Single battery, battery pack and power utilization device

Abstract

The invention discloses a single battery, a battery pack and a power utilization device, and belongs to the technical field of batteries. The cover plate is connected with the shell and covers the accommodating cavity, and the cover plate is provided with an anti-explosion hole; the anti-explosion valve covers the anti-explosion hole, the anti-explosion valve comprises a bearing part, a weak part and a protruding part, the bearing part is connected to the weak part in a surrounding mode, the weak part is connected to the protruding part in a surrounding mode, the bearing part is connected with the cover plate, the weak part is configured to be damaged when impacted by preset pressure, and the protruding part protrudes towards the side away from the electrode assembly; and the convex part is provided with a concave part which is concave towards one side close to the electrode assembly. The area of the explosion-proof valve is S mm < 2 >, the area of the convex part is S1 mm < 2 >, the area of the concave part is S2 mm < 2 >, and the conditions that 0.6 < = S1 / S < = 0.85 and 0.15 < = S2 / S1 < = 0.2 are met. By limiting the proportion of the protruding part in the area of the anti-explosion valve and the proportion of the concave part in the area of the protruding part, it can be ensured that the anti-explosion valve absorbs and disperses stress, and the problem that the anti-explosion valve deforms and cracks or is opened in advance is avoided.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and specifically relates to a single cell, a battery pack and an electrical device. Background Art

[0002] Lithium-ion batteries are currently widely used in various fields such as transportation power supply, electric energy storage power supply, new energy storage power supply, aerospace and military industry due to their large capacity, high operating voltage, strong charge retention ability and long cycle life. The cover plate in the battery is usually integrated with poles, explosion-proof valves and other structures. Among them, the main function of the explosion-proof valve is to release pressure and exhaust. It is used for the directional release of internal high-temperature and high-pressure gas when the battery cell has thermal runaway due to mechanical impact, internal abnormal lap short circuit and other reasons, thereby improving the safety performance of the battery pack. However, in the processes of liquid injection, pre-charging formation, and capacity division in the single cell process, there is a repeated positive and negative alternating pressure difference between the inside of the battery and the outside world, which causes deformation, cracking, premature opening of the explosion-proof valve and other problems, seriously affecting the battery process yield and safety performance. Summary of the invention

[0003] Purpose of the invention: The embodiments of the present application provide a single cell, a battery pack and an electrical device, aiming to solve the technical problems of deformation, cracking and premature opening of the explosion-proof valve due to pressure difference during the battery preparation process.

[0004] Technical solution: The present application embodiment provides a single battery, including:

[0005] A housing having a receiving cavity;

[0006] An electrode assembly, the electrode assembly is located in the accommodating cavity;

[0007] A cover plate, which is connected to the shell and covers the accommodating cavity, and is provided with an explosion-proof hole;

[0008] An explosion-proof valve, the explosion-proof valve cover seals the explosion-proof hole, the explosion-proof valve comprises a bearing portion, a weak portion and a protruding portion, the bearing portion is connected to the weak portion in a surrounding manner, the weak portion is connected to the protruding portion in a surrounding manner, the bearing portion is connected to the cover plate, the weak portion is configured to be destroyed when subjected to a preset pressure impact, the protruding portion protrudes from the connection with the weak portion toward a side away from the electrode assembly, and a concave portion is provided on the protruding portion and is concave toward a side close to the electrode assembly;

[0009] Among them, the area of ​​the explosion-proof valve is S mm 2 The area of ​​the protrusion is S1 mm 2 , the area of ​​the concave portion is S2mm 2 , satisfying: 0.6≤S1 / S≤0.85, 0.15≤S2 / S1≤0.2.

[0010] In some embodiments, the protrusion includes a first sub-protrusion and a second sub-protrusion, the first sub-protrusion is arranged around the second sub-protrusion, and the recess is arranged between the first sub-protrusion and the second sub-protrusion and connected to the first sub-protrusion and the second sub-protrusion respectively.

[0011] In some embodiments, the area of ​​the first sub-convex portion is S3 mm 2 The area of ​​the second sub-convex part is S4 mm 2 , satisfying: 0.45≤S3 / S≤0.65, 0.05≤S4 / S≤0.08.

[0012] In some embodiments, there are multiple recesses, and the multiple recesses are arranged in an array on the protruding portion, and one of two adjacent recesses is arranged around the other.

[0013] In some embodiments, the area S2 of the recess satisfies: 0.1≤S2 / S≤0.15.

[0014] In some embodiments, the bearing portion is connected to a side of the cover plate close to the electrode assembly, and the protruding portion protrudes into the explosion-proof hole.

[0015] In some embodiments, a limiting groove is provided on one side of the cover plate close to the electrode assembly. The limiting groove is arranged around the explosion-proof hole and is provided on one side of the cover plate close to the electrode assembly. The bearing portion is arranged in the limiting groove.

[0016] In some embodiments, along the thickness direction of the cover plate, there is a minimum dimension L1 between the bottom wall of the limiting groove and the side of the cover plate close to the electrode assembly, and the bearing portion has a maximum dimension L2, satisfying: L1≥L2.

[0017] In some embodiments, along the thickness direction of the cover plate, the cover plate has a maximum dimension L3, and a maximum dimension L4 is present between a side of the protrusion away from the electrode assembly and a side of the cover plate close to the electrode assembly, satisfying: L3≥L4.

[0018] Accordingly, an embodiment of the present application provides a battery pack, comprising the above-mentioned single battery.

[0019] Correspondingly, an embodiment of the present application provides an electrical device, including the above-mentioned single battery, or including the above-mentioned battery pack.

