Battery and battery pack

Abstract

The utility model provides a battery and a battery pack, the battery comprises a shell, the shell comprises a top wall, a bottom wall and a plurality of side walls, the top wall and the bottom wall are oppositely arranged, the plurality of side walls are arranged between the top wall and the bottom wall, and the ratio of the length of the shell to the width of the shell is greater than 3; the liquid injection hole is formed in the side wall; wherein the height of the side wall is set to be H, the distance between the center of the liquid injection hole and the top wall is set to be h, and h / H is larger than or equal to 0.4 and smaller than or equal to 0.6.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a battery and a battery pack. Background Art

[0002] In related technologies, the battery's injection hole is usually set on the top wall of the shell, especially for blade batteries. The width of the blade battery is much smaller than its length. Therefore, setting the injection hole above the top wall will lead to longer infiltration time of the core package and longer exhaust channel, which will lead to low production efficiency of the blade battery. Utility Model Content

[0003] The embodiments of the present utility model provide a battery and a battery pack, which can improve the technical problem of long battery filling time caused by setting the filling hole on the top wall of the battery.

[0004] In a first aspect, an embodiment of the present invention provides a battery, comprising:

[0005] a housing, the housing comprising a top wall and a bottom wall disposed opposite to each other, and a plurality of side walls, the plurality of side walls being disposed between the top wall and the bottom wall, wherein a ratio of a length of the housing to a width of the housing is not less than 3;

[0006] A liquid injection hole is provided on the side wall;

[0007] The height of the side wall is set to H, the distance between the center of the injection hole and the top wall is set to h, and h / H satisfies: 0.4≤h / H≤0.6.

[0008] In one embodiment, the sidewall includes a first sidewall and a second sidewall disposed opposite to each other, and a third sidewall and a fourth sidewall disposed opposite to each other, and a surface area of the first sidewall or the second sidewall is smaller than a surface area of the third sidewall or the fourth sidewall;

[0009] The injection hole is provided on the first side wall or the second side wall, and the center of the injection hole coincides with the center of the first side wall or the center of the second side wall.

[0010] In one embodiment, a sealing cover is further included, which is used to seal the liquid injection hole. The side wall is provided with a first welding area, and the sealing cover is welded to the side wall in the first welding area. The side wall includes a first side edge and a second side edge that are oppositely arranged. The first side edge and the second side edge are located between the top wall and the bottom wall. The minimum distance between the first welding area and the first side edge is not less than 3 mm, and / or the minimum distance between the first welding area and the second side edge is not less than 3 mm.

[0011] In one embodiment, the projected area of the injection hole on the side wall is set to s, the projected area of the first welding area on the side wall is set to m, and s / m satisfies: 0.1≤s / m≤0.4.

[0012] In one embodiment, the diameter of the first welding area is set to 7 mm to 8 mm; and / or the diameter of the injection hole is set to 3 mm to 5 mm.

[0013] In one embodiment, the surface area of the side wall is set to M, and m / M satisfies: 0.01≤m / M≤0.2.

[0014] In one embodiment, the first welding area is set to a circular welding area, the side wall includes a second area, the circular welding area is located in the second area, the wide side of the second area is tangent to the circular welding area, the length of the second area is equal to the width of the first side wall, the surface area of the second area is set to N, and m / N satisfies: 0.1≤m / N≤0.6.

[0015] In one embodiment, an explosion-proof valve is further included, and the explosion-proof valve and the liquid injection hole are arranged on the same side wall.

[0016] In one embodiment, the minimum distance between the explosion-proof valve and the first welding area is set to be no less than 20 mm.

[0017] In one embodiment, a pole piece assembly is further included, and an exhaust channel is formed between the outer surface of the pole piece assembly and the inner wall of the shell, and the exhaust channel includes a first exhaust channel and a second exhaust channel, the first exhaust channel and the second exhaust channel are connected to each other at the injection hole, and are connected to the injection hole, the first exhaust channel extends from the inner side of the top wall to the inner side of the side wall, and the second exhaust channel extends from the inner side of the bottom wall to the inner side of the side wall.

[0018] In a second aspect, an embodiment of the present invention provides a battery pack, which includes a plurality of the above-mentioned batteries and a box, wherein the plurality of the above-mentioned batteries are arranged in the box.

