Single battery and battery pack

Abstract

The embodiment of the utility model discloses a single battery and a battery pack. The single battery comprises a shell and a battery pack, the electrode assembly is contained in the shell and comprises an electrode body and a tab, the tab comprises a folding part and an extending part, the folding part is arranged on the electrode body, and the extending part is connected with the end, away from the electrode body, of the folding part; the cover plate is connected to the shell; the insulating part is arranged between the electrode assembly and the cover plate, and the insulating part is arranged close to the tab; an avoiding hole is formed in the insulating part in a penetrating manner; the extending part and at least part of the folding part are arranged in the avoiding hole in a penetrating manner; a first inclined wall is arranged on the folding part, a second inclined wall is arranged on the hole wall of the receding hole, the second inclined wall faces the first inclined wall, and the first inclined wall and the second inclined wall are both arranged in an inclined mode relative to the first direction. According to the battery cell, poor tearing of the tabs caused by pressing the folding parts of the tabs when the insulating part is assembled is avoided, so that an electronic conduction path in the battery cell is optimized, and the power performance of the battery cell is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a single cell and a battery pack. Background Art

[0002] With the rapid development of the new energy industry, batteries with high capacity, high cycle life and high safety performance have been widely used and developed. At the same time, there is an urgent need for batteries with larger capacity, longer durability and greater safety. Power performance is one of the core performances of secondary batteries. Therefore, how to improve the power performance of secondary batteries has become an urgent problem to be solved. Utility Model Content

[0003] The embodiments of the present application provide a single cell and a battery pack to improve the power performance of the single cell.

[0004] In order to solve the above technical problems, the embodiments of the present application disclose the following technical solutions:

[0005] In one aspect, a single cell is provided, having a first orientation, and comprising: a housing;

[0006] An electrode assembly is accommodated in the housing, and the electrode assembly comprises: an electrode body and a pole ear, the pole ear comprises a gathering portion and an extension portion, the gathering portion is arranged on the electrode body, and the extension portion is connected to an end of the gathering portion away from the electrode body;

[0007] a cover plate connected to the housing; and

[0008] An insulating member is disposed between the electrode assembly and the cover plate, and the insulating member is disposed close to the electrode tab;

[0009] Wherein, the insulating member is penetrated with an avoidance hole, and the extension portion and at least a part of the retracted portion are arranged through the avoidance hole;

[0010] The gathering portion is provided with a first inclined wall, the hole wall of the avoidance hole is provided with a second inclined wall, the second inclined wall is arranged toward the first inclined wall, and the first inclined wall and the second inclined wall are both arranged obliquely relative to the first direction.

[0011] In addition to or as an alternative to one or more features disclosed above, the angle between the first inclined wall and the first direction is α, and the angle between the second inclined wall and the first direction is β, satisfying: α≤β.

[0012] In addition to or as an alternative to one or more of the features disclosed above, two first inclined walls are provided, and the two first inclined walls are arranged opposite to each other in the first direction;

[0013] Two second inclined walls are provided, the two second inclined walls are arranged opposite to each other in the first direction, and each second inclined wall faces a corresponding first inclined wall.

[0014] In addition to or as an alternative to one or more of the features disclosed above, the single battery further has a second direction intersecting with the first direction,

[0015] The thickness of the insulating member in the second direction is H1 mm, and the maximum height of the gathered portion in the second direction is H2 mm, satisfying: H1≤H2.

[0016] In addition to or as an alternative to one or more of the features disclosed above, the single battery further has a third direction intersecting the first direction and the second direction in pairs;

[0017] The maximum length of the pole ear in the third direction is L1 mm, and the maximum length of the avoidance hole in the third direction is L2 mm, satisfying: 0.3≤L1 / L2≤1.

[0018] In addition to one or more of the features disclosed above, or as an alternative, the single cell further includes: an electrical connector, wherein the electrical connector is disposed between the cover plate and the insulating member, and the extension portion passes through the electrical connector and is electrically connected to the electrical connector.

[0019] In addition to or as an alternative to one or more of the features disclosed above, the electrical connector is provided with a penetration hole, and the extension portion penetrated through the avoidance hole is penetrated through the penetration hole;

[0020] A recessed portion is provided on a side of the electrical connector away from the electrode assembly. The recessed portion is located on a side of the penetration hole along a first direction. The extension portion penetrated through the penetration hole is welded to the recessed portion.

[0021] In addition to or as an alternative to one or more of the features disclosed above, the electrode assembly is provided with at least two groups;

[0022] At least two avoidance holes are provided, and the retracted portion of each group of electrode assemblies is passed through a corresponding avoidance hole; or

[0023] The avoidance hole is provided with one, and the retracted parts of the plurality of electrode assemblies are all penetrated through the same avoidance hole.

[0024] In addition to or as an alternative to one or more of the features disclosed above, the insulating member includes: a first support portion, the first support portion having a first sub-hole formed therein; and

[0025] A second supporting portion, wherein a second sub-hole is formed on the second supporting portion, the second supporting portion is fixedly connected to the first supporting portion to form the insulating member, and the first sub-hole and the second sub-hole are enclosed to form the avoidance hole.

[0026] On the other hand, a battery pack is further disclosed. In addition to or as an alternative to one or more of the features disclosed above, the battery pack may include a containing box; and a single cell as described in any of the above items, wherein the single cell is accommodated in the containing box.

