Single battery, battery pack and power-consuming device

Abstract

The present application discloses a single cell, a battery pack and an electrical device, belonging to the technical field of batteries. It includes a housing, and a top cover plate is connected to the housing to seal the accommodation cavity. The first insulating member includes a body and a plurality of first bosses. The body is arranged at an interval from the electrode assembly. One side of the body facing away from the electrode assembly is connected to the top cover plate. The plurality of first bosses are respectively arranged on both sides of the body along the length direction and are respectively in contact with the top cover plate and the electrode assembly. The maximum dimension of the first boss in the thickness direction of the top cover plate is h1 mm, and the dimension of the top cover plate in the thickness direction is H mm, satisfying: 0.62 ≤ h1 / (h1 + H) ≤ 0.85. By defining the proportional relationship between the thickness of the first boss and the total thickness of the top cover plate and the first boss, while meeting the energy density requirements and limiting the electrode assembly, the occupied space of the first boss and the top cover plate is reduced, and the short-circuit defect caused by the first boss pressing the electrode assembly is avoided, thereby improving the safety of the single cell.

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] A single cell generally consists of a top cover sheet, a lower insulating member, a shell, etc. The top cover sheet and the lower insulating member are assembled together by ultrasonic heat fusion. Usually, a plurality of bosses are provided on the side of the lower insulating member facing the electrode assembly. The bosses are used to abut the electrode assembly to prevent the electrode assembly from moving in the shell and causing insulation failure. The existing boss design is unreasonable, resulting in reduced safety of single cells. 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 problem of reduced safety of single cells due to unreasonable boss setting.

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

[0005] A housing having a receiving cavity;

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

[0007] A top cover sheet connected to the shell and covering the accommodating cavity, wherein the top cover sheet has a thickness direction and a length direction intersecting with the thickness direction;

[0008] A first insulating member is located in the accommodating cavity, the first insulating member comprises a body and a plurality of first bosses connected to the body, the body is spaced apart from the electrode assembly, a side of the body away from the electrode assembly is connected to the top cover sheet, the plurality of first bosses are respectively arranged on both sides of the body along the length direction, and both sides of the first bosses along the thickness direction are respectively in contact with the top cover sheet and the electrode assembly;

[0009] The maximum dimension of the first boss along the thickness direction is h1 mm, and the maximum dimension of the top cover sheet along the thickness direction is H mm, satisfying: 0.62≤h1 / (h1+H)≤0.85.

[0010] In some embodiments, a single cell battery comprises:

[0011] The explosion-proof valve, the top cover sheet has a pressure relief hole, the explosion-proof valve is connected to the top cover sheet and covers the pressure relief hole;

[0012] The first insulating member further includes a second boss, which is disposed between two adjacent first bosses, and both sides of the second boss along the length direction are connected to the body;

[0013] The dimension of the second boss in the thickness direction is h2 mm, satisfying: 0.9≤h1 / h2≤1.1.

[0014] In some embodiments, the battery cell satisfies:

[0015] (a) 4≤h1≤8;

[0016] (b) 1.4≤H≤2.5.

[0017] In some embodiments, a dimension of the second boss along the thickness direction X is h2 mm, which satisfies: 4≤h2≤8.

[0018] In some embodiments, a dimension of the body in a thickness direction is h3 mm, satisfying: 0.4≤h3≤0.8.

[0019] In some embodiments, the first insulating member further includes a second boss, the second boss is disposed between two adjacent first bosses, and both sides of the second boss along the length direction are connected to the body; both sides of the second boss along the thickness direction are respectively abutted against the top cover sheet and the electrode assembly, and the total contact area between the first boss and the second boss and the electrode assembly is s1mm 2 The end surface of the top cover sheet facing away from the first insulating member is the first surface, and the area of ​​the first surface is S mm 2 , satisfying: 0.046≤s1*h1 / [(h1+H)*S]≤0.116.

[0020] In some embodiments, the battery cell satisfies:

[0021] (c) 610≤s1≤970;

[0022] (d) 7100≤S≤8100.

[0023] In some embodiments, the first boss has a first surface and a second surface arranged opposite to each other along the thickness direction, the first surface is connected to the top cover sheet, the second surface abuts against the electrode assembly, the first boss has at least one second groove, the second groove has an opening, and the opening passes through at least one of the first surface and the second surface.

[0024] In some embodiments, the opening passes through the second surface, and the maximum dimension between the second groove and the second surface in the thickness direction is h4 mm, satisfying: 2≤h4≤8.

[0025] In some embodiments, the main body and the first boss are separately provided.

[0026] In some embodiments, the body and the first boss are integrally formed.

[0027] In some embodiments, the body is connected to the first boss by heat fusion.

[0028] In some embodiments, the body is snap-connected to the first boss.

[0029] In some embodiments, one of the main body and the first boss is provided with a limiting hole, and the other of the main body and the first boss is provided with a clamping portion, and the clamping portion is embedded in the limiting hole.