[0019] Beneficial effects of the embodiments of the present utility model:

[0020] In an embodiment of the present invention, the injection hole is arranged on the side wall, and the ratio of the distance h between the center of the injection hole and the top wall to the height H of the side wall, that is, h / H satisfies: 0.4≤h / H≤0.6, thereby ensuring that the center of the injection hole is as close as possible to the center of the side wall, which is conducive to shortening the injection time to a minimum. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 This is a three-dimensional schematic diagram of a battery at one angle provided by an embodiment of the present utility model;

[0023] Figure 2 This is a three-dimensional schematic diagram of a battery from another angle provided by an embodiment of the present utility model;

[0024] Figure 3 This is a schematic side cross-sectional view of a battery provided in an embodiment of the present utility model;

[0025] Figure 4 This is a schematic diagram of the sealing structure of the liquid injection hole provided in an embodiment of the present utility model;

[0026] Figure 5 It is a schematic structural diagram of a side wall provided by an embodiment of the present utility model;

[0027] Figure 6 yes Figure 5 A partial enlarged view of

[0028] Figure 7 yes Figure 6 A magnified view of point A;

[0029] Figure 8 yes Figure 6 Enlarged view of point B;

[0030] Figure Number:

[0031] 1. Battery; 10. Housing; 11. Top wall; 12. Bottom wall; 13. Side walls; 131. First side wall; 132. Second side wall; 133. Third side wall; 134. Fourth side wall; 135. First side edge; 136. Second side edge; 20. Pole piece assembly; 30. Injection hole; 31. Sealing cover; 32. Sealing column; 33. First welding area; 34. Second area; 351. First exhaust channel; 352. Second exhaust channel; 40. Explosion-proof valve; DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention. In the present invention, unless otherwise specified, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inside" and "outside" refer to the outline of the device.

[0033] Embodiments of the present application provide a battery pack, which can be a power battery pack used to store electrical energy and serve as a power source for electric vehicles and hybrid vehicles. The battery pack can also be an energy storage battery pack, which includes an energy storage container and is used to store electrical energy to provide various functions for power systems, such as a smart mobile grid. The battery pack includes a housing, multiple single cells 1, and a BMS (battery management system).

[0034] The enclosure is used to secure and protect multiple battery cells and other components. It can be assembled from several sub-enclosures. Suitable materials for the enclosure include metal or plastic, offering excellent shock resistance, waterproofing, and insulation. The enclosure has a hollow interior, which can be divided into a battery chamber for housing multiple batteries and an electrical chamber for housing the BMS and other fixed components.

[0035] Multiple single cells are arranged in a matrix within the battery cavity. The cells can be connected in series, in parallel, or in a combination of these, ensuring the battery pack has a capacity and power suitable for use in electrical equipment. Cells include lithium-ion batteries, nickel-metal hydride batteries, lead-acid batteries, lithium iron phosphate batteries, or composite materials.

[0036] The battery pack also includes multiple connecting plates, each of which is used to connect the positive and negative electrodes of two adjacent batteries, so that the positive and negative electrodes of multiple batteries have a stable series-parallel connection structure. The materials used to prepare the connecting plates include copper, aluminum, or a copper-aluminum composite material.

[0037] As a power battery pack or energy storage battery pack, the battery pack also includes a BMS (battery management system), which is used to monitor, protect and manage the working status of the battery pack. The BMS can monitor and balance the voltage and temperature of each single cell, and can also control the power and protection functions of the battery pack during charging and discharging.

[0038] The embodiment of the present application provides a single battery 1, such as Figure 1 、 Figure 2 and Figure 3 As shown, the single battery 1 includes a shell 10, a pole piece assembly 20, and an electrolyte.

[0039] Taking the square single cell 1 as an example, the shell 10 is configured to be made of a metal material with certain mechanical strength and corrosion resistance. Suitable metal materials include nickel or steel. The shell 10 has a hollow inner cavity, and the pole piece assembly is accommodated in the inner cavity of the shell 10. The shell 10 is used to fix and protect the pole piece assembly.

