Single battery, battery pack and power utilization device

Abstract

The invention discloses a single battery, a battery pack and a power utilization device, and belongs to the technical field of batteries, the single battery comprises a shell, an electrode assembly and a cover plate, and the shell is provided with an end opening; the electrode assembly is arranged in the shell; the cover plate is connected with the shell and covers the end opening; the thickness of the shell is T mm, the perimeter of the end opening is C mm, T is larger than or equal to 0.3 and smaller than or equal to 0.8, and C is larger than or equal to 100 and smaller than or equal to 500. By limiting the thickness T of the shell and the perimeter C of the end opening, the problem that the shell is prone to deformation or damage in the production, transportation and use processes due to poor alignment in the shell bending process is solved, the shell bending forming yield can be effectively guaranteed, the shell welding seam welding effect is guaranteed, and the product quality is improved. Therefore, the production yield of the shell is effectively improved, the production cost is reduced, and the safety and reliability of the single battery are ensured.

Description

Technical Field

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

[0002] Lithium-ion batteries are currently widely used in various fields such as transportation power supply, electric energy storage power supply, new energy energy storage power supply, aerospace and military industry due to their large capacity, high operating voltage, strong charge retention ability and long cycle life.

[0003] The shell of a single cell is one of the most critical structural parts of a single cell. Its structural design has a significant impact on the structural strength of the shell itself, production cost, and the yield rate of the single cell manufacturing process. At present, in order to improve the space utilization rate of the battery pack and increase the energy density of the battery pack, the single cell is gradually developing towards a blade structure. At present, the shell of a single cell is mainly produced by bending aluminum plates and then laser welding or high-frequency welding. However, due to the unreasonable design of the shell size, it will affect the shell molding and shell welding yield. Summary of the invention

[0004] 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 that unreasonable shell size design affects shell molding and shell welding yield.

[0005] Technical solution: The present application embodiment provides a single battery, including:

[0006] a housing having an open end;

[0007] An electrode assembly is disposed in the housing;

[0008] A cover plate is connected to the shell and covers the end opening;

[0009] The thickness of the shell is T mm, the circumference of the end opening is C mm, and the following conditions are satisfied: 0.3≤T≤0.8, 100≤C≤500.

[0010] In some embodiments, the single battery satisfies: 0.3≤T≤0.35, 100≤C≤120.

[0011] In some embodiments, the single battery satisfies: 0.35≤T≤0.8, 120≤C≤500.

[0012] In some embodiments, the dimension of the end opening in the first direction is L mm, the dimension of the end opening in the second direction is W mm, and the following conditions are satisfied: 4.5≤L / W≤12, and the first direction and the second direction intersect.

[0013] In some embodiments, a dimension L of the end opening in the first direction satisfies: L≤190.

[0014] In some embodiments, a dimension W of the end opening in the second direction satisfies: W ≥ 13.5.

[0015] In some embodiments, the size of the shell in the third direction is H mm, the thickness of the shell is T mm, and the third direction intersects the first direction and the second direction respectively, satisfying:

[0016] L×H≤1.2×10 5 , L≤190, 0.3≤T≤0.8.

[0017] In some embodiments, the battery cell satisfies at least one of the following characteristics:

[0018] a)L×H≤8×10 4 , L≤130, 0.3≤T≤0.5;

[0019] b)8×10 4 ≤L×H≤1.2×10 5 , 130≤L≤190, 0.5≤T≤0.8.

[0020] In some embodiments, the dimension of the shell in the third direction is H mm, the circumference of the end opening is C mm, and the following conditions are satisfied: H≤600, 220≤C≤450, 1500≤L×W≤10000.

[0021] Accordingly, an embodiment of the present application provides a battery pack, comprising the above-mentioned single battery.

[0022] Correspondingly, an embodiment of the present application provides an electrical device, including the above-mentioned single battery, or including the above-mentioned battery pack.

[0023] Beneficial effects: The single cell of the embodiment of the present application includes a shell, an electrode assembly and a cover plate, wherein the shell has an end opening; the electrode assembly is arranged in the shell; the cover plate is connected to the shell and covers the end opening; wherein the thickness of the shell is T mm, the perimeter of the end opening is C mm, and the following conditions are satisfied: 0.3≤T≤0.8, 100≤C≤500. By limiting the thickness T of the shell and the perimeter C of the end opening, the problem of poor alignment of the shell during the bending process, which leads to easy deformation or damage of the shell during production, transportation and use, can be avoided, the yield of the shell bending forming can be effectively guaranteed, and the welding effect of the shell weld can be guaranteed, thereby effectively improving the production yield of the shell, reducing the production cost, and ensuring the safety and reliability of the single cell.

[0024] 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.

[0025] 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

[0026] 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.

[0027] Figure 1 is an exploded diagram of a single cell of an embodiment of the present application;

[0028] Figure 2 is a structural schematic diagram of a housing according to an embodiment of the present application;

[0029] Figure 3 It is a cross-sectional view of a single cell according to an embodiment of the present application.

[0030] Figure numerals: 1, shell; 2, electrode assembly; 3, cover plate; 4, explosion-proof valve; 5, first insulating film; 6, second insulating film; 7, third insulating film; 8, pole; 10, end opening; 11, first surface; 12, second surface; 100, accommodating cavity; X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0031] 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.

[0032] 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.

[0033] The applicant noted that lithium-ion batteries are currently widely used in various fields such as transportation power supply, electric energy storage power supply, new energy storage power supply, aerospace and military industry due to their advantages such as large capacity, high operating voltage, strong charge retention ability and long cycle life. The battery shell is one of the most critical structural parts of the single cell. Its structural design has an important impact on the structural strength of the shell itself, production cost, and the yield of the single cell process. At present, in order to improve the space utilization rate of the battery pack and increase the energy density of the battery pack, the single cell is gradually developing towards a blade structure. At present, the shell of the single cell is mainly produced by bending the aluminum plate and then laser welding or high-frequency welding. However, due to the unreasonable design of the shell size, it will affect the shell molding and shell welding yield.