[0030] Accordingly, an embodiment of the present application provides a battery pack, comprising the above-mentioned single cell battery.

[0031] Correspondingly, an embodiment of the present application provides an electrical device, including the above-mentioned single battery, or the above-mentioned battery pack.

[0032] Beneficial effects: The single cell battery of the embodiment of the present application includes a shell, an electrode assembly, a top cover sheet and a first insulating member. The shell has a accommodating cavity. The electrode assembly is located in the accommodating cavity. The top cover sheet is connected to the shell and covers the accommodating cavity, and the top cover sheet has a thickness direction and a length direction intersecting the thickness direction. The first insulating member is located in the accommodating cavity, and the first insulating member includes a main body and a plurality of first bosses connected to the main body, the main body and the electrode assembly are arranged at intervals, and the side of the main body away from the electrode assembly is connected to the top cover sheet, and the plurality of first bosses are respectively arranged on both sides of the main body along the length direction, and the first bosses are respectively abutted against the top cover sheet and the electrode assembly on both sides along the thickness direction. Among them, the maximum dimension of the first boss along the thickness direction is h1mm, and the maximum dimension of the top cover sheet in the thickness direction is H mm, satisfying: 0.62≤h1 / (h1+H)≤0.85. The present application reduces the space occupied by the first boss and the top cover sheet by limiting the proportional relationship between the thickness of the first boss and the thickness of the top cover sheet while meeting the energy density requirements and limiting the electrode assembly, thereby avoiding short circuits caused by the first boss compressing the electrode assembly, thereby effectively improving the safety of the single cell.

[0033] 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.

[0034] 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

[0035] 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.

[0036] Figure 1 is a schematic structural diagram of a single cell according to an embodiment of the present application;

[0037] Figure 2 is an exploded diagram of a single cell of an embodiment of the present application;

[0038] Figure 3 is an exploded view of a top cover sheet and a first insulating member of an embodiment of the present application;

[0039] Figure 4 is a schematic structural diagram of a top cover sheet and a first insulating member in an embodiment of the present application;

[0040] Figure 5 is a cross-sectional view of a top cover sheet and a first insulating member according to an embodiment of the present application;

[0041] Figure 6 is a schematic structural diagram of a first insulating member of a first embodiment of the present application;

[0042] Figure 7 is a schematic structural diagram of a second first insulating member in an embodiment of the present application;

[0043] Figure 8 is a schematic structural diagram of a third first insulating member in an embodiment of the present application;

[0044] Fig. 9 is a schematic structural diagram of a fourth first insulating member in an embodiment of the present application;

[0045] Fig.10 is a schematic structural diagram of a fifth first insulating member in an embodiment of the present application;

[0046] Fig.11 is an exploded view of a fifth first insulating member of an embodiment of the present application;

[0047] Fig.12 is a structural schematic diagram of a sixth first insulating member of an embodiment of the present application;

[0048] Fig.13 is a partial schematic diagram of a sixth first insulating member of an embodiment of the present application;

[0049] Fig.14 yes Fig.13 A magnified view of part A;

[0050] Fig.15 It is a structural schematic diagram of a first boss according to an embodiment of the present application.

[0051] 1. Shell; 2. Top cover; 3. First insulating member; 4. Explosion-proof valve; 5. Electrode assembly; 6. Protective patch; 10. Accommodating cavity; 20. Pressure relief hole; 21. First surface; 22. Pole hole; 23. Pole; 30. Main body; 31. First boss; 32. Second boss; 300. Clamping part; 301. First extension part; 310. First surface; 311. Second surface; 312. Second groove; 313. Boss body; 314. Recessed part; 315. Limiting hole; 316. Air hole; 317. First sub-boss; 318. Second extension part; 320. Connecting part; 321. Limiting part; 322. First groove; 3000. Protrusion; 3120. Opening; 3210. Through hole; X, thickness direction; Y, length direction. DETAILED DESCRIPTION

[0052] 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.

[0053] 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.

[0054] A single cell generally consists of a top cover sheet, a lower insulating member, a shell, etc. The top cover sheet and the lower insulating member are assembled together by ultrasonic hot melting. Usually, a plurality of bosses are provided on the side of the lower insulating member facing the electrode assembly. The bosses are used to abut the electrode assembly to prevent the electrode assembly from moving in the shell and causing insulation failure. If the boss is set too high, it will compress the pole piece and cause a short circuit. If the boss is set too low, it cannot effectively limit the electrode assembly, resulting in reduced safety of the single cell.

