Battery cell, battery pack, and electric device
By optimizing the protrusion design and limiting its thickness ratio with the top cover plate, the problem of reduced individual cell safety caused by unreasonable protrusion design was solved. This achieved stable positioning and pressure relief functions for the electrode assembly, thereby improving the safety and energy density of the individual cells.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SUNWODA MOBILITY ENERGY TECHNOLOGY CO LTD
- Filing Date
- 2025-11-21
- Publication Date
- 2026-06-25
AI Technical Summary
The existing boss design is unreasonable, which reduces the safety of individual cells and may cause the electrode components to move inside the casing, resulting in insulation failure or short circuit.
By limiting the ratio of the thickness of the first boss to the thickness of the top cover plate, the energy density requirements are ensured and the electrode assembly is limited, while reducing the space occupied by the boss and the top cover plate and avoiding short circuit problems caused by pressure on the electrode assembly. Multiple first and second bosses are used to limit and relieve pressure on the electrode assembly respectively.
It effectively improves the safety and energy density of individual cells, prevents electrode component movement and short circuits, and ensures the stability and reasonable layout of the insulation structure.
Smart Images
Figure CN2025136729_25062026_PF_FP_ABST
Abstract
Description
Individual batteries, battery packs and electrical devices
[0001] This application claims priority to Chinese Patent Application No. 202411844555.4, filed on December 16, 2024, entitled "Single Battery, Battery Pack and Power Consumption Device", the entire contents of which are incorporated herein by reference. Technical Field
[0002] This application belongs to the field of battery technology, specifically relating to a single cell, a battery pack, and an electrical device. Background Technology
[0003] A single battery cell typically consists of a top cover, a lower insulating component, and a casing. The top cover and the lower insulating component are assembled together using ultrasonic heat fusion. The lower insulating component usually has multiple protrusions on the side facing the electrode assembly. These protrusions abut against the electrode assembly to prevent it from moving within the casing and causing insulation failure. Current protrusion designs are flawed, leading to reduced safety of the single battery cell. Summary of the Invention
[0004] This application provides a single battery cell, a battery pack, and an electrical device, aiming to solve the technical problem of reduced safety of single batteries caused by unreasonable protrusion settings.
[0005] In a first aspect of this application, a single-cell battery is provided. The single-cell battery includes a housing, an electrode assembly, a top cover, and a first insulating member. The housing has a receiving cavity. The electrode assembly is located in the receiving cavity. The top cover, connected to the housing and sealing the receiving cavity, has a thickness direction and a length direction intersecting the thickness direction. The first insulating member, located in the receiving cavity, includes a body and a plurality of first protrusions connected to the body. The body is spaced apart from the electrode assembly, and the side of the body facing away from the electrode assembly is connected to the top cover. The plurality of first protrusions are respectively disposed on both sides of the body along the length direction. Each first protrusion abuts against the top cover and the electrode assembly on both sides along the thickness direction. The maximum dimension of the first protrusion along the thickness direction is h1 mm, and the maximum dimension of the top cover in the thickness direction is H mm, where h1 and H satisfy: 0.62≤h1 / (h1+H)≤0.85.
[0006] In some embodiments, the single battery cell further includes: an explosion-proof valve, a top cover having a pressure relief hole, the explosion-proof valve being connected to the top cover and sealing the pressure relief hole. The first insulating member further includes a second boss, the second boss being disposed between the first bosses located on both sides of the body along its length direction, and both sides of the second boss along its length direction being connected to the body. The second boss has a thickness dimension of h2 mm, and h2 and h1 satisfy: 0.9≤h1 / h2≤1.1.
[0007] In some embodiments, 4 ≤ h1 ≤ 8, and / or 1.4 ≤ H ≤ 2.5.
[0008] In some embodiments, the dimension of the second boss along the thickness direction X is h2 mm, where h2 satisfies: 4≤h2≤8.
[0009] In some embodiments, the dimension of the body in the thickness direction is h3 mm, where h3 satisfies: 0.4≤h3≤0.8.
[0010] In some embodiments, the first insulating member further includes a second boss disposed between the first bosses located on both sides of the body along its length direction, with both sides of the second boss connected to the body along the length direction. The two sides of the second boss along its thickness direction abut against the top cover plate and the electrode assembly, respectively. The total contact area between the first and second bosses and the electrode assembly is s1 mm. 2 The end face of the top cover sheet facing away from the first insulating element is the first surface, and the area of the first surface is S mm. 2 s1 and S satisfy: 0.046≤s1*h1 / [(h1+H)*S]≤0.116.
[0011] In some embodiments, 610≤s1≤970, and / or, 7100≤S≤8100.
[0012] In some embodiments, the first boss has a first surface and a second surface disposed opposite to each other in the thickness direction, the first surface being connected to a top cover sheet and the second surface abutting against an electrode assembly, the first boss having at least one second groove having an opening that penetrates at least one of the first surface and the second surface.
[0013] In some embodiments, the opening extends through the second surface, and the maximum distance between the bottom wall of the second groove and the second surface in the thickness direction is h4 mm, where h4 satisfies: 0.2 mm ≤ h4 ≤ 0.6 mm.
[0014] In some embodiments, the body and the first boss are separate components that are attached together.
[0015] In some embodiments, the body and the first boss are integrally formed.
[0016] In some embodiments, the body is thermally fused to the first boss.
[0017] In some embodiments, the body is snapped into connection with the first protrusion.
[0018] In some embodiments, one of the body and the first protrusion is provided with a limiting hole, and the other of the body and the first protrusion is provided with a snap-fit portion, which is embedded in the limiting hole.
