Single battery and battery pack

Abstract

The utility model relates to the technical field of batteries, in particular to a single battery and a battery pack, the single battery comprises a shell, an electrode assembly and an insulating part, the insulating part comprises an insulating part, a first coating part, a second coating part, a third coating part and a fourth coating part, and the insulating part covers a third side wall deviating from a pole; two sides of the insulating part in the first direction are connected with first coating parts, the first coating parts cover the first side walls, two sides of the first coating parts in the second direction are connected with second coating parts, and the second coating parts cover the second side walls; the two sides, in the second direction, of the insulating part are connected with third wrapping parts, and the third wrapping parts cover the second side walls. The two sides, in the first direction, of the third wrapping part are connected with fourth wrapping parts, the fourth wrapping parts cover the first side walls, and the fourth wrapping parts and the third wrapping part are of an integrated structure. According to the invention, the contact between the fallen charged particles and the shell can be avoided as much as possible, so that the shell is prevented from being corroded as much as possible, and the durability and stability of the battery are 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] The battery shell is generally made of metal. When the shell comes into contact with negative charged particles, the shell will be corroded. After the shell is corroded, there is a risk of electrolyte leakage from the shell. At present, the method of coating the electrode assembly with an insulating film is mostly used to limit the free movement of ions inside the battery, improve the stability of the battery, prevent the leakage of negative charged particles inside the battery, and isolate the battery from the external environment, thereby improving the durability and insulation performance of the battery.

[0003] However, when the existing insulating film is used to cover the electrode assembly, it is difficult to cover the four corners of the electrode assembly, and there is still a problem that the negative electrode charged particles contact the shell at the four corners, causing corrosion of the shell. Utility Model Content

[0004] The present application provides a single cell and a battery pack to solve the technical problem that the existing battery pack is prone to corrosion at the four corners of the shell.

[0005] The present application provides a single battery, comprising:

[0006] A shell having a first direction, a second direction and a third direction which are perpendicular to each other;

[0007] An electrode assembly, wherein the electrode assembly has two opposite first side walls in a first direction, two opposite second side walls in a second direction, and two opposite third side walls in a third direction, and a pole of a single battery is disposed through the housing and connected to a pole piece at a third side wall;

[0008] An insulating member, comprising an insulating portion, a first covering portion, a second covering portion, a third covering portion and a fourth covering portion, wherein the insulating portion covers a third side wall away from the pole;

[0009] The insulating portion is connected to first covering portions on both sides in the first direction, the first covering portions cover the first side wall, and the first covering portions are connected to second covering portions on both sides in the second direction, the second covering portions cover the second side wall;

[0010] The insulating portion is connected to third covering portions at two sides in the second direction respectively, and the third covering portions cover the second side wall;

[0011] The third covering portion is connected to the fourth covering portion at two sides in the first direction respectively. The fourth covering portion covers the first side wall. The fourth covering portion and the third covering portion are an integral structure.

[0012] As one of the optional embodiments of this solution, the electrode assembly includes a positive electrode sheet, a negative electrode sheet and a separator, the separator is arranged between the positive electrode sheet and the negative electrode sheet, the separator includes a stacking layer and a coating layer, and the coating layer is closer to the inner wall of the shell relative to the stacking layer;

[0013] The covering layer includes a stacking portion and a first isolating portion, wherein the first isolating portion is connected to a side of the stacking portion away from the pole, and covers a side away from the stacking layer and the positive and negative electrode sheets away from the pole.

[0014] As one of the optional embodiments of this solution, the electrode assembly is formed by winding a positive electrode sheet, a negative electrode sheet and a separator, and the stacking layer is connected to one side of the coating layer in the second direction;

[0015] The covering layer further includes a second isolating portion connected to a side of the first isolating portion away from the stacking portion in the first direction, and the second isolating portion covers the stacking layer and a side of the positive electrode sheet and the negative electrode sheet away from the stacking portion.

[0016] As one of the optional embodiments of this solution, the electrode assembly is formed by stacking a positive electrode sheet, a negative electrode sheet and a separator, and the stacking layer is connected to one side of the coating layer in the second direction;

[0017] There are multiple coating layers, and each coating layer is stacked along the first direction. The stacked layers are stacked between adjacent coating layers in the first direction. The first isolation portion of each coating layer is stacked on the stacked layers and the side of the positive and negative electrodes away from the poles.

