Cover plate assembly and sodium ion battery

Abstract

The utility model belongs to the technical field of battery structures, and discloses a cover plate assembly and a sodium ion battery. The cover plate assembly comprises a cover plate body, a pole, an anti-explosion valve, a first insulating part and an insulating patch, the pole penetrates through the cover plate body in an insulating mode, the anti-explosion valve is arranged on the cover plate body in a sealing mode and provided with an opening area, and the opening area can be broken to conduct explosion venting. The first insulating part is used for insulating the cover plate body and a battery cell in the shell, the insulating patch is arranged on one side, far away from the shell, of the cover plate body, the insulating patch is provided with a first hole and a second hole, the pole penetrates through the first hole, the area of the second hole is not smaller than that of the opening area, and the second hole is overlapped with the opening area. The insulating patch can prevent short circuit between the end part of the pole and the cover plate body caused by mistakenly touching the conductive component, and does not influence normal outflow of gas, so that the explosion venting effect is ensured, the safety of the battery is greatly improved, and the explosion possibility is reduced.

Description

Technical Field

[0001] This utility model relates to the field of battery structure technology, and in particular to a cover plate assembly and a sodium-ion battery. Background Technology

[0002] Secondary batteries, with their advantages of high reliability, good safety, compact size, and light weight, have been widely used in many fields, including but not limited to electronic products, military and aerospace, the automotive industry, and energy storage systems. Among them, cylindrical batteries are widely recognized in the market due to their high production efficiency. These batteries use a wound structure, which makes their production process more automated and standardized, resulting in lower costs.

[0003] To meet market demands for high energy density, high efficiency, and high-performance batteries, existing cylindrical batteries have been trending towards larger sizes. However, larger cells, due to their greater volume and pressure variations, present higher safety requirements. Current battery structures suffer from unstable and slow explosion-proof designs, significantly impacting battery safety and stability. Particularly in cases of excessive internal pressure or thermal runaway, failure to effectively and promptly release the pressure can lead to battery explosions or fires, posing serious safety hazards.

[0004] Therefore, there is an urgent need for a cover plate assembly and a sodium-ion battery to solve the above-mentioned technical problems. Utility Model Content

[0005] One objective of this invention is to provide a cover assembly that facilitates the stable and rapid discharge of gas from inside the battery, thereby achieving a deflation effect and reducing the possibility of battery explosion.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A cover assembly, mounted on the casing of a cylindrical battery, the cover assembly comprising:

[0008] A cover plate body, wherein the cover plate body is disposed at the end of the housing;

[0009] The electrode post is insulated and passes through the cover plate body;

[0010] An explosion-proof valve is sealed to the cover plate body and has an opening area that can be ruptured to release the explosion.

[0011] A first insulating element is disposed on the side of the cover plate body close to the housing to insulate the cover plate body from the battery cells inside the housing.

[0012] An insulating patch is attached to the cover plate body on the side away from the housing. The insulating patch has a first hole and a second hole. The pole is inserted through the first hole. The area of ​​the second hole is not less than the area of ​​the opening area, and the second hole overlaps with the opening area.

[0013] Preferably, the first insulating member is provided with a grid structure, which facilitates airflow, and the grid structure is positioned directly opposite the opening area.

[0014] Preferably, the cover plate assembly further includes a current collector, the battery cell includes a current collector, and the current collector is electrically connected between the current collector and the terminal post.

[0015] The current collector is provided with a third hole, which is positioned directly opposite the opening area, and the area of ​​the third hole is not less than the area of ​​the opening area.

[0016] Preferably, the first insulating member has a positioning groove on the side close to the current collector, and the current collector can be inserted into the positioning groove in a limiting manner.

[0017] Preferably, the first insulating member has a protrusion on the side close to the current collector, the protrusion extends around the circumferential direction of the first insulating member, and the protrusion has at least one positioning groove, the groove opening of the positioning groove facing the current collector.

[0018] Preferably, the protrusion has a notch, which is used to limit and accommodate the current collector plate.