[0019] In a second aspect of this application, a battery pack is provided, comprising a single battery cell provided according to the first aspect of this application.
[0020] In a third aspect of this application, an electrical device is provided, including a single battery cell provided according to the first aspect of this application, or a battery pack provided according to the second aspect of this application.
[0021] The single-cell battery of this application embodiment includes a casing, an electrode assembly, a top cover, and a first insulating member. The casing has a receiving cavity. The electrode assembly is located in the receiving cavity. The top cover is connected to the casing and seals the receiving cavity. The top cover has a thickness direction and a length direction intersecting the thickness direction. The first insulating member is located in the receiving cavity. The first insulating member includes a body and a plurality of first protrusions connected to the body. The body is spaced apart from the electrode assembly, and the side of the body facing away from the electrode assembly is connected to the top cover. The plurality of first protrusions are respectively disposed on both sides of the body along the length direction. Each first protrusion abuts against the top cover and the electrode assembly on both sides along the thickness direction. The maximum dimension of the first protrusion along the thickness direction is h1 mm, and the maximum dimension of the top cover in the thickness direction is H mm. h1 and H satisfy: 0.62≤h1 / (h1+H)≤0.85. This application limits the ratio of the thickness of the first protrusion to the thickness of the top cover plate, thereby meeting energy density requirements and limiting the electrode assembly while reducing the space occupied by the first protrusion and the top cover plate, and avoiding short circuit failure caused by the first protrusion pressing on the electrode assembly, thus effectively improving the safety of the single cell.
[0022] The battery pack of this application embodiment includes the above-described single battery cell, and therefore the battery pack can have all the technical features and beneficial effects of the above-described single battery cell, which will not be repeated here.
[0023] The electrical device in this application includes the above-mentioned single battery or battery pack. Therefore, the electrical device can have all the technical features and beneficial effects of the above-mentioned single battery or battery pack, which will not be repeated here. Attached Figure Description
[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0025] Figure 1 is a schematic diagram of the structure of a single battery according to an embodiment of this application;
[0026] Figure 2 is an exploded view of a single battery cell according to an embodiment of this application;
[0027] Figure 3 is an exploded view of a top cover sheet and a first insulating member according to an embodiment of this application;
[0028] Figure 4 is a structural schematic diagram of a top cover sheet and a first insulating member according to an embodiment of this application;
[0029] Figure 5 is a cross-sectional view of a top cover sheet and a first insulating member according to an embodiment of this application;
[0030] Figure 6 is a structural schematic diagram of a first embodiment of the first insulating member of this application;
[0031] Figure 7 is a structural schematic diagram of a second embodiment of the first insulating member according to an embodiment of this application;
[0032] Figure 8 is a structural schematic diagram of a third embodiment of the first insulating member of this application;
[0033] Figure 9 is a structural schematic diagram of the fourth embodiment of the first insulating member of this application;
[0034] Figure 10 is a structural schematic diagram of the fifth embodiment of the first insulating member of this application;
[0035] Figure 11 is an exploded view of a fifth embodiment of the first insulating member of this application;
[0036] Figure 12 is a schematic diagram of the sixth embodiment of the first insulating member of this application;
[0037] Figure 13 is a partial schematic diagram of a sixth embodiment of the first insulating member of this application;
[0038] Figure 14 is an enlarged view of part A in Figure 13;
[0039] Figure 15 is a schematic diagram of the structure of a first boss according to an embodiment of this application.
[0040] Explanation of reference numerals in the attached drawings: 1. Housing; 2. Top cover plate; 3. First insulating component; 4. Explosion-proof valve; 5. Electrode assembly; 6. Protective patch; 10. Receiving cavity; 20. Pressure relief hole; 21. First surface; 22. Electrode post hole; 23. Electrode post; 30. Body; 31. First boss; 32. Second boss; 300. Snap-fit part; 301. First extension part; 310. First surface; 311. Second surface; 312. Second groove; 313. Boss body; 314. Recess; 315. Limiting hole; 316. Vent hole; 317. First sub-bore; 318. Second extension part; 320. Connecting part; 321. Limiting part; 322. First groove; 3000. Protrusion; 3120. Opening; 3210. Through hole; X, thickness direction; Y, length direction. Detailed Implementation
[0041] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0042] In the description of this application, it should be understood that the terms "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "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 application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. 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, features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, and "at least one" can mean one, two, or more, unless otherwise explicitly specified. In the description of this application, "perpendicular" is not limited to being perfectly perpendicular at 90°. For example, it is considered perpendicular in the range of 80° to 100°. Similarly, "parallel" is not limited to being perfectly parallel. For example, it is considered parallel in the range of 10°.
[0043] A single battery cell typically consists of a top cover, a lower insulating component, and a casing. The top cover and the lower insulating component are assembled together using ultrasonic heat fusion. The lower insulating component usually has multiple protrusions on the side facing the electrode assembly. These protrusions abut against the electrode assembly, preventing it from moving within the casing and causing insulation failure. If the protrusions are too high, they will compress the electrode plates, leading to short circuits. If the protrusions are too low, they will not effectively limit the electrode assembly, reducing the safety of the single battery cell.