[0020] Beneficial effects: The single cell battery of the embodiment of the present application includes a shell, an electrode assembly, a cover plate and an explosion-proof valve. The shell has a accommodating cavity; the electrode assembly is located in the accommodating cavity; the cover plate is connected to the shell and covers the accommodating cavity, and the cover plate is provided with an explosion-proof hole; the explosion-proof valve covers the explosion-proof hole, and the explosion-proof valve includes a bearing portion, a weak portion and a protruding portion, the bearing portion is connected around the weak portion, the weak portion is connected around the protruding portion, the bearing portion is connected to the cover plate, the weak portion is configured to be destroyed when subjected to a preset pressure shock, the protruding portion protrudes from the connection with the weak portion toward the side away from the electrode assembly, and the protruding portion is provided with a recessed portion that is recessed toward the side close to the electrode assembly. The area of ​​the explosion-proof valve is S mm 2 The area of ​​the protrusion is S1 mm 2 The area of ​​the concave portion is S2 mm 2 , satisfying: 0.6≤S1 / S≤0.85, 0.15≤S2 / S1≤0.2. By limiting the ratio of the protrusion to the area of ​​the explosion-proof valve and the ratio of the concave to the area of ​​the protrusion, it is ensured that the arrangement of the protrusion and the concave can effectively absorb and disperse the stress caused to the explosion-proof valve by the pressure difference between the inside of the accommodating cavity and the outside of the shell during the production of the single battery, and avoid the deformation of the explosion-proof valve due to the pressure difference, which leads to the cracking or premature opening of the explosion-proof valve, thereby effectively improving the production yield of the single battery and improving the safety and reliability of the single battery.

[0021] The battery pack of the embodiment of the present application includes the above-mentioned single battery, so the battery pack can have all the technical features and beneficial effects of the above-mentioned single battery, which will not be repeated here.

[0022] The electrical device of the embodiment of the present application includes the above-mentioned single cell or the above-mentioned battery pack, so the electrical device can have all the technical features and beneficial effects of the above-mentioned single cell or battery pack, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 is an exploded diagram of a single cell of an embodiment of the present application;

[0025] Figure 2 is a cross-sectional view of a cover plate according to an embodiment of the present application;

[0026] Figure 3 is a top view of an explosion-proof valve according to an embodiment of the present application;

[0027] Figure 4 is a bottom view of an explosion-proof valve according to an embodiment of the present application;

[0028] Figure 5 is a top view of an explosion-proof valve according to another embodiment of the present application;

[0029] Figure 6 It is a bottom view of an explosion-proof valve according to another embodiment of the present application;

[0030] Figure 7 It is a cross-sectional view of an explosion-proof valve according to an embodiment of the present application.

[0031] Figure numerals: 1, shell; 2, electrode assembly; 3, cover plate; 4, explosion-proof valve; 10, accommodating chamber; 30, explosion-proof hole; 31, limiting groove; 40, bearing part; 41, weak part; 42, protrusion; 310, bottom wall; 410, notch; 420, recess; 421, first sub-protrusion; 422, second sub-protrusion; X, thickness direction. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0033] In the description of the present application, it should be understood that the terms "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "multiple" means two or more, and at least one means one, two or more, unless otherwise clearly and specifically defined. In the description of this application, "vertical" means completely vertical at 90° or almost completely vertical, for example, an angle within the range of 80° to 100° is considered vertical. Similarly, "parallel" means completely parallel or almost completely parallel, for example, an angle within 10° of completely parallel is considered parallel.

[0034] The applicant noted that lithium-ion batteries are currently widely used in various fields such as transportation power supply, electric energy storage power supply, new energy storage power supply, aerospace and military industry due to their large capacity, high operating voltage, strong charge retention ability and long cycle life. The cover plate in the battery is usually integrated with poles, explosion-proof valves and other structures. Among them, the main function of the explosion-proof valve is to release pressure and exhaust. It is used for the directional release of internal high-temperature and high-pressure gas when the battery cell has thermal runaway due to mechanical impact, internal abnormal lap short circuit and other reasons, thereby improving the safety performance of the battery pack. However, in the processes of liquid injection, pre-charging formation, and capacity division in the single cell process, there is a repeated positive and negative alternating pressure difference between the inside of the battery and the outside world, which causes deformation, cracking, premature opening of the explosion-proof valve and other problems, seriously affecting the battery process yield and safety performance.

[0035] In view of this, the single cell of the embodiment of the present application includes a shell, an electrode assembly, a cover plate and an explosion-proof valve. The shell has a accommodating cavity; the electrode assembly is located in the accommodating cavity; the cover plate is connected to the shell and covers the accommodating cavity, and the cover plate is provided with an explosion-proof hole; the explosion-proof valve covers the explosion-proof hole, and the explosion-proof valve includes a bearing portion, a weak portion and a protruding portion, the bearing portion is connected around the weak portion, the weak portion is connected around the protruding portion, the bearing portion is connected to the cover plate, the weak portion is configured to be destroyed when subjected to a preset pressure shock, the protruding portion protrudes from the connection with the weak portion toward the side away from the electrode assembly, and the protruding portion is provided with a recessed portion that is recessed toward the side close to the electrode assembly. The area of ​​the explosion-proof valve is S mm 2 The area of ​​the protrusion is S1 mm 2 The area of ​​the concave portion is S2 mm 2 , satisfying: 0.6≤S1 / S≤0.85, 0.15≤S2 / S1≤0.2. By limiting the ratio of the protrusion to the area of ​​the explosion-proof valve and the ratio of the concave to the area of ​​the protrusion, it is ensured that the arrangement of the protrusion and the concave can effectively absorb and disperse the stress caused to the explosion-proof valve by the pressure difference between the inside of the accommodating cavity and the outside of the shell during the production of the single battery, and avoid the deformation of the explosion-proof valve due to the pressure difference, which leads to the cracking or premature opening of the explosion-proof valve, thereby effectively improving the production yield of the single battery and improving the safety and reliability of the single battery.

[0036] In the present application, a single cell may include a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery or a magnesium-ion battery, etc., and the embodiments of the present application do not limit this. A single cell may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this. Single cells are generally divided into three types according to the packaging method: cylindrical single cells, square single cells and soft-pack single cells, and the embodiments of the present application do not limit this.

[0037] The following is a detailed description of the single cell, battery pack and electrical device of the present application in conjunction with the accompanying drawings. The features of the following embodiments and implementations can be combined with each other if there is no conflict.