[0055] In view of this, the present application provides a single cell battery, comprising a shell, an electrode assembly, a top cover sheet and a first insulating member. The shell has a receiving cavity. The electrode assembly is located in the receiving cavity. The electrode assembly may be a winding structure. Specifically, the positive electrode sheet, the diaphragm and the negative electrode sheet are stacked in sequence and wound more than two turns to form an electrode assembly, and the electrode assembly may also be a laminated structure. Specifically, the electrode assembly includes a plurality of positive electrode sheets and a plurality of negative electrode sheets, and the diaphragm is arranged between the positive electrode sheets and the negative electrode sheets. The positive electrode sheets, the diaphragm and the negative electrode sheets are stacked along the height direction Z. The top cover sheet is connected to the shell and covers the receiving cavity, and the top cover sheet has a thickness direction and a length direction intersecting the thickness direction. The top cover sheet has a pole hole that penetrates along the thickness direction, and the pole is passed through the pole hole and connected to the top cover sheet. The first insulating member is located in the accommodating cavity. The first insulating member includes a body and a plurality of first bosses connected to the body. The body is spaced apart from the electrode assembly. The side of the body facing away from the electrode assembly is connected to the top cover sheet. The plurality of first bosses are respectively arranged on both sides of the body along the length direction. The first boss faces the electrode assembly and is connected to the electrode assembly. Among them, the maximum dimension of the first boss along the thickness direction is h1mm, and the maximum dimension of the top cover sheet in the thickness direction is Hmm, satisfying: 0.62≤h1 / (h1+H)≤0.85. The present application reduces the occupied space of the first boss and the top cover sheet while meeting the energy density requirements and limiting the electrode assembly by limiting the thickness of the first boss to a certain extent, so as to avoid the positive and negative electrode sheets piercing the diaphragm or directly overlapping due to the first boss pressing the electrode assembly, thereby preventing the problem of short circuit of the electrode assembly, thereby effectively improving the safety of the single cell.

[0056] 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.

[0057] refer to Figures 1 to 5The present application provides a single cell battery, comprising a shell 1, an electrode assembly 5, a top cover sheet 2 and a first insulating member 3. The shell 1 has a accommodating cavity 10. The electrode assembly 5 is located in the accommodating cavity 10. The electrode assembly 5 may be a winding structure. Specifically, the positive electrode sheet, the diaphragm and the negative electrode sheet are sequentially stacked and wound more than two turns to form the electrode assembly 5, and the electrode assembly 5 may also be a laminated structure. Specifically, the electrode assembly 5 includes a plurality of positive electrode sheets and a plurality of negative electrode sheets, and the diaphragm is arranged between the positive electrode sheets and the negative electrode sheets. The positive electrode sheets, the diaphragm and the negative electrode sheets are stacked along the height direction Z. The top cover sheet 2 is connected to the shell 1 and covers the accommodating cavity 10, and the top cover sheet 2 has a thickness direction X and a length direction Y intersecting with the thickness direction X. The first insulating member 3 is located in the accommodating cavity 10. The first insulating member 3 includes a body 30 and a plurality of first bosses 31 connected to the body 30. The body 30 is spaced apart from the electrode assembly 5. The side of the body 30 facing away from the electrode assembly 5 is connected to the top cover sheet 2. The plurality of first bosses 31 are respectively arranged on both sides of the body 30 along the length direction Y. The first bosses 31 are respectively abutted against the top cover sheet 2 and the electrode assembly 5 along both sides of the thickness direction X. Since the electrode assembly 5 expands during the charging and discharging process, the electrode assembly 5 is not completely fixed and will move along the thickness direction X under vibration conditions. The first bosses 31 are used to limit the electrode assembly 5 and prevent the electrode assembly 5 from moving in the thickness direction X. Among them, the maximum size of the first boss 31 along the thickness direction X is h1 mm, and the maximum size of the top cover sheet 2 in the thickness direction X is H mm, which satisfies: 0.62≤h1 / (h1+H)≤0.85. The present application reduces the space occupied by the first boss 31 and the top cover sheet 2 while meeting the energy density requirements and limiting the electrode assembly 5 by limiting the thickness of the first boss 31 relative to the total thickness of the top cover sheet 2 and the first boss 31, thereby avoiding the problem of the positive and negative electrodes piercing the diaphragm and overlapping or directly overlapping due to the first boss 31 pressing the electrode assembly 5, and thus causing the electrode assembly 5 to short-circuit. The safety of the single cell can be effectively improved.

[0058] In some embodiments, specifically, the number of first bosses 31 can be two, the two first bosses 31 are spaced apart and respectively connected to the two ends of the main body 30 along the length direction Y, and in the thickness direction (X), the side of the first boss 31 facing the top cover sheet 2 is flush with the side of the main body 30 facing the top cover sheet 2, and the side of the first boss 31 away from the top cover sheet 2 exceeds the side of the main body 30 away from the top cover sheet 2.

[0059] exist Figures 1 to 5In the illustrated embodiment, the single cell includes an explosion-proof valve 4, the top cover sheet 2 has a pressure relief hole 20, and the explosion-proof valve 4 is connected to the top cover sheet 2 and covers the pressure relief hole 20. The single cell includes a protective patch 6, which covers the pressure relief hole 20 and is located on the side of the explosion-proof valve 4 away from the electrode assembly 5. The protective patch 6 is used to protect the explosion-proof valve 4 to prevent it from deforming after collision, extrusion or friction, and ensure that the explosion-proof valve 4 can work normally when pressure relief is required. When the internal pressure or temperature of the single cell reaches a predetermined threshold, the weak structure provided in the explosion-proof valve 4 is destroyed, thereby forming an opening 3120 or channel for internal pressure or temperature relief.