[0034] In view of this, the single cell of the embodiment of the present application includes a shell, an electrode assembly and a cover plate, wherein the shell has an end opening; the electrode assembly is arranged in the shell; the cover plate is connected to the shell and covers the end opening; wherein the thickness of the shell is T mm, the perimeter of the end opening is C mm, and the following conditions are satisfied: 0.3≤T≤0.8, 100≤C≤500. By limiting the thickness T of the shell and the perimeter C of the end opening, the problem of poor alignment of the shell during the bending process, which leads to easy deformation or damage of the shell during production, transportation and use, can be avoided, the yield of the shell bending forming can be effectively guaranteed, and the welding effect of the shell weld can be guaranteed, thereby effectively improving the production yield of the shell, reducing the production cost, and ensuring the safety and reliability of the single cell.

[0035] 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.

[0036] Figure 1 is an exploded diagram of a single cell of an embodiment of the present application; Figure 2 is a schematic structural diagram of a housing 1 according to an embodiment of the present application. Figure 3 is a cross-sectional view of a single cell according to an embodiment of the present application. Figures 1 to 3 The single cell of the embodiment of the present application includes a shell 1, an electrode assembly 2, a cover plate 3, and a pole 8 penetrating the cover plate 3. The shell 1 has an end opening 10; the electrode assembly 2 is arranged in the shell 1; the cover plate 3 is connected to the shell 1 and covers the end opening 10. The shell 1 is a rectangular structure with open ends. The shell 1 is formed into the approximate shape of the shell 1 by bending an aluminum plate, and the two ends of the aluminum plate are connected by welding to form a complete shell 1. Correspondingly, two cover plates 3 are provided, and the two cover plates 3 are used to cover the end openings 10 at both ends of the shell 1, and the cover plate 3 is sealed and connected to the shell 1 to form a receiving cavity 100. The electrode assembly 2 is arranged in the receiving cavity.

[0037] In some embodiments, the thickness of the shell 1 is T mm, and the perimeter of the end opening 10 is C mm, satisfying: 0.3≤T≤0.8, 100≤C≤500. The shell 1 of the embodiment of the present application is formed by bending an aluminum plate into the approximate shape of the shell 1, and connecting the two ends of the aluminum plate by welding to form a complete shell 1. It can be understood that the perimeter C of the end opening 10 is the length of the aluminum plate, and the perimeter C of the end opening 10 is 2(L+W), and the thickness of the shell 1 is the thickness of the aluminum plate. By limiting the thickness T of the shell and the perimeter C of the end opening, the problem of poor alignment of the shell during the bending process, which leads to easy deformation or damage of the shell during production, transportation and use, can be avoided, the yield of the shell bending forming can be effectively guaranteed, and the welding effect of the shell weld can be guaranteed, thereby effectively improving the production yield of the shell, reducing the production cost, and ensuring the safety and reliability of the single battery.

[0038] exist Figure 1In the illustrated embodiment, the single cell further includes a first insulating film 5, a second insulating film 6 and a third insulating film 7. The first insulating film 5 is coated on the side of the housing 1 away from the electrode assembly 2, the second insulating film 6 is coated on the side of the electrode assembly 2 close to the housing 1, and the third insulating film 7 is coated on the side of the cover plate 3 away from the accommodating cavity 100. The first insulating film 5, the second insulating film 6 and the third insulating film 7 can be an insulating film made of PP (polypropylene) or Mylar made of polyester polymer material, and this application does not limit this. The first insulating film 5, the second insulating film 6 and the third insulating film 7 play the role of electrical insulation, corrosion prevention and absorption of part of the external impact.

[0039] In some embodiments, the thickness T of the shell 1 can be any one of 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, or any two of the range values. By limiting the thickness T of the shell 1, the present application avoids, on the one hand, poor bending and alignment of the aluminum plate and insufficient strength of the shell 1 caused by the thickness T of the shell 1 being too thin, which in turn causes the shell 1 to be easily deformed or damaged during production, transportation and use; on the other hand, it avoids the thickness T of the shell 1 being too thick, which leads to increased material costs and increased weight of the shell 1.

[0040] In some embodiments, the perimeter C of the end opening 10 can be any one of 100, 150, 200, 250, 300, 350, 400, 450, 500, or any two of the range values. By limiting the perimeter C of the end opening 10, the present application can ensure that the size of the shell 1 is not too small to affect the space utilization of the battery pack; on the other hand, it can ensure that the size of the shell 1 is not too large to avoid poor alignment caused by increased bending difficulty, thereby affecting the molding of the shell 1 and the welding yield of the shell 1 and the cover plate 3.

[0041] In some embodiments, the single cell further satisfies: 0.3≤T≤0.35, 100≤C≤120. That is, when the circumference C of the end opening 10 further satisfies less than or equal to 120, the thickness T of the shell 1 can be any one of 0.3, 0.31, 0.32, 0.33, 0.34, 0.35 or a range of any two of them. When the circumference C of the end opening 10 is small, the overall size of the shell 1 is relatively small, and the stress it bears is also relatively small. Even if the thickness T of the shell 1 is small, it can meet the strength requirements of the shell 1, so that the shell 1 is not easily deformed or damaged during production, transportation and use. At the same time, the circumference C of the end opening 10 is small, which makes the bending operation of the aluminum plate relatively easy to control, and can avoid the problem of poor bending alignment of the aluminum plate, ensuring a good alignment effect, thereby not affecting the molding and welding yield of the shell 1.

[0042] In some embodiments, the single cell further satisfies: 0.35≤T≤0.8, 120≤C≤500. That is, when the circumference of the end opening 10 further satisfies being greater than or equal to 120, the thickness T of the shell 1 can be any one of 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8 or any two range values. When the circumference C of the end opening 10 is large, the overall size of the shell 1 is relatively large, and the stress it bears is also relatively large. By increasing the thickness T of the shell 1 and ensuring the strength of the welding part of the shell 1, it can be ensured that the strength requirements of the shell 1 are met, and the problem of weak welds and easy cracking can be avoided. At the same time, the circumference C of the end opening 10 is large, and by increasing the thickness T of the shell 1, the problem of poor bending and alignment of the aluminum plate can be avoided, and a good alignment effect can be ensured, thereby not affecting the molding and welding yield of the shell 1.

[0043] In an embodiment of the present application, by setting a shell 1 of different sizes of T and C, the electrode assembly 2 and the cover plate 3 are inserted into the shell, and a sealing test is performed to verify whether the welding yield of the shell 1 meets the design requirements. The verification results are shown in Table 1.