[0038] Figure 1 is an exploded diagram of a single cell of an embodiment of the present application; Figure 2 is a cross-sectional view of a cover plate 3 according to an embodiment of the present application; Figure 3 is a top view of an explosion-proof valve 4 according to an embodiment of the present application; Figure 4 It is a bottom view of an explosion-proof valve 4 according to an embodiment of the present application; Figure 5 is a top view of an explosion-proof valve 4 according to another embodiment of the present application; Figure 6 It is a bottom view of an explosion-proof valve 4 according to another embodiment of the present application; Figure 7 It is a cross-sectional view of an explosion-proof valve 4 according to an embodiment of the present application.

[0039] refer to Figures 1 to 7 The embodiment of the present application provides a single cell, a battery pack and an electrical device, including a shell 1, an electrode assembly 2, a cover plate 3 and an explosion-proof valve 4. The shell 1 has a housing chamber 10; the electrode assembly 2 is located in the housing chamber 10; the cover plate 3 is connected to the shell 1 and covers the housing chamber 10, the cover plate 3 is provided with an explosion-proof hole 30, the explosion-proof valve 4 covers the explosion-proof hole 30, the explosion-proof valve 4 includes a bearing portion 40, a weak portion 41 and a protruding portion 42, the bearing portion 40 is connected to the weak portion 41 around, the weak portion 41 is connected to the protruding portion 42 around, the bearing portion 40 is connected to the cover plate 3, and the weak portion 41 is configured to be destroyed when impacted by a preset pressure. When the internal pressure of the single cell is too high (for example, the internal pressure is too high due to overcharging), the weak portion 41 of the explosion-proof valve 4 is destroyed by the preset pressure to release the gas inside the single cell, thereby reducing the internal pressure of the single cell and preventing the single cell from exploding due to excessively rapid pressurization inside the single cell. The protrusion 42 protrudes from the connection with the weak portion 41 toward the side away from the electrode assembly 2, and a recess 420 is provided on the protrusion 42, which is recessed toward the side close to the electrode assembly 2. The arrangement of the protrusion 42 and the recess 420 can avoid stress concentration. The area of ​​the explosion-proof valve 4 is S mm 2 The area of ​​the protrusion 42 is S1 mm 2 , the area of ​​the concave portion 420 is S2 mm 2 , satisfying: 0.8≤S1 / S≤0.85, 0.15≤S2 / S1≤0.2. The protrusion 42 and the recess 420 can absorb and disperse the stress caused by the pressure difference between the accommodating cavity 10 and the outside of the shell 1 on the explosion-proof valve 4 during the production of the single battery, and avoid the deformation of the weak part 41 due to the pressure difference, which may cause the weak part 41 to crack or the explosion-proof valve 4 to open prematurely, thereby effectively improving the production yield of the single battery and improving the safety and reliability of the single battery.

[0040] In some embodiments, the area of ​​the protrusion 42 is S1 mm 2 , the area of ​​explosion-proof valve 4 is S mm 2 , satisfying: 0.6≤S1 / S≤0.85. When the ratio of the area S1 of the protrusion 42 to the area S of the explosion-proof valve 4 is too large, it can be understood that the area occupied by the protrusion 42 in the explosion-proof valve 4 is too large, thereby occupying the space of the weak part 41. This may cause the weak part 41 to fail to be destroyed normally when subjected to a preset pressure, affecting the function of the explosion-proof valve 4 to release the internal gas. When the ratio of the area S1 of the protrusion 42 to the area S of the explosion-proof valve 4 is too small, the area of ​​the protrusion 42 is too small to fully absorb and disperse the pressure difference stress from the production process of the single battery, and it is easy to cause the weak part 41 to crack due to stress concentration or cause the explosion-proof valve 4 to open the valve prematurely, reducing the safety and reliability of the single battery. By limiting the ratio range of the area S1 of the protrusion 42 to the area S of the explosion-proof valve 4, the area of ​​the protrusion 42 and the area of ​​the explosion-proof valve 4 are controlled within a certain ratio range, which can ensure that the protrusion 42 reaches a relatively ideal state when playing the role of absorbing and dispersing stress. The protrusion 42 will not be too small to effectively disperse stress, nor will it be too large to affect the pressure relief function of the explosion-proof valve 4. A reasonable area ratio helps the explosion-proof valve 4 to quickly release internal gas when the internal pressure of the single battery is too high, reduce the internal pressure, and improve the safety and reliability of the single battery.

[0041] In some embodiments, the area of ​​the protrusion 42 is S1 mm 2 , the area of ​​the concave portion 420 is S2 mm 2 , satisfying: 0.15≤S2 / S1≤0.2. The area of ​​the concave portion 420 occupied by the protrusion 42 is too small, and the concave portion 420 cannot fully absorb and disperse the internal pressure of the single cell, resulting in certain restrictions when the explosion-proof valve 4 should be opened normally to release the pressure, and the valve cannot be opened in time and effectively, which may cause the internal pressure of the single cell to be unable to be released in time, increasing the risk of danger to the single cell. The concave portion 420 occupied too large an area of ​​the protrusion 42, which may cause the protrusion 42 to deform abnormally and crack during the single cell process. By limiting the ratio range of the area S2 of the concave portion 420 to the area S1 of the protrusion 42, the problem of constrained valve opening and abnormal deformation and cracking of the protrusion 42 can be avoided. In the single cell process, the explosion-proof valve 4 can more effectively disperse the pressure from the inside and outside of the single cell, so that the stress distribution on the explosion-proof valve 4 is more uniform, reducing the risk of local stress concentration, so that the explosion-proof valve 4 can be opened in time and accurately when it is impacted by the preset pressure, preventing the single cell from catching fire and exploding, and improving the safety performance of the single cell.