[0060] exist Figures 3 to 13 In the illustrated embodiment, the first insulating member 3 further includes a second boss 32, which is disposed between two adjacent first bosses 31, and both sides of the second boss 32 along the length direction Y are connected to the body 30. The second boss 32 is disposed opposite to the pressure relief hole 20 in the thickness direction X, and the second boss 32 protrudes relative to the body 30 toward one side of the electrode assembly 5. The second boss 32 includes a connecting portion 320 and a limiting portion 321 connected to each other, and both sides of the connecting portion 320 are respectively connected to the body 30, and the connecting portion 320 and the limiting portion 321 are enclosed to form a first groove 322, and the limiting portion 321 has a plurality of through holes 3210, and the through holes 3210 are connected to the first groove 322, and the explosion-proof valve 4 is disposed toward the limiting portion 321 along the thickness direction X. The provision of the first groove 322 can prevent the explosion-proof valve 4 from contacting the first insulating member 3, thereby affecting the normal use of the explosion-proof valve 4. The second boss 32 is provided with a plurality of through holes 3210 . When the internal pressure or temperature of the single battery reaches a predetermined threshold, the explosion-proof valve 4 is actuated or the weak structure in the explosion-proof valve 4 is destroyed, and the pressure is released in time through the plurality of through holes 3210 , the first groove 322 and the pressure relief hole 20 .

[0061] In some embodiments, the second boss 32 is spaced apart from the electrode assembly 5 in the thickness direction X. In this arrangement, the second boss 32 protrudes relative to the body 30 toward the side of the electrode assembly 5, which can prevent the explosion-proof valve 4 from being impacted by external forces and affecting its normal use. In addition, the second boss 32 is provided with a plurality of through holes 3210, a first groove 322 and a pressure relief hole 20 to release pressure in time. In other embodiments, the second boss 32 abuts against the electrode assembly 5 in the thickness direction X. In this arrangement, while ensuring the normal use of the explosion-proof valve 4, it can limit the electrode assembly 5 and prevent the electrode assembly 5 from moving in the thickness direction X.

[0062] exist Figure 5In the illustrated embodiment, the maximum dimension of the first boss 31 along the thickness direction X is h1 mm, and the dimension of the second boss 32 along the thickness direction X is h2 mm, satisfying: 0.9≤h1 / h2≤1.1. It can be understood that if the dimension h2 of the second boss 32 along the thickness direction X is too small relative to the dimension h1 of the first boss 31 along the thickness direction X, so that h1 / h2 is too large, it may affect the spatial layout between the second boss 32 and the explosion-proof valve 4, resulting in the explosion-proof valve 4 being hindered when it is in motion; if the dimension h2 of the second boss 32 along the thickness direction X is too large relative to the dimension h1 of the first boss 31 along the thickness direction X, so that h1 / h2 is too small, it may occupy too much space, so that the limiting effect of the first boss 31 on the electrode assembly 5 is affected, or the overall thickness of the single battery is increased, which is not conducive to meeting the energy density requirements. If the dimension h2 of the second boss 32 in the thickness direction X is larger than the dimension h1 of the first boss 31 in the thickness direction X, so that h1 / h2 is between 1 and 1.1, since the second boss 32 is provided with multiple through holes 3210, its overall structural strength is relatively low, and a certain deformation can be generated when it abuts against the electrode assembly 5, so that the first boss 31 can abut against the electrode assembly 5, and then can work together with the first boss 31 to limit the electrode assembly 5, so as to prevent the electrode assembly 5 from moving in the thickness direction X. The embodiment of the present application limits the ratio range of the size of the first boss 31 in the thickness direction X to the size of the second boss 32 in the thickness direction X to maintain a reasonable size ratio between the first boss 31 and the second boss 32 to ensure the stability of the overall structure of the first insulating member 3. The first boss 31 is used to limit the electrode assembly 5 to prevent it from moving in the thickness direction X, and the second boss 32 is mainly used to cooperate with the pressure relief function of the explosion-proof valve 4 and prevent the explosion-proof valve 4 from contacting the body 30 and the electrode assembly 5. In some embodiments, the first boss 31 and the second boss 32 can jointly limit the electrode assembly 5.

[0063] exist Figure 5 In the illustrated embodiment, the dimension h1mm of the first boss 31 along the thickness direction X satisfies: 4≤h1≤8. Specifically, the dimension h1 of the first boss 31 along the thickness direction X can be any one of 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8 or a range between any two values. When the above range is met, the first boss 31 can effectively limit the electrode assembly 5, meet the energy density requirements, and prevent the positive and negative electrode sheets from piercing the diaphragm or directly overlapping due to the first boss 31 pressing the electrode assembly 5, thereby causing the electrode assembly 5 to short-circuit badly, effectively improving the safety of the single battery.