[0019] Preferably, the diameter of the first insulating member is smaller than that of the cover plate body, so as to form a welding area on the outer periphery of the cover plate body, the welding area being used to weld and connect the housing.

[0020] The beneficial effects of the cover assembly provided by this utility model are that when the battery experiences a short circuit or thermal runaway, the gas can be quickly discharged from the casing through the opening of the explosion-proof valve, thereby avoiding a continuous increase in pressure. In addition, the insulating patch can prevent a short circuit between the end of the terminal and the cover body through accidental contact with conductive parts, and will not affect the normal flow of gas, thus ensuring the explosion relief effect, greatly improving the safety of the battery and reducing the possibility of explosion.

[0021] Another objective of this invention is to provide a sodium-ion battery with high safety.

[0022] To achieve this objective, the present invention adopts the following technical solution:

[0023] A sodium-ion battery includes a housing, a cell, and a cover assembly as described above, wherein the cover assembly is disposed at at least one end of the housing to seal the cell within the housing.

[0024] Preferably, the battery cell includes a positive electrode and a negative electrode, both of which include empty foil areas.

[0025] The sodium-ion battery also includes a current collector, which is used to make a conductive connection between the empty foil area and the corresponding terminals of the cover plate assembly.

[0026] Preferably, both the positive electrode and the negative electrode include a material area, and a separator is sandwiched between the positive electrode and the negative electrode, the separator extending 1.2-1.8 mm beyond the material area.

[0027] The advantages of the sodium-ion battery provided by this utility model are as follows: By setting the above-mentioned cover plate assembly, when the battery experiences a short circuit or thermal runaway, the gas can be quickly discharged from the casing through the opening of the explosion-proof valve, thereby avoiding the continuous increase of pressure. In addition, the insulating patch can not only prevent short circuits between the end of the terminal and the cover plate body due to accidental contact with conductive parts, but also will not affect the normal flow of gas, ensuring the realization of the explosion relief effect, greatly improving the safety of the battery and reducing the possibility of explosion. Attached Figure Description

[0028] Figure 1 This is a partially exploded view of the sodium-ion battery provided by this utility model;

[0029] Figure 2 This is a perspective view of the cover plate assembly provided by this utility model;

[0030] Figure 3 This is a perspective view of the insulating patch provided by this utility model;

[0031] Figure 4 This is a front view of the cover plate assembly provided by this utility model;

[0032] Figure 5 This is a side view of the cover plate assembly provided by this utility model;

[0033] Figure 6 This is a front view of the first insulating member provided by this utility model;

[0034] Figure 7 This is a schematic diagram of the battery cell provided by this utility model.

[0035] In the picture:

[0036] 1. Shell;

[0037] 2. Cover plate body;

[0038] 3. Pole post;

[0039] 4. Explosion-proof valve;

[0040] 5. First insulating component; 51. Protrusion; 511. Positioning groove; 512. Notch; 52. Grid structure;

[0041] 6. Insulating patch; 61. First hole; 62. Second hole;

[0042] 7. Second insulating component;

[0043] 100, positive electrode plate; 200, negative electrode plate; 300, diaphragm. Detailed Implementation

[0044] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0045] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0046] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0047] In the description of this embodiment, the terms "upper," "lower," "right," and "left," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0048] The following is based on Figures 1 to 7 This invention introduces the cover plate assembly and sodium-ion battery provided by this utility model.

[0049] refer to Figure 1 As shown, this sodium-ion battery includes a casing 1, a cover assembly, and a battery cell. The casing 1 is a cylindrical tubular structure open at both ends, with a cover assembly at at least one open end to seal the interior of the casing 1. The battery cell is disposed inside the casing 1. When the casing 1 is sealed, it can form an electrical connection with the outside through the cover assembly, thereby enabling power supply and charging operations.