[0044] In view of this, this application provides a single-cell battery, including a casing, an electrode assembly, a top cover sheet, and a first insulating member. The casing has a receiving cavity. The electrode assembly is located in the receiving cavity. The cell of the electrode assembly can be, but is not limited to, a wound core. Specifically, the cell can be formed by sequentially stacking and winding a positive electrode sheet, a separator, and a negative electrode sheet two or more times. The cell of the electrode assembly can also be a stacked structure. Specifically, the cell can include multiple positive electrode sheets, multiple negative electrode sheets, and multiple separators. The multiple positive electrode sheets, multiple separators, and multiple negative electrode sheets are stacked, with each separator located between adjacent positive and negative electrode sheets. The top cover sheet is connected to the casing and seals the receiving cavity. The top cover sheet has a thickness direction and a length direction intersecting the thickness direction. The top cover sheet has a through-hole along the thickness direction, with the electrode post passing through the through-hole and connected to the top cover sheet. The first insulating member is located in the receiving cavity and includes a body and multiple first protrusions connected to the body. The body and electrode assembly are spaced apart, with the side of the body facing away from the electrode assembly connected to the top cover plate. Multiple first protrusions are respectively disposed on both sides of the body along its length. Each first protrusion faces and abuts against the electrode assembly. Alternatively, each first protrusion abuts against both the top cover plate and the electrode assembly on both sides along its thickness direction. The maximum dimension of the first protrusion along its thickness direction is h1 mm, and the maximum dimension of the top cover plate along its thickness direction is H mm, where h1 and H satisfy: 0.62 ≤ h1 / (h1+H) ≤ 0.85.
[0045] This application limits the ratio of the thickness of the first protrusion to the total thickness of the top cover and the first protrusion. This satisfies the energy density requirements and limits the electrode assembly, while reducing the space occupied by the first protrusion and the top cover. It also avoids the problem of the positive and negative electrode plates piercing the separator and overlapping or directly overlapping after the first protrusion presses on the electrode assembly, which could lead to a short circuit in the electrode assembly. This effectively improves the safety of the single cell.
[0046] The single-cell battery, battery pack, and power-consuming device of this application will be described in detail below with reference to the accompanying drawings. Unless otherwise specified, the features of the following embodiments and implementations can be combined with each other.
[0047] Figure 1 is a structural schematic diagram of a single-cell battery according to an embodiment of this application. Figure 2 is an exploded view of a single-cell battery according to an embodiment of this application. Figure 3 is an exploded view of a top cover sheet and a first insulating member according to an embodiment of this application. Figure 4 is a structural schematic diagram of a top cover sheet and a first insulating member according to an embodiment of this application. Figure 5 is a cross-sectional view of a top cover sheet and a first insulating member according to an embodiment of this application. Figure 6 is a structural schematic diagram of a first embodiment of the first insulating member according to an embodiment of this application. Figure 7 is a structural schematic diagram of a second embodiment of the first insulating member according to an embodiment of this application. Figure 8 is a structural schematic diagram of a third embodiment of the first insulating member according to an embodiment of this application. Figure 9 is a structural schematic diagram of a fourth embodiment of the first insulating member according to an embodiment of this application. Figure 10 is a structural schematic diagram of a fifth embodiment of the first insulating member according to an embodiment of this application. Figure 11 is an exploded view of a fifth embodiment of the first insulating member according to an embodiment of this application. Figure 12 is a structural schematic diagram of a sixth embodiment of the first insulating member according to an embodiment of this application. Figure 13 is a partial schematic diagram of a sixth embodiment of the first insulating member according to an embodiment of this application. Figure 14 is an enlarged view of part A in Figure 13. Figure 15 is a structural schematic diagram of a first boss according to an embodiment of this application.
[0048] Referring to Figures 1 to 5, this application provides a single-cell battery, including a housing 1, an electrode assembly 5, a top cover 2, and a first insulating member 3. The housing 1 has a receiving cavity 10. The electrode assembly 5 is located in the receiving cavity 10. The cell of the electrode assembly 5 can be, but is not limited to, a wound core. Specifically, the cell can be formed by sequentially stacking and winding a positive electrode, a separator, and a negative electrode two or more times. The cell of the electrode assembly 5 can also be a stacked structure. Specifically, the cell can include multiple positive electrode sheets, multiple negative electrode sheets, and multiple separators. The multiple positive electrode sheets, multiple separators, and multiple negative electrode sheets are stacked, with each separator located between adjacent positive and negative electrode sheets. The top cover 2 is connected to the housing 1 and covers the receiving cavity 10. The top cover 2 has a thickness direction X and a length direction Y intersecting the thickness direction X. The first insulating member 3 is located in the receiving cavity 10 and includes a body 30 and multiple first protrusions 31 connected to the body 30. The body 30 is spaced apart from the electrode assembly 5, and the side of the body 30 facing away from the electrode assembly 5 is connected to the top cover plate 2. A plurality of first protrusions 31 are respectively disposed on both sides of the body 30 along the length direction Y. Each first protrusion 31 abuts against the top cover plate 2 and the electrode assembly 5 on both sides along the thickness direction X.
[0049] Because the electrode assembly 5 expands during charging and discharging, it is not completely fixed in the receiving cavity 10. Under vibration conditions, the electrode assembly 5 may move along the thickness direction X. The first boss 31 is used to limit the electrode assembly 5 and prevent it from moving along the thickness direction X. The maximum dimension of the first boss 31 along the thickness direction X is h1 mm, and the maximum dimension of the top cover plate 2 along the thickness direction X is H mm. h1 and H satisfy: 0.62≤h1 / (h1+H)≤0.85.
[0050] This application limits the ratio of the thickness of the first protrusion 31 to the total thickness of the top cover plate 2 and the first protrusion 31. While meeting the energy density requirements and limiting the electrode assembly 5, it reduces the space occupied by the first protrusion 31 and the top cover plate 2. This avoids the problem of the positive and negative electrode plates piercing the separator and overlapping or directly overlapping after the first protrusion 31 presses on the electrode assembly 5, which could lead to a short circuit in the electrode assembly 5. This effectively improves the safety of the single cell.