[0027] One of the above technical solutions has the following advantages or beneficial effects: the present application arranges the first inclined wall of the gathering part and the second inclined wall of the avoidance hole at intervals so that the insulating part avoids the gathering part of the pole ear, thereby avoiding the insulation part from compressing the gathering part of the pole ear during assembly, causing poor tearing of the pole ear, and avoiding damage to the pole ear, thereby optimizing the electron conduction path in the single cell and improving the power performance of the single cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0029] Figure 1 is a three-dimensional structural view of a single cell provided according to an embodiment of the present application;

[0030] Figure 2 is an exploded structural view of a single cell provided according to an embodiment of the present application;

[0031] Figure 3 is a three-dimensional structural view of an electrode assembly and an insulating member provided according to an embodiment of the present application;

[0032] Figure 4 is a cross-sectional view of the electrode assembly and the insulating member at AA according to an embodiment of the present application;

[0033] Figure 5 yes Figure 4 A local enlarged view of point B;

[0034] Figure 6 is a three-dimensional structural view of an electrode assembly provided according to an embodiment of the present application;

[0035] Figure 7 is a three-dimensional structural view of an insulating member provided according to an embodiment of the present application;

[0036] Figure 8 is a three-dimensional structural view of an insulating member provided according to another embodiment of the present application;

[0037] Fig. 9is a three-dimensional structural view of an insulating member provided according to another embodiment of the present application;

[0038] Fig.10 It is an exploded structural view of a battery pack provided according to an embodiment of the present application.

[0039] Description of reference numerals:

[0040] 100. Single cell;

[0041] 110. Shell;

[0042] 120, electrode assembly; 121, electrode body; 122, electrode ear; 1221, gathering portion; 12211, first inclined wall; 1222, extension portion;

[0043] 130, electrical connector; 131, through hole; 132, recessed portion;

[0044] 140, cover plate;

[0045] 150, insulating member; 151, avoidance hole; 1511, first sub-hole; 1512, second sub-hole; 152, second inclined wall; 153, first supporting portion; 154, second supporting portion;

[0046] 200, containing box body; 300, top cover; DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and beneficial effects of this application more clear, the following further describes this application in detail in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the specific implementation methods described in this specification are only for explaining this application, not for limiting this application.

[0048] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply 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 only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" refers to two or more, unless otherwise clearly and specifically defined.

[0049] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0050] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0051] The existing battery is composed of insulating parts, electrode assemblies, metal connecting sheets, shells and cover plates. In order to ensure the insulation arrangement between the electrode assemblies and the metal connecting sheets, the insulating parts are placed close to the roots of the positive and negative tabs in the existing battery. However, there is an unbendable area at the root of the tabs. If the insulating parts are placed close to the roots of the tabs, it is easy to cause the tabs to tear, which can easily cause a short circuit in the battery and affect the safety performance of the battery. Secondly, the insulating parts are above the unbendable area at the root of the tabs. The insulating parts will take up extra height space inside the battery, reducing the capacity of the battery.

[0052] In order to solve the above problems, in the embodiments of the present application, refer to Figures 1 to 9 The present application provides a single cell 100, wherein the single cell 100 has a first direction X, a second direction Z, and a third direction Y intersecting each other. Exemplarily, the single cell 100 has a first direction X, a second direction Z, and a third direction Y perpendicular to each other. Exemplarily, in the present application, the first direction X is the width direction of the single cell 100, the second direction Z is the height direction of the single cell 100, and the third direction Y is the length direction of the single cell 100.

[0053] Here, “perpendicular” refers to a state where the angle formed by straight lines, straight lines and planes, or planes and planes is 89° to 91°.

[0054] The single cell 100 may be a secondary battery, which refers to a battery that can be used continuously by activating active materials by charging after the battery is discharged. Exemplarily, the single cell 100 may be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel metal hydride battery or a nickel cadmium battery, but is not limited thereto.

[0055] The single battery 100 may be a cylindrical battery, a prismatic battery, a soft-pack battery, or a battery in other shapes.

[0056] Specifically, the single battery 100 includes: a housing 110 , an electrode assembly 120 , an electrical connector 130 , a cover plate 140 and an insulating member 150 .

[0057] Specifically, the electrode assembly 120 is accommodated in the shell 110, and the electrode assembly 120 includes: an electrode body 121 and a pole ear 122, the pole ear 122 includes a folding portion 1221 and an extension portion 1222, the folding portion 1221 is arranged on the electrode body 121, the extension portion 1222 is connected to an end of the folding portion 1221 away from the electrode body 121, and the folding portion 1221 cannot be bent; the cover plate 140 is connected to the shell 110; the insulating member 150 is arranged between the electrode assembly 120 and the cover plate 140, and the insulating member 150 is arranged close to the pole ear 122; the electrical connector 130 is arranged between the cover plate 140 and the insulating member 150, and the extension portion 1222 passes through the electrical connector 130 and is electrically connected to the electrical connector 130.

[0058] The housing 110 may be made of a strong material such as metal, but is not limited thereto. For example, the housing 110 is made of an aluminum profile, but is not limited thereto.