[0044] Table 1:

[0045] C / (mm) T / (mm) Verify the results Example 1 105 0.3 Shell 1 production has no obvious abnormality Example 2 105 0.3 Shell 1 production has no obvious abnormality Example 3 115 0.3 Shell 1 production has no obvious abnormality Example 4 115 0.3 Shell 1 production has no obvious abnormality Example 5 125 0.35 Shell 1 production has no obvious abnormality Example 6 125 0.35 Shell 1 production has no obvious abnormality Example 7 125 0.4 Shell 1 production has no obvious abnormality Example 8 125 0.4 Shell 1 production has no obvious abnormality Comparative Example 1 125 0.3 The welding yield of shell 1 weld is 94.15% Comparative Example 2 125 0.3 The welding yield of shell 1 weld is 95.68%

[0046] In the embodiment of the present application, the welding yield of the shell 1 weld can be verified by a sealing test. Specifically, the assembled single battery is placed in a helium mass spectrometer leak detector to detect whether there is helium leakage. When the helium leak rate is less than 1×10 -7 / Pa.m 3 When the sealing requirements are met, this application does not limit the method for detecting the welding yield.

[0047] Referring to Example 1 to Example 4 in Table 1, when the perimeter C of the end opening 10 satisfies 100≤C≤120, the thickness T of the shell 1 can be 0.3. That is, when the perimeter C of the end opening 10 is small, an aluminum plate with a thickness T of 0.3 is used to bend and weld to form the shell 1. The shell 1 has no obvious abnormality during production, and the helium leak rate of the single cell is less than 1×10 -7 / Pa.m 3 , the sealing requirements are met, and the molding and welding yield of the shell 1 meet the design requirements.

[0048] Referring to Example 5 to Example 8 in Table 1, when the perimeter C of the end opening 10 satisfies 120≤C≤500, the thickness T of the shell 1 can be 0.35 or 0.4. That is, when the perimeter C of the end opening 10 is large, an aluminum plate with a T greater than or equal to 0.35 is used to bend and weld to form the shell 1. The shell 1 has no obvious abnormality during production, and the helium leak rate of the single battery is less than 1×10 -7 / Pa.m 3 , the sealing requirements are met, and the molding and welding yield of the shell 1 meet the design requirements.

[0049] As shown in Table 1, when the perimeter C of the end opening 10 is 125 and the thickness T of the shell 1 is 0.3, the helium leak rate of some samples is greater than 1×10 -7 / Pa.m 3 The welding yield of the shell 1 weld is 94.15%, which is low and does not meet the design requirements. It is understandable that when the perimeter C of the end opening 10 is large, the thickness T of the shell 1 is small, which may lead to insufficient strength of the shell 1 and easy deformation during production, transportation and use, especially in the process of bending and forming the aluminum plate, which is prone to poor alignment, thereby affecting the forming and welding yield of the shell 1.

[0050] As shown in Table 1, when the perimeter C of the end opening 10 is 125 and the thickness T of the shell 1 is 0.3, the helium leak rate of some samples is greater than 1×10 -7 / Pa.m 3 The welding yield of the shell 1 weld is 95.68%, which is low and does not meet the design requirements. It is understandable that when the perimeter C of the end opening 10 is large, the thickness T of the shell 1 is small, which may lead to insufficient strength of the shell 1 and easy deformation during production, transportation and use, especially in the bending process of the aluminum plate, which is prone to poor alignment, thereby affecting the molding and welding yield of the shell 1.

[0051] The present application can effectively ensure the yield of aluminum plate bending and the welding effect of the shell 1 by reasonably designing the circumference C of the end opening 10 and the thickness T of the shell 1, thereby effectively improving the production yield of the shell 1, reducing production costs, and ensuring the safety and reliability of the single battery.

[0052] In some embodiments, the dimension of the end opening 10 in the first direction X is L mm, and the dimension of the end opening 10 in the second direction Y is W mm. The first direction X and the second direction Y intersect, and satisfy: 4.5≤L / W≤12. The first direction X is the length direction of the end opening 10, and the second direction Y is the width direction of the end opening 10, and the length direction and the width direction are perpendicular. By limiting the ratio range of the dimension L of the end opening 10 in the first direction X to the dimension W of the end opening 10 in the second direction Y, the dimension of the end opening 10 of the shell 1 is controlled, so that when the electrode assembly 2 and the cover plate 3 are assembled into the shell, the shell 1 is prevented from being crushed or bumped, which greatly improves the yield rate of the cover plate 3 and the electrode assembly 2 into the shell, and also improves the production efficiency; in addition, it can also ensure that the flatness of the shell 1 meets the design requirements, thereby improving the yield rate of the sealing welding after the cover plate 3 and the shell 1 are assembled, and reducing the production cost.

[0053] In some embodiments, the dimension L of the end opening 10 in the first direction X satisfies: L≤190. Exemplarily, the dimension L of the end opening 10 in the first direction X can be any one of 60.75, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190 or any two range values. The single cell of the embodiment of the present application further satisfies L≤190 on the premise of satisfying 4.5≤L / W≤12, which can avoid the dimension L of the end opening 10 in the first direction X being too long, resulting in poor flatness of the end opening 10, and avoid the cover plate 3 and the electrode assembly 2 from being crushed or bumped when the shell 1 is inserted into the shell, thereby reducing material loss, improving the incoming material yield of the single cell, improving the assembly efficiency of the single cell, and further improving the production efficiency of the single cell.

[0054] In some embodiments, the dimension W of the end opening 10 in the second direction Y satisfies: W≥13.5. The single cell of the embodiment of the present application further satisfies W≥13.5 on the premise of satisfying 4.5≤L / W≤12, so as to avoid the dimension W of the end opening 10 in the second direction Y being too small, and avoid the cover plate 3 and the electrode assembly 2 from being crushed or bumped when the shell 1 is inserted into the shell, thereby reducing material loss, improving the incoming material yield of the single cell, improving the assembly efficiency of the single cell, and further improving the production efficiency of the single cell.

[0055] In the embodiment of the present application, by setting a shell 1 of different sizes W and L, the electrode assembly 2 and the cover plate 3 are inserted into the shell, and the size of the end opening 10 is verified to meet the design requirements from aspects such as flatness test and sealing test. The verification results are shown in Table 2.