[0018] As one of the optional embodiments of the present solution, there are multiple second covering parts, and the second covering parts on the same second side wall are stacked.

[0019] As one of the optional embodiments of the present solution, the height of the third covering portion in the third direction is H1 mm, 15≤H1≤25, and the height of the fourth covering portion in the third direction is H2 mm, H2=H1.

[0020] As one of the optional embodiments of the present solution, the length of the fourth covering portion in the second direction is L1 mm, 5≤L1≤15.

[0021] As one of the optional embodiments of the present solution, along the second direction, the third covering portion is arranged on a side of the second covering portion away from the second side wall; along the first direction, the fourth covering portion is arranged on a side of the first covering portion away from the first side wall.

[0022] As one of the optional embodiments of the present solution, there is a bonding layer between the first covering portion and the fourth covering portion, and there is an adhesive layer between the second covering portion and the third covering portion.

[0023] As one of the optional embodiments of the present solution, it also includes a fixing member, which is attached to the surface of the insulating member facing away from the electrode assembly and covers at least a portion of the area corresponding to the first side wall and at least a portion of the area corresponding to the second side wall.

[0024] The present application also provides a battery pack, comprising any of the above single cells.

[0025] One of the above technical solutions has the following advantages or beneficial effects:

[0026] By providing an insulating member, the insulating part of the insulating member covers the third side wall, the first covering part covers the first side wall, the second covering part and the third covering part cover the second side wall, and the fourth covering part covers the first side wall, so that each side wall of the electrode assembly can be covered, and because the third covering part and the fourth covering part are an integrated structure, when the insulating member covers the electrode assembly, it can cover the four corners of the electrode assembly. In this way, the charged particles can be prevented from contacting with the shell as much as possible, and the shell corrosion can be prevented as much as possible, which helps to improve the durability and stability of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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.

[0028] Figure 1 is an exploded view of a single cell provided in Example 1 of the present application;

[0029] Figure 2 This is a schematic diagram of the structure in which the insulating member provided in Example 1 of the present application is coated on the electrode assembly;

[0030] Figure 3 is an expanded view of the insulating member provided in Example 1 of the present application;

[0031] Figure 4 is a front view of the insulating member and the fixing member provided in Example 1 of the present application;

[0032] Figure 5 is a side view of a wound electrode assembly provided in Example 1 of the present application;

[0033] Figure 6 is an expanded view of the separator in the wound electrode assembly provided in Example 1 of the present application;

[0034] Figure 7 is a side view of a stacked electrode assembly provided in Example 2 of the present application;

[0035] Figure 8 is an expanded view of the diaphragm in the stacked electrode assembly provided in Example 2 of the present application;

[0036] Fig. 9 is a top view of a stacked electrode assembly provided in Example 2 of the present application;

[0037] Fig.10 is a schematic diagram of a coating layer in an electrode assembly provided in Example 3 of the present application;

[0038] Fig.11 It is a schematic diagram of the stacked layers in the electrode assembly provided in Example 3 of the present application.

[0039] Reference numerals:

[0040] 10. Shell; 20. Electrode assembly; 210. First side wall; 220. Second side wall; 230. Third side wall; 240. Diaphragm; 241. Laminated layer; 242. Coating layer; 243. Laminated part; 244. First isolating part; 245. Second isolating part; 250. Positive electrode sheet; 260. Negative electrode sheet; 30. Insulating member; 310. Insulating part; 320. First coating part; 330. Second coating part; 340. Third coating part; 350. Fourth coating part; 40. Fixing member; 410. First fixing part; 420. Second fixing part. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be clearly and completely described 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 making creative work are within the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application and are not used to limit the present application. In the present application, unless otherwise stated, the directional words used, such as "up", "down", "left", and "right", generally refer to the up, down, left, and right of the device in actual use or working state, specifically the drawing direction in the accompanying drawings.

[0042] In this application, unless otherwise clearly specified and limited, the terms "connected", "connected", "stacked" and the like should be understood in a broad sense, for example, it can be fixedly connected, detachably connected, or integrated; it can be directly connected, or indirectly connected 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.