[0040] The shell 10 includes a top wall 11 and a bottom wall 12 that are arranged opposite to each other, and a plurality of side walls connected between the top wall 11 and the bottom wall 12. The plurality of side walls include a first side wall 131 and a second side wall 132 that are arranged opposite to each other, and a third side wall 133 and a fourth side wall 134 that are arranged opposite to each other. Taking the blade battery as an example, the surface area of the first side wall 131 and the second side wall 132 is smaller than the surface area of the third side wall 133 and the fourth side wall 134. In one example, the plurality of side walls and the bottom wall 12 are integrally formed into a main shell with an open structure, and the top wall 11 is configured as a top cover assembly and connected to the opening of the main shell. The top cover assembly generally includes a cover plate and a lower plastic, etc. The cover plate is welded to the main shell, and the lower plastic is fixed to the cover plate.

[0041] The electrode assembly 20 includes a positive electrode sheet, a separator and a negative electrode sheet. The separator is arranged between the positive electrode sheet and the negative electrode sheet and is used to separate the positive electrode sheet and the negative electrode sheet. The electrode assembly 20 can wind the positive electrode sheet, the separator and the negative electrode sheet to form a core assembly. The electrode assembly 20 can also stack the positive electrode sheet, the separator and the negative electrode sheet to form a laminated assembly.

[0042] The electrolyte is filled inside the battery 1 so that the internal structure of the battery, such as the positive electrode sheet and the negative electrode sheet, is fully immersed in the electrolyte. The electrolyte acts as an ion transmission carrier between the positive electrode sheet and the negative electrode sheet, maintaining the continuity of electron transmission inside the battery, so that the battery can be charged and discharged normally.

[0043] The battery 1 also includes a pole, which is fixed on the lower plastic. At least two poles are spaced apart on the top wall, and the two poles can be one or both of the positive poles and the negative poles.

[0044] In the prior art, the battery's injection port is typically located on the top wall of the housing. This requires at least one terminal, an explosion-proof valve, and a liquid injection port. This complicates the top wall's manufacturing process and increases processing costs. Furthermore, during horizontal battery formation, electrolyte overflow can occur, resulting in a poor appearance and potentially causing personal injury to on-site production operators. This is particularly true for blade batteries, whose width is much smaller than their length. Therefore, placing the injection port on the top wall results in a longer core pack soaking time and a longer formation venting path. This, in turn, leads to low production efficiency and a poor appearance of the formation interface.

[0045] The embodiment of the present application optimizes the structure of the battery 1 and arranges the liquid injection hole 30 on the side wall, thereby improving the technical problem of the long liquid injection time of the battery 1.

[0046] refer to Figures 1 to 3 as well as Figure 5 Taking a square battery as an example, a liquid injection hole 30 is provided on the side wall, and the liquid injection device injects electrolyte into the interior of the shell 10 through the liquid injection hole 30. Among them, the height of the side wall is set to H, the distance between the center of the liquid injection hole 30 and the top wall 11 is set to h, and the distance between the center of the liquid injection hole 30 and the bottom wall 12 is set to d. In a preferred embodiment, the ratio of the distance h between the center of the liquid injection hole 30 and the top wall 11 to the height H of the side wall, that is, h / H satisfies: 0.4≤h / H≤0.6. In a specific embodiment, h / H can be 0.4, 0.43, 0.48, 0.5, 0.53, 0.57, 0.6, or a value between any two of the above values, or a range between any two of the above values.

[0047] When the injection hole 30 is adjusted from the top wall 11 to the side wall, the structure of the top wall can be significantly simplified. For example, there is no need to set a injection hole and its sealing structure on the top wall, thereby reducing the processing cost of the battery 1.

[0048] Furthermore, since the injection hole 30 is provided on the side wall, when the battery 1 is formed horizontally, electrolyte overflow will not occur, thereby effectively improving the problem of poor battery appearance caused by formation, and also benefiting the safety of production operators.

[0049] Through research, the inventors also discovered that when the ratio of the distance h between the center of the injection hole 30 and the top wall 11 to the height H of the side wall, i.e., h / H, satisfies the following conditions: 0.4≤h / H≤0.6, the corresponding ratio of the distance d between the center of the injection hole 30 and the bottom wall 12 to the height H of the side wall, i.e., d / H, satisfies the following conditions: 0.4≤d / H≤0.6. This ensures that the center of the injection hole 30 is as close to the center of the side wall as possible, thereby facilitating the shortest injection time. When h / H is set to less than 0.4, the corresponding distance d / H between the center of the injection hole 30 and the bottom wall 12 is greater than 0.6, which results in the time for the electrolyte to reach the top wall from the injection hole being less than the time for the electrolyte to reach the bottom wall from the injection hole, thereby affecting the overall electrolyte infiltration rate. Furthermore, when h / H is set to be greater than 0.6, the corresponding distance d / H between the center and west of the injection hole 30 and the bottom wall 12 is less than 0.4, which will cause the time for the electrolyte to reach the top wall from the injection hole to be greater than the time for the electrolyte to reach the bottom wall from the injection hole, thereby affecting the overall infiltration rate of the electrolyte.

