A single cell
By setting bulges on the peripheral wall of the individual battery casing to form an exhaust channel, the problem of slow high-temperature airflow discharge speed is solved, thereby improving the safety of the individual battery in the event of thermal runaway.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CALB GROUP CO LTD
- Filing Date
- 2025-04-14
- Publication Date
- 2026-06-19
AI Technical Summary
Existing single-cell batteries have a slow rate of high-temperature gas discharge during thermal runaway, resulting in low safety.
A protruding bulge is provided on the peripheral wall of the casing to form an exhaust channel, supporting the battery cell to quickly discharge high-temperature airflow. The high-temperature airflow first flows through the bulge and then turns to flow between the battery cell and the bottom wall, reducing flow rate loss.
It increases the exhaust speed of high-temperature airflow, thereby improving the safety of a single battery cell during thermal runaway.
Smart Images
Figure CN224384457U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of battery technology, and in particular to a single-cell battery. Background Technology
[0002] Each individual battery cell is equipped with an explosion-proof valve and terminals. When a single battery cell experiences thermal runaway, the explosion-proof valve opens, allowing hot air to escape. If the hot air escapes slowly, it will result in low safety during thermal runaway of the individual battery cell.
[0003] How to increase the exhaust speed of high-temperature airflow to improve the safety of a single battery cell during thermal runaway is a technical problem that needs to be solved by those skilled in the art. Utility Model Content
[0004] To solve the above-mentioned technical problems, this application provides a single battery cell, which includes a battery cell, an explosion-proof valve, and a housing. The battery cell is located inside the housing. The housing includes a bottom wall and a peripheral wall surrounding the bottom wall. The explosion-proof valve is disposed on the bottom wall. The peripheral wall has a protrusion that protrudes into the housing. The protrusion supports the battery cell so that an exhaust channel is formed between the battery cell and the bottom wall.
[0005] The aforementioned single battery cell has a protrusion on its peripheral wall that protrudes into the casing. This protrusion supports the battery cell, thus forming an exhaust channel between the battery cell and the bottom wall of the casing. When the single battery cell experiences thermal runaway, the high-temperature airflow can quickly flow to the exhaust channel. Since the exhaust channel is close to the explosion-proof valve, the high-temperature airflow in the exhaust channel can be quickly discharged from the opened explosion-proof valve. Therefore, the discharge speed of the high-temperature airflow is increased, thereby improving the safety of the single battery cell during thermal runaway.
[0006] Furthermore, during thermal runaway, the high-temperature airflow bends between the cell and the peripheral wall and flows between the cell and the bottom wall. Since the convex bulge is located on the peripheral wall, the high-temperature airflow passes through the convex bulge before the bend. In other words, the high-temperature airflow first flows through the convex bulge between the cell and the peripheral wall and then bends to flow between the cell and the bottom wall. Before the bend, the flow rate of the high-temperature airflow is relatively fast. At this time, the flow rate loss when flowing through the convex bulge is small. Therefore, the high-temperature airflow is discharged at a relatively fast speed, thus ensuring the safety of a single cell during thermal runaway. Attached Figure Description
[0007] Figure 1 A perspective view of a first embodiment of a single-cell battery provided in this application;
[0008] Figure 2 for Figure 1 Another perspective view;
[0009] Figure 3 for Figure 1A partial view of the interior of the middle shell;
[0010] Figure 4 for Figure 1 Top view of the middle shell with the top wall hidden;
[0011] Figure 5 This is a top view of the second embodiment of the single-cell battery provided in this application with the casing hidden from the top wall.
[0012] Figure 6 A partial view of the interior of the casing in the third embodiment of the single-cell battery provided in this application;
[0013] Figure 7 A partial view of the interior of the casing in the fourth embodiment of the single-cell battery provided in this application.
[0014] The annotations in the attached figures are explained as follows:
[0015] 100 Shell, 101 Bottom wall, 102 Peripheral wall, 1021 Long side wall, 1022 Short side wall, 103 Top wall;
[0016] 200 convex bulge; 300 explosion-proof valve; 400 pole; 500 battery cell; 600 insulating tray; 700 exhaust channel. Detailed Implementation
[0017] This application provides a single-cell battery. To enable those skilled in the art to better understand the technical solution of this application, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments.
[0018] like Figures 1-3 As shown, the single battery provided in this application includes a cell 500, a terminal post 400, an explosion-proof valve 300, and a casing 100.
