising the battery core structure as claimed in any one of claims 1 to 9.

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