[0056] Table 2:

[0057]

[0058]

[0059] In the embodiments of the present application, the crushing and bumping scratches on the surface of the shell 1 can be verified by visual inspection, touch inspection, etc., and the present application does not impose any restrictions on this.

[0060] In the embodiments of the present application, the flatness test can be performed by a feeler gauge measurement method. Specifically, the housing 1 is placed on a workbench, and the end opening 10 is placed toward the workbench. Feeler gauges of different thicknesses are inserted into the gap between the surface of the housing 1 and the workbench, and the largest gap is tried. Feeler gauge sheets of different thicknesses are tried in order from thin to thick, until a feeler gauge thickness that can just fit into the gap is found. The feeler gauge thickness can be used as an approximate indicator of the flatness of the housing 1, and the present application does not limit the flatness detection method.

[0061] In the embodiment of the present application, the welding yield of the housing 1 and the cover plate 3 can be verified by a sealing test. Specifically, the assembled single battery is placed in a helium mass spectrometer leak detector to detect whether there is helium leakage. When the helium leak rate is less than 1×10 -7 / Pa.m 3 When the sealing requirements between the shell 1 and the cover plate 3 are met, the present application does not limit the detection method of welding yield.

[0062] Referring to Examples 9 to 16 in Table 2, the dimension L of the end opening 10 in the first direction X, the dimension W of the end opening 10 in the second direction Y, and L / W satisfy L≤190, W≥13.5, and 4.5≤L / W≤12. Through the flatness test, the sealing test, and the observation of the surface of the shell 1, it can be concluded that when the cover plate 3 and the electrode assembly 2 are assembled into the shell, the proportion of the shell 1 being crushed or bumped in multiple samples is low, the flatness of the end opening 10 of multiple samples is good, the sealing meets the standard, and the welding yield of the cover plate 3 and the shell 1 is high, ensuring the reliability and safety of the single battery.

[0063] As shown in Example 17 in Table 2, the dimension L of the end opening 10 in the first direction X is 210, the dimension W of the end opening 10 in the second direction Y is 14.5, and the ratio of the dimension L of the end opening 10 in the first direction X to the dimension W of the end opening 10 in the second direction Y is 13.1, and the ratio of L / W is too large. The flatness test shows that since the dimension L of the end opening 10 in the first direction X is too long, the flatness of the end opening 10 of multiple samples is poor, resulting in a high proportion of poor flatness.

[0064] As shown in Example 18 of Table 2, the dimension L of the end opening 10 in the first direction X is 210, the dimension W of the end opening 10 in the second direction Y is 14.5, and the ratio of the dimension L of the end opening 10 in the first direction X to the dimension W of the end opening 10 in the second direction Y is 13.1, and the ratio of L / W is relatively large. By observing the surface of the shell 1, it is found that since the dimension L of the end opening 10 in the first direction X is too long, there are multiple samples of the cover plate 3 and the electrode assembly 2 when assembled into the shell, which are easy to interfere with the shell 1, resulting in crushing or bumping the shell 1, resulting in a low yield of the cover plate 3 and the electrode assembly 2 into the shell.

[0065] As shown in Table 2, Example 19, the dimension L of the end opening 10 in the first direction X is 175, the dimension W of the end opening 10 in the second direction Y is 14.5, and the ratio of the dimension L of the end opening 10 in the first direction X to the dimension W of the end opening 10 in the second direction Y is 12.1, and the ratio of L / W is too large. The sealing test shows that because the dimension L of the end opening 10 in the first direction X is too long, there are multiple samples with a helium leak rate greater than 1×10 -7 / Pa.m 3 , the welding yield of the cover plate 3 and the shell 1 is low.

[0066] As shown in Example 20 in Table 2, the dimension L of the end opening 10 in the first direction X is 135, the dimension W of the end opening 10 in the second direction Y is 13, and the ratio of the dimension L of the end opening 10 in the first direction X to the dimension W of the end opening 10 in the second direction Y is 10.4. By observing the surface of the shell 1, it is found that since the dimension W of the end opening 10 in the second direction Y is relatively small, there are multiple samples of the cover plate 3 and the electrode assembly 2 when assembled into the shell, which are easy to interfere with the shell 1, resulting in crushing or bumping the shell 1, resulting in a low shell yield of the cover plate 3 and the electrode assembly 2.

[0067] As shown in Example 21 of Table 2, the dimension L of the end opening 10 in the first direction X is 120, the dimension W of the end opening 10 in the second direction Y is 13, and the ratio of the dimension L of the end opening 10 in the first direction X to the dimension W of the end opening 10 in the second direction Y is 9.2. By observing the surface of the shell 1, it is found that since the dimension W of the end opening 10 in the second direction Y is relatively small, there are multiple samples of the cover plate 3 and the electrode assembly 2 when assembled into the shell, which are easy to interfere with the shell 1, resulting in crushing or bumping the shell 1, resulting in a low shell yield of the cover plate 3 and the electrode assembly 2.

[0068] As shown in Example 22 of Table 2, the dimension L of the end opening 10 in the first direction X is 60, the dimension W of the end opening 10 in the second direction Y is 14.5, and the ratio of the dimension L of the end opening 10 in the first direction X to the dimension W of the end opening 10 in the second direction Y is 4.1. Since the dimension L of the end opening 10 in the first direction X is relatively small, the ratio L / W is relatively small, so that when the single battery cells are arranged in the battery pack, the space utilization rate of the battery pack is relatively low, and the space cannot be fully utilized to arrange more battery cells.

[0069] The present application solves the problems of low shell-entry yield of the cover plate 3 and the electrode assembly 2 and low welding yield of the cover plate 3 and the shell 1 during the assembly process caused by unreasonable size design of the end opening 10 of the shell 1 by reasonably designing the size L of the end opening 10 in the first direction X and the size W of the end opening 10 in the second direction Y, thereby reducing material loss, improving the incoming material yield of the single cell, improving the assembly efficiency of the single cell, and further improving the production efficiency of the single cell.