[0059] The cover plate 140 can be integrally formed with the housing 110, that is, the cover plate 140 and the housing 110 are an integrated structure; the cover plate 140 can also be fixedly connected to the housing 110, for example, the cover plate 140 is fixedly connected to one end of the housing 110 by welding or other processes. This is not specifically limited in this application and can be specifically set according to actual circumstances. For example, in this application, the cover plate 140 and the housing 110 are separately set, and the cover plate 140 and the housing 110 are sealed by laser welding.

[0060] The tab 122 may be a positive tab or a negative tab, which is not specifically limited in the present application and may be selected according to actual circumstances.

[0061] The insulating member 150 , the electrical connector 130 and the cover plate 140 are stacked in the second direction Z, and the electrical connector 130 is located between the insulating member 150 and the cover plate 140 to form a stacked structure.

[0062] The material of the electrical connector 130 may be copper, iron, aluminum, steel or aluminum alloy, but is not limited thereto.

[0063] The insulating member 150 is made of at least one of polyphenylene sulfide (PPS), polypropylene (PP), polycarbonate (PC), and polyethylene terephthalate (PET), but is not limited thereto.

[0064] Among them, the single cell 100 also includes an electrolyte, a pole and other functional components. The electrolyte can be a conventional electrolyte or a special electrolyte with additives added. The electrolyte is used to soak the electrode assembly 120. Among them, the electrode assembly 120 is a component in the single cell 100 where an electrochemical reaction occurs, and the electrode assembly 120 can be one or more. The electrode assembly 120 is mainly formed by winding a positive electrode sheet, a diaphragm and a negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active substances constitute the electrode body 121, and the parts of the positive electrode sheet and the negative electrode sheet without active substances constitute the pole ears. During the charge and discharge process of the single cell 100, the positive electrode active substance and the negative electrode active substance react with the electrolyte, and the pole ears are electrically connected to the poles to form a current loop, so that the single cell 100 can be used normally.

[0065] Specifically, the insulating member 150 is penetrated by a avoidance hole 151, and the extension portion 1222 and at least part of the retracted portion 1221 are passed through the avoidance hole 151 to preliminarily avoid the retracted portion 1221 of the tab 122 to prevent the insulating member 150 from pressing the retracted portion 1221 of the tab 122 and causing the tab to tear badly.

[0066] Specifically, a first inclined wall 12211 is provided on the gathering portion 1221, and a second inclined wall 152 is provided on the hole wall of the avoidance hole 151, and the second inclined wall 152 is arranged toward the first inclined wall 12211, and the first inclined wall 12211 and the second inclined wall 152 are both arranged obliquely relative to the first direction X, that is, the first inclined wall 12211 of the gathering portion 1221 and the second inclined wall 152 of the avoidance hole 151 are spaced apart, that is, the gathering portion 1221 and the avoidance hole 151 of the insulating member 150 are spaced apart, so that the insulating member 150 avoids the gathering portion 1221 of the pole ear 122, so as to avoid the gathering portion 1221 of the pole ear 122 being compressed during assembly of the insulating member 150 to cause poor tearing of the pole ear, and avoid damage to the pole ear 122, thereby optimizing the electronic conduction path in the single cell 100, improving the power performance of the single cell 100, and improving the production efficiency of the single cell 100.

[0067] In one embodiment, referring to Figures 4 to 5, the angle between the first inclined wall 12211 and the first direction X is α, and the angle between the second inclined wall 152 and the first direction X is β, which satisfies: α≤β. That is, the angle β between the second inclined wall 152 and the first direction X is not less than the angle α between the first inclined wall 12211 and the first direction X, so that the first inclined wall 12211 and the second inclined wall 152 are arranged at intervals, so that the insulating member 150 can avoid the gathered portion 1221 of the tab 122, effectively avoiding the side wall of the avoidance hole 151 from pressing the gathered portion 1221 of the tab 122 to cause the tab to tear poorly, thereby optimizing the electronic conduction path in the single battery 100 and improving the power performance of the single battery 100.

[0068] The angle α between the first inclined wall 12211 and the first direction X can be obtained by disassembling the actual single battery 100, measuring the angle between the first inclined wall 12211 of the retracted portion 1221 on the electrode assembly 120 and the first direction X multiple times using a measuring tool, and calculating the average value. The measuring tool can be an angle measuring instrument, but is not limited thereto.

[0069] The angle β between the second inclined wall 152 and the first direction X can be obtained by disassembling the actual single battery 100, cutting the insulating member 150 with a cutting device to obtain a sample to be measured of the insulating member 150, and measuring the angle between the second inclined wall 152 on the sample to be measured and the first direction X with a measuring tool for multiple times and calculating the average value. The measuring tool can be an angle measuring instrument, but is not limited thereto.

[0070] In one embodiment, in order to ensure the rationality of the overall structure of the single cell 100, the angle α between the first inclined wall 12211 and the first direction X is specifically designed in the present application, that is, the inclination angle of the first inclined wall 12211 is designed. Specifically, the angle α between the first inclined wall 12211 and the first direction X also satisfies: 0<α<90°. That is, the angle α between the first inclined wall 12211 and the first direction X can be controlled within the range of 0~90° (not taking the two endpoint values ​​of 0 and 90°). For example, the ratio of the angle α between the first inclined wall 12211 and the first direction X can be 5°, 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80° or 89°, or a range consisting of any two of them. The above specific values ​​of the angle α are given only as examples, and any value within the range of 0~90° (not taking the two endpoint values ​​of 0 and 90°) is within the protection scope of the present application.