[0050] In a further preferred embodiment, the setting position of the injection hole 30 satisfies: h / H=0.5, d / H=0.5, so that the time for the electrolyte to reach the top wall from the injection hole is basically the same as the time for the electrolyte to reach the bottom wall from the injection hole, so that the overall injection efficiency of the battery is fastest.

[0051] Continue to refer Figure 1 and Figure 2 Taking the blade battery as an example, the sidewalls include a first sidewall 131 and a second sidewall 132, as well as a third sidewall 133 and a fourth sidewall 134. The surface area of the first sidewall 131 is equal to the surface area of the second sidewall 132, the surface area of the third sidewall 133 is equal to the surface area of the fourth sidewall 134, and the surface area of the first sidewall 131 or the surface area of the second sidewall 132 is smaller than the surface area of the third sidewall 133 or the surface area of the fourth sidewall 134. In a preferred embodiment, the liquid injection hole 30 is provided on the first sidewall 131 or the second sidewall 132, and the center of the liquid injection hole 30 coincides with the center of the first sidewall 131 or the center of the second sidewall 132.

[0052] In the blade battery, since the width of the battery 1 is much smaller than the length of the battery, specifically, the ratio between the length of the battery and the width of the battery is not less than 3, wherein the length direction of the battery is as follows Figure 2 The X direction of the battery is as follows: Figure 2 The Y direction is the same as the Y direction, so the injection hole 30 is placed on the side wall. The electrolyte infiltrates the electrode assembly along the width of the battery, which can significantly shorten the electrode assembly infiltration time and thus reduce the number of electrolyte injection cycles. The inventors further compared the number of injection cycles for the same blade battery, as shown in Table 1 below.

[0053] Table 1 Number of injection cycles of blade batteries

[0054] Serial number Liquid injection hole setting position Number of injection cycles 1 Top wall 5 2 Sidewall center 3

[0055] From the data in Table 1, it can be seen that compared with setting the injection hole on the top wall, when the injection hole is set in the center of the side wall, the electrolyte is injected from the middle of the battery, which is conducive to accelerating the electrolyte infiltration rate, so that the number of battery injection cycles can be significantly reduced, among which the number of injection cycles is reduced from 5 times to 3 times. Correspondingly, the injection time can be reduced by about 20 minutes, thereby effectively improving the injection efficiency.

[0056] like Figure 4 As shown, battery 1 also includes a liquid injection hole sealing structure for sealing liquid injection hole 30. After the liquid injection operation is completed, the liquid injection hole sealing structure is sealed within the liquid injection hole 30, thereby maintaining the sealing performance of the entire battery and preventing electrolyte overflow. The liquid injection hole sealing structure includes a sealing cover 31 and a sealing post 32. The liquid injection hole 30 is configured as a countersunk hole located on the side wall. The sealing post 32 seals the interior of the liquid injection hole 30. The sealing cover 31 is used to seal the open end of the liquid injection hole 30. The diameter of the sealing cover 31 is larger than the inner diameter of the liquid injection hole 30.

[0057] Continue to refer Figure 4 、 Figure 5 and Figure 6 The sealing cover 31 is preferably welded to the side wall 13. The side wall 13 includes a first side 135 and a second side 136 that are oppositely disposed. The sealing cover 31 is welded to the side wall 13 within a first welding area 33. The distance L between the edge of the first welding area 33 and the first side 135 is not less than 3 mm. Correspondingly, the distance L between the edge of the first welding area 33 and the second side 136 is not less than 3 mm. The distance between the edge of the first welding area 33 and the first side 135 or the second side 136 can be understood as the minimum distance between the first welding area 33 and the first side 135 or the second side 136.