[0070] In some embodiments, the size of the end opening 10 in the first direction X is L mm, the size of the shell 1 in the third direction Z is H mm, the thickness of the shell 1 is T mm, and the third direction Z intersects the first direction X and the second direction Y respectively, satisfying: L×H≤1.2×10 5 , L≤190, 0.3≤T≤0.8. The shell 1 of the embodiment of the present application is formed by bending an aluminum plate into the approximate shape of the shell 1, and connecting the two ends of the aluminum plate by welding to form a complete shell 1. It can be understood that the first direction X is the length direction of the end opening 10, the second direction Y is the width direction of the end opening 10, the third direction Z is the extension direction of the shell 1 and the third direction Z is perpendicular to the first direction X and the second direction Y respectively. The shell 1 has a first surface 11 arranged oppositely along the second direction Y, and the surface area of ​​the first surface 11 is greater than the second surface 12 arranged oppositely along the first direction X, and L×H refers to the surface area S1 of the first surface 11. The present application can ensure that the flatness of the first surface 11 meets the requirements by limiting the surface area S1 of the first surface 11, the size L of the end opening 10 in the first direction X, and the thickness T of the shell 1. Specifically, in the embodiments of the present application, the flatness of the first surface 11 is required to satisfy an outer convexity of ≤0.8mm and an inner concave of ≤0.5mm, thereby preventing the electrode assembly 2 from interfering with the shell 1 when entering the shell, causing the electrode assembly 2 to be scratched by the shell 1, thereby improving the structural strength of the first surface 11 and the production yield of the shell 1, and ensuring the safety and reliability of the single cell.

[0071] In addition, a battery pack is provided in an embodiment of the present application, comprising the above-mentioned single cell, wherein a plurality of single cells are arranged in the battery pack, and a partition is provided between adjacent single cells to position the single cells. By limiting the surface area S1 of the first surface 11, the dimension L of the end opening 10 in the first direction X, and the thickness T of the housing 1, poor assembly due to poor flatness of the first surface 11 during assembly of the single cells and deformation of the large surface of the battery pack after assembly are avoided, thereby ensuring the structural strength of the first surface 11 of the battery pack, and ensuring the reliability and safety of the battery pack.

[0072] In some embodiments, the single cell further satisfies: L×H≤8×10 4 , L≤130, 0.3≤T≤0.5. When the surface area S1 of the first surface 11 is less than or equal to 8×10 4 , and when the dimension L of the end opening 10 in the first direction X is less than or equal to 130, the thickness T of the shell 1 can be between 0.3 and 0.5. Exemplarily, the thickness T of the shell 1 can be any one of 0.3, 0.35, 0.4, 0.45, 0.5 or a range of any two of them. When the surface area S1 of the first surface 11 and the dimension L of the end opening 10 in the first direction X are small, the stress borne by the shell 1 is relatively small. Therefore, even if the thickness of the shell 1 is thin, it can meet the strength requirements, and at the same time, the material cost and the overall weight of the shell 1 can be reduced. Such a configuration can avoid relative interference between the electrode assembly 2 and the shell 1 when it is inserted into the shell, causing the electrode assembly 2 to be scratched by the shell 1, thereby ensuring that the structural strength and flatness of the first surface 11 formed after the aluminum plate is bent and welded meet the design requirements, ensuring the safety and reliability of the single battery.

[0073] In some other embodiments, the single cell further satisfies: 8×10 4 ≤L×H≤1.2×10 5 , 130≤L≤190, 0.5≤T≤0.8. When the surface area S1 of the first surface 11 is 8×10 4 to 1.2×10 5, and when the dimension L of the end opening 10 in the first direction X is between 130 and 190, the thickness T of the shell 1 can be between 0.5 and 0.8. Exemplarily, the thickness T of the shell 1 can be any one of 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8 or a range of any two of them. When the surface area S1 of the first surface 11 and the dimension L of the end opening 10 in the first direction X are large, the stress borne by the shell 1 is also relatively large. Therefore, it is necessary to increase the thickness of the shell 1 to meet the strength requirements of the shell 1, so as to prevent the first surface 11 from having obvious convexity and concave after the aluminum plate is bent, thereby avoiding relative interference with the shell 1 when the electrode assembly 2 is put into the shell, causing the electrode assembly 2 to be scratched by the shell 1, thereby ensuring that the structural strength and flatness of the first surface 11 formed after the aluminum plate is bent and welded meet the design requirements, and ensure the safety and reliability of the single battery.

[0074] In the embodiment of the present application, by setting a shell 1 of different sizes S1, L and T, the electrode assembly 2 and the cover plate 3 are inserted into the shell, and a flatness test is performed to detect whether there is any abnormality on the surface of the shell 1 of the single cell and the battery pack. The verification results are shown in Table 3.

[0075] Table 3:

[0076]

[0077]

[0078] In the embodiment of the present application, the flatness test can be performed by a feeler gauge measurement method. Specifically, the first surface 11 is placed on a workbench, and feeler gauges of different thicknesses are inserted into the gap between the first surface 11 and the workbench to try to find the largest gap. Feeler gauge sheets of different thicknesses are tried in order from thin to thick until a feeler gauge thickness that can just fit into the gap is found. The feeler gauge thickness can be used as an approximate indicator of the flatness of the housing 1, and the present application does not limit the flatness detection method.

[0079] As shown in Table 3, Example 23 and Example 24, the surface area S1 of the first surface 11 is 7.0×10 4 and 7.5×10 4 , the dimension L of the end opening 10 in the first direction X is 110, and the thickness T of the shell 1 is 0.3 and 0.4 respectively, satisfying L×H≤8×10 4 , L≤130, 0.3≤T≤0.5. Since the surface area S1 of the first surface 11 and the dimension L of the end opening 10 in the first direction X are relatively small, the stress borne by the shell 1 is relatively small, and the thin shell 1 thickness T can meet the strength requirements of the shell 1. The verification result shows that the flatness yield of the first surface 11 is normal, and no large surface deformation problem is found in the battery pack, which meets the design requirements.

[0080] As shown in Table 3, Example 25 and Example 26, the surface area S1 of the first surface 11 is 7.5×10 4 , the dimension L of the end opening 10 in the first direction X is 145, and the thickness T of the shell 1 is 0.5. When the dimension L of the end opening 10 in the first direction X increases, the strength of the shell 1 can be enhanced by increasing the thickness T of the shell 1. The verification result shows that the flatness of the first surface 11 is normal, and no large surface deformation problem is found in the battery pack, which meets the design requirements.