[0071] Furthermore, the angle α between the first inclined wall 12211 and the first direction X also satisfies: 2°<α<60°. That is, the angle α between the first inclined wall 12211 and the first direction X can be controlled within the range of 2°~60° (not taking the two endpoint values ​​of 2° and 60°). For example, the ratio of the angle α between the first inclined wall 12211 and the first direction X can be 2°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55° or 59°, or a range consisting of any two of them. The above specific values ​​of the angle α are given only as examples, and any value within the range of 2°~60° (not taking the two endpoint values ​​of 2° and 60°) is within the protection scope of the present application.

[0072] The present application limits the angle α between the first slanted wall 12211 and the first direction X to be within the range of 0° to 90° (not taking the two endpoint values ​​of 0° and 90°). Further, the angle α between the first slanted wall 12211 and the first direction X is limited to be within the range of 2° to 60° (not taking the two endpoint values ​​of 2° and 60°). The angle between the first slanted wall 12211 and the first direction X is reasonably designed to avoid tearing during the retracting operation of the pole ear 122, thereby ensuring the structural integrity of the pole ear 122.

[0073] In one embodiment, in order to ensure the rationality of the overall structure of the single cell 100, the angle β between the second inclined wall 152 and the first direction X is specifically designed in the present application, that is, the inclination angle of the second inclined wall 152 is designed. Specifically, the angle β between the second inclined wall 152 and the first direction X also satisfies: 0<β<90°. That is, the angle β between the second inclined wall 152 and the first direction X can be controlled within the range of 0~90° (not taking the two endpoint values ​​of 0 and 90°). For example, the ratio of the angle β between the second inclined wall 152 and the first direction X can be 5°, 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80° or 89°, or a range consisting of any two of them. The above specific values ​​of the angle β are given only as examples, and any value within the range of 0~90° (not taking the two endpoint values ​​of 0 and 90°) is within the protection scope of the present application.

[0074] Furthermore, the angle β between the second inclined wall 152 and the first direction X also satisfies: 2°<β<60°. That is, the angle β between the second inclined wall 152 and the first direction X can be controlled within the range of 2°~60° (not taking the two endpoint values ​​of 2° and 60°). For example, the ratio of the angle β between the second inclined wall 152 and the first direction X can be 2°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55° or 59°, or a range consisting of any two of them. The above specific values ​​of the angle β are given only as examples, and any value within the range of 2°~60° (not taking the two endpoint values ​​of 2° and 60°) is within the protection scope of the present application.

[0075] The present application limits the angle β between the second slanted wall 152 and the first direction X to within the range of 0 to 90° (not taking the two endpoint values ​​of 0 and 90°), and further limits the angle β between the second slanted wall 152 and the first direction X to within the range of 2° to 60° (not taking the two endpoint values ​​of 2° and 60°), so as to reasonably design the angle β between the second slanted wall 152 and the first direction X, and further enables the insulating member 150 to avoid the gathered portion 1221 of the pole lug 122, so as to avoid the insulating member 150 from compressing the gathered portion 1221 of the pole lug 122 during assembly, causing poor tearing of the pole lug, and avoiding damage to the pole lug 122, thereby optimizing the electronic conduction path in the single cell 100 and improving the power performance of the single cell 100.

[0076] In one embodiment, referring to Figures 4 to 5 There are two first slanted walls 12211 and two second slanted walls 152, the two first slanted walls 12211 are arranged opposite to each other in the first direction X, the two second slanted walls 152 are arranged opposite to each other in the first direction X, and each second slanted wall 152 faces a corresponding first slanted wall 12211, so that the plurality of second slanted walls 152 and the corresponding first slanted wall 12211 are arranged at intervals, and further the insulating member 150 avoids the gathered portion 1221 of the pole ear 122, so as to avoid the insulating member 150 from compressing the gathered portion 1221 of the pole ear 122 during assembly, causing poor tearing of the pole ear, and avoiding damage to the pole ear 122, thereby optimizing the electronic conduction path in the single battery 100 and improving the power performance of the single battery 100.

[0077] In one embodiment, referring to Figures 4 to 5, the thickness of the insulating member 150 in the second direction Z is H1 mm, and the maximum height of the gathered portion 1221 in the second direction Z is H2 mm, satisfying: H1≤H2. That is, the maximum height H2 mm of the gathered portion 1221 in the second direction Z is not less than the thickness H1 mm of the insulating member 150 in the second direction Z, so as to ensure that the thickness H1 mm of the insulating member 150 in the second direction Z does not exceed the maximum height H2 mm of the gathered portion 1221 in the second direction Z, thereby reducing the space occupied by the insulating member 150 in the housing 110, improving the space occupancy rate of the electrode assembly 120, and finally improving the energy density of the single battery 100.

[0078] The thickness H1 mm of the insulating member 150 in the second direction Z can be obtained by disassembling the actual single battery 100, measuring the distance between two outer surfaces of the insulating member 150 arranged opposite to each other in the second direction Z multiple times using a measuring tool, and calculating the average value. The measuring tool can be any one of a ruler, a vernier caliper, or other dimension measuring instruments, but is not limited thereto.

[0079] The maximum height H2 mm of the gathered portion 1221 in the second direction Z can be obtained by disassembling the actual single battery 100, measuring the distance between two opposite ends of the gathered portion 1221 on the electrode assembly 120 in the second direction Z multiple times using a measuring tool, and calculating the average value. The measuring tool can be any one of a ruler, a vernier caliper, or other dimension measuring instruments, but is not limited thereto.