[0064] exist Figure 5In the illustrated embodiment, the dimension h2mm of the second boss 32 along the thickness direction X satisfies: 4≤h2≤8. Specifically, the dimension h2 of the second boss 32 along the thickness direction X can be any one of 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8 or a range between any two values. When the above range is satisfied, the second boss 32 can cooperate with the pressure relief function of the explosion-proof valve 4 and prevent the explosion-proof valve 4 from contacting the body 30 and the electrode assembly 5. When the internal pressure or temperature of the single cell reaches a predetermined threshold, it can ensure that the internal gas is timely discharged through the multiple through holes 3210, the first groove 322 and the pressure relief hole 20, thereby ensuring the safety of the single cell. Further, when the second boss 32 can abut against the electrode assembly 5, by limiting the dimension of the second boss 32 along the thickness direction X, the electrode assembly 5 can be limited without pressing the electrode assembly 5 to cause a short circuit, thereby preventing the electrode assembly 5 from moving in the thickness direction X, and effectively improving the safety of the single cell.

[0065] exist Figure 5 In the illustrated embodiment, the maximum dimension of the top cover sheet 2 in the thickness direction X is H mm, satisfying: 1.4≤H≤2.5. Specifically, the maximum dimension H of the top cover sheet 2 in the thickness direction X can be any one of 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4 or a range between any two values. When the above range is satisfied, the structural strength of the top cover sheet 2 can be ensured, and deformation caused by external extrusion, collision, etc. during the use of the single battery can be avoided, while reducing the volume occupied by the top cover sheet 2, which is conducive to improving the energy density of the single battery.

[0066] exist Figure 5 In the illustrated embodiment, the dimension of the body 30 in the thickness direction X is h3 mm, satisfying: 0.4≤h3≤0.8. Specifically, the dimension h3 of the body 30 in the thickness direction X can be any one of 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8 or a range between any two values. The body 30 is disposed between the first boss 31 and the second boss 32. When the dimension h3 of the body 30 in the thickness direction X satisfies the above range, the body 30 can be prevented from occupying too much space in the thickness direction X while ensuring the structural stability of the first insulating member 3, thereby improving the energy density of the single battery.

[0067] In some embodiments, the first insulating member 3 further includes a second boss 32, which is disposed between two adjacent first bosses 31, and both sides of the second boss 32 along the length direction Y are connected to the body 30, and both sides of the second boss 32 along the thickness direction X are respectively in contact with the top cover sheet 2 and the electrode assembly 5, and the total contact area between the first boss 31 and the second boss 32 and the electrode assembly 5 is s1mm 2 The end surface of the top cover sheet 2 facing away from the first insulating member 3 is the first surface 21, and the area of ​​the first surface 21 is Smm 2 , satisfying: 0.046≤s1*h1 / [(h1+H)*S]≤0.116. It can be understood that s1*h1 is the volume of the first boss 31 and the second boss 32 , and H*S is the volume of the top cover sheet 2 . If the embodiment of the present application further limits the contact area s1 between the first boss 31 and the second boss 32 and the electrode assembly 5 and the area S of the first surface 21 on the basis of limiting the ratio range of h1 / (h1+H), on the one hand, it can avoid the first boss 31 and the second boss 32 occupying too much space and compressing the electrode assembly 5, resulting in the positive and negative electrode sheets piercing the diaphragm and overlapping or directly overlapping, and then causing the electrode assembly 5 to short-circuit. On the other hand, it can avoid the first boss 31 and the second boss 32 being too small in size and easily deformed, thereby ensuring the structural strength of the first boss 31 and the second boss 32, so as to effectively limit the movement of the electrode assembly 5 in the thickness direction X, thereby improving the stability and safety of the single cell; in addition, a reasonable volume ratio helps to improve the energy density of the single cell while ensuring the structural stability of the first insulating member 3 and the top cover sheet 2.

[0068] In some embodiments, specifically, the second boss 32 can be set to one, and in the thickness direction X, the side of the second boss 32 facing the top cover sheet 2 is flush with the side of the main body 30 facing the top cover sheet 2, and the side of the second boss 32 away from the top cover sheet 2 exceeds the side of the main body 30 away from the top cover sheet 2.

[0069] In some embodiments, the area s1 of the first boss 31 and the second boss 32 in contact with the electrode assembly 5 satisfies: 610≤s1≤970. Specifically, the area s1 of the first boss 31 and the second boss 32 in contact with the electrode assembly 5 can be any one of 610, 650, 700, 750, 800, 850, 900, 950, 970 or a range between any two values. If the area of ​​contact between the first boss 31 and the second boss 32 and the electrode assembly 5 is too small, deformation is likely to occur, and the electrode assembly 5 cannot be effectively limited. If the area of ​​contact between the first boss 31 and the second boss 32 and the electrode assembly 5 is too large, the positive and negative electrodes will be compressed to puncture the diaphragm and overlap or directly overlap, resulting in a short circuit problem of the electrode assembly 5. The embodiment of the present application can ensure the structural strength of the first boss 31 and the second boss 32 by limiting the contact area s1 of the first boss 31 and the second boss 32 with the electrode assembly 5, so as to effectively limit the movement of the electrode assembly 5 in the thickness direction X, thereby improving the stability and safety of the single battery.