[0050] Specifically, in this embodiment, reference is made to... Figures 2 to 4 As shown, taking the cover plate assembly located at the negative electrode end as an example, the cover plate assembly includes a cover plate body 2, an electrode post 3, an explosion-proof valve 4, a first insulating component 5, and an insulating patch 6. The cover plate body 2 adopts a metal sheet structure, such as an aluminum sheet, which can be welded to the aluminum housing 1. The cover plate body 2 has a through hole for the electrode post 3 to pass through. One end of the electrode post 3 is located inside the housing 1 through this through hole, and the other end is located outside the housing 1, allowing current to flow into and out of the battery cell through the electrode post 3. The cover plate body 2 also has a mounting hole for installing the explosion-proof valve 4, which is sealed at the mounting hole. The explosion-proof valve 4 has an opening area. When the pressure inside the housing 1 exceeds a preset value, the opening area ruptures, allowing gas inside the housing 1 to flow out through the rupture. This prevents the pressure inside the housing 1 from continuously increasing during a short circuit or thermal runaway, thus achieving the technical effect of explosion venting. Optionally, in this embodiment, the cover plate body 2 is also provided with a liquid injection hole for injecting electrolyte.

[0051] The first insulating element 5 is disposed on the side of the cover plate body 2 close to the housing 1, and can insulate the cover plate body 2 from the battery cell, preventing the cover plate body 2 from directly contacting the battery cell and causing short circuits. Simultaneously, the insulating patch 6 is disposed on the side of the cover plate body 2 away from the housing 1, which can prevent short circuits between the end of the electrode post 3 and the cover plate body 2 due to accidental contact with conductive parts. Furthermore, the insulating patch 6 is provided with a first hole 61 and a second hole 62. The first hole 61 is used for the electrode post 3 to pass through, allowing the end of the electrode post 3 to be located outside the housing 1. The second hole 62 overlaps with the aforementioned opening area. When the opening area ruptures, gas can quickly and easily flow out of the housing 1 through the ruptured opening area and the second hole 62, preventing the pressure from continuously increasing and achieving a deflation effect.

[0052] With the aforementioned cover assembly, in the event of a short circuit or thermal runaway in the battery, the gas can be quickly discharged from the housing 1 through the opening of the explosion-proof valve 4, thereby preventing the continuous increase of pressure. Furthermore, the insulating patch 6 can prevent a short circuit between the end of the terminal post 3 and the cover body 2 due to accidental contact with conductive parts, and will not affect the normal flow of gas, ensuring the realization of the explosion relief effect, greatly improving the safety of the battery and reducing the possibility of explosion.

[0053] More specifically, see reference Figure 1 As shown, the cover assembly also includes a second insulating member 7, which is disposed on the side of the cover body 2 away from the battery cell, and a portion of the second insulating member 7 extends into the through hole to insulate the terminal post 3 from the cover body 2. In this embodiment, the second insulating member 7 has a square flange structure that abuts against the cover body 2, thereby limiting the second insulating member 7 along the axial direction of the terminal post 3. Correspondingly, the first hole 61 is also square to facilitate the flange structure to directly abut against the cover body 2, thereby reducing the axial length of the entire battery.

[0054] Preferably, such as Figure 2 As shown, in this embodiment, the first insulating member 5 is provided with a grid structure 52. The grid structure 52 is composed of multiple intersecting rod-shaped parts, and airflow channels are formed between the rod-shaped parts, which can facilitate the flow of gas from one side of the first insulating member 5 to the other side. At the same time, the grid structure 52 can also ensure the structural strength of the first insulating member 5, ensuring that the first insulating member 5 can withstand usage scenarios such as vibration.

[0055] It should be noted that in this embodiment, the cover plate assembly also includes a current collector (not shown in the figure). The battery cell includes a positive electrode 100 and a negative electrode 200. Both the positive electrode 100 and the negative electrode 200 are provided with current collectors. The current collector can be welded between the corresponding polarity electrode post 3 and the current collector, thereby making corresponding conductive connections between the positive electrode post 3 and the positive electrode 100, and between the negative electrode post 3 and the negative electrode 200. A third hole is provided on the current collector, which is directly opposite the opening area, and the area of ​​the third hole is not less than the area of ​​the opening area. When the internal pressure of the housing 1 causes the opening area to rupture, the gas will flow sequentially through the third hole, the grid structure 52, the opening area, and the second hole 62, thereby quickly and conveniently flowing out of the housing 1, achieving the explosion relief effect.