[0019] The housing 100 is used to house the battery cell 500 and isolate it from the external environment. The housing 100 includes a bottom wall 101, a peripheral wall 102 surrounding the bottom wall 101, and a top wall 103 opposite to the bottom wall 101. An explosion-proof valve 300 is disposed on the bottom wall 101, and a protrusion 200 protruding into the housing 100 is provided on the peripheral wall 102. In the figure, the electrode post 400 is disposed on the top wall 103 of the housing 100; alternatively, it can also be disposed on the bottom wall 101 or the peripheral wall 102.
[0020] The battery cell 500 is located within the housing 100. The battery cell 500 includes stacked positive electrode plates, negative electrode plates, and a separator. The separator is located between the positive and negative electrode plates. The battery cell can be a wound battery cell formed by winding stacked units of positive electrode plates, negative electrode plates, and separators along the length of the electrode plates, or a stacked battery cell formed by stacking several layers of positive electrode plates, several layers of negative electrode plates, and several layers of separators along the thickness of the electrode plates. The positive electrode plate includes a positive electrode active material, which can be any one or a combination of lithium iron phosphate, lithium nickel cobalt manganese oxide, or lithium manganese iron phosphate. The negative electrode plate includes a negative electrode active material, which can be any one or a combination of artificial graphite, natural graphite, hard carbon, soft carbon, or silicon-based materials.
[0021] The protrusion 200 is used to support the cell 500 to form an exhaust channel 700 between the cell 500 and the bottom wall 101 of the housing 100.
[0022] In the aforementioned single battery cell, since a protrusion 200 is provided on the peripheral wall 102 of the casing 100, which protrudes into the casing 100 and supports the cell 500, an exhaust channel 700 can be formed between the cell 500 and the bottom wall 101 of the casing 100. When the single battery cell experiences thermal runaway, the high-temperature airflow can quickly flow to the exhaust channel 700. Since the exhaust channel 700 is close to the explosion-proof valve 300, the high-temperature airflow in the exhaust channel 700 can be quickly discharged from the opened explosion-proof valve 300. Therefore, the discharge speed of the high-temperature airflow is increased, thereby improving the safety of the single battery cell during thermal runaway.
[0023] Furthermore, during thermal runaway, the high-temperature airflow turns from between the cell 500 and the peripheral wall 102 to between the cell 500 and the bottom wall 101. Since the convex 200 is located on the peripheral wall 102, the high-temperature airflow passes through the convex 200 before turning. In other words, the high-temperature airflow first passes through the convex 200 between the cell 500 and the peripheral wall 102 and then turns to between the cell 500 and the bottom wall 101. Before turning, the flow rate of the high-temperature airflow is relatively fast. At this time, the flow rate loss when passing through the convex 200 is small. Therefore, the high-temperature airflow is discharged quickly, thus ensuring the safety of the single cell during thermal runaway.
[0024] In some embodiments, the overlapping area of the orthographic projection of the protrusion 200 on the bottom wall 101 and the orthographic projection of the cell 500 on the bottom wall 101 is in the range of 5% to 50% of the orthographic projection area of the cell 500 on the bottom wall 101, specifically 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, and 50%. If this ratio is too small, the contact area between the protrusion 200 and the cell 500 is too small, which cannot reliably support the cell 500 and is easy to damage the cell 500. If this ratio is too large, the protrusion 200 occupies a large exhaust space, which is not conducive to the rapid exhaust of high-temperature airflow, and therefore is not conducive to the safety of the single cell in the event of thermal runaway. By controlling the ratio of the overlapping area of the orthographic projection of the convex 200 on the bottom wall 101 and the orthographic projection of the cell 500 on the bottom wall 101 to the orthographic projection area of the cell 500 on the bottom wall 101 within the above-mentioned range, it is possible to ensure that the convex 200 reliably supports the cell 500 and to ensure the safety of the single cell in the event of thermal runaway.