[0070] In some embodiments, the end surface of the top cover sheet 2 on the side away from the first insulating member 3 is the first surface 21, and the area S of the first surface 21 satisfies: 7100≤S≤8100. Specifically, the area S of the first surface 21 can be any one of 7100, 7200, 7300, 7400, 7500, 7600, 7700, 7800, 7900, 8000, 8100 or a range between any two values. If the area of ​​the first surface 21 is too large, the energy density of the single cell is affected. If the area of ​​the first surface 21 is too small, the layout of the pole 23, explosion-proof valve 4, first insulating member 3, electrode assembly 5 and other structures on the top cover sheet 2 may be affected, resulting in a decrease in the structural strength of the top cover sheet 2 and affecting the safety of the single cell. The embodiment of the present application limits the area of ​​the first surface 21 to ensure the reasonable layout of the top cover sheet 2, the first insulating member 3, the electrode assembly 5 and other structures, ensure the energy density of the single cell, and help improve the stability and safety of the single cell.

[0071] In the embodiments of the present application, the upper and lower surfaces of the first boss 31 along the thickness direction X are clamped by a digital caliper to measure the maximum dimension h1 of the first boss 31 along the thickness direction X. The upper and lower surfaces of the second boss 32 along the thickness direction X are clamped by a digital caliper to measure the maximum dimension h2 of the second boss 32 along the thickness direction X. The upper and lower surfaces of the top cover sheet 2 along the thickness direction X are clamped by a digital caliper to measure the maximum dimension H of the top cover sheet 2 along the thickness direction X. The area S of the first surface 21 and the total area s1 of the first boss 31 and the second boss 32 in contact with the electrode assembly 5 are measured by a digital caliper, and it is tested whether the single cells in different embodiments meet the energy density requirements, whether they pass the mechanical safety test, and whether they can limit the movement of the electrode assembly 5. The test results refer to Table 1.

[0072] Table 1:

[0073]

[0074] In some embodiments, energy density = (A*V) / W, where A is the rated capacity of the single cell, W is the weight of the single cell, and V is the rated voltage of the single cell. For example, taking a single cell with a model number of 39202 as an example, the qualified range of its battery energy density is 170-195Wh / kg.

[0075] In some embodiments, a mechanical safety test is performed under the standard GB38031-2020 "Safety Requirements for Power Batteries for Electric Vehicles" to determine whether the single cell battery will have at least one of fire, leakage, and explosion. OK means that the safety performance requirements can be met, and NG means that at least one of fire, leakage, and explosion occurs, and the safety performance requirements are not met.

[0076] In some embodiments, vibration testing, bump simulation testing, and other methods are used to simulate the bumps encountered by the electric vehicle during driving, and determine whether the electrode assembly 5 is moving.

[0077] In some embodiments, referring to Comparative Example 1, when the maximum dimension h1 of the first boss 31 along the thickness direction X is too small, resulting in h1 / (h1+H)<0.62, although the energy density of the single battery meets the requirements, it does not pass the mechanical safety test, does not meet the safety performance requirements, and cannot effectively limit the movement of the electrode assembly 5. It can be understood that since the electrode assembly 5 expands during the charging and discharging process, the electrode assembly 5 is not completely fixed, and will move along the thickness direction X under vibration conditions. If the size of the first boss 31 is too small, the movement of the electrode assembly 5 cannot be effectively limited. When the dimension h2 of the second boss 32 in the thickness direction X is too large relative to the dimension h1 of the first boss 31 in the thickness direction X, resulting in h1 / h2<0.9, only the second boss 32 abuts against the electrode assembly 5 in the thickness direction X, and the movement of the electrode assembly 5 cannot be effectively limited. When only the second boss 32 can abut against the electrode assembly 5 in the thickness direction X, the contact area s1 of the first boss 31 and the second boss 32 with the electrode assembly 5 is too small and the area S of the first surface 21 is too large, s1*h1 / [(h1+H)*S]<0.046, and the first insulating member 3 cannot effectively limit the movement of the electrode assembly 5.