[0056] Optionally, refer to Figures 4 to 6 As shown, a positioning groove 511 is provided on the side of the first insulating member 5 near the current collector, allowing the current collector to be inserted into the positioning groove 511 for fixation. Specifically, a protrusion 51 is provided on the side of the first insulating member 5 near the current collector. The height of the protrusion 51 is 1.5 to 2.5 mm (as shown by dimension m in the figure), and the width is 1.2 to 1.8 mm (as shown by dimension p in the figure). The protrusion 51 extends around the circumference of the first insulating member 5 and has at least one positioning groove 511. The positioning groove 511 is fan-shaped, with its opening facing the current collector. The width of the opening is 0.3 to 1 mm (as shown by dimension n in the figure) to facilitate insertion of the current collector. Simultaneously, the protrusion 51 also has a notch 512, which can be used to limit and accommodate the current collector plate. By using the positioning groove 511 and the notch 512, the strength of the protrusion 51 can be ensured without encroaching on the space of the housing 1, and the current collector and the current collector plate are both confined to the first insulating member 5, thereby facilitating the improvement of the overall structural strength of the battery.

[0057] It should be noted that the diameter of the first insulating member 5 is smaller than that of the cover plate body 2, so as to form a welding area on the outer periphery of the cover plate body 2. The welding area is used to weld and connect the housing 1. Optionally, the width of the welding area is 0.6 mm, that is, the first insulating member 5 is 0.6 mm smaller than the cover plate body 2.

[0058] This invention also provides a sodium-ion battery, which includes a casing 1, a battery cell, and a cover assembly as described above. At least one end of the casing 1 is provided with the cover assembly to seal the battery cell within the casing 1. By providing the cover assembly, in the event of a short circuit or thermal runaway, the gas can be quickly discharged from the casing 1 through the opening of the explosion-proof valve 4, thereby preventing a continuous increase in pressure. Furthermore, the insulating patch 6 not only prevents a short circuit between the end of the terminal post 3 and the cover body 2 due to accidental contact with conductive parts, but also does not affect the normal flow of gas, ensuring the explosion-proof effect and greatly improving battery safety, reducing the possibility of explosion.

[0059] refer to Figure 7 As shown, the battery cell includes a positive electrode 100, a negative electrode 200, and a separator 300. The positive electrode 100 adopts a full-tab design, characterized by a pre-reserved empty foil area outside the material area. This empty foil area, after being flattened, forms the aforementioned current collector for current output and input. To enhance the performance and safety of the positive electrode 100, a ceramic coating with a width between 2.5 and 3.5 mm is applied between the material area and the empty foil area. This ceramic coating effectively prevents short circuits and avoids encroaching on the positive electrode material area or the tab area, thus affecting the cell's capacity. The width of the positive electrode empty foil area is precisely controlled between 4.5 and 5.5 mm to ensure sufficient strength of the flattened tab while avoiding excessive encroachment on the positive electrode material area.

[0060] The negative electrode 200 also adopts a full tab design with reserved empty foil area. The width of this empty foil area is set at 6 to 7 millimeters to balance the relationship between tab strength and cell capacity. During the winding process, the negative electrode 200 is first placed between two layers of separator 300 and initially wound 0.5 turns. Then, the positive electrode 100 is added to ensure that the negative electrode completely covers the positive electrode, forming a stable electrochemical structure. At the end of winding, the negative electrode 200 extends beyond the positive electrode 100 by a certain length on the outer ring. This extension length is typically between 5 and 30 millimeters to accommodate the electrochemical reaction requirements inside the cell. Of course, the empty foil area can also form the aforementioned current collector after being flattened.