[0051] In some embodiments, specifically, two first protrusions 31 may be provided, with the two first protrusions 31 spaced apart and respectively connected to both ends of the body 30 along the length direction Y. In the thickness direction X, the side of the first protrusion 31 facing the top cover plate 2 is flush with the side of the body 30 facing the top cover plate 2, and the side of the first protrusion 31 away from the top cover plate 2 extends beyond the side of the body 30 away from the top cover plate 2.
[0052] In the embodiments shown in Figures 1 to 5, the individual battery includes an explosion-proof valve 4, and a top cover plate 2 has a pressure relief hole 20. The explosion-proof valve 4 is connected to the top cover plate 2 and seals the pressure relief hole 20. The individual battery includes a protective patch 6, which covers the pressure relief hole 20 and is located on the side of the explosion-proof valve 4 away from the electrode assembly 5. The protective patch 6 is used to protect the explosion-proof valve 4, preventing it from deforming after being subjected to impact, compression, or friction, and ensuring that the explosion-proof valve 4 can work normally when pressure relief is required. When the internal pressure or temperature of the individual battery reaches a predetermined threshold, the weak structure provided in the explosion-proof valve 4 is destroyed, thereby forming an opening or channel for the internal pressure or temperature to be released.
[0053] In the embodiments shown in Figures 3 to 13, the first insulating member 3 further includes a second protrusion 32, which is disposed between two first protrusions 31 located on both sides of the body 30 along the length direction Y. Both sides of the second protrusion 32 along the length direction Y are connected to the body 30. The second protrusion 32 and the pressure relief hole 20 are disposed opposite each other in the thickness direction X, and the second protrusion 32 protrudes relative to the side of the body 30 facing the electrode assembly 5. The second protrusion 32 includes a connecting portion 320 and a limiting portion 321 connected together. The connecting portion 320 is connected to the body 30 and the limiting portion 321 on both sides of the thickness direction X, respectively. The connecting portion 320 and the limiting portion 321 enclose a first groove 322, the opening of which faces the explosion-proof valve 4. The limiting portion 321 has a plurality of through holes 3210, which communicate with the first groove 322. The explosion-proof valve 4 is disposed along the thickness direction X facing the limiting portion 321. The first groove 322 prevents the explosion-proof valve 4 from contacting the first insulating component 3, thus avoiding interference with its normal operation. The second protrusion 32 has multiple through holes 3210. When the internal pressure or temperature of a single battery cell reaches a predetermined threshold, the explosion-proof valve 4 activates, or a weak structure within the explosion-proof valve 4 is damaged. The internal pressure of the single battery cell can then be promptly released through the multiple through holes 3210, the first groove 322, and the pressure relief hole 20.
[0054] In some embodiments, the second protrusion 32 is spaced apart from the electrode assembly 5 in the thickness direction X. This arrangement, where the second protrusion 32 protrudes relative to the body 30 towards the electrode assembly 5, prevents the explosion-proof valve 4 from being affected by external impacts and thus ensures its normal operation. Furthermore, by providing multiple through holes 3210 on the second protrusion 32, the internal pressure of the individual battery can be promptly released through the multiple through holes 3210, the first groove 322, and the pressure relief hole 20. In other embodiments, the second protrusion 32 abuts against the electrode assembly 5 in the thickness direction X. This arrangement, while ensuring the normal operation of the explosion-proof valve 4, also limits the movement of the electrode assembly 5 in the thickness direction X, preventing it from shifting.
[0055] In the embodiment shown in Figure 5, the maximum dimension of the first protrusion 31 along the thickness direction X is h1 mm, and the dimension of the second protrusion 32 along the thickness direction X is h2 mm, where h2 and h1 satisfy: 0.9 ≤ h1 / h2 ≤ 1.1. It is understood that if the dimension h2 of the second protrusion 32 along the thickness direction X is too small relative to the dimension h1 of the first protrusion 31 along the thickness direction X, resulting in an excessively large h1 / h2, it may affect the spatial arrangement between the second protrusion 32 and the explosion-proof valve 4, causing the explosion-proof valve 4 to be obstructed during operation. If the dimension h2 of the second protrusion 32 along the thickness direction X is too large relative to the dimension h1 of the first protrusion 31 along the thickness direction X, resulting in an excessively small h1 / h2, it may occupy too much space, affecting the limiting effect of the first protrusion 31 on the electrode assembly 5, or increasing the overall thickness of the single battery cell, which is detrimental to meeting energy density requirements. When the dimension h2 of the second boss 32 in the thickness direction X is larger than the dimension h1 of the first boss 31 in the thickness direction X (for example, when h1 / h2 is between 1 and 1.1), the second boss 32, having multiple through holes 3210, allows it to deform to a certain extent when it abuts against the electrode assembly 5, enabling the first boss 31 to abut against the electrode assembly 5. Thus, the second boss 32 and the first boss 31 work together to limit the electrode assembly 5, preventing it from shifting in the thickness direction X.
[0056] This application embodiment limits the ratio range of the size of the first boss 31 in the thickness direction X to the size of the second boss 32 in the thickness direction X to maintain a reasonable dimensional ratio between the first boss 31 and the second boss 32, thereby ensuring the stability of the overall structure of the first insulating member 3. The first boss 31 is used to limit the electrode assembly 5 to prevent it from moving in the thickness direction X, while the second boss 32 is mainly used to cooperate with the pressure relief function of the explosion-proof valve 4 and to prevent the explosion-proof valve 4 from contacting the body 30 and the electrode assembly 5. In some embodiments, the first boss 31 and the second boss 32 can jointly limit the electrode assembly 5.