[0080] In one embodiment, in order to ensure the rationality of the overall structure of the single cell 100, the thickness H1 mm of the insulating member 150 in the second direction Z and the maximum height H2 mm of the gathered portion 1221 in the second direction Z are specifically designed in this application. Specifically, the thickness H1 mm of the insulating member 150 in the second direction Z and the maximum height H2 mm of the gathered portion 1221 in the second direction Z also satisfy: 0.03≤H1 / H2≤1. That is, the ratio of the thickness H1 mm of the insulating member 150 in the second direction Z and the maximum height H2 mm of the gathered portion 1221 in the second direction Z can be controlled within the range of 0.1 to 1. For example, H1 / H2 can be one of 0.03, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1 or a range consisting of any two of them. The above specific values ​​of H1 / H2 are given for example only, and any value within the range of 0.03 to 1 is within the protection scope of this application.

[0081] Furthermore, the thickness H1 mm of the insulating member 150 in the second direction Z and the maximum height H2 mm of the gathered portion 1221 in the second direction Z also satisfy: 0.25≤H1 / H2≤0.8. That is, the ratio of the thickness H1 mm of the insulating member 150 in the second direction Z and the maximum height H2 mm of the gathered portion 1221 in the second direction Z can be controlled within the range of 0.25 to 0.8. For example, H1 / H2 can be a range consisting of one of 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75 or 0.8 or any two of them. The above specific values ​​of H1 / H2 are given for example only, and any value within the range of 0.25 to 0.8 is within the protection scope of the present application.

[0082] The present application limits the ratio of the thickness H1 mm of the insulating member 150 in the second direction Z to the maximum height H2 mm of the gathering portion 1221 in the second direction Z to be within the range of 0.1 to 1, and further limits the ratio of the thickness H1 mm of the insulating member 150 in the second direction Z to the maximum height H2 mm of the gathering portion 1221 in the second direction Z to be within the range of 0.25 to 0.8, so as to reasonably design the dimensional relationship between the insulating member 150 and the gathering portion 1221, further ensure that the thickness H1 mm of the insulating member 150 in the second direction Z does not exceed the maximum height H2 mm of the gathering portion 1221 in the second direction Z, thereby reducing the space occupied by the insulating member 150 in the shell 110, improving the space occupancy rate of the electrode assembly 120, and ultimately improving the energy density of the single battery 100.

[0083] In one embodiment, the thickness H1 mm of the insulating member 150 in the second direction Z also satisfies: 0.1≤H1≤0.5. That is, the thickness H1 mm of the insulating member 150 in the second direction Z can be controlled within the range of 0.1 mm to 0.5 mm. For example, H1 mm can be one of 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm or 0.5 mm, or a range consisting of any two of them. The above specific values ​​of H1 mm are given for example only, and any value within the range of 0.1 mm to 0.5 mm is within the protection scope of the present application.

[0084] The maximum height H2 mm of the gathered portion 1221 in the second direction Z also satisfies: 0.5≤H2≤3.5. That is, the maximum height H2 mm of the gathered portion 1221 in the second direction Z can be controlled within the range of 0.5 mm to 3.5 mm. For example, H2 mm can be one of 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm or 3.5 mm, or a range consisting of any two of them. The above specific values ​​of H2 mm are given for example only, and any value within the range of 0.5 mm to 3.5 mm is within the protection scope of the present application.

[0085] In one embodiment, referring to Figure 6 to Figure 7 In order to further ensure the rationality of the overall structure of the single cell 100, the maximum length of the pole ear 122 in the third direction Y is L1 mm, and the maximum length of the avoidance hole 151 in the third direction Y is L2 mm, satisfying: 0.3≤L1 / L2≤1. That is, the ratio of the maximum length L1 mm of the pole ear 122 in the third direction Y to the maximum length L2 mm of the avoidance hole 151 in the third direction Y can be controlled within the range of 0.3 to 1. For example, L1 / L2 can be one of 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1 or a range consisting of any two of them. The above specific values ​​of L1 / L2 are given for example only, and any value within the range of 0.3 to 1 is within the protection scope of this application. The present application limits the ratio of the maximum length L1 mm of the pole tab 122 in the third direction Y to the maximum length L2 mm of the avoidance hole 151 in the third direction Y within the range of 0.3 to 1, thereby further allowing the insulating member 150 to avoid the retracted portion 1221 of the pole tab 122, thereby avoiding the insulating member 150 from compressing the retracted portion 1221 of the pole tab 122 during assembly, thereby avoiding poor tearing of the pole tab and damaging the pole tab 122, thereby optimizing the electronic conduction path in the single cell 100 and improving the power performance of the single cell 100.

[0086] The maximum length L1 mm of the tab 122 in the third direction Y can be obtained by disassembling the actual single battery 100, measuring the distance between the two ends of the tab 122 on the electrode assembly 120 that are oppositely arranged in the third direction Y with a measuring tool for multiple times, and calculating the average value. The measuring tool can be any one of a ruler, a vernier caliper, or other dimension measuring instruments, but is not limited thereto.