[0081] As shown in Table 3, Examples 27 to 29, the surface areas S1 of the first surface 11 are 1.0×10 5 and 7.5×10 4 , the dimension L of the end opening 10 in the first direction X is 110, and the thickness T of the shell 1 is 0.3 and 0.4 respectively, satisfying 8×10 4 ≤L×H≤1.2×10 5 , 130≤L≤190, 0.5≤T≤0.8. When the surface area S1 of the first surface 11 and the dimension L of the end opening 10 in the first direction X are large, the stress on the shell 1 also increases. The thicker shell 1 thickness T can meet the strength requirements of the shell 1, and when the aluminum plate is bent and welded to form the shell 1, the problem of poor flatness can be avoided. The verification result shows that there is no abnormality in the flatness yield of the first surface 11, and no large surface deformation problem is found in the battery pack, which meets the design requirements.

[0082] As shown in Table 3, Example 30, the surface area S1 of the first surface 11 is 7.5×10 4 , the dimension L of the end opening 10 in the first direction X is 135, and the thickness T of the shell 1 is 0.4. The verification result shows that the flatness yield of the first surface 11 is low, and no large surface deformation problem is found in the battery pack, which does not meet the design requirements. It is understandable that the dimension L of the end opening 10 in the first direction X is too large, which may increase the difficulty of the aluminum plate bending operation, and then cause the problem of poor bending alignment of the aluminum plate and poor flatness of the first surface 11.

[0083] As shown in Table 3, Example 31, the surface area S1 of the first surface 11 is 7.5×10 4, the dimension L of the end opening 10 in the first direction X is 135, and the thickness T of the shell 1 is 0.4. The verification result shows that the flatness yield of the first surface 11 is low. During the formation stage of the single cell battery, it was found that the proportion of slight deformation of the first surface 11 was 20%, which did not meet the design requirements. It is understandable that the dimension L of the end opening 10 in the first direction X is too large, which may increase the difficulty of the aluminum plate bending operation, and then cause the aluminum plate bending alignment to be poor and the flatness of the first surface 11 to be poor. Among them, during the formation stage of single cell battery production, 20% of the samples had slight deformation of the first surface 11, which reduced the reliability and safety of the single cell battery.

[0084] As shown in Table 3, Example 32, the surface area S1 of the first surface 11 is 1.0×10 5 , the dimension L of the end opening 10 in the first direction X is 160, and the thickness T of the shell 1 is 0.5. When the surface area S1 of the first surface 11 and the dimension L of the end opening 10 in the first direction X meet the requirements, but the thickness T of the shell 1 is too small, the verification result is that the flatness yield of the first surface 11 is low, and the deformation ratio of the first surface 11 of the battery pack is 20%. It can be understood that when the thickness T of the shell 1 cannot meet the strength requirements of the shell 1, the aluminum plate is prone to poor alignment after bending, and the convexity and concave of the first surface 11 after the shell 1 is bent and formed exceed the standard, which leads to a low flatness yield. Among the multiple samples, 20% of the samples have the problem of deformation of the first surface 11 of the battery pack.

[0085] As shown in Table 3, Example 33, the surface area S1 of the first surface 11 is 1.0×10 5 , the dimension L of the end opening 10 in the first direction X is 160, and the thickness T of the shell 1 is 0.5. When the surface area S1 of the first surface 11 and the dimension L of the end opening 10 in the first direction X meet the requirements, but the thickness T of the shell 1 is too small, the verification result is that the flatness yield of the first surface 11 is low, and the deformation ratio of the first surface 11 of the battery pack is 20%. It can be understood that when the thickness T of the shell 1 cannot meet the strength requirements of the shell 1, the aluminum plate is prone to poor alignment after bending, and the convexity and concave of the first surface 11 after the shell 1 is bent and formed exceed the standard, which leads to a low flatness yield.

[0086] The present application can effectively improve the problem of excessive convexity and concavity on the first surface 11 after the shell 1 is bent and formed by reasonably designing the surface area S1 of the first surface 11 of the single cell, the dimension L of the end opening 10 in the first direction X, and the thickness T of the shell 1, thereby effectively improving the production yield of the shell 1, ensuring the structural strength of the first surface 11 during the production of the single cell, and the structural strength of the first surface 11 of the battery pack, and ensuring the reliability and safety of the single cell and the battery pack.

[0087] In some embodiments, a single cell includes a shell 1, an electrode assembly 2 and a cover plate 3, wherein the shell 1 has an end opening 10; the electrode assembly 2 is disposed in the shell 1; and the cover plate 3 is connected to the shell 1 and covers the end opening 10. An explosion-proof valve 4 is usually disposed on the cover plate 3, which is used to be destroyed when the single cell has thermal runaway, so as to discharge the high-temperature and high-pressure gas generated along the exhaust path in the shell 1. Among them, the size of the end opening 10 in the first direction X is L mm, the size of the end opening 10 in the second direction Y is W mm, the size of the shell 1 in the third direction Z is H mm, the circumference of the end opening 10 is C mm, and the single cell satisfies at least one of the following characteristics: H≤600, 220≤C≤450, 1500≤L×W≤10000. The shell 1 of the embodiment of the present application is formed into the approximate shape of the shell 1 by bending an aluminum plate, and the two ends of the aluminum plate are connected by welding to form a complete shell 1. The first direction X is the length direction of the end opening 10, the second direction Y is the width direction of the end opening 10, and the third direction Z is the extension direction of the shell 1, wherein the first direction X, the second direction Y and the third direction Z are perpendicular to each other. It can be understood that the perimeter C of the end opening 10 is the length of the aluminum plate, and the perimeter C of the end opening 10 = 2 (L + W), and the cross-sectional area S2 of the end opening 10 = L × W. When a single cell has thermal runaway, high-temperature and high-pressure gas will be generated. To ensure safety, it is necessary to ensure that the exhaust flow rate of high-temperature and high-pressure gas and the time taken for the gas to travel from the failure point to the explosion-proof valve 4 match the gas production volume, gas production rate and exhaust area of ​​the explosion-proof valve 4 of the single cell, so as to achieve the balance of gas production, internal gas circulation and discharge of the single cell failure, avoid danger caused by imbalance in gas production and discharge, and thus improve the safety performance of the single cell and battery pack. Reasonable control of the dimension H of the shell 1 in the third direction Z, the circumference C of the end opening 10 and the cross-sectional area S2 of the end opening 10 helps to reduce the internal pressure of the single cell in the case of thermal runaway, reduce the risks of fire and explosion, and ensure the stability and reliability of the single cell.