[0043] The shell of the battery is generally made of metal. When the shell contacts the negative charged particles, the shell will be corroded. After the shell is corroded, there is a risk of electrolyte leakage from the shell. At present, the method of coating the electrode assembly with an insulating film is mostly adopted to limit the free movement of ions inside the battery and prevent the leakage of negative charged particles inside the battery. However, when the existing insulating film is coated on the electrode assembly, it is impossible to coat the four corners of the electrode assembly. The negative charged particles can still contact the shell from the four corners of the insulating film, causing shell corrosion. It can be understood that the above four corners are the connection positions of the first side wall and the second side wall.

[0044] To this end, the present application provides a single cell, wherein the bottom of the single cell is covered by a diaphragm, and the bottom and four corners are covered by an insulating member, so as to achieve a good isolation effect and prevent the shell from being corroded as much as possible. The structure of the single cell is described below. It can be understood that the single cell can be a winding type or a stacked type, etc., which is not limited here.

[0045] For details, see Figure 1 and Figure 2 , the single cell includes a shell 10, the shell 10 has a first direction X, a second direction Y and a third direction Z that are perpendicular to each other, and an electrode assembly 20 is arranged in the shell 10. The electrode assembly 20 has two opposite first side walls 210 in the first direction X, two opposite second side walls 220 in the second direction Y, and two opposite third side walls 230 in the third direction Z. The poles (not shown in the figure) of the single cell are arranged in the shell 10 and connected to the pole pieces at the third side wall 230. In the electrode assembly 20, the poles include positive poles and negative poles, and the pole pieces include positive pole pieces and negative pole pieces. The positive poles are connected to the positive pole pieces, and the negative poles are connected to the negative pole pieces. It can be understood that the electrode assembly 20 is not a cubic structure. For the wound electrode assembly 20, the second side wall 220 is a curved surface; the first side wall 210, the second side wall 220 and the third side wall 230 are defined here only for explanation and description, and will not limit the scope of protection of the present application.

[0046] See also Figure 1 and Figure 2The single cell further includes an insulating member 30, which covers the side of the electrode assembly 20 away from the pole, and the insulating member 30 extends from the side away from the pole to the side of the pole. Specifically, the insulating member 30 includes an insulating portion 310, a first covering portion 320, a second covering portion 330, a third covering portion 340, and a fourth covering portion 350. The insulating portion 310 covers the third side wall 230 away from the pole, and the insulating portion 310 is connected to the first covering portion 320 on both sides of the first direction X, and the first covering portion 320 covers the first side wall 210, and the first covering portion 320 is connected to the second covering portion 330 on both sides of the second direction Y, and the second covering portion 330 covers the second side wall 220, and the insulating portion 310 is connected to the third covering portion 340 on both sides of the second direction Y, and the third covering portion 340 covers the second side wall 220. The third covering portion 340 is connected to the fourth covering portion 350 at two sides in the first direction X. The fourth covering portion 350 covers the first side wall 210 . The fourth covering portion 350 and the third covering portion 340 are an integral structure.

[0047] The insulating part 310 covers the third side wall 230, the first covering part 320 covers the first side wall 210, the second covering part 330 and the third covering part 340 cover the second side wall 220, and the fourth covering part 350 covers the first side wall 210, so that each side wall of the electrode assembly 20 can be covered, and since the third covering part 340 and the fourth covering part 350 are an integral structure, when the insulating part 30 covers the electrode assembly 20, the four corners of the electrode assembly 20 can be covered. Thereby, the charged particles can be prevented from contacting with the shell 10 as much as possible, and the corrosion of the shell 10 can be prevented as much as possible, which helps to improve the durability and stability of the battery. It can be understood that the four corners refer to the connection position between the first side wall 210 and the second side wall 220, which is only used for explanation.

[0048] For further information, see Figure 1 and Figure 2 , there are multiple second covering parts 330. In this embodiment, each first covering part 320 is connected to a second covering part 330 on both sides of the second direction Y, that is, each second side wall 220 has two second covering parts 330. The second covering parts 330 on the same second side wall 220 are stacked, so as to minimize or even avoid the charged particles from flowing out of the gap between the two second covering parts 330 on the same second side wall 220 and contacting the shell 10, thereby effectively reducing the probability of the shell 10 being corroded and achieving a better isolation effect.