[0057] In the embodiment shown in Figure 5, the dimension of the first protrusion 31 along the thickness direction X is h1 mm, where h1 satisfies: 4 ≤ h1 ≤ 8. Specifically, the dimension h1 of the first protrusion 31 along the thickness direction X can be any one of 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, or a range between any two values. When the above range is satisfied, the first protrusion 31 can effectively limit the electrode assembly 5, meet the energy density requirements, and prevent the positive and negative electrode sheets from piercing the separator and overlapping or directly overlapping due to the first protrusion 31 pressing on the electrode assembly 5, thereby preventing a short circuit in the electrode assembly 5 and effectively improving the safety of the single cell.
[0058] In the embodiment shown in Figure 5, the second protrusion 32 has a dimension h2 mm along the thickness direction X, where h2 satisfies: 4 ≤ h2 ≤ 8. Specifically, the dimension h2 of the second protrusion 32 along the thickness direction X can be any one of 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, or a range between any two values. When the above range is satisfied, the second protrusion 32 can cooperate with the pressure relief function of the explosion-proof valve 4 and prevent the explosion-proof valve 4 from contacting the body 30 and the electrode assembly 5. When the internal pressure or temperature of the single cell reaches a predetermined threshold, it can ensure that the internal gas is released in a timely manner through multiple through holes 3210, the first groove 322, and the pressure relief hole 20, thereby ensuring the safety of the single cell. Furthermore, when the second protrusion 32 can abut against the electrode assembly 5, by limiting the dimension of the second protrusion 32 along the thickness direction X, it can limit the electrode assembly 5 without compressing it and causing a short circuit, preventing the electrode assembly 5 from moving in the thickness direction X, effectively improving the safety of the single cell.
[0059] In the embodiment shown in Figure 5, the maximum dimension of the top cover 2 in the thickness direction X is H mm, where H satisfies: 1.4 ≤ H ≤ 2.5. Specifically, the maximum dimension H of the top cover 2 in the thickness direction X can be any one or any two values from 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, and 2.5. When the above range is satisfied, the structural strength of the top cover 2 can be ensured, preventing deformation due to external compression or collision during the use of the single battery cell, while reducing the volume occupied by the top cover 2, which is beneficial to improving the energy density of the single battery cell.
[0060] In the embodiment shown in Figure 5, the dimension of the body 30 in the thickness direction X is h3 mm, where h3 satisfies: 0.4 ≤ h3 ≤ 0.8. Specifically, the dimension h3 of the body 30 in the thickness direction X can be any one or any two of the following values: 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, and 0.8. The body 30 is disposed between the first protrusion 31 and the second protrusion 32. When the dimension h3 of the body 30 in the thickness direction X satisfies the above-mentioned range, the structural stability of the first insulating member 3 can be ensured while avoiding the body 30 occupying too much space in the thickness direction X, thereby improving the energy density of the single cell.
[0061] In some embodiments, the first insulating member 3 further includes a second protrusion 32, which is disposed between two first protrusions 31 located on both sides of the body 30 along the length direction Y. Both sides of the second protrusion 32 along the length direction Y are connected to the body 30, and both sides of the second protrusion 32 along the thickness direction X abut against the top cover plate 2 and the electrode assembly 5, respectively. The total contact area between the first protrusion 31 and the second protrusion 32 and the electrode assembly 5 is s1 mm. 2 The end face of the top cover 2 facing away from the first insulating member 3 is the first surface 21, and the area of the first surface 21 is S mm. 2 s1 and S satisfy: 0.046≤s1*h1 / [(h1+H)*S]≤0.116.
[0062] It is understood that, based on the defined range of the ratio h1 / (h1+H), this application embodiment further defines the relationship between the total contact area s1 of the first protrusion 31 and the second protrusion 32 with the electrode assembly 5 and the area S of the first surface 21. This avoids the problem of the positive and negative electrodes piercing the separator and overlapping or directly overlapping due to excessive space occupied by the first protrusion 31 and the second protrusion 32, which could lead to a short circuit in the electrode assembly 5. On the other hand, it avoids the problem of the first protrusion 31 and the second protrusion 32 being too small, which could easily cause deformation, thus ensuring the structural strength of the first protrusion 31 and the second protrusion 32, effectively limiting the movement of the electrode assembly 5 in the thickness direction X, thereby improving the stability and safety of the single cell. Furthermore, a reasonable volume ratio helps to improve the energy density of the single cell while ensuring the structural stability of the first insulating member 3 and the top cover plate 2.
[0063] In some embodiments, specifically, the second protrusion 32 may be provided as one, and in the thickness direction X, the side of the second protrusion 32 facing the top cover plate 2 is flush with the side of the body 30 facing the top cover plate 2, and the side of the second protrusion 32 away from the top cover plate 2 extends beyond the side of the body 30 away from the top cover plate 2.
[0064] In some embodiments, the total contact area s1 between the first protrusion 31 and the second protrusion 32 and the electrode assembly 5 satisfies: 610 ≤ s1 ≤ 970. Specifically, the total contact area s1 between the first protrusion 31 and the second protrusion 32 and the electrode assembly 5 can be any one value or a range between any two values of 610, 650, 700, 750, 800, 850, 900, 950, and 970. If the contact area between the first protrusion 31 and the second protrusion 32 and the electrode assembly 5 is too small, deformation is likely to occur, thus failing to effectively limit the electrode assembly 5. If the contact area between the first protrusion 31 and the second protrusion 32 and the electrode assembly 5 is too large, it will compress the electrode assembly 5, causing the positive and negative electrode plates to pierce the separator and overlap or directly overlap, resulting in a short circuit in the electrode assembly 5. This application embodiment limits the total contact area s1 between the first protrusion 31 and the second protrusion 32 and the electrode assembly 5, thereby ensuring the structural strength of the first protrusion 31 and the second protrusion 32, effectively limiting the movement of the electrode assembly 5 in the thickness direction X, and thus improving the stability and safety of the single cell.