[0061] The separator 300, acting as an insulating layer between the positive electrode 100 and the negative electrode 200, plays a crucial role in preventing direct contact between the two, which could lead to a short circuit. During the winding process, an overhang structure is designed between the separator 300 and the negative electrode, and between the negative electrode and the positive electrode; that is, the separator 300 and the negative electrode 200 extend beyond the edge of the positive electrode 100 during winding. This design helps to further reduce the risk of short circuits and improve the safety of the battery cell. The distance between the separator 300 and the super-negative electrode material area on both sides of the positive and negative electrodes is strictly controlled between 1.2 and 1.8 mm. This distance range ensures the safety performance of the battery cell while maximizing the use of the internal space of the casing 1, thereby increasing the capacity of the battery cell.

[0062] During the cell manufacturing process, the entire winding process begins with the pre-winding of the left and right separators 300. Subsequently, the negative electrode 200 is placed between the two separators 300, and the positive electrode 100 is gradually added as the winding progresses. After the winding is completed, the separators 300 need to be wound another 0.25 to 5 turns to finish, ensuring that the negative electrode 200 is completely covered.

[0063] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0064] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A cover plate assembly, mounted on the casing (1) of a cylindrical battery, characterized in that, The cover plate assembly includes: Cover body (2), the cover body (2) is disposed at the end of the housing (1); The pole (3) is insulated and inserted through the cover plate body (2); An explosion-proof valve (4) is sealed on the cover plate body (2) and has an opening area that can be broken to release the explosion. A first insulating member (5) is disposed on the side of the cover plate body (2) close to the housing (1) to insulate the battery cells inside the cover plate body (2) and the housing (1); An insulating patch (6) is attached to the cover plate body (2) on the side away from the housing (1). The insulating patch (6) is provided with a first hole (61) and a second hole (62). The pole post (3) passes through the first hole (61). The area of ​​the second hole (62) is not less than the area of ​​the opening area. The second hole (62) overlaps with the opening area.

2. The cover plate assembly according to claim 1, characterized in that, The first insulating member (5) is provided with a grid structure (52), which facilitates airflow and is positioned directly opposite the opening area.

3. The cover plate assembly according to claim 1, characterized in that, The cover plate assembly further includes a current collector, the battery cell includes a current collector, and the current collector is electrically connected between the current collector and the terminal (3). The current collector is provided with a third hole, which is positioned directly opposite the opening area, and the area of ​​the third hole is not less than the area of ​​the opening area.

4. The cover plate assembly according to claim 3, characterized in that, The first insulating member (5) has a positioning groove (511) on the side close to the current collector, and the current collector can be inserted into the positioning groove (511) for a limited position.

5. The cover plate assembly according to claim 4, characterized in that, The first insulating member (5) has a protrusion (51) on the side close to the current collector. The protrusion (51) extends around the circumferential direction of the first insulating member (5). The protrusion (51) has at least one positioning groove (511) with the groove opening facing the current collector.

6. The cover plate assembly according to claim 5, characterized in that, The protrusion (51) has a notch (512) for limiting and accommodating the collector plate.

7. The cover plate assembly according to claim 1, characterized in that, The diameter of the first insulating member (5) is smaller than that of the cover plate body (2) to form a welding area on the outer periphery of the cover plate body (2), the welding area being used to weld the housing (1).

8. A sodium-ion battery, characterized in that, The sodium-ion battery includes a housing (1), a cell, and a cover assembly as described in any one of claims 1-7, wherein the cover assembly is disposed at at least one end of the housing (1) to seal the cell within the housing (1).

9. The sodium-ion battery according to claim 8, characterized in that, The battery cell includes a positive electrode (100) and a negative electrode (200), both of which include empty foil areas. The sodium-ion battery also includes a current collector, which is used to make a conductive connection between the empty foil area and the terminal post (3) of the cover plate assembly.

10. The sodium-ion battery according to claim 9, characterized in that, Both the positive electrode (100) and the negative electrode (200) include a material area, and a separator (300) is sandwiched between the positive electrode (100) and the negative electrode (200), the separator (300) extending 1.2-1.8 mm beyond the material area.

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