[0025] In some embodiments, such as Figure 3 As shown, the protrusion height of the convex bulge 200 relative to the peripheral wall 102 is defined as H, and the range of H is: 1mm ≤ H ≤ 5mm, specifically 1mm, 2mm, 3mm, 4mm, and 5mm. If the protrusion height H of the convex bulge 200 relative to the peripheral wall 102 is too small, the contact area between the convex bulge 200 and the cell 500 is small, which cannot reliably support the cell 500 and is easily damaged. If the protrusion height H of the convex bulge 200 relative to the peripheral wall 102 is too large, it will cause the convex bulge 200 to break easily, and it will also cause the convex bulge 200 to occupy a large exhaust space, which is not conducive to the rapid exhaust of high-temperature airflow, thus being detrimental to the safety of the single cell during thermal runaway. Controlling H within the above range can ensure that the convex bulge 200 reliably supports the cell 500 and is not easily damaged, and can also ensure that the convex bulge 200 is not easily broken, and can also ensure the safety of the single cell during thermal runaway.
[0026] In some embodiments, the ratio of the length of the protrusion 200 in the circumferential direction of the peripheral wall 102 to the circumference of the peripheral wall 102 ranges from 0.2 to 0.6, specifically 0.2, 0.3, 0.4, 0.5, and 0.6. If this ratio is too small, the contact area between the protrusion 200 and the battery cell 500 is small, which cannot reliably support the battery cell 500 and makes it easy to damage the battery cell 500. If this ratio is too large, it will cause the protrusion 200 to extend to the corner position between different side walls of the peripheral wall 102, causing the corner position of the peripheral wall 102 of the housing 100 to be stress concentrated, making the corner position of the peripheral wall 102 of the housing 100 easy to damage, and also making it difficult to form the protrusion 200. Controlling this ratio within the above range can ensure that the protrusion 200 reliably supports the battery cell 500 and is not easily damaged, can ensure that the protrusion 200 is easy to form, and can also ensure that the corner position of the peripheral wall 102 of the housing 100 is not easily damaged. It should be noted that when multiple convex hulls 200 are set, the length of the convex hull 200 in the circumferential direction of the peripheral wall 102 refers to the sum of the lengths of all convex hulls 200 in the circumferential direction of the peripheral wall 102. For example, Figure 4 In this context, L1 is the sum of L2, L3, and L4.
[0027] In some embodiments, such as Figure 5 As shown, a single battery cell includes an insulating support plate 600, which is supported on a protrusion 200, and a battery cell 500 is supported on the insulating support plate 600. In this case, the convex 200 does not directly contact the battery cell 500, so designing the convex 200 to be smaller will not damage the battery cell 500. Therefore, the ratio of the overlapping area of the orthographic projection of the convex 200 on the bottom wall 101 and the orthographic projection of the battery cell 500 on the bottom wall 101 to the orthographic projection area of the battery cell 500 on the bottom wall 101 can be further narrowed to 5%~30%, specifically, 5%, 10%, 15%, 20%, 25%, 30%; the range of the convex height H of the convex 200 relative to the peripheral wall 102 can be further narrowed to 1mm~4mm, specifically, 1mm, 2mm, 3mm, 4mm; the range of the ratio of the length of the convex 200 in the circumferential direction of the peripheral wall 102 to the circumference of the peripheral wall 102 can be further narrowed to 0.2~0.4, specifically, 0.2, 0.25, 0.3, 0.35, 0.4.
[0028] In some embodiments, such as Figure 6As shown, the single-cell battery includes an insulating support plate 600, which is supported on the bottom wall 101. The side of the insulating support plate 600 facing the cell 500 is flush with the side of the protrusion 200 facing the cell 500, so that the insulating support plate 600 and the protrusion 200 together support the cell 500. In this case, since the insulating support plate 600 shares part of the weight of the cell 500, the weight of the cell 500 borne by the protrusion 200 is smaller. Therefore, a smaller contact area between the protrusion 200 and the cell 500 can also ensure the reliability of the support of the cell 500. Therefore, the ratio of the overlapping area of the orthographic projection of the protrusion 200 on the bottom wall 101 and the orthographic projection of the cell 500 on the bottom wall 101 to the orthographic projection area of the cell 500 on the bottom wall 101 can be further narrowed to 5%~20%, specifically, it can be 5%, 10%, 15%, or 20%.
[0029] Specifically, such as Figure 6 As shown, when the insulating plate 600 is supported on the bottom wall 101, it is preferable that the insulating plate 600 has a recessed area on the side near the bottom wall 101, so that a space for high-temperature airflow can be formed between the recessed area and the bottom wall 101, which is more conducive to the rapid discharge of high-temperature airflow.