[0049] Specifically, along the second direction Y, the third covering portion 340 is disposed on a side of the second covering portion 330 away from the second side wall 220; along the first direction X, the fourth covering portion 350 is disposed on a side of the first covering portion 320 away from the first side wall 210. That is, when installing the insulating member 30, the first covering portion 320 is firstly covered on the first side wall 210, then the second covering portion 330 is covered on the second side wall 220, then the third covering portion 340 is covered on the second covering portion 330 on the second side wall 220, and finally the fourth covering portion 350 is covered on the first covering portion 320 on the first side wall 210. In this way, better covering and insulation effects can be achieved.

[0050] In some embodiments, see Figure 3 , Figure 3 Schematic diagram of the insulating member 30 in the unfolded state. In the unfolded state, there is a first gap T1 mm between the fourth covering portion 350 and the first covering portion 320, 0.5≤T1≤1; there is a second gap T2 mm between the fourth covering portion 350 and the second covering portion 330, 0.5≤T2≤1. By setting the first gap and the second gap, it is possible to avoid inadequate die cutting as much as possible, the fourth covering portion 350 is connected with the first covering portion 320 and the second covering portion 330, and the normal bending effect of the insulating member 30 can also be ensured.

[0051] See also Figure 2 , Figure 3 , the electrode assembly 20 has a width W in the first direction X, a length L in the second direction Y, and a height H in the third direction Z. The first covering portion 320 has a width D1 mm, H+3≤D1≤H+6; the insulating portion 310 has a length D2 mm in the unfolded state, L+0.5≤D2≤L+1. The insulating portion 310 has a width W1 mm ​​in the unfolded state, W+0.5≤W1≤W+1.5; the insulating member 30 has a maximum width C1 mm, D2+W+6≤C1≤D2+W+8; the insulating member 30 also has a maximum length D3 mm, D3=2D1+W1. D1, D2, W1, C1 and D3 can achieve effective insulation covering of the electrode assembly 20 within the specified size range without causing a significant decrease in the energy density of the single battery.

[0052] See also Figure 3 and Figure 4 , the height of the third covering portion 340 in the third direction Z is H1 mm, the height of the fourth covering portion 350 in the third direction Z is H2 mm, H2=H1, that is, the heights of the third covering portion 340 and the fourth covering portion 350 in the third direction Z are the same, thereby achieving a better covering effect on the side of the electrode assembly 20 away from the pole, and minimizing the leakage of charged particles from the gaps in the insulating member 30 to achieve a good insulation effect.

[0053] Further, the height of the third covering portion 340 in the third direction Z satisfies 15≤H1≤25, for example, H1 may be 15, 20, 25, etc.; the length of the fourth covering portion 350 in the second direction Y is L1 mm, 5≤L1≤15, for example, L1 may be 5, 10, 15, etc. In this way, the present embodiment can ensure a good insulation effect between the electrode assembly 20 and the housing 10 by reasonably setting the size of the fourth covering portion 350.

[0054] The performance of the technical solution provided in the embodiments of the present application is evaluated in conjunction with specific embodiments.

[0055] Examples 1 to 10 are provided, wherein Examples 1 to 3 satisfy 15≤H1≤25, Examples 4 and 5 do not satisfy 15≤H1≤25; wherein Examples 6 to 8 satisfy 5≤L1≤15, Examples 9 and 10 do not satisfy 5≤L1≤15. Specific parameters and test results are detailed in Table 1.

[0056] Table 1

[0057] project <![CDATA[H1 mm]]> <![CDATA[L1 mm]]> Shell corrosion rate Example 1 15 10 1.00％ Example 2 20 10 0.00％ Example 3 25 10 0.00％ Example 4 10 10 5.00％ Example 5 30 10 0.00％ Example 6 20 5 1.00％ Example 7 20 10 0.00％ Example 8 20 15 0.00％ Example 9 20 2 3.00％ Example 10 20 20 0.00％

[0058] The shell corrosion rate is defined as the ratio of the number of corroded electrode assemblies in a batch of electrode assemblies to the total number of electrode assemblies. When calculating the shell corrosion rate, take the above-mentioned electrode assemblies 20 in this application, each group of samples is 1000EA (pieces), use a multimeter or other electrical testing tools to measure the negative electrode side voltage in the electrode assembly, if the negative electrode side voltage is lower than 0.7V, it is judged as corrosion, and then calculate the shell corrosion rate based on the number of electrode assemblies with negative electrode side voltage lower than 0.7V in 1000EA. If it is found that the negative electrode side voltage of 10EA electrode assemblies is lower than 0.7V, the corrosion rate is 1%.