[0078] With reference to Examples 1 to 6, when the ratio of the thickness of the first boss 31 to the total thickness of the top cover sheet 2 and the first boss 31 satisfies 0.62≤h1 / (h1+H)≤0.85, by reasonably setting the dimensions of the first boss 31 and the top cover sheet 2, it is possible to ensure that the movement of the electrode assembly 5 is effectively restricted while reducing the space occupied by the first boss 31 and the top cover sheet 2, thereby avoiding the positive and negative electrode sheets piercing the diaphragm and overlapping or directly overlapping due to the first boss 31 pressing the electrode assembly 5, thereby avoiding the problem of short circuit of the electrode assembly 5, thereby effectively improving the safety of the single cell and increasing the energy density of the single cell. When the ratio between the size of the first boss 31 in the thickness direction X and the size of the second boss 32 in the thickness direction X satisfies 0.9≤h1 / h2≤1.1, the stability of the overall structure of the first insulating member 3 is ensured by limiting the reasonable size ratio between the first boss 31 and the second boss 32. The first boss 31 is used to limit the electrode assembly 5 to prevent it from moving in the thickness direction X, while the second boss 32 is mainly used to cooperate with the pressure relief function of the explosion-proof valve 4 and prevent the explosion-proof valve 4 from contacting the body 30 and the electrode assembly 5. In some embodiments, the first boss 31 and the second boss 32 can jointly limit the electrode assembly 5.

[0079] Referring to Comparative Example 2, when the maximum dimension h1 of the first boss 31 along the thickness direction X is too large, resulting in h1 / (h1+H)>0.85, the first boss 31 occupies too much internal space, resulting in the energy density of the single battery being too low to meet the requirements. When the contact area s1 of the first boss 31 and the second boss 32 with the electrode assembly 5 is too large and the area S of the first surface 21 is too small, resulting in s1*h1 / [(h1+H)*S]>0.116, the contact area of ​​the first boss 31 and the second boss 32 with the electrode assembly 5 is too large, which will compress the electrode assembly 5, causing the positive and negative electrodes to pierce the diaphragm and overlap or directly overlap, and then the electrode assembly 5 will have a short circuit problem, affecting the safety of the single battery.

[0080] In some embodiments, the material of the first insulating member 3 may be at least one of PP (polypropylene), PET (polyethylene terephthalate) or PPS (polyphenylene sulfide).

[0081] In some embodiments, the first boss 31 has a first surface 310 and a second surface 311 that are arranged opposite to each other along the thickness direction X, the first surface 310 is connected to the top cover sheet 2, the second surface 311 is connected to the electrode assembly 5, and the first boss 31 has at least one second groove 312, the second groove 312 has an opening 3120, and the opening 3120 passes through at least one of the first surface 310 and the second surface 311. While meeting the strength of the first boss 31, the provision of the second groove 312 can reduce the weight of the first boss 31, reduce the use of materials for the first insulating member 3, reduce costs, and improve the energy density of the single battery.

[0082] exist Figure 3 , Figures 6 to 13 In the illustrated embodiment, the opening 3120 of the second groove 312 is disposed on the first surface 310, and the second surface 311 is provided with a plurality of spaced-apart air holes 316. The setting of the air holes 316 can reduce the obstruction of the first boss 31 to the gas flow, thereby facilitating the gas to flow toward the explosion-proof valve 4 disposed on the top cover sheet 2.

[0083] In some embodiments, the opening 3120 of the second groove 312 is disposed on the second surface 311, and the second groove 312 is recessed from the second surface 311 to the first surface 310. This configuration can reduce the weight of the first boss 31, reduce the use of materials for the first insulating member 3, reduce costs, and improve the energy density of the single battery. Figure 8 , the number of the first groove 322 is one. Fig. 9There are multiple second grooves 312, and the multiple second grooves 312 are arranged at intervals to divide the first boss 31 into multiple first sub-bosses 317. By limiting the depth of the second grooves 312, multiple first sub-bosses 317 can be connected or not connected.

[0084] exist Fig. 9 In the illustrated embodiment, the opening 3120 passes through the second surface 311, and a height difference is formed between the bottom wall of the second groove 312 and the second surface 311. The maximum dimension of the second groove 312 and the second surface 311 in the thickness direction X is h4, which satisfies 0.2mm≤h4≤0.6mm. Specifically, the maximum dimension h4 of the second groove 312 and the second surface 311 in the thickness direction X can be any one of 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, and 0.6mm, or a range between any two values. When the above range is met, the height difference formed between the bottom wall of the second groove 312 and the second surface 311 can increase the friction between the first boss 31 and the electrode assembly 5, and prevent the electrode assembly 5 and the first boss 31 from sliding relative to each other.

[0085] In some embodiments, the body 30 and the first boss 31 are separately provided. Such a configuration can improve the versatility of the parts, and multiple electrode assemblies 5 can share the first boss 31, thereby reducing mold opening costs.

[0086] In some embodiments, the body 30 and the first boss 31 are integrally formed.

[0087] In some embodiments, the body 30 , the first boss 31 , and the second boss 32 are integrally formed.

[0088] In some embodiments, the body 30 is connected to the first boss 31 by heat melting. Specifically, the connecting portion 320 of the body 30 and the first boss 31 can be heated to melt the surface of the connecting portion 320 of the body 30 and the first boss 31 to connect the body 30 and the first boss 31.