[0065] In some embodiments, the end face of the top cover 2 facing away from the first insulating member 3 is the first surface 21, and the area of the first surface 21 is S, where S satisfies: 7100 ≤ S ≤ 8100. Specifically, the area S of the first surface 21 can be any one or any two of the following values: 7100, 7200, 7300, 7400, 7500, 7600, 7700, 7800, 7900, 8000, and 8100. If the area of the first surface 21 is too large, it will affect the energy density of the single battery. If the area of the first surface 21 is too small, it may affect the layout of the pole post 23, explosion-proof valve 4, first insulating member 3, electrode assembly 5, and other structures on the top cover 2, resulting in a reduction in the structural strength of the top cover 2 and affecting the safety of the single battery. This embodiment of the application limits the area of the first surface 21 to ensure a reasonable layout of the top cover 2, first insulating member 3, electrode assembly 5, and other structures, thereby ensuring the energy density of the single battery and helping to improve the stability and safety of the single battery.
[0066] In the embodiments of this application, the maximum dimension h1 of the first protrusion 31 along the thickness direction X is measured by clamping the upper and lower surfaces of the first protrusion 31 along the thickness direction X with a digital caliper. The maximum dimension h2 of the second protrusion 32 along the thickness direction X is measured by clamping the upper and lower surfaces of the second protrusion 32 along the thickness direction X with a digital caliper. The maximum dimension H of the top cover 2 along the thickness direction X is measured by clamping the upper and lower surfaces of the top cover 2 along the thickness direction X with a digital caliper. The area S of the first surface 21 and the total contact area s1 between the first protrusion 31 and the second protrusion 32 and the electrode assembly 5 are measured by digital caliper. The individual cells in different embodiments are tested to determine whether they meet the energy density requirements, whether they pass the mechanical safety test, and whether they can limit the movement of the electrode assembly 5. The test results are shown in Table 1.
[0067] Table 1:
[0068] In some embodiments, energy density = (A*V) / W, where A is the rated capacity of a single battery cell, W is the weight of a single battery cell, and V is the rated voltage of a single battery cell. For example, taking a single battery cell of model 39202 as an example, its acceptable energy density range is 170–195 Wh / kg.
[0069] In some embodiments, mechanical safety tests are conducted under the GB38031-2020 standard "Safety Requirements for Power Batteries for Electric Vehicles" to determine whether a single battery cell will catch fire, leak, or explode. OK indicates that the safety performance requirements are met, while NG indicates that at least one of the following has occurred: fire, leak, or explosion, and the safety performance requirements are not met.
[0070] In some embodiments, vibration tests, bump simulation tests, and other methods are used to simulate the bumpy conditions encountered by an electric vehicle during driving, and to determine whether the electrode assembly 5 exhibits any movement.
[0071] In some embodiments, referring to Comparative Example 1, when the maximum dimension h1 of the first protrusion 31 along the thickness direction X is too small, resulting in h1 / (h1+H) < 0.62, although the energy density of the single cell meets the requirements, it fails the mechanical safety test, does not meet the safety performance requirements, and cannot effectively limit the movement of the electrode assembly 5. It is understood that because the electrode assembly 5 expands during charging and discharging, it is not completely fixed and will move along the thickness direction X under vibration conditions. If the size of the first protrusion 31 is too small, it cannot effectively limit the movement of the electrode assembly 5. When the dimension h2 of the second protrusion 32 in the thickness direction X is too large relative to the dimension h1 of the first protrusion 31 in the thickness direction X, resulting in h1 / h2 < 0.9, only the second protrusion 32 abuts against the electrode assembly 5 in the thickness direction X, which cannot effectively limit the movement of the electrode assembly 5. When only the second protrusion 32 can abut against the electrode assembly 5 in the thickness direction X, the contact area s1 between the first protrusion 31 and the second protrusion 32 and the electrode assembly 5 is too small and the area S of the first surface 21 is too large. s1*h1 / [(h1+H)*S]<0.046, the first insulating member 3 cannot effectively restrict the movement of the electrode assembly 5.
[0072] Referring to Embodiments 1 to 6, when the ratio of the thickness of the first protrusion 31 to the total thickness of the top cover plate 2 and the first protrusion 31 satisfies 0.62≤h1 / (h1+H)≤0.85, by reasonably setting the dimensions of the first protrusion 31 and the top cover plate 2, while ensuring effective restriction of the movement of the electrode assembly 5, the space occupied by the first protrusion 31 and the top cover plate 2 can be reduced. This avoids the positive and negative electrode plates from piercing the separator and overlapping or directly overlapping due to the first protrusion 31 pressing on the electrode assembly 5, which would lead to a short circuit in the electrode assembly 5. This effectively improves the safety of the single cell and increases the energy density of the single cell.
[0073] When the ratio of the dimension of the first boss 31 in the thickness direction X to the dimension of the second boss 32 in the thickness direction X satisfies 0.9≤h1 / h2≤1.1, the stability of the overall structure of the first insulating member 3 is ensured by limiting the reasonable dimensional ratio between the first boss 31 and the second boss 32. The first boss 31 is used to limit the electrode assembly 5 to prevent it from moving in the thickness direction X, while the second boss 32 is mainly used to cooperate with the pressure relief function of the explosion-proof valve 4 and to prevent the explosion-proof valve 4 from contacting the body 30 and the electrode assembly 5. In some embodiments, the first boss 31 and the second boss 32 can jointly limit the electrode assembly 5.