[0042] exist Figures 2 to 7In the illustrated embodiment, the protrusion 42 includes a first sub-protrusion 421 and a second sub-protrusion 422, the first sub-protrusion 421 is arranged around the second sub-protrusion 422, and the recess 420 is arranged between the first sub-protrusion 421 and the second sub-protrusion 422 and connected to the first sub-protrusion 421 and the second sub-protrusion 422 respectively. The shape of the explosion-proof valve 4 can be circular or elliptical, and correspondingly, the shapes of the protrusion 42 and the recess 420 can be arranged corresponding to the shape of the explosion-proof valve 4, so as to help the stress on the explosion-proof valve 4 to be more evenly distributed. Figure 7 The cross-sectional shapes of the first sub-convex part 421, the second sub-convex part 422 and the concave part 420 can be arc-shaped, circular arc-shaped, etc., and the cross-sectional shapes of the first sub-convex part 421, the concave part 420 and the second sub-convex part 422 arranged in sequence from the outside to the inside can be wavy lines. In this way, on the one hand, stress concentration can be avoided; on the other hand, by setting the first sub-convex part 421, the second sub-convex part 422 and the concave part 420, a large elastic deformation can be performed, so that the stress caused to the explosion-proof valve 4 by the pressure difference between the inside of the accommodating cavity 10 and the outside of the shell 1 during the production of the single battery can be more effectively absorbed and dispersed, and the risk of the weak part 41 cracking due to stress or the explosion-proof valve 4 opening prematurely can be further reduced.

[0043] In some embodiments, there are multiple recesses 420, and the multiple recesses 420 are arranged on the protrusion 42, and one of two adjacent recesses 420 is arranged around the other. In some embodiments, the multiple recesses 420 can be connected to each other. In other embodiments, multiple protrusions can be arranged on the protrusion 42 at intervals.

[0044] In some embodiments, the area of ​​the first sub-convex portion 421 is S3 mm 2, satisfying: 0.45≤S3 / S≤0.65. That is, the area of ​​the first sub-convex portion 421 on the explosion-proof valve 4 accounts for between 45% and 65%. When the area of ​​the first sub-convex portion 421 is too large, since the first sub-convex portion 421 usually bears the main role of absorbing and dispersing stress, but when the area of ​​the first sub-convex portion 421 is too large, it may undergo excessive elastic deformation due to the stress caused by the internal and external pressure difference during the production process, which may exceed the bearing limit of the material of the explosion-proof valve 4, thereby causing the explosion-proof valve 4 to have abnormal convex deformation, or even cracking, affecting the safety and reliability of the single battery. When the area of ​​the first sub-convex portion 421 is too small, the first sub-convex portion 421 with an area that is too small cannot fully exert its stress absorption and dispersion functions, so that more stress may be concentrated on the weak portion 41 and other parts, increasing the risk of cracking of the weak portion 41 due to stress concentration or premature opening of the explosion-proof valve 4, and there is a risk of abnormal concave deformation and cracking of the explosion-proof valve 4. By reasonably designing the ratio range of the area S3 of the first sub-convex portion 421 to the area S of the explosion-proof valve 4, on the one hand, the stress can be effectively dispersed and absorbed to ensure the structural stability of the explosion-proof valve 4 and reduce the risk of deformation and cracking of the explosion-proof valve 4; on the other hand, the explosion-proof valve 4 can be prevented from opening prematurely, and can be opened normally when the internal pressure of the battery reaches a preset value, thereby releasing the pressure in time and improving the safety and reliability of the single battery.

[0045] In some embodiments, the area of ​​the second sub-protrusion 422 is S4 mm 2 , satisfying: 0.05≤S4 / S≤0.08, that is, the area of ​​the second sub-protrusion 422 on the explosion-proof valve 4 accounts for between 5% and 8%. When the area of ​​the second sub-protrusion 422 is too large, the second sub-protrusion 422 usually also has a certain elastic deformation ability to absorb and disperse stress. However, when the area of ​​the second sub-protrusion 422 is too large, the amplitude of its elastic deformation is too large and may exceed the bearing limit of the material of the explosion-proof valve 4, thereby causing the overall convex deformation of the explosion-proof valve 4 to be abnormal, or even cracking, affecting the safety and reliability of the single cell. When the area of ​​the second sub-protrusion 422 is too small, during the single cell manufacturing process, the explosion-proof valve 4 will be affected by the pressure generated by the internal battery reaction and the external environment. The area of ​​the second sub-protrusion is too small to effectively resist the pressure caused by the internal and external pressure difference, which leads to a concave problem in the middle of the explosion-proof valve 4, that is, the location of the second sub-protrusion 422. By reasonably designing the ratio range of the area S4 of the second sub-convex portion 422 to the area S of the explosion-proof valve 4, it is possible to effectively prevent the inner concave problem in the middle of the explosion-proof valve 4 or the abnormal outer convex deformation and cracking of the explosion-proof valve 4 as a whole, thereby ensuring the structural integrity and normal function of the explosion-proof valve 4 and improving the safety and reliability of the single battery.

[0046] In some embodiments, the area of ​​the recess 420 is S2 mm. 2, satisfying: 0.1≤S2 / S≤0.15. That is, the area of ​​the recess 420 on the explosion-proof valve 4 accounts for between 10% and 15%. When the area of ​​the recess 420 is too small, it may cause the problem of constrained valve opening after the single cell produces gas in the capacity separation process. It can be understood that the capacity separation process refers to the process of capacity sorting of single cells. By charging and discharging the single cells, measuring their actual capacity, and classifying batteries with similar capacity into one category, the single cells may produce gas due to chemical reactions during the charging and discharging process and apply pressure to the explosion-proof valve. The insufficient area of ​​the recess 420 makes it impossible for the recess 420 to fully absorb and disperse the internal pressure of the single cell, resulting in certain restrictions on the explosion-proof valve 4 when it should be opened normally to release the pressure, and the valve cannot be opened in time and effectively, which may cause the internal pressure of the single cell to be unable to be released in time, increasing the risk of danger to the single cell. When the area of ​​the concave portion 420 is too large, it will occupy the area of ​​the first sub-convex portion 421 and the second sub-convex portion 422, which may cause the explosion-proof valve 4 to have abnormal cracking due to internal concave deformation during the manufacturing process of the single battery. By reasonably designing the ratio range of the area S2 of the concave portion 420 to the area S of the explosion-proof valve 4, the problem of constrained valve opening caused by the small area of ​​the concave portion 420 and the abnormal cracking of the explosion-proof valve 4 due to the large area can be effectively prevented, ensuring the stability of the performance of the explosion-proof valve 4, and being able to open normally when the internal pressure of the battery reaches the preset value, releasing the pressure in time, and improving the safety and reliability of the single battery.