[0058] The sealing cover 31 is welded to the side wall 13, and the width of the weld between the two is set to be no less than 2 mm. To prevent interference between the battery-securing fixture and the laser equipment used for welding, sufficient spacing must be left between the edge of the first welding area 33 and the first side 135 or the second side 136. The inventors have discovered that if the distance L between the edge of the first welding area 33 and the first side 135, and the distance L between the edge of the first welding area 33 and the second side 136, is set to no less than 3 mm, the weld width requirements can be met while also preventing interference between the battery-securing fixture and the laser equipment used for welding. If the distance L between the edge of the first welding area 33 and the first side 135, and the distance L between the edge of the first welding area 33 and the second side 136, are set to less than 3 mm, the weld width between the sealing cover 31 and the side wall 13 will not meet the requirements. Furthermore, interference between the fixture used to secure the battery and the laser equipment used for welding may occur, thereby affecting the welding process.

[0059] Continue to refer Figure 5 、 Figure 6 and Figure 7 The projected area of the injection hole 30 on the side wall 13 is set to s, and the projected area of the first welding area 33 on the side wall 13 is set to m. The ratio of the projected area s of the injection hole 30 on the side wall 13 to the projected area m of the first welding area 33 on the side wall 13, i.e., s / m, satisfies the following: 0.1≤s / m≤0.4. In specific implementations, s / m can be 0.1, 0.15, 0.18, 0.2, 0.25, 0.27, 0.3, 0.34, 0.37, 0.4, or any value between any two of the above values, or a range between any two of the above values.

[0060] Through research, the inventors found that if s / m is less than 0.1, while the welding area of the first welding zone 33 remains unchanged, the area of the liquid injection hole 30 is correspondingly smaller, that is, the aperture of the liquid injection hole 30 is smaller, which in turn affects the injection rate of the liquid injection hole 30. If s / m is greater than 0.4, while the area of the liquid injection hole 30 remains unchanged, the welding area of the first welding zone 33 is correspondingly smaller, which can lead to a cold weld, thereby reducing the bonding strength between the sealing cover 31 and the side wall 13, thereby affecting the sealing performance of the liquid injection hole 30 and causing the battery itself to leak.

[0061] In some preferred implementations, the diameter of the first welding area 33 is set to 7 mm to 8 mm. In specific implementations, the diameter of the first welding area 33 can be 7.0 mm, 7.3 mm, 7.4 mm, 7.6 mm, 7.7 mm, 7.8 mm, 7.9 mm, 8.0 mm, or a value between any two of the above values, or a range between any two of the above values.

[0062] When the diameter of the first welding area 33 is set to be less than 7 mm, the welding area of the first welding area 33 will be insufficient, resulting in a cold weld. When the diameter of the first welding area 33 is set to be greater than 8 mm, the distance between the edge of the first welding area 33 and the first side 135 or the second side 136 will be too close, resulting in an insufficient weld width and even interference between the fixture used to fix the battery and the laser equipment used for welding.

[0063] In some preferred embodiments, the diameter of the injection hole 30 is set to 3 mm to 5 mm. In specific embodiments, the diameter of the injection hole 30 can be 3.0 mm, 3.3 mm, 3.5 mm, 3.7 mm, 3.8 mm, 4.0 mm, 4.3 mm, 4.5 mm, 4.7 mm, 4.9 mm, 5.0 mm, or a value between any two of the above values, or a range between any two of the above values.

[0064] When the diameter of the injection hole 30 is set to be less than 3 mm, the injection efficiency of the electrolyte will be greatly affected. When the diameter of the injection hole 30 is set to be greater than 5 mm, the area of the first welding area 33 will be increased, which may easily lead to a cold weld in the first welding area 33.

[0065] Continue to refer Figure 5 and Figure 6 The surface area of the side wall 13 is set to M, and the ratio of the projected area m of the first welding region 33 on the side wall 13 to the surface area M of the side wall 13, i.e., m / M, satisfies the following: 0.01≤m / M≤0.2. In specific implementations, m / M can be 0.01, 0.02, 0.05, 0.07, 0.09, 0.10, 0.13, 0.15, 0.17, 0.19, 0.2, or a value between any two of the aforementioned values, or a range between any two of the aforementioned values.

[0066] The inventors have discovered that if m / M is set to greater than 0.2, while the surface area of the sidewall 13 remains unchanged, the weld area of the first weld zone 33 is too large, resulting in poor welding, which in turn affects the sealing performance of the injection hole and causes battery leakage. If m / M is set to less than 0.01, while the surface area of the sidewall 13 remains unchanged, the weld area of the first weld zone 33 is small. Consequently, the area of the injection hole 30 is also set to be smaller, i.e., the aperture of the injection hole 30 is too small, which in turn affects injection efficiency.