[0059] It can be seen that the insulation effect between the electrode assembly and the shell is good in the above-mentioned embodiments 1 to 10. In particular, when 15≤H1≤25 and 5≤L1≤15 are satisfied, the insulating member can be effectively wrapped, and the insulation effect between the electrode assembly and the shell is good and the cost is moderate.

[0060] See also Figure 5 and Figure 6 , Figure 5 is a side view of the electrode assembly 20, Figure 6: is a schematic diagram of the insulating member 30 in the unfolded state in this embodiment. The electrode assembly 20 includes a positive electrode sheet, a negative electrode sheet and a separator 240, and the separator 240 is arranged between the positive electrode sheet and the negative electrode sheet. In some embodiments, the electrode assembly 20 is formed by winding the positive electrode sheet, the negative electrode sheet and the separator 240, and the separator 240 includes a stacking layer 241 and a coating layer 242, and the coating layer 242 is close to the inner wall of the shell 10 relative to the stacking layer 241, and the stacking layer 241 is connected to one side of the coating layer 242 in the second direction Y. The coating layer 242 includes a stacking portion 243 and a first isolating portion 244, and the first isolating portion 244 is connected to the side of the stacking portion 243 away from the pole, and the first isolating portion 244 covers the side away from the stacking layer 241 and the positive electrode sheet and the negative electrode sheet away from the pole.

[0061] It is not difficult to understand that in this embodiment, the length of the first isolation portion 244 in the second direction Y is equal to the length of the electrode assembly 20 in the second direction Y; the length of the first isolation portion 244 in the first direction X is the length of the electrode assembly 20 in the first direction X plus a tolerance, and the tolerance is 0.5 to 1.5 mm, that is, the first isolation portion 244 has a length D4 mm in the unfolded state, and the length of the electrode assembly 20 in the first direction X is D mm, D+0.5≤D4≤D+1.5.

[0062] After the electrode assembly 20 is wound, the first isolation part 244 can cover the stacked layer 241 and the positive and negative electrodes on the side away from the pole to avoid contact between the charged particles and the shell 10 as much as possible, and then cooperate with the insulating part 30 to cover the side of the electrode assembly 20 away from the pole to achieve better isolation effect.

[0063] In some embodiments, the coating layer 242 further includes a second isolating portion 245, which is connected to the side of the first isolating portion 244 away from the stacking portion 243 in the first direction X, and the second isolating portion 245 covers the stacking layer 241 and the positive electrode sheet 250 and the negative electrode sheet 260 away from the stacking portion 243. That is, in some embodiments, the length of the first isolating portion 244 in the unfolded state may be greater than D+1.5, and the portion of the first isolating portion 244 with a length greater than D+1.5 is referred to as the second isolating portion 245, and the second isolating portion 245 has a length D5 mm in the unfolded state, 0<D5≤H. By providing the second isolating portion 245, a better coating effect can be achieved for the stacking layer 241, the positive electrode sheet and the negative electrode sheet, and the charged particles can be further prevented from contacting the shell 10 as much as possible, and the shell 10 can be better prevented from corrosion.

[0064] See also Figure 7-Figure 9In some embodiments, the electrode assembly 20 is formed by stacking a positive electrode sheet 250, a negative electrode sheet 260 and a separator 240, and the stacking layer 241 is connected to a coating layer 242 on both sides of the second direction Y. There are multiple coating layers 242, and each coating layer 242 is stacked along the first direction X. The stacking layer 241 is stacked between adjacent coating layers 242 in the first direction X, and the first isolation portion 244 of each coating layer 242 is stacked on the stacking layer 241 and the side of the positive electrode sheet 250 and the negative electrode sheet 260 away from the pole. It can be understood that in this embodiment, the coating layer 242 is preferably two layers, and the two layers of coating layers 242 are spaced apart on both sides close to the inner wall of the shell 10 in the first direction X, and the stacking layer 241 is spaced apart between two adjacent layers of coating layers 242. The first isolation portions 244 of two adjacent coating layers 242 are at least partially overlapped on the third side wall 230 away from the pole. Thus, it is possible to prevent the charged particles from flowing out from the gap between the two first isolation parts 244 as much as possible, and to prevent the charged particles from contacting the shell 10 as much as possible, thereby preventing the shell 10 from corroding.