[0047] In the embodiment of the present application, different explosion-proof valves 4 of S2, S3 and S4 are provided and welded to the cover plate 3 for actual measurement and verification, and whether abnormal conditions occur in the explosion-proof valve 4 during the single cell manufacturing process is tracked. The verification results are shown in Table 1.

[0048] Table 1:

[0049]

[0050]

[0051] As shown in Table 1, Example 1, the area S of the explosion-proof valve 4 is 110 mm 2 , the area of ​​the protrusion 42 is 93mm 2 , the area S2 of the concave portion 420 is 16 mm 2 The area S3 of the first sub-protrusion 421 is 71 mm 2 , the area S4 of the second sub-protrusion 422 is 6 mm 2, S1 / S=0.85, S2 / S=0.15, S3 / S=0.65, S4 / S=0.05, S2 / S1=0.17. It meets the requirements of 0.6≤S1 / S≤0.85, 0.1≤S2 / S≤0.15, 0.45≤S3 / S≤0.65, 0.05≤S4 / S≤0.08, 0.15≤S2 / S1≤0.2. By reasonably setting the area ratio of the first sub-convex portion 421, the second sub-convex portion 422 and the concave portion 420 on the explosion-proof valve 4, the stress can be effectively absorbed and dispersed, avoiding the problems of the explosion-proof valve such as convex deformation, abnormal cracking, concave or constrained valve opening.

[0052] As shown in Table 1, Example 2, the area S of the explosion-proof valve 4 is 110 mm 2 , the area S1 of the protrusion 42 is 91 mm 2 , the area S2 of the concave portion 420 is 15 mm 2 , the area S3 of the first sub-convex portion 421 is 68 mm 2 , the area S4 of the second sub-protrusion 422 is 8 mm 2 , S1 / S=0.83, S2 / S=0.14, S3 / S=0.62, S4 / S=0.07, S2 / S1=0.16. It meets the requirements of 0.6≤S1 / S≤0.85, 0.1≤S2 / S≤0.15, 0.45≤S3 / S≤0.65, 0.05≤S4 / S≤0.08, 0.15≤S2 / S1≤0.2. By reasonably setting the area ratio of the first sub-convex portion 421, the second sub-convex portion 422 and the concave portion 420 on the explosion-proof valve 4, the stress can be effectively absorbed and dispersed, avoiding the problems of abnormal cracking of the explosion-proof valve due to convex deformation, concave or constrained valve opening.

[0053] As shown in Table 1, Example 3, the area S of the explosion-proof valve 4 is 110 mm 2 , the area S1 of the protrusion 42 is 82 mm 2 , the area S2 of the concave portion 420 is 14 mm 2 The area S3 of the first sub-protrusion 421 is 62 mm 2 , the area S4 of the second sub-protrusion 422 is 6 mm 2, S1 / S=0.75, S2 / S=0.13, S3 / S=0.56, S4 / S=0.05, S2 / S1=0.17. It meets the requirements of 0.6≤S1 / S≤0.85, 0.1≤S2 / S≤0.15, 0.45≤S3 / S≤0.65, 0.05≤S4 / S≤0.08, 0.15≤S2 / S1≤0.2. By reasonably setting the area ratio of the first sub-convex portion 421, the second sub-convex portion 422 and the concave portion 420 on the explosion-proof valve 4, the stress can be effectively absorbed and dispersed, avoiding the problems of the explosion-proof valve such as convex deformation, abnormal cracking, concave or constrained valve opening.

[0054] As shown in Table 1, Example 4, the area S of the explosion-proof valve 4 is 110 mm 2 , the area S1 of the protrusion 42 is 79 mm 2 , the area S2 of the concave portion 420 is 13 mm 2 The area S3 of the first sub-protrusion 421 is 58 mm 2 , the area S4 of the second sub-protrusion 422 is 8 mm 2 , S1 / S=0.72, S2 / S=0.12, S3 / S=0.53, S4 / S=0.07, S2 / S1=0.16. It meets the requirements of 0.6≤S1 / S≤0.85, 0.1≤S2 / S≤0.15, 0.45≤S3 / S≤0.65, 0.05≤S4 / S≤0.08, 0.15≤S2 / S1≤0.2. By reasonably setting the area ratio of the first sub-convex portion 421, the second sub-convex portion 422 and the concave portion 420 on the explosion-proof valve 4, the stress can be effectively absorbed and dispersed, avoiding the problems of abnormal cracking of the explosion-proof valve due to convex deformation, concave or constrained valve opening.

[0055] As shown in Table 1, Example 5, the area S of the explosion-proof valve 4 is 110 mm 2 , the area S1 of the protrusion 42 is 71 mm 2 , the area S2 of the concave portion 420 is 12 mm 2 , the area S3 of the first sub-convex portion 421 is 53 mm 2 , the area S4 of the second sub-protrusion 422 is 6 mm 2, S1 / S=0.65, S2 / S=0.11, S3 / S=0.48, S4 / S=0.05, S2 / S1=0.17. It meets the requirements of 0.6≤S1 / S≤0.85, 0.1≤S2 / S≤0.15, 0.45≤S3 / S≤0.65, 0.05≤S4 / S≤0.08, 0.15≤S2 / S1≤0.2. By reasonably setting the area ratio of the first sub-convex portion 421, the second sub-convex portion 422 and the concave portion 420 on the explosion-proof valve 4, the stress can be effectively absorbed and dispersed, avoiding the problems of abnormal cracking of the explosion-proof valve due to convex deformation, concave or constrained valve opening.