[0067] Continue to refer Figure 5 、 Figure 6 and Figure 8The first welding region 33 is configured as a circular welding region, and the sidewall 13 includes a second region 34. The first welding region 33 is located within the second region 34. Specifically, the second region 34 circumscribes the circular welding region along its width direction. The length of the second region 34 is equal to the width of the first sidewall 13. The surface area of the second region 34 is configured as N. The ratio of the projected area m of the first welding region 33 on the sidewall 13 to the surface area N of the second region 34, i.e., m / N, satisfies the following: 0.1≤m / N≤0.6. In specific implementations, m / N can be configured as 0.1, 0.14, 0.2, 0.23, 0.25, 0.28, 0.3, 0.35, 0.38, 0.40, 0.42, 0.48, 0.5, 0.52, 0.58, 0.6, or any value between any two of the aforementioned values, or a range between any two of the aforementioned values.

[0068] Through research, the inventors discovered that if m / N is set to greater than 0.6, while the area N of the second region 34 where the sidewall 13 is located remains unchanged, the weld area of the first weld region 33 is too large, resulting in a distance L between the edge of the first weld region 33 and the first side edge 135 or the second side edge 136 less than 3 mm. This can lead to interference between the battery fixture and the laser welding equipment used for welding, and even insufficient weld width in the first weld region 33, thereby affecting the sealing stability of the sealing cover 31. If m / N is set to less than 0.1, while the area N of the second region 34 where the sidewall 13 is located remains unchanged, the weld area of the first weld region 33 is small, and accordingly, the area of the liquid injection hole 30 is small, that is, the aperture of the liquid injection hole 30 is relatively small, which in turn affects the liquid injection efficiency.

[0069] Battery 1 also includes an explosion-proof valve 40, a key component for protecting the safety of battery 1. When the pressure inside battery 1 exceeds a preset threshold, valve 40 automatically opens, releasing the high-pressure airflow inside the battery, thereby reducing the pressure inside the battery and preventing the battery from rupturing or exploding. In related art, explosion-proof valves are typically located on the top wall, which in turn results in an overly complex top wall structure.

[0070] refer to Figure 6 In the embodiment of the present application, the explosion-proof valve 40 and the liquid injection hole 30 are disposed on the same side wall 13, so that only the terminal post needs to be disposed on the top wall, thereby effectively simplifying the top wall structure of the battery 1 and reducing the manufacturing cost of the battery 1. Furthermore, the location of the terminal post of the battery 1 on the top wall separates the battery's electrical connection structure from the battery's exhaust structure and liquid injection structure, thereby improving the safety performance of the battery 1.

[0071] Continue to refer Figure 6As shown, the distance between the edge of the explosion-proof valve 40 and the edge of the first welding area 33 is set to be no less than 20 mm. The distance between the edge of the explosion-proof valve 40 and the edge of the first welding area 33 can be understood as the minimum distance between the explosion-proof valve 40 and the first welding area 33.

[0072] Through research, the inventors discovered that if the distance between the edge of the explosion-proof valve 40 and the edge of the first welding zone 33 is set to less than 20 mm, the high-energy laser used during the welding of the sealing cover 31 to the side wall 13 can affect the explosion-proof valve 40, resulting in unstable valve opening pressure of the explosion-proof valve 40. Furthermore, if the distance between the edge of the explosion-proof valve 40 and the edge of the first welding zone 33 is set to less than 20 mm, electrolyte overflow during the injection process can also cause contamination of the explosion-proof valve and even corrosion of the explosion-proof valve, thereby affecting its normal operation. The maximum distance between the explosion-proof valve 40 and the edge of the first welding zone 33 needs to be adaptively adjusted according to the height of the side wall 13 and is not further limited in the embodiments of this application.

[0073] Continue to refer Figure 3 An exhaust channel is formed between the outer surface of the electrode assembly 20 and the inner wall of the housing 10. During the formation process of the battery, the bubbles in the electrolyte are evacuated through the exhaust channel by means of negative pressure, which is beneficial to maintain the consistency of the electrolyte. Figure 3 As shown, a structural schematic diagram of the exhaust channel of the battery is provided, and the exhaust channel includes a first exhaust channel 351 and a second exhaust channel 352. The first exhaust channel 351 and the second exhaust channel 352 converge at the injection hole 30, wherein the first exhaust channel 351 extends from the inner side of the top wall 11 to the inner side of the side wall, and the second exhaust channel 352 extends from the inner side of the bottom wall 12 to the inner side of the side wall.