[0087] The maximum length L2 mm of the avoidance hole 151 in the third direction Y can be obtained by disassembling the actual single battery 100, measuring the distance between two hole walls of the avoidance hole 151 of the insulating member 150 that are arranged opposite to each other in the third direction Y using a measuring tool for multiple times, and calculating the average value. The measuring tool can be any one of a ruler, a vernier caliper, or other dimension measuring instruments, but is not limited thereto.

[0088] Furthermore, the maximum length L1 mm of the pole lug 122 in the third direction Y and the maximum length L2 mm of the avoidance hole 151 in the third direction Y also satisfy: 0.5≤L1 / L2≤0.8. That is, the ratio of the maximum length L1 mm of the pole lug 122 in the third direction Y and the maximum length L2 mm of the avoidance hole 151 in the third direction Y can be controlled within the range of 0.3 to 0.8. For example, L1 / L2 can be a range consisting of one of 0.5, 0.55, 0.6, 0.65, 0.7, 0.75 or 0.8 or any two of them. The above specific values ​​of L1 / L2 are given for example only, and any value within the range of 0.5 to 0.8 is within the protection scope of this application. The present application limits the ratio of the maximum length L1 mm of the pole tab 122 in the third direction Y to the maximum length L2 mm of the avoidance hole 151 in the third direction Y within the range of 0.5 to 0.8, thereby further allowing the insulating member 150 to avoid the retracted portion 1221 of the pole tab 122, thereby avoiding the insulating member 150 from compressing the retracted portion 1221 of the pole tab 122 during assembly, thereby avoiding poor tearing of the pole tab and damaging the pole tab 122, thereby optimizing the electronic conduction path in the single cell 100 and improving the power performance of the single cell 100.

[0089] In one embodiment, referring to Figure 6 , the maximum length L1 mm of the tab 122 in the third direction Y also satisfies: 10≤L1≤70. That is, the maximum length L1 mm of the tab 122 in the third direction Y can be controlled within the range of 10mm to 70mm. For example, L1mm can be one of 10mm, 20mm, 30mm, 40mm, 50mm, 60mm or 70mm or a range consisting of any two of them. The above specific values ​​of L1 are given for example only, and any value within the range of 10mm to 70mm is within the protection scope of this application.

[0090] The maximum length L2 mm of the avoidance hole 151 in the third direction Y also satisfies: 20≤L2≤90. For example, L2 mm can be 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm or 90 mm. Since the tab 122 is to be staggered with the avoidance hole 151 so that the tab 122 extends from the avoidance hole 151, the value of L2 mm is usually 10 to 20 mm greater than the value of L2 mm. The above specific values ​​of L2 mm are given for example only, and any value within the range of 20 mm to 90 mm is within the protection scope of the present application.

[0091] Furthermore, the maximum length L1 mm of the tab 122 in the third direction Y also satisfies: 25≤L1≤60. That is, the maximum length L1 mm of the tab 122 in the third direction Y can be controlled within the range of 25 mm to 60 mm. For example, L1 mm can be one of 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm or 60 mm or a range consisting of any two of them. The above specific values ​​of L1 / L2 are given for example only, and any value within the range of 25 mm to 60 mm is within the protection scope of this application.

[0092] The present application limits the maximum length L1 mm of the pole lug 122 in the third direction Y to within the range of 10 mm to 70 mm, and further limits the maximum length L1 mm of the pole lug 122 in the third direction Y to within the range of 25 mm to 60 mm, so as to reasonably design the structural dimensions of the pole lug 122, so as to ensure the basic functions of the pole lug 122 while further avoiding contact between the pole lug 122 and the insulating member 150, avoiding compression of the gathered portion 1221 of the pole lug 122 during assembly of the insulating member 150 to cause poor tearing of the pole lug, and avoiding damage to the pole lug 122, thereby optimizing the electronic conduction path in the single cell 100 and improving the power performance of the single cell 100.

[0093] In one embodiment, referring to Figure 2 The electrical connector 130 is provided with a penetration hole 131, and the extension portion 1222 that penetrates the avoidance hole 151 is penetrated in the penetration hole 131, so that the overall structure of the single battery 100 is compact, while reducing the space occupied by the pole ear 122, increasing the space occupancy rate of the electrode body 121 of the electrode assembly 120, and ultimately improving the energy density of the single battery 100.

[0094] Specifically, a recessed portion 132 is provided on the side of the electrical connector 130 that is away from the electrode assembly 120. The recessed portion 132 is located on the side of the penetration hole 131 along the first direction X. The extension portion 1222 penetrated through the penetration hole 131 is welded to the recessed portion 132 to further reduce the space occupied by the pole ear 122, increase the space occupancy rate of the electrode body 121 of the electrode assembly 120, and ultimately improve the energy density of the single cell 100.

[0095] In one embodiment, referring to Figure 7 The electrode assembly 120 is provided in at least two groups.

[0096] The insulating member 150 is integrally formed, and at least two avoidance holes 151 are provided. The retracted portion 1221 of each group of electrode assemblies 120 is passed through a corresponding avoidance hole 151, so that the multiple pole ears 122 on the electrode assembly 120 can be separated by using the multiple avoidance holes 151 on the insulating member 150 to avoid contact between two pole ears 122 and cause a short circuit in the single battery 100, thereby ensuring the normal use of the single battery 100.