[0074] Referring to Comparative Example 2, when the maximum dimension h1 of the first protrusion 31 along the thickness direction X is too large, resulting in h1 / (h1+H)>0.85, the first protrusion 31 occupies too much internal space, leading to insufficient energy density of the single cell and failing to meet requirements. When the contact area s1 between the first protrusion 31 and the second protrusion 32 and the electrode assembly 5 is too large and the area S of the first surface 21 is too small, resulting in s1*h1 / [(h1+H)*S]>0.116, the contact area between the first protrusion 31 and the second protrusion 32 and the electrode assembly 5 is too large. This can cause the positive and negative electrode plates to puncture the separator and overlap or directly overlap, leading to short circuit problems in the electrode assembly 5 and affecting the safety of the single cell.
[0075] In some embodiments, the material of the first insulating element 3 may be at least one of PP (polypropylene), PET (polyethylene terephthalate), or PPS (polyphenylene sulfide).
[0076] In some embodiments, the first boss 31 has a first surface 310 and a second surface 311 disposed opposite to each other along the thickness direction X. The first surface 310 is connected to the top cover plate 2, and the second surface 311 is connected to the electrode assembly 5. The first boss 31 has at least one second groove 312, and the second groove 312 has an opening 3120 that penetrates at least one of the first surface 310 and the second surface 311. While satisfying the strength requirements of the first boss 31, the provision of the second groove 312 can reduce the weight of the first boss 31, reduce the amount of material used in the first insulating member 3, reduce costs, and increase the energy density of the single cell.
[0077] In the embodiments shown in Figures 3 to 6, the opening 3120 of the second groove 312 is provided on the first surface 310, and the second surface 311 is provided with a plurality of spaced vent holes 316. The vent holes 316 can reduce the obstruction of the first protrusion 31 to the gas flow, and facilitate the gas to flow toward the explosion-proof valve 4 provided on the top cover plate 2.
[0078] In some embodiments, referring to Figures 8 and 9, the opening 3120 of the second groove 312 is disposed on the second surface 311, and the second groove 312 is recessed from the second surface 311 toward the first surface 310. This arrangement reduces the weight of the first boss 31, reduces the amount of material used in the first insulating member 3, lowers costs, and increases the energy density of the single battery cell. Referring to Figure 8, there is one first groove 322. Referring to Figure 9, there are multiple second grooves 312, which are spaced apart to divide the first boss 31 into multiple first sub-boobs 317. By limiting the depth of the recess of the second groove 312, the multiple first sub-boobs 317 can be connected or not connected.
[0079] In the embodiment shown in Figure 9, the opening 3120 penetrates the second surface 311, and a height difference is formed between the bottom wall of the second groove 312 and the second surface 311. The maximum distance between the bottom wall of the second groove 312 and the second surface 311 in the thickness direction X is h4, where h4 satisfies 0.2mm ≤ h4 ≤ 0.6mm. Specifically, the maximum distance h4 between the bottom wall of the second groove 312 and the second surface 311 in the thickness direction X can be any one of 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, and 0.6mm, or a range between any two of these values. When the above range is satisfied, the height difference formed between the bottom wall of the second groove 312 and the second surface 311 can increase the friction between the first boss 31 and the electrode assembly 5, preventing relative sliding between the electrode assembly 5 and the first boss 31.
[0080] In some embodiments, the body 30 and the first boss 31 are separate components but attached together. This arrangement improves the versatility of the parts, allowing multiple electrode assemblies 5 to share the first boss 31 and reducing mold opening costs.
[0081] In some embodiments, the body 30 and the first boss 31 are integrally formed.
[0082] In some embodiments, the body 30 is integrally formed with the first boss 31 and the second boss 32.
[0083] In some embodiments, the body 30 and the first boss 31 are thermally fused together. Specifically, the connection portion 320 between the body 30 and the first boss 31 can be heated to melt the surface of the connection portion 320 between the body 30 and the first boss 31 to connect the body 30 and the first boss 31.
[0084] In other embodiments, the body 30 is snap-fitted to the first protrusion 31. One of the body 30 and the first protrusion 31 has a limiting hole 315, and the other has a snap-fit portion 300, which is fitted into the limiting hole 315. Specifically, in the embodiments shown in Figures 12 to 15, the body 30 has a first extension 301 with multiple spaced-apart snap-fit portions 300, and the first protrusion 31 has a second extension 318 with multiple spaced-apart limiting holes 315. The limiting holes 315 correspond one-to-one with the snap-fit portions 300, and the snap-fit portions 300 pass through the limiting holes 315. A protrusion 3000 is provided on the side of the snap-fit portion 300 away from the body 30. The protrusion 3000 is made of a flexible material and can deform to a certain extent. The snap-fit portion 300 is limited by the protrusion 3000. The first extension 301 and the second extension 318 are connected by a snap-fit portion 300 embedded in the limiting hole 315. This configuration simplifies the structure, allowing multiple electrode assemblies 5 to share the first boss 31, thus reducing mold opening costs.
[0085] This application provides a battery pack including the aforementioned individual battery cells. A battery pack can be a single physical module comprising one or more individual battery cells to provide higher voltage and capacity. When there are multiple individual battery cells, they can be connected in series, parallel, or a combination thereof.
[0086] This application provides an electrical device, including the aforementioned single battery or battery pack. The battery pack provides power to the electrical device. The electrical device can be a mobile phone, portable device, laptop, electric vehicle, electric car, ship, spacecraft, electric toy, or power tool, etc. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.