[0065] See also Fig.10 and Fig.11 In some embodiments, the electrode assembly 20 is formed by stacking the positive electrode sheet 250, the negative electrode sheet 260 and the separator 240, but the stacking layer 241 and the coating layer 242 are not connected. The coating layer 242 is specifically two layers in this embodiment, and the coating layer 242 is closer to the inner wall of the shell 10 relative to the stacking layer 241; the stacking layer 241 is provided with multiple layers, and the stacking layer 241 is stacked between two adjacent coating layers 242. The first isolation parts 244 of two adjacent coating layers 242 overlap at least partially on the third side wall 230 away from the pole side. In this way, it is possible to avoid the charged particles from flowing out from the gap between the two first isolation parts 244 as much as possible, and to avoid the charged particles from contacting the shell 10 as much as possible, causing corrosion of the shell 10.

[0066] It is not difficult to understand that the insulating member 30 can be coated on any of the above-mentioned electrode assemblies 20. After the insulating member 30 coats the electrode assembly 20, the insulating member 30 needs to be fixed. For this purpose, the single battery of the present application also includes a fixing member 40. The fixing member 40 is specifically a tape in this embodiment. The fixing member 40 is attached to the surface of the insulating member 30 facing away from the electrode assembly 20, and at least covers at least the area corresponding to the first side wall 210 and at least part of the area of ​​the second side wall 220.

[0067] For details, see Figure 2In this embodiment, two fixing members 40 are provided. In other embodiments, there may be more than one fixing member 40, which is not limited here. The fixing member 40 includes a first fixing portion 410 and a second fixing portion 420. Two second fixing portions 420 are provided and are respectively connected to both sides of the first fixing portion 410 in the first direction X; the first fixing portion 410 covers at least part of the first covering portion 320 and the fourth covering portion 350, and the second fixing portion 420 covers at least part of the second covering portion 330. By providing the fixing member 40, the insulating member 30 can be fixed, and the insulating member 30 can be prevented from unfolding during the installation process as much as possible to achieve a better covering effect.

[0068] In some embodiments, there is a bonding layer (not shown) between the first covering portion 320 and the fourth covering portion 350, and there is an adhesive layer between the second covering portion 330 and the third covering portion 340. It is understood that the adhesive layer between the first covering portion 320 and the fourth covering portion 350 can be coated on the first covering portion 320 or the fourth covering portion 350; the adhesive layer between the second covering portion 330 and the third covering portion 340 can be set on the second covering portion 330 or the third covering portion 340, which is not limited here. As a result, the third covering portion 340 and the fourth covering portion 350 can be fixed without the aid of the fixing member 40, which helps save materials and facilitates the fixing operation.

[0069] The present application also provides a battery pack, including the above-mentioned single cell. The single cell covers the positive electrode sheet 250, the negative electrode sheet 260 and the stacking layer 241 through the separator 240, and then covers the electrode assembly 20 through the insulating member 30, which can cover the four corners of the electrode assembly 20, thereby preventing the charged particles from falling off and contacting the shell 10 to connect the shell 10 and the electrode assembly 20, thereby preventing the shell 10 from being corroded as much as possible, which helps to improve the durability and stability of the battery.

[0070] The above description is only a partial implementation method of the embodiments of the present application and does not constitute any form of limitation on the application. The protection scope of the embodiments of the present application is not limited thereto. Any simple modifications, equivalent changes and modifications that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the embodiments of the present application should be covered within the protection scope of the embodiments of the present application.