[0056] As shown in Table 1, Example 6, the area S of the explosion-proof valve 4 is 110 mm 2 , the area S1 of the protrusion 42 is 68 mm 2 , the area S2 of the concave portion 420 is 11 mm 2 The area S3 of the first sub-protrusion 421 is 49 mm 2 , the area S4 of the second sub-protrusion 422 is 8 mm 2 , S1 / S=0.62, S2 / S=0.1, S3 / S=0.45, S4 / S=0.07, S2 / S1=0.16. It meets the requirements of 0.6≤S1 / S≤0.85, 0.1≤S2 / S≤0.15, 0.45≤S3 / S≤0.65, 0.05≤S4 / S≤0.08, 0.15≤S2 / S1≤0.2. By reasonably setting the area ratio of the first sub-convex portion 421, the second sub-convex portion 422 and the concave portion 420 on the explosion-proof valve 4, the stress can be effectively absorbed and dispersed, avoiding the problems of abnormal cracking of the explosion-proof valve due to convex deformation, concave or constrained valve opening.

[0057] As shown in Table 1, the area S of the explosion-proof valve 4 is 110 mm 2 , the area S1 of the protrusion 42 is 89 mm 2 , the area S2 of the concave portion 420 is 16 mm 2 The area S3 of the first sub-protrusion 421 is 69 mm 2 , the area S4 of the second sub-protrusion 422 is 4 mm 2 , S1 / S=0.81, S2 / S=0.15, S3 / S=0.63, S4 / S=0.04, S2 / S1=0.18. It meets the requirements of 0.6≤S1 / S≤0.85, 0.1≤S2 / S≤0.15, 0.45≤S3 / S≤0.65, 0.15≤S2 / S1≤0.2. It does not meet the requirement of 0.05≤S4 / S≤0.08. It can be understood that the area S4 of the second sub-convex portion 422 is too small to effectively resist the pressure caused by the internal and external pressure difference, resulting in a concave in the middle of the explosion-proof valve 4, affecting the structural integrity and normal function of the explosion-proof valve 4.

[0058] As shown in Table 1, comparative example 2, the area S of the explosion-proof valve 4 is 110 mm 2 , the area S1 of the protrusion 42 is 91 mm 2 , the area S2 of the concave portion 420 is 16 mm 2 , the area S3 of the first sub-convex portion 421 is 65 mm 2 , the area S4 of the second sub-protrusion 422 is 10 mm 2 , S1 / S=0.83, S2 / S=0.15, S3 / S=0.59, S4 / S=0.09, S2 / S1=0.18. The requirements of 0.6≤S1 / S≤0.85, 0.1≤S2 / S≤0.15, 0.45≤S3 / S≤0.65, 0.15≤S2 / S1≤0.2 are met. The requirement of 0.05≤S4 / S≤0.08 is not met. It can be understood that the area S4 of the second sub-protrusion 422 is too large, which will cause the elastic deformation amplitude of the second sub-protrusion 422 to be too large when absorbing and dispersing stress, exceeding the bearing limit of the explosion-proof valve 4 material, resulting in abnormal convex deformation of the explosion-proof valve 4 as a whole, and even cracking, which affects the safety and reliability of the single battery.

[0059] As shown in Table 1, comparative example 3, the area S of the explosion-proof valve 4 is 110 mm 2 , the area S1 of the protrusion 42 is 88 mm 2 , the area S2 of the concave portion 420 is 10 mm 2 The area S3 of the first sub-convex portion 421 is 70 mm 2 , the area S4 of the second sub-protrusion 422 is 8 mm 2 , S1 / S=0.80, S2 / S=0.09, S3 / S=0.64, S4 / S=0.07, S2 / S1=0.11. It meets the requirements of 0.6≤S1 / S≤0.85, 0.1≤S2 / S≤0.15, 0.45≤S3 / S≤0.65, 0.05≤S4 / S≤0.08. It does not meet the requirements of 0.1≤S2 / S≤0.15 and 0.15≤S2 / S1≤0.2. It can be understood that the area S2 of the recess 420 is too small, so that the recess 420 cannot fully absorb and disperse the internal pressure of the single battery, resulting in certain restrictions on the explosion-proof valve 4 when it should be opened normally to release the pressure, and the valve cannot be opened in time and effectively, resulting in the problem of constrained valve opening.

[0060] As shown in Table 1, the area S of the explosion-proof valve 4 is 110 mm 2 , the area S1 of the protrusion 42 is 96 mm 2 , the area S2 of the concave portion 420 is 18 mm 2 The area S3 of the first sub-convex portion 421 is 70 mm2 , the area S4 of the second sub-protrusion 422 is 8 mm 2 , S1 / S=0.87, S2 / S=0.16, S3 / S=0.64, S4 / S=0.07, S2 / S1=0.19. Satisfy the requirements of 0.45≤S3 / S≤0.65, 0.05≤S4 / S≤0.08, 0.15≤S2 / S1≤0.2. Do not meet the requirements of 0.6≤S1 / S≤0.85 and 0.1≤S2 / S≤0.15. It can be understood that when the area S1 of the protrusion 42 is relatively large and the area S2 of the recess 420 is too large, the recess 420 may be excessively elastically deformed during the production process due to the stress caused by the internal and external pressure difference, which exceeds the bearing limit of the explosion-proof valve material, thereby causing the explosion-proof valve to be abnormally deformed and even cracked, affecting the safety and reliability of the single battery.

[0061] As shown in Table 1, comparative example 5, the area S of the explosion-proof valve 4 is 110 mm 2 , the area S1 of the protrusion 42 is 94 mm 2 , the area S2 of the concave portion 420 is 15 mm 2 The area S3 of the first sub-protrusion 421 is 73 mm 2 , the area S4 of the second sub-protrusion 422 is 6 mm 2 , S1 / S=0.85, S2 / S=0.14, S3 / S=0.66, S4 / S=0.05, S2 / S1=0.16. The requirements of 0.6≤S1 / S≤0.85, 0.1≤S2 / S≤0.15, 0.05≤S4 / S≤0.08, 0.15≤S2 / S1≤0.2 are met. The requirement of 0.45≤S3 / S≤0.65 is not met. It can be understood that the area S3 of the first sub-convex portion 421 is too large, resulting in excessive elastic deformation of the first sub-convex portion 421 during the production process due to the stress caused by the internal and external pressure difference, which exceeds the bearing limit of the explosion-proof valve 4 material, thereby causing the explosion-proof valve 4 to have abnormal convex deformation or even cracking, affecting the safety and reliability of the single battery.