[0087] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.
[0088] The foregoing has provided a detailed description of a single battery, battery pack, and power device provided in the embodiments of this application, and specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the technical solutions and core ideas of this application. 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 of the technical features; and these 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 application.
Claims
1. A single-cell battery, comprising: The shell (1) has a receiving cavity (10); Electrode assembly (5) is located in the receiving cavity (10); A top cover (2) is connected to the housing (1) and seals the receiving cavity (10). The top cover (2) has a thickness direction (X) and a length direction (Y) intersecting the thickness direction (X). A first insulating member (3) is located in the receiving cavity (10). The first insulating member (3) includes a body (30) and a plurality of first protrusions (31) connected to the body (30). The body (30) is spaced apart from the electrode assembly (5). The side of the body (30) facing away from the electrode assembly (5) is connected to the top cover plate (2). The plurality of first protrusions (31) are respectively disposed on both sides of the body (30) along the length direction (Y). Each first protrusion (31) abuts against the top cover plate (2) and the electrode assembly (5) on both sides along the thickness direction (X). Wherein, the maximum dimension of the first boss (31) along the thickness direction (X) is h1 mm, the maximum dimension of the top cover plate (2) along the thickness direction (X) is H mm, and h1 and H satisfy: 0.62≤h1 / (h1+H)≤0.
85.
2. The single-cell battery according to claim 1, wherein, The single battery cell also includes: An explosion-proof valve (4), wherein the top cover plate (2) has a pressure relief hole (20), the explosion-proof valve (4) is connected to the top cover plate (2) and seals the pressure relief hole (20); and The first insulating member (3) further includes a second boss (32), which is disposed between the first bosses (31) located on both sides of the body (30) along the length direction (Y). Both sides of the second boss (32) along the length direction (Y) are connected to the body (30). The second boss (32) has a dimension of h2mm in the thickness direction (X), and h2 and h1 satisfy: 0.9≤h1 / h2≤1.
1.
3. The single-cell battery according to claim 2, wherein, The second boss (32) has a dimension of h2mm along the thickness direction (X), where h2 satisfies: 4≤h2≤8.
4. The single-cell battery according to claim 2, wherein, The second boss (32) includes a connecting part (320) and a limiting part (321) that are connected to each other. The connecting portion (320) is connected to the body (30) and the limiting portion (321) on both sides in the thickness direction (X), respectively. The connecting portion (320) and the limiting portion (321) together form a first groove (322), the opening of which faces the explosion-proof valve (4). The limiting part (321) has a plurality of through holes (3210), which are connected to the first groove (322).
5. The single-cell battery according to claim 1, wherein, 4≤h1≤8, and / or, 1.4≤H≤2.
5.
6. The single-cell battery according to claim 1, wherein, The body (30) has a dimension of h3 mm in the thickness direction (X), where h3 satisfies: 0.4 ≤ h3 ≤ 0.
8.
7. The single-cell battery according to claim 1, wherein, The first insulating member (3) further includes a second boss (32), which is disposed between the first bosses (31) located on both sides of the body (30) along the length direction (Y). Both sides of the second boss (32) along the length direction (Y) are connected to the body (30), and both sides of the second boss (32) along the thickness direction (X) abut against the top cover plate (2) and the electrode assembly (5), respectively. The total contact area between the first boss (31) and the second boss (32) and the electrode assembly (5) is s1mm. 2 The end face of the top cover plate (2) facing away from the first insulating member (3) is the first surface (21), and the area of the first surface (21) is S mm. 2 The s1 and the S satisfy: 0.046≤s1*h1 / [(h1+H)*S]≤0.
116.
8. The single-cell battery according to claim 7, wherein, 610≤s1≤970, and / or, 7100≤S≤8100.
9. The single-cell battery according to claim 1, wherein, The first boss (31) has a first surface (310) and a second surface (311) disposed opposite to each other along the thickness direction (X). The first surface (310) is connected to the top cover plate (2), and the second surface (311) abuts against the electrode assembly (5). The first boss (31) has at least one second groove (312), and the second groove (312) has an opening (3120) that penetrates at least one of the first surface (310) and the second surface (311).
10. The single-cell battery according to claim 9, wherein, The opening (3120) penetrates the second surface (311), and the maximum distance between the bottom wall of the second groove (312) and the second surface (311) in the thickness direction (X) is h4mm, where h4 satisfies: 0.2mm≤h4≤0.6mm.
11. The single-cell battery according to claim 9, wherein, The opening (3120) of the second groove (312) is provided on the first surface (310), and the second surface (311) is provided with a plurality of vent holes (316) spaced apart.
12. The single-cell battery according to claim 1, wherein, The body (30) and the first boss (31) are separate parts attached together, or the body (30) and the first boss (31) are integrally formed parts.
13. The single-cell battery according to claim 12, wherein, The body (30) is thermally fused to the first boss (31).
14. The single-cell battery according to claim 12, wherein, The body (30) is snapped into connection with the first boss (31).
15. The single-cell battery according to claim 14, wherein, One of the body (30) and the first boss (31) is provided with a limiting hole (315), and the other of the body (30) and the first boss (31) is provided with a snap-fit part (300), which is embedded in the limiting hole (315).
16. The single-cell battery according to claim 15, wherein, The snap-fit part (300) is provided with a protrusion (3000), which passes through the limiting hole (315) to connect the snap-fit part (300) with the limiting hole (315).
17. A battery pack, wherein, The single-cell battery includes any one of claims 1 to 16.
18. An electrical appliance, wherein, It includes the single cell battery as described in any one of claims 1 to 16, or the battery pack as described in claim 17.