[0030] In some embodiments, the battery cell 500 is covered with an insulating film, which can be a polypropylene film or a polyester film. The thickness of the insulating film ranges from 0.02mm to 0.5mm, specifically 0.02mm, 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, and 0.5mm. In this case, the insulating film can effectively buffer the force exerted on the battery cell 500 by the protrusion 200, so even if the contact area between the protrusion 200 and the battery cell 500 is small, it will not damage the battery cell 500. Therefore, the ratio of the overlapping area of the orthographic projection of the protrusion 200 on the bottom wall 101 and the orthographic projection of the battery cell 500 on the bottom wall 101 to the orthographic projection area of the battery cell 500 on the bottom wall 101 can be further limited to 5% to 40%, specifically 5%, 10%, 15%, 20%, 25%, 30%, 35%, and 40%.
[0031] In some embodiments, such as Figure 3As shown, the distance B between the convex bulge 200 and the bottom wall 101 in the direction perpendicular to the bottom wall 101 is defined. The range of B is: 3mm ≤ B ≤ 5mm, specifically 3mm, 3.5mm, 4mm, 4.5mm, and 5mm. If B is too large, it will result in low energy density of the single cell and require more electrolyte to effectively wet the cell 500, leading to high electrolyte consumption and high cost of the single cell. If B is too small, the convex bulge 200 will be difficult to form at the angle between the side wall and the bottom wall 101, and stress concentration and easy damage will also occur at the angle between the side wall and the bottom wall 101. Controlling B within the above range can ensure the energy density and cost of the single cell, ensure that the convex bulge 200 is easy to form, and ensure that the angle between the side wall and the bottom wall 101 is not easily damaged.
[0032] In some embodiments, the convex bulge 200 is integrally formed with the peripheral wall 102 of the housing 100, thus providing a high degree of robustness between the convex bulge 200 and the housing 100. Specifically, it can be integrally stamped or integrally cast.
[0033] In some embodiments, such as Figure 3 As shown, a recess is formed on the outer surface of the peripheral wall 102 of the housing 100 corresponding to the position of the protrusion 200. This facilitates the molding of the housing 100, and the recessed position can act as a buffer to prevent the protrusion 200 from breaking during long-term use.
[0034] In some embodiments, such as Figure 4 As shown, the peripheral wall 102 includes two oppositely arranged long sidewalls 1021 and two oppositely arranged short sidewalls 1022. The length of the long sidewalls 1021 in the circumferential direction of the peripheral wall 102 is greater than the length of the short sidewalls 1022 in the circumferential direction of the peripheral wall 102. At least one protrusion 200 is provided on each of the two long sidewalls 1021 and the two short sidewalls 1022, so as to more stably support the battery cell 500.
[0035] In some embodiments, the sum of the lengths of all the protrusions 200 on a single long sidewall 1021 in the circumferential direction of the peripheral wall 102 is greater than the sum of the lengths of all the protrusions 200 on a single short sidewall 1022 in the circumferential direction of the peripheral wall 102. This provides more stable support for the battery cell 500.
[0036] In some embodiments, such as Figure 4 As shown, a protrusion 200 is centrally located on the long sidewall 1021 along the circumference of the peripheral wall 102. This means the protrusion 200 on the long sidewall 1021 is relatively far from the short sidewall 1022, thus having less impact on the flow velocity of the high-temperature airflow in the gap between the corner of the short sidewall 1022 and the long sidewall 1021 and the battery cell 500, which facilitates the rapid discharge of the high-temperature airflow.
[0037] In some embodiments, such as Figure 7 As shown, multiple protrusions 200 are sequentially spaced along the circumference of the peripheral wall 102 on a single long sidewall 1021. In the figure, two protrusions are provided, but more than two can also be provided. This provides better support for the battery cell 500.
[0038] In some embodiments, such as Figure 7 As shown, multiple protrusions 200 are sequentially spaced along the circumference of the peripheral wall 102 on a single long sidewall 1021. The distance between adjacent protrusions 200 on a single long sidewall 1021 along the circumference of the peripheral wall 102 is defined as C, where C ranges from 5mm to 30mm, specifically 5mm, 10mm, 15mm, 20mm, 25mm, and 30mm. If C is too large, the length of a single protrusion 200 will be too small, making it easy to damage the cell 500. If C is too small, it will significantly affect the flow rate of the high-temperature airflow in the gap between the long sidewall 1021 and the cell 500, hindering the rapid discharge of the high-temperature airflow. Controlling C within the above range can prevent the protrusions 200 from damaging the cell 500 and also ensure the integrity of the single cell in the event of thermal runaway.