[0062] As shown in Table 1, the area S of the explosion-proof valve 4 is 110 mm 2 , the area S1 of the protrusion 42 is 69 mm 2 , the area S2 of the concave portion 420 is 15 mm 2 The area S3 of the first sub-protrusion 421 is 48 mm 2 , the area S4 of the second sub-protrusion 422 is 6 mm 2, S1 / S=0.63, S2 / S=0.14, S3 / S=0.44, S4 / S=0.05, S2 / S1=0.22. The requirements of 0.6≤S1 / S≤0.85, 0.1≤S2 / S≤0.15, 0.05≤S4 / S≤0.08 are met. The requirements of 0.45≤S3 / S≤0.65 and 0.15≤S2 / S1≤0.2 are not met. It can be understood that the area S3 of the first sub-convex portion 421 is too small. The first sub-convex portion 421 with too small an area cannot fully exert its stress absorption and dispersion functions, so that more stress may be concentrated in the weak portion 41 and other parts, resulting in the problem of abnormal deformation and cracking of the explosion-proof valve 4. In addition, the concave portion 420 occupies too large an area of ​​the protruding portion 42, which will also cause the problem of abnormal deformation and cracking of the protruding portion 42 in the single cell manufacturing process.

[0063] As shown in Table 1, comparative example 7, the area S of the explosion-proof valve 4 is 110 mm 2 , the area S1 of the protrusion 42 is 95 mm 2 , the area S2 of the concave portion 420 is 16 mm 2 The area S3 of the first sub-convex portion 421 is 70 mm 2 The area S4 of the second sub-protrusion 422 is 9 mm 2 , S1 / S=0.86, S2 / S=0.15, S3 / S=0.64, S4 / S=0.08, S2 / S1=0.17. It meets the requirements of 0.1≤S2 / S≤0.15, 0.45≤S3 / S≤0.65, 0.05≤S4 / S≤0.08, 0.15≤S2 / S1≤0.2. It does not meet the requirement of 0.6≤S1 / S≤0.85. It can be understood that the area S1 of the protrusion 42 is too large, occupying the space of the weak part 41. This may cause the weak part 41 to fail to be destroyed normally when subjected to the preset pressure, affecting the function of the explosion-proof valve 4 to release the internal gas. After the single cell produces gas inside the capacity division process, there is a problem of constraining the valve opening.

[0064] As shown in Table 1, the area S of the explosion-proof valve 4 is 110 mm 2 , the area S1 of the protrusion 42 is 65 mm 2 , the area S2 of the concave portion 420 is 11 mm 2 The area S3 of the first sub-protrusion 421 is 48 mm 2 , the area S4 of the second sub-protrusion 422 is 6 mm 2, S1 / S=0.59, S2 / S=0.10, S3 / S=0.44, S4 / S=0.05, S2 / S1=0.17. The requirements of 0.1≤S2 / S≤0.15, 0.05≤S4 / S≤0.08, 0.15≤S2 / S1≤0.2 are met. The requirements of 0.6≤S1 / S≤0.85 and 0.45≤S3 / S≤0.65 are not met. It can be understood that the area S1 of the protrusion 42 is too small to fully absorb and disperse the pressure difference stress from the production process of the single battery, which is easy to cause the weak part 41 to crack due to stress concentration or cause the explosion-proof valve 4 to open prematurely. In addition, the area S3 of the first sub-protrusion 421 is too small. The first sub-protrusion 421 with a small area cannot fully exert its stress absorption and dispersion functions, so that more stress may be concentrated on the weak part 41 and other parts, resulting in abnormal deformation and cracking of the explosion-proof valve 4.

[0065] In some embodiments, a notch 410 is provided at the weak portion 41, and the notch 410 is provided around the protrusion 42. By providing the notch 410, the weak portion 41 can be more accurately ruptured at the notch 410 when subjected to a preset pressure, ensuring that the explosion-proof valve 4 releases the internal gas of the single cell in time at an appropriate pressure, thereby effectively reducing the internal pressure and preventing the single cell from being dangerous.

[0066] In some embodiments, the notch 410 may be disposed on a side of the weak portion 41 away from the electrode assembly 2 and recessed toward the electrode assembly 2. In other embodiments, the notch 410 may be disposed on a side of the weak portion 41 close to the electrode assembly 2 and recessed away from the electrode assembly 2. Figure 3 , Figure 5 and Figure 7 In the illustrated embodiment, the notch 410 is disposed on a side of the weak portion 41 away from the electrode assembly 2 and is recessed toward the electrode assembly 2. The notch 410 may be formed by laser etching or by mechanical processing, and the present application does not limit this.

[0067] exist Figure 2 and Figure 7 In the illustrated embodiment, the bearing portion 40 is connected to the side of the cover plate 3 close to the electrode assembly 2, and the protruding portion 42 protrudes into the explosion-proof hole 30. The explosion-proof valve 4 is arranged on the side of the cover plate 3 close to the electrode assembly 2, which can avoid the problem of the explosion-proof valve 4 being easily damaged by scratches when welding the explosion-proof valve 4 on the outer wall of the cover plate 3, and ensure the connection stability between the explosion-proof valve 4 and the cover plate 3.

[0068] exist Figure 2 and Figure 7In the illustrated embodiment, a limiting groove 31 is provided on one side of the cover plate 3 close to the electrode assembly 2. The limiting groove 31 is arranged around the explosion-proof hole 30 and is arranged on one side of the cover plate 3 close to the electrode assembly 2. The bearing portion 40 is arranged in the limiting groove 31. The limiting groove 31 can play a role in positioning and fixing the explosion-proof valve 4. By providing the limiting groove 31 on the cover plate 3 and arranging the explosion-proof valve 4 in the limiting groove 31, the explosion-proof valve 4 will not occupy the space of the electrode assembly 2 in the accommodating cavity 10, thereby improving the energy density and performance of the single battery.