[0097] In another embodiment, referring to Figure 8 The insulating member 150 is integrally formed, and an avoidance hole 151 is provided. The retracted portions 1221 of the plurality of electrode assemblies 120 are all penetrated through the same avoidance hole 151, so as to facilitate the processing and forming of the insulating member 150, and at the same time facilitate the assembly and forming of the single battery 100, thereby improving the production efficiency of the single battery 100.

[0098] In one embodiment, referring to Fig. 9 The insulating member 150 is a split structure. Specifically, the insulating member 150 includes: a first supporting portion 153 and a second supporting portion 154 .

[0099] Specifically, the first support portion 153 is provided with a first sub-hole 1511 and the second support portion 154, the second support portion 154 is provided with a second sub-hole 1512, the second support portion 154 is fixedly connected to the first support portion 153 to form an integral structure to constitute the insulating member 150, and the first sub-hole 1511 and the second sub-hole 1512 are enclosed to form an avoidance hole 151, so as to facilitate the assembly and molding of the single cell 100 and improve the production efficiency of the single cell 100.

[0100] The first support portion 153 and the second support portion 154 can be assembled into an integral structure by means of hot melting, snap connection or other connection methods.

[0101] The materials of the first support portion 153 and the second support portion 154 may be the same or different, which is not specifically limited in the present application and may be selected according to actual circumstances.

[0102] On the other hand, in the embodiments of the present application, referring to Fig.10 The present application also provides a battery pack, which may include: a containing box 200; and a single cell 100 as described in any of the above embodiments, wherein the single cell 100 is accommodated in the containing box 200.

[0103] The battery pack may be a three-layer battery pack of single cell-battery module-battery pack, or a module-free battery pack of two layers of single cell-battery pack.

[0104] On the other hand, in an embodiment of the present application, the present application further provides an electric device, including a battery pack as described above, the battery pack serving as a power supply for the electric device. The above-mentioned electric device may be, but is not limited to, a mobile device (such as a mobile phone, a laptop computer, etc.), an electric vehicle (such as a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, etc.), an electric train, a ship and a satellite, an energy storage system, etc.

[0105] In order to better understand the technical solution of the present application, a lithium-ion battery is taken as an example for further explanation below.

[0106] This embodiment provides a method for preparing a lithium ion battery, and the specific process is as follows:

[0107] 1. Preparation of positive electrode

[0108] The positive electrode active material is lithium iron phosphate, the conductive agent is conductive carbon black SP, and the binder is PVDF, which are mixed in a mass ratio of 96:2:2, and then NMP is added as a solvent for mixing, and stirred under vacuum until the system becomes uniform to obtain a positive electrode slurry; the positive electrode slurry is evenly coated on both sides of the positive electrode current collector aluminum foil, and then transferred to a 120°C oven for drying, and then rolled, slit, and cut into pieces to obtain a positive electrode sheet.

[0109] 2. Preparation of negative electrode sheet

[0110] The negative electrode active material graphite, the conductive agent conductive carbon black SP, the thickener CMC, and the binder SBR are mixed in a mass ratio of 96.2:1.2:1.2:1.4, and then deionized water is added as a solvent for mixing, and stirred under vacuum until the system becomes uniform to obtain a negative electrode slurry; the negative electrode slurry is evenly coated on both sides of the negative electrode collector copper foil, and then transferred to a 110°C oven for drying, and then rolled, slit, and cut to obtain a negative electrode sheet.

[0111] 3. Preparation of electrolyte

[0112] Ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) are mixed in a mass ratio of 3:4:3 to obtain an organic solvent, 1 mol / L of LiPF6 is added and mixed evenly, and then vinylene carbonate, vinyl sulfate and lithium difluorophosphate are added to prepare an electrolyte.

[0113] 4. Preparation of diaphragm

[0114] PP film is used as the separator.

[0115] 5. Preparation of lithium-ion batteries

[0116] The positive electrode sheet and the negative electrode sheet prepared by the above steps are dried and then used together with the separator to prepare a wound electrode assembly by a winding machine. The first pole ear and the second pole ear are welded to the end cover, and the welded electrode assembly with the top cover is placed in an aluminum shell for packaging; the lithium-ion battery is obtained by perfusing the electrolyte and forming a constant capacity.

[0117] The lithium-ion batteries of the embodiments and comparative examples are all prepared according to the above-mentioned preparation method. The structural dimensions and performance test data of the embodiments and comparative examples are shown in Table 1, Table 2 and Table 3.

[0118] Among them, Examples 1 to 36 in Table 1 are all prepared according to the above method. The differences between Examples 2 to 36 and Example 1 are: changes in the values ​​of α, β, H1, H2, H1 / H2, L1, L2 and L1 / L2.

[0119] The specific test items of the batteries prepared in the embodiments and comparative examples are as follows:

[0120] 1. Test method for whether the lithium-ion battery tab is torn

[0121] After assembling the lithium-ion battery, let it stand for 30 minutes, then disassemble the lithium-ion battery and observe whether the tabs are torn.

[0122] 2. Test method for energy density of lithium-ion batteries

[0123] At 25°C, let the lithium-ion battery stand for 30 minutes, charge it to the cut-off voltage with a current of 1C, let it stand for 30 minutes, and then discharge it to the cut-off voltage with a current of 1C, and record the actual discharge energy; weigh the lithium-ion battery with an electronic balance; the ratio of the actual discharge energy of 1C to the weight is the actual energy density of the lithium-ion battery. Among them, when the energy density of the lithium-ion battery is greater than 177Wh / kg, the energy density of the lithium-ion battery meets the standard and can meet the power requirements of the module.