[0088] In some embodiments, the present application limits the dimension H of the shell 1 in the third direction Z. On the one hand, it can avoid the problem that the dimension H of the shell 1 in the third direction Z is too small, which leads to excessive concentration of gas discharge during thermal runaway of the single cell, causing excessive local pressure in the shell 1, and further causing the shell 1 to rupture; on the other hand, it can avoid the problem that the dimension H of the shell 1 in the third direction Z is too large, which leads to a long exhaust path for high-temperature and high-pressure gas, thereby increasing the exhaust time.

[0089] In some embodiments, the perimeter C of the end opening 10 can be any one of 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, or a range of values ​​between any two values. By limiting the perimeter C of the end opening 10, the present application can, on the one hand, avoid the increased difficulty in bending the aluminum plate caused by the excessive size of the shell 1, which in turn leads to poor flatness, low strength of the shell 1, and other problems, and avoid deformation or rupture of the shell 1 when the single cell is thermally runaway; on the other hand, it can avoid the perimeter C of the end opening 10 being too small, resulting in narrow space and affecting the flow of high-temperature and high-pressure gas on the exhaust path in the shell 1. In addition, it can also avoid the size of the shell 1 being too small to affect the space utilization of the battery pack.

[0090] In some embodiments, the cross-sectional area S2 of the end opening 10 can be any one of 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, 9000, 9500, 10000 or a range between any two values. By limiting the cross-sectional area S2 of the end opening 10, the present application can avoid the risk of the cross-sectional area S2 of the end opening 10 being too small, causing the high-temperature and high-pressure gas flow rate generated during thermal runaway of the single cell to be too fast, thereby causing the shell 1 to rupture and leak. At the same time, too small a cross-sectional area S2 will limit the gas discharge flow rate and affect the exhaust effect; on the other hand, it can avoid the problem of the cross-sectional area S2 of the end opening 10 being too large, causing the gas discharge time to increase, the exhaust rate to decrease, and the exhaust effect to be affected.

[0091] In the embodiment of the present application, by setting a shell 1 of different sizes H, C and S2, the electrode assembly 2 and the cover plate 3 are placed in the shell, and the safety of the single cell is tested through a single cell thermal runaway safety test. The verification results are shown in Table 4.

[0092] Table 4:

[0093]

[0094]

[0095] The thermal runaway safety test of the single battery in this application is carried out in accordance with the safety requirements for power batteries for electric vehicles in GB38031-2020. A steel needle of a specific diameter is used to pierce the battery cell at a specified speed to observe the reaction of the battery cell. If the single battery does not catch fire or explode within the set time, it is considered to have passed the thermal runaway safety test of the single battery.

[0096] As shown in Table 4, Example 34 and Example 35, the dimensions H of the housing 1 in the third direction Z are 600 and 550 respectively, the perimeter C of the end opening 10 is 276, and the cross-sectional area S2 of the end opening 10 is 2360 and 2160 respectively, satisfying the conditions of H≤600, 220≤C≤450, 1500≤S2≤10000. The verification result is that the passing rate of the thermal runaway safety test of the single battery is 100%, that is, all samples have passed the thermal runaway safety test.

[0097] As shown in Table 4, Example 36 to Example 39, the dimension H of the housing 1 in the third direction Z is 550, the perimeter C of the end opening 10 is 240, and the cross-sectional area S2 of the end opening 10 is between 1751 and 2000, satisfying the conditions of H≤600, 220≤C≤450, 1500≤S2≤10000. Compared with Example 34 and Example 35, the perimeter C of the end opening 10 and the cross-sectional area S2 of the end opening 10 of Example 36 to Example 39 are smaller, but multiple samples can still meet the requirements of the thermal runaway safety test. It shows that within a certain range, the size parameters of the end opening 10 are appropriately adjusted to ensure that the flow rate and flow rate of gas emission are moderate, thereby ensuring the safety of the single battery.

[0098] As shown in Table 4, Examples 40 to 42, the dimension H of the shell 1 in the third direction Z is 550, the perimeter C of the end opening 10 is 236 and 238 respectively, and the cross-sectional area S2 of the end opening 10 is between 1545 and 1734, satisfying the conditions of H≤600, 220≤C≤450, 1500≤S2≤10000. Compared with Examples 36 to 39, the perimeter C of the end opening 10 and the cross-sectional area S2 of the end opening 10 of Examples 40 to 42 are smaller, which has a certain impact on the gas flow, but multiple samples can still meet the requirements of the thermal runaway safety test. It shows that within a certain range, the safety of the single cell can still be guaranteed by appropriately adjusting the size parameters of the end opening 10.

[0099] As shown in Table 4, Example 43 to Example 45, the dimension H of the shell 1 in the third direction Z is 550, the perimeter C of the end opening 10 is 218 and 220 respectively, and the cross-sectional area S2 of the end opening 10 is between 1564 and 1581. The verification results show that the passing rates of the thermal runaway safety test of the single battery are 60%, 20% and 40% respectively, that is, at least some of the multiple samples do not meet the requirements of the thermal runaway safety test. It can be understood that although the dimension H of the shell 1 in the third direction Z and the cross-sectional area S2 of the end opening 10 meet the conditions of H≤600, 1500≤S2≤10000, the perimeter C of the end opening 10 is too small, resulting in a small gas discharge channel, and the high-temperature and high-pressure gas is not discharged smoothly during thermal runaway, and the pressure accumulation is easy to cause fire or explosion.