[0069] exist Figure 7 In the illustrated embodiment, along the thickness direction X of the cover plate 3, there is a minimum dimension L1 between the bottom wall 310 of the limit groove 31 and the side of the cover plate 3 close to the electrode assembly 2, and the bearing portion 40 has a maximum dimension L2, satisfying: L1 ≥ L2. It can be understood that by limiting the minimum dimension L1 between the bottom wall 310 of the limit groove 31 and the side of the cover plate 3 close to the electrode assembly 2 to be greater than or equal to the maximum dimension L2 of the bearing portion 40, it is possible to prevent the explosion-proof valve 4 from protruding from the lower surface of the cover plate 3, thereby preventing the explosion-proof valve 4 from occupying the space of the electrode assembly 2 in the accommodating cavity 10, thereby improving the energy density and performance of the single cell. Furthermore, it is also possible to prevent the explosion-proof valve 4 from colliding or scratching with other components under vibration conditions, thereby reducing the possibility of danger to the single cell due to damage to the explosion-proof valve 4.

[0070] exist Figure 7 In the illustrated embodiment, along the thickness direction X of the cover plate 3, the cover plate 3 has a maximum dimension L3, and the side of the protrusion 42 away from the electrode assembly 2 and the side of the cover plate 3 close to the electrode assembly 2 have a maximum dimension L4, satisfying: L3 ≥ L4. It can be understood that by limiting the maximum dimension L3 of the cover plate to be greater than or equal to the maximum dimension L4 between the side of the protrusion 42 away from the electrode assembly 2 and the side of the cover plate 3 close to the electrode assembly 2, it is possible to avoid the protrusion 42 of the explosion-proof valve 4 from exceeding the upper surface of the cover plate 3 and causing external collision or scratching, reducing the risk of failure of the explosion-proof valve 4 due to damage by external forces, and ensuring that the explosion-proof valve 4 can function normally when needed.

[0071] The present application embodiment provides a battery pack, including the above-mentioned single battery, so the battery pack can have all the technical features and beneficial effects of the above-mentioned single battery, which will not be repeated here. The battery pack also includes a box body, wherein at least one single battery is accommodated inside the box body.

[0072] Correspondingly, the embodiment of the present application also provides an electrical device, including the above-mentioned single cell, or, including the above-mentioned battery pack, so the electrical device can have all the technical features and beneficial effects of the above-mentioned single cell or battery pack, which will not be repeated here. The electrical device can be a mobile phone, a portable device, a laptop computer, an electric car, an electric car, a ship, a spacecraft, an electric toy, and an electric tool. For example, spacecraft include airplanes, rockets, space shuttles, and spacecrafts; electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys; electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers.

[0073] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0074] The above is a detailed introduction to a single cell battery, a battery pack and an electrical device provided in the embodiments of the present application, and specific examples are used to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solution and its core idea of ​​the present application; ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the present application.

Claims

1. A single cell battery, characterized in that: include: A housing having a receiving cavity; an electrode assembly, wherein the electrode assembly is located in the accommodating cavity; A cover plate, the cover plate is connected to the shell and covers the accommodating cavity, and the cover plate is provided with an explosion-proof hole; An explosion-proof valve, the explosion-proof valve covers the explosion-proof hole, the explosion-proof valve comprises a bearing portion, a weak portion and a protruding portion, the bearing portion is connected to the weak portion in a surrounding manner, the weak portion is connected to the protruding portion in a surrounding manner, the bearing portion is connected to the cover plate, the weak portion is configured to be destroyed when subjected to a preset pressure impact, the protruding portion protrudes from a connection with the weak portion toward a side away from the electrode assembly, and the protruding portion is provided with a concave portion that is concave toward a side close to the electrode assembly; Wherein, the area of ​​the explosion-proof valve is S mm 2 The area of ​​the protrusion is S1 mm 2 , the area of ​​the concave portion is S2mm 2 , satisfying: 0.6≤S1 / S≤0.85, 0.15≤S2 / S1≤0.

2.

2. The single cell according to claim 1, characterized in that: The protrusion includes a first sub-protrusion and a second sub-protrusion, the first sub-protrusion is arranged around the second sub-protrusion, and the recess is arranged between the first sub-protrusion and the second sub-protrusion, and is connected to the first sub-protrusion and the second sub-protrusion respectively.

3. The single cell according to claim 2, characterized in that: The area of ​​the first sub-convex portion is S3 mm 2 The area of ​​the second sub-convex portion is S4 mm 2 , satisfying: 0.45≤S3 / S≤0.65, 0.05≤S4 / S≤0.

08.

4. The single cell according to claim 1, characterized in that: The number of the recessed parts is plural, and the plurality of recessed parts are arranged in an array on the protruding part, and one of two adjacent recessed parts is arranged around the other one.

5. The single cell according to claim 1 or 4, characterized in that: The area S2 of the concave portion satisfies: 0.1≤S2 / S≤0.

15.

6. The single cell according to claim 1, characterized in that: The bearing portion is connected to a side of the cover plate close to the electrode assembly, and the protruding portion protrudes into the explosion-proof hole.

7. The single cell according to claim 1 or 6, characterized in that: A limiting groove is provided on one side of the cover plate close to the electrode assembly. The limiting groove is arranged around the explosion-proof hole and is provided on one side of the cover plate close to the electrode assembly. The bearing portion is arranged in the limiting groove.

8. The single cell according to claim 7, characterized in that: Along the thickness direction of the cover plate, there is a minimum dimension L1 between the bottom wall of the limiting groove and the side of the cover plate close to the electrode assembly, and the bearing portion has a maximum dimension L2, satisfying: L1≥L2.

9. The single cell according to claim 1, characterized in that: Along the thickness direction of the cover plate, the cover plate has a maximum dimension L3, and a maximum dimension L4 is present between a side of the protrusion away from the electrode assembly and a side of the cover plate close to the electrode assembly, satisfying: L3≥L4.

10. A battery pack, characterized in that: The invention comprises the single cell according to any one of claims 1 to 9.

11. An electrical device, characterized in that: The method comprises the single cell according to any one of claims 1 to 9, or comprises the battery pack according to claim 10.

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