Claims

1. A single cell battery, characterized in that: include: A housing (10), wherein the housing (10) has a first direction (X), a second direction (Y), and a third direction (Z) which are perpendicular to each other; An electrode assembly (20), the electrode assembly (20) having two opposite first side walls (210) in the first direction (X), two opposite second side walls (220) in the second direction (Y), and two opposite third side walls (230) in the third direction (Z), the pole of the single cell passing through the shell (10) and connected to a pole piece at one of the third side walls (230); An insulating member (30), comprising an insulating portion (310), a first covering portion (320), a second covering portion (330), a third covering portion (340), and a fourth covering portion (350), wherein the insulating portion (310) covers a third side wall (230) facing away from the pole; The insulating portion (310) is connected to the first covering portion (320) on both sides in the first direction (X), and the first covering portion (320) covers the first side wall (210); the first covering portion (320) is connected to the second covering portion (330) on both sides in the second direction (Y), and the second covering portion (330) covers the second side wall (220); The third covering portion (340) is respectively connected to both sides of the insulating portion (310) in the second direction (Y), and the third covering portion (340) covers the second side wall (220); The third covering portion (340) is connected to fourth covering portions (350) on both sides in the first direction (X), respectively; the fourth covering portion (350) covers the first side wall (210); the fourth covering portion (350) and the third covering portion (340) are an integral structure.

2. The single cell according to claim 1, characterized in that: The electrode assembly (20) comprises a positive electrode sheet (250), a negative electrode sheet (260) and a separator (240), wherein the separator (240) is arranged between the positive electrode sheet (250) and the negative electrode sheet (260), and the separator (240) comprises a stacked layer (241) and a coating layer (242), wherein the coating layer (242) is closer to the inner wall of the housing (10) relative to the stacked layer (241); The coating layer (242) includes a stacking portion (243) and a first isolating portion (244), wherein the first isolating portion (244) is connected to a side of the stacking portion (243) away from the pole, and the first isolating portion (244) covers a side away from the stacking layer (241) and the positive electrode sheet (250) and the negative electrode sheet (260) away from the pole.

3. The single cell according to claim 2, characterized in that: The electrode assembly (20) is formed by winding the positive electrode sheet (250), the negative electrode sheet (260) and the separator (240), and the stacked layer (241) is connected to one side of the coating layer (242) in the second direction (Y); The coating layer (242) also includes a second isolating portion (245), which is connected to the first isolating portion (244) on a side away from the stacking portion (243) in the first direction (X), and the second isolating portion (245) covers the stacking layer (241) and the positive electrode sheet (250) and the negative electrode sheet (260) on a side away from the stacking portion (243).

4. The single cell according to claim 2, characterized in that: The electrode assembly (20) is formed by stacking the positive electrode sheet (250), the negative electrode sheet (260) and the separator (240), and the stacking layer (241) is connected to one side of the coating layer (242) in the second direction (Y); The number of the coating layers (242) is multiple, and each of the coating layers (242) is stacked along the first direction (X), the stacked layer (241) is stacked between adjacent coating layers (242) in the first direction (X), and the first isolation portion (244) of each of the coating layers (242) is stacked on the stacked layer (241) and on the side of the positive electrode sheet and the negative electrode sheet away from the pole.

5. The single cell according to claim 1, characterized in that: The number of the second covering parts (330) is plural, and the second covering parts (330) on the same second side wall (220) are stacked.

6. The single cell according to claim 1, characterized in that: The height of the third covering portion (340) in the third direction (Z) is H1 mm, 15≤H1≤25, and the height of the fourth covering portion (350) in the third direction (Z) is H2 mm, H2=H1.

7. The single cell according to claim 1, characterized in that: The length of the fourth covering portion (350) in the second direction (Y) is L1 mm, 5≤L1≤15.

8. The single cell according to claim 1, characterized in that: Along the second direction (Y), the third covering portion (340) is arranged on a side of the second covering portion (330) away from the second side wall (220); along the first direction (X), the fourth covering portion (350) is arranged on a side of the first covering portion (320) away from the first side wall (210).

9. The single cell according to claim 1, characterized in that: There is a bonding layer between the first covering portion (320) and the fourth covering portion (350), and there is an adhesive layer between the second covering portion (330) and the third covering portion (340).

10. The single cell according to claim 1, characterized in that: It also includes a fixing member (40), which is attached to the surface of the insulating member (30) facing away from the electrode assembly (20) and covers at least a portion of the area corresponding to the first side wall (210) and at least a portion of the area corresponding to the second side wall (220).

11. A battery pack, characterized in that: The invention comprises a single cell as claimed in any one of claims 1 to 10.

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