[0100] As shown in Table 4, Example 46 and Example 47, the dimension H of the shell 1 in the third direction Z is 550, the circumference C of the end opening 10 is 227, and the cross-sectional area S2 of the end opening 10 is 1350. The verification results show that the passing rates of the thermal runaway safety test of the single cell are 60% and 40% respectively, that is, at least some of the multiple samples do not meet the requirements of the thermal runaway safety test. It can be understood that although the dimension H of the shell 1 in the third direction Z and the circumference C of the end opening 10 meet the conditions of H≤600, 220≤C≤450, the cross-sectional area S2 of the end opening 10 is too small, resulting in too fast flow rate of high-temperature and high-pressure gas generated when the single cell thermal runaway occurs, and there is a risk of causing the shell 1 to rupture and leak. At the same time, the too small cross-sectional area S2 will limit the discharge flow of the gas and affect the exhaust effect.

[0101] As shown in Example 48 of Table 4, the dimension H of the shell 1 in the third direction Z is 650, the perimeter C of the end opening 10 is 276, and the cross-sectional area S2 of the end opening 10 is 2160. The verification result is that the passing rate of the thermal runaway safety test of the single battery is 60%, that is, at least some of the samples do not meet the requirements of the thermal runaway safety test. It can be understood that although the perimeter C of the end opening 10 and the cross-sectional area S2 of the end opening 10 meet the conditions of 220≤C≤450, 1500≤S2≤10000, the dimension H of the shell 1 in the third direction Z is too large, resulting in a longer exhaust path for high-temperature and high-pressure gas during thermal runaway, which affects the timeliness of gas exhaust.

[0102] As shown in Table 4, Example 49, the dimension H of the shell 1 in the third direction Z is 700, the circumference C of the end opening 10 is 276, and the cross-sectional area S2 of the end opening 10 is 2160. The verification result is that the passing rate of the thermal runaway safety test of the single battery is 20%, that is, at least some of the multiple samples do not meet the requirements of the thermal runaway safety test. It can be understood that although the circumference C of the end opening 10 and the cross-sectional area S2 of the end opening 10 meet the conditions of 220≤C≤450, 1500≤S2≤10000, the dimension H of the shell 1 in the third direction Z is larger than that of Example 48, resulting in a longer exhaust path for high-temperature and high-pressure gas during thermal runaway, affecting the timeliness of gas exhaust, and thus increasing safety risks.

[0103] As shown in Table 4, Example 50, the dimension H of the shell 1 in the third direction Z is 750, the circumference C of the end opening 10 is 276, and the cross-sectional area S2 of the end opening 10 is 2160. The verification result is that the passing rate of the thermal runaway safety test of the single cell is 0%, that is, all samples do not meet the requirements of the thermal runaway safety test. It can be understood that although the circumference C of the end opening 10 and the cross-sectional area S2 of the end opening 10 meet the conditions of 220≤C≤450, 1500≤S2≤10000, the dimension H of the shell 1 in the third direction Z is larger than that of Example 48 and Example 49, resulting in a longer exhaust path of high-temperature and high-pressure gas during thermal runaway, thereby increasing the exhaust time, affecting the timeliness of gas exhaust, resulting in difficulty in gas exhaust, and the inability to release the pressure accumulation in time, thereby causing fire or explosion.

[0104] The present application reasonably designs the dimension H of the shell 1 in the third direction Z, the perimeter C of the end opening 10, and the cross-sectional area S2 of the end opening 10, so as to effectively ensure that the high-temperature and high-pressure gas generated inside the single cell when thermally controlled is discharged to the outside of the shell 1 along the exhaust path in a timely manner, thereby achieving a balance between the gas production, internal gas circulation, and discharge of the single cell failure, avoiding danger caused by imbalance in gas production and discharge, and thus improving the safety performance of the single cell and battery pack. Reasonable control of the dimension H of the shell 1 in the third direction Z, the perimeter C of the end opening 10, and the cross-sectional area S2 of the end opening 10 helps to reduce the internal pressure of the single cell in the case of thermal runaway, reduce the risk of fire, explosion, etc., and ensure the stability and reliability of the single cell.

[0105] Correspondingly, the embodiment of the present application also provides an electrical device, including the above-mentioned single cell, or, including the above-mentioned battery pack, so the electrical device can have all the technical features and beneficial effects of the above-mentioned single cell or battery pack, which will not be repeated here. The electrical device can be a mobile phone, a portable device, a laptop computer, an electric car, an electric car, a ship, a spacecraft, an electric toy, and an electric tool. For example, spacecraft include airplanes, rockets, space shuttles, and spacecrafts; electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys; electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers.

[0106] 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.

[0107] 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 an open end; An electrode assembly is disposed in the housing; A cover plate connected to the shell and covering the end opening; The thickness of the shell is T mm, the circumference of the end opening is C mm, and the following conditions are satisfied: 0.3≤T≤0.8, 100≤C≤500.

2. The single cell according to claim 1, characterized in that: The single cell meets the following requirements: 0.3≤T≤0.35, 100≤C≤120.

3. The single cell according to claim 1, characterized in that: The single cell battery satisfies: 0.35≤T≤0.8, 120≤C≤500.

4. The single cell according to any one of claims 2 and 3, characterized in that: The dimension of the end opening in the first direction is L mm, and the dimension of the end opening in the second direction is W mm, satisfying: 4.5≤L / W≤12, and the first direction and the second direction intersect.

5. The single cell according to claim 4, characterized in that: The dimension L of the end opening in the first direction satisfies: L≤190; and / or The dimension W of the end opening in the second direction satisfies: W≥13.

5.

6. The single cell according to claim 4, characterized in that: The size of the shell in the third direction is H mm, the thickness of the shell is T mm, and the third direction intersects with the first direction and the second direction respectively, satisfying: L×H≤1.2×10 5 ,L≤190,0.3≤T≤0.8。 7. The single cell according to claim 6, characterized in that: The single cell meets at least one of the following characteristics: a)L×H≤8×10 4 ,L≤130,0.3≤T≤0.5; b)8×10 4 ≤L×H≤1.2×10 5 ,130≤L≤190,0.5≤T≤0.8。 8. The single cell according to claim 4, characterized in that: The dimension of the shell in the third direction is H mm, the circumference of the end opening is C mm, and the following conditions are satisfied: H≤600, 220≤C≤450, 1500≤L×W≤10000.

9. A battery pack, characterized in that: The invention comprises the single cell according to any one of claims 1 to 8.

10. An electrical device, characterized in that: The method comprises the single cell according to any one of claims 1 to 8, or comprises the battery pack according to claim 9.

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