[0039] In some embodiments, such as Figure 4 or Figure 7 As shown, a protrusion 200 is centrally located on the perimeter of the short sidewall 102. This means the protrusion 200 on the short sidewall 1022 is relatively far from the long sidewall 1021, thus having less impact on the flow velocity of the high-temperature airflow in the gap between the corner of the short sidewall 1022 and the long sidewall 1021 and the battery cell 500, which facilitates the rapid discharge of the high-temperature airflow.
[0040] The above examples illustrate the principles and implementation methods of this application. The descriptions of these embodiments are merely for the purpose of helping to understand the method and core ideas of this application. It should be noted that several improvements and modifications can be made to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this application.
Claims
1. A single-cell battery, characterized in that, The single battery includes a cell, an explosion-proof valve, and a housing. The cell is located inside the housing. The housing includes a bottom wall and a peripheral wall surrounding the bottom wall. The explosion-proof valve is disposed on the bottom wall. The peripheral wall has a protrusion that protrudes into the housing. The protrusion is used to support the cell so that an exhaust channel is formed between the cell and the bottom wall.
2. The single-cell battery according to claim 1, characterized in that, The ratio of the overlapping area of the orthographic projection of the convex bulge on the bottom wall and the orthographic projection of the battery cell on the bottom wall to the orthographic projection area of the battery cell on the bottom wall is 5% to 50%.
3. The single-cell battery according to claim 1, characterized in that, The range of the convex height H of the convex hull relative to the peripheral wall is: 1mm≤H≤5mm.
4. The single-cell battery according to claim 1, characterized in that, The ratio of the length of the convex hull in the circumferential direction of the peripheral wall to the circumference of the peripheral wall is in the range of 0.2 to 0.
6.
5. The single-cell battery according to claim 1, characterized in that, The single battery includes an insulating support plate, which is supported on the protrusion. The battery cell is supported on the insulating support plate. The overlapping area of the orthographic projection of the protrusion on the bottom wall and the orthographic projection of the battery cell on the bottom wall is in the range of 5% to 30% of the orthographic projection area of the battery cell on the bottom wall.
6. The single-cell battery according to claim 1, characterized in that, The single cell includes an insulating support plate supported on the bottom wall. The side of the insulating support plate facing the cell is flush with the side of the cell facing the cell, so as to support the cell together with the protrusion. The ratio of the overlapping area of the orthographic projection of the protrusion on the bottom wall and the orthographic projection of the cell on the bottom wall to the orthographic projection area of the cell on the bottom wall is in the range of 5% to 20%.
7. The single-cell battery according to claim 1, characterized in that, The battery cell is covered with an insulating film with a thickness ranging from 0.02mm to 0.5mm. The ratio of the overlapping area of the orthographic projection of the protrusion on the bottom wall and the orthographic projection of the battery cell on the bottom wall to the orthographic projection area of the battery cell on the bottom wall ranges from 5% to 40%.
8. The single-cell battery according to claim 1, characterized in that, The distance B between the convex bulge and the bottom wall in the direction perpendicular to the bottom wall is in the range of 3mm ≤ B ≤ 5mm.
9. The single-cell battery according to claim 1, characterized in that, The convex bulge is integrally formed with the peripheral wall of the shell.
10. The single-cell battery according to claim 1, characterized in that, The outer surface of the housing forms a recess corresponding to the position of the convex bulge.
11. The single-cell battery according to any one of claims 1-10, characterized in that, The peripheral wall includes two oppositely arranged long sidewalls and two oppositely arranged short sidewalls. The length of the long sidewalls in the circumferential direction of the peripheral wall is greater than the length of the short sidewalls in the circumferential direction of the peripheral wall. At least one convex hull is provided on each of the long sidewalls and each of the short sidewalls.
12. The single-cell battery according to claim 11, characterized in that, The sum of the lengths of all the convex humps on a single long sidewall in the circumferential direction of the peripheral wall is greater than the sum of the lengths of all the convex humps on a single short sidewall in the circumferential direction of the peripheral wall.
13. The single-cell battery according to claim 11, characterized in that, A single convex hull is provided centered on the perimeter of the peripheral wall on a single long sidewall, or multiple convex hulls are provided sequentially at intervals on the perimeter of the peripheral wall on a single long sidewall.
14. The single-cell battery according to claim 11, characterized in that, A convex hull is provided centered on the perimeter of the peripheral wall on a single short sidewall.