[0089] In other embodiments, the body 30 is connected to the first boss 31 by snapping. One of the body 30 and the first boss 31 is provided with a limiting hole 315, and the other of the body 30 and the first boss 31 is provided with a snap-fitting portion 300, which is embedded in the limiting hole 315. Figures 12 to 15In the embodiment shown, the body 30 is provided with a first extension portion 301, the first extension portion 301 is provided with a plurality of spaced clamping portions 300, the first boss 31 is provided with a second extension portion 318, the second extension portion 318 is provided with a plurality of spaced limiting holes 315, the limiting holes 315 correspond to the positions of the clamping portions 300, the clamping portions 300 are penetrated through the limiting holes 315, and the side of the clamping portion 300 away from the body 30 is provided with a protrusion 3000, the protrusion 3000 is made of a flexible material and can produce a certain deformation. The clamping portion 300 is limited by the protrusion 3000. The first extension portion 301 and the second extension portion 318 are connected by the clamping portion 300 embedded in the limiting hole 315. With such a configuration, the structure is simple, and multiple electrode assemblies 5 can share the first boss 31, reducing the mold opening cost.

[0090] Accordingly, an embodiment of the present application provides a battery pack, including the above-mentioned single cell. The battery pack can be a single physical module including one or more single cells to provide higher voltage and capacity. When there are multiple single cells, the multiple single cells can be connected in series, in parallel or in a mixed manner.

[0091] Accordingly, an embodiment of the present application provides an electrical device, including the above-mentioned single cell battery, or the above-mentioned battery pack. The battery pack is a power supply for the electrical device. The electrical device may be a mobile phone, a portable device, a laptop computer, an electric vehicle, an electric car, a ship, a spacecraft, an electric toy, an electric tool, and the like. For example, spacecraft include airplanes, rockets, space shuttles, and spacecrafts, and the like; electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like; 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, and the like.

[0092] 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.

[0093] 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, located in the accommodating cavity; A top cover sheet connected to the shell and covering the accommodating cavity, wherein the top cover sheet has a thickness direction and a length direction intersecting with the thickness direction; A first insulating member is located in the accommodating cavity, the first insulating member comprises a body and a plurality of first bosses connected to the body, the body is spaced apart from the electrode assembly, the side of the body facing away from the electrode assembly is connected to the top cover sheet, the plurality of first bosses are respectively arranged on both sides of the body along the length direction, and the first bosses are respectively abutted against the top cover sheet and the electrode assembly on both sides along the thickness direction; the first insulating member further comprises a second boss, the second boss is arranged between two adjacent first bosses, the second bosses are connected to the body on both sides along the length direction, and the second bosses are respectively abutted against the top cover sheet and the electrode assembly on both sides along the thickness direction; The maximum dimension of the first boss along the thickness direction is h1 mm, the maximum dimension of the top cover sheet in the thickness direction is H mm, and the total contact area between the first boss and the second boss and the electrode assembly is s1 mm. 2 The end surface of the top cover sheet facing away from the first insulating member is the first surface, and the area of ​​the first surface is Smm 2 , satisfying: 0.62≤h1 / (h1+H)≤0.85, 0.046≤s1*h1 / [(h1+H)*S]≤0.116, 4≤h1≤8, 1.4≤H≤2.5, 610≤s1≤970, 7100≤S≤8100.

2. The single cell according to claim 1, characterized in that: The single cell battery comprises: An explosion-proof valve, wherein the top cover sheet has a pressure relief hole, and the explosion-proof valve is connected to the top cover sheet and covers the pressure relief hole; The first insulating member further includes a second boss, the second boss is disposed between two adjacent first bosses, and both sides of the second boss along the length direction are connected to the body; The dimension of the second boss in the thickness direction is h2 mm, satisfying: 0.9≤h1 / h2≤1.

1.

3. The single cell according to claim 2, characterized in that: A dimension of the second boss along the thickness direction, h2 mm, satisfies: 4≤h2≤8.

4. The single cell according to claim 1, characterized in that: The dimension of the main body in the thickness direction is h3 mm, satisfying: 0.4≤h3≤0.

8.

5. The single cell according to claim 1, characterized in that: The first boss has a first surface and a second surface arranged opposite to each other along the thickness direction, the first surface is connected to the top cover sheet, the second surface abuts the electrode assembly, the first boss has at least one second groove, the second groove has an opening, and the opening passes through at least one of the first surface and the second surface.

6. The single cell according to claim 5, characterized in that: The opening passes through the second surface, and the maximum dimension of the second groove and the second surface in the thickness direction is h4 mm, satisfying: 2≤h4≤8.

7. The single cell according to claim 1, characterized in that: The main body and the first boss are separately provided, or the main body and the first boss are integrally provided.

8. The single cell according to claim 7, characterized in that: The main body is connected to the first boss by thermal melting.

9. The single cell according to claim 7, characterized in that: The main body is clamped and connected to the first boss.

10. The single cell according to claim 9, characterized in that: One of the body and the first boss is provided with a limiting hole, and the other of the body and the first boss is provided with a clamping portion, and the clamping portion is embedded in the limiting hole.

11. A battery pack, characterized in that: A single cell comprising the single cell according to any one of claims 1 to 10.

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

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