[0074] Compared to setting the injection hole 30 on the top wall 11, the path of the exhaust channel on both sides of the injection hole 30 is basically equal to the height of the battery, making the exhaust channel of the entire battery longer. In the embodiment of the present application, the injection hole 30 is set on the side wall 13, and the exhaust channel on both sides of the injection hole 30 is basically equal to half the height of the battery, which can effectively reduce the distance of the formation exhaust channel, which is conducive to faster discharge of gas inside the battery. Furthermore, because the injection hole 30 is set close to the center of the side wall 13, the distance between the first exhaust channel 351 and the second exhaust channel 352 is roughly the same, which is conducive to improving the formation efficiency.

[0075] The above is a detailed introduction to the embodiments of the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of the present invention. At the same time, for those skilled in the art, based on the idea of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A battery, characterized in that: include: a housing, the housing comprising a top wall and a bottom wall disposed opposite to each other, and a plurality of side walls, the plurality of side walls being disposed between the top wall and the bottom wall, wherein a ratio of a length of the housing to a width of the housing is not less than 3; A liquid injection hole is provided on the side wall; The height of the side wall is set to H, the distance between the center of the injection hole and the top wall is set to h, and h / H satisfies: 0.4≤h / H≤0.

6.

2. The battery according to claim 1, characterized in that The sidewalls include a first sidewall and a second sidewall that are opposite to each other, and a third sidewall and a fourth sidewall that are opposite to each other, wherein the surface area of the first sidewall or the second sidewall is smaller than the surface area of the third sidewall or the fourth sidewall; The injection hole is provided on the first side wall or the second side wall, and the center of the injection hole coincides with the center of the first side wall or the center of the second side wall.

3. The battery according to claim 1 or 2, characterized in that It also includes a sealing cover, which is used to seal the liquid injection hole. The side wall is provided with a first welding area. The sealing cover is welded to the side wall in the first welding area. The side wall includes a first side edge and a second side edge that are oppositely arranged. The first side edge and the second side edge are located between the top wall and the bottom wall. The minimum distance between the first welding area and the first side edge is not less than 3 mm, and / or the minimum distance between the first welding area and the second side edge is not less than 3 mm.

4. The battery according to claim 3, characterized in that The projected area of the injection hole on the side wall is set to s, the projected area of the first welding area on the side wall is set to m, and s / m satisfies: 0.1≤s / m≤0.

4.

5. The battery according to claim 4, characterized in that The diameter of the first welding area is set to 7mm to 8mm; and / or, The diameter of the injection hole is set to 3mm to 5mm.

6. The battery according to claim 5, characterized in that The surface area of the side wall is set to M, and m / M satisfies: 0.01≤m / M≤0.

2.

7. The battery according to claim 5, characterized in that The first welding area is set to a circular welding area, the side wall includes a second area, the circular welding area is located in the second area, the wide side of the second area is tangent to the circular welding area, the length of the second area is equal to the width of the first side wall, the surface area of the second area is set to N, and m / N satisfies: 0.1≤m / N≤0.

6.

8. The battery according to any one of claims 4 to 7, characterized in that: It also includes an explosion-proof valve, which is arranged on the same side wall as the liquid injection hole.

9. The battery according to claim 8, characterized in that The minimum distance between the explosion-proof valve and the first welding area is set to be no less than 20 mm.

10. The battery according to claim 1, characterized in that It also includes a pole piece assembly, an exhaust channel is formed between the outer surface of the pole piece assembly and the inner wall of the shell, the exhaust channel includes a first exhaust channel and a second exhaust channel, the first exhaust channel and the second exhaust channel are connected to each other at the injection hole, and are connected to the injection hole, the first exhaust channel extends from the inner side of the top wall to the inner side of the side wall, and the second exhaust channel extends from the inner side of the bottom wall to the inner side of the side wall.

11. A battery pack, characterized in that: The battery pack includes a plurality of batteries according to any one of claims 1 to 10, and a box, wherein the plurality of batteries are arranged in the box.

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