[0124] Table 1 Parameters and test results of Examples 1 to 36

[0125]

[0126]

[0127] From the data in Table 1, it can be seen that in Examples 31 to 32 and Examples 35 to 36, the specific parameters of the lithium-ion batteries exceeded the parameter range in this application, the tabs in the lithium-ion batteries were torn, and the lithium-ion batteries did not show the corresponding performance and did not meet the requirements. In Examples 33 to 34, the specific parameters of the lithium-ion batteries exceeded the parameter range in this application, the energy density of the lithium-ion batteries was less than 177Wh / kg, and the lithium-ion batteries did not show the corresponding performance and did not meet the requirements.

[0128] It can be seen that the present application limits the angle β between the second inclined wall 152 and the first direction X to be not less than the angle α between the first inclined wall 12211 and the first direction X, limits the ratio of the maximum length L1 mm of the pole ear 122 in the third direction Y to the maximum length L2 mm of the avoidance hole 151 in the third direction Y to be within the range of 0.03 to 1, so that the insulating member 150 avoids the retracted portion 1221 of the pole ear 122, avoids the insulation member 150 from compressing the retracted portion 1221 of the pole ear 122 during assembly, and avoids the pole ear 122 from being damaged, thereby optimizing the electronic conduction path in the single cell 100 and improving the power performance of the single cell 100; by limiting the maximum height H2 mm of the retracted portion 1221 in the second direction Z to be not less than the thickness H1 mm of the insulating member 150 in the second direction Z, it is ensured that the thickness H1 mm of the insulating member 150 in the second direction Z does not exceed the maximum height H2 mm of the retracted portion 1221 in the second direction Z. mm, which reduces the space occupied by the insulating member 150 inside the shell 110, increases the space occupancy rate of the electrode assembly 120, and improves the energy density of the single battery 100.

[0129] The introduction provided in the above steps is only used to help understand the method, structure and core idea of ​​the present application. For ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A single battery having a first direction, characterized in that: include: case; An electrode assembly is accommodated in the housing, and the electrode assembly comprises: an electrode body and a pole ear, the pole ear comprises a gathering portion and an extension portion, the gathering portion is arranged on the electrode body, and the extension portion is connected to an end of the gathering portion away from the electrode body; a cover plate connected to the housing; and An insulating member is disposed between the electrode assembly and the cover plate, and the insulating member is disposed close to the electrode tab; Wherein, the insulating member is penetrated with an avoidance hole, and the extension portion and at least a part of the retracted portion are arranged through the avoidance hole; The gathering portion is provided with a first inclined wall, the hole wall of the avoidance hole is provided with a second inclined wall, the second inclined wall is arranged toward the first inclined wall, and the first inclined wall and the second inclined wall are both arranged obliquely relative to the first direction.

2. The single cell according to claim 1, characterized in that: The included angle between the first inclined wall and the first direction is α, and the included angle between the second inclined wall and the first direction is β, satisfying: α≤β.

3. The single cell according to claim 1, characterized in that: There are two first inclined walls, and the two first inclined walls are arranged opposite to each other in the first direction; Two second inclined walls are provided, the two second inclined walls are arranged opposite to each other in the first direction, and each second inclined wall faces a corresponding first inclined wall.

4. The single cell according to any one of claims 1 to 3, characterized in that: The single battery also has a second direction intersecting with the first direction, The thickness of the insulating member in the second direction is H1 mm, and the maximum height of the gathered portion in the second direction is H2 mm, satisfying: H1≤H2.

5. The single cell according to any one of claims 1 to 3, characterized in that: The single cell further has a third direction intersecting the first direction and the second direction in pairs; The maximum length of the pole ear in the third direction is L1 mm, and the maximum length of the avoidance hole in the third direction is L2 mm, satisfying: 0.3≤L1 / L2≤1.

6. The single cell according to claim 1, characterized in that: The single cell further includes: an electrical connector, wherein the electrical connector is disposed between the cover plate and the insulating member, and the extension portion passes through the electrical connector and is electrically connected to the electrical connector.

7. The single cell according to claim 6, characterized in that: The electrical connector is provided with a penetration hole, and the extension portion penetrated through the avoidance hole is penetrated through the penetration hole; A recessed portion is provided on a side of the electrical connector away from the electrode assembly. The recessed portion is located on a side of the penetration hole along a first direction. The extension portion penetrated through the penetration hole is welded to the recessed portion.

8. The single cell according to claim 1, characterized in that: The electrode assembly is provided with at least two groups; At least two avoidance holes are provided, and the retracted portion of each group of electrode assemblies is passed through a corresponding avoidance hole; or The avoidance hole is provided with one, and the retracted parts of the plurality of electrode assemblies are all penetrated through the same avoidance hole.

9. The single cell according to claim 1, characterized in that: The insulating member comprises: a first supporting portion, a first sub-hole being formed on the first supporting portion; and A second supporting portion, wherein a second sub-hole is formed on the second supporting portion, the second supporting portion is fixedly connected to the first supporting portion to form the insulating member, and the first sub-hole and the second sub-hole are enclosed to form the avoidance hole.

10. A battery pack, characterized in that: include: Containing box; as well as The single cell according to any one of claims 1 to 9, wherein the single cell is housed in the housing case.

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