Battery cell and battery module

Abstract

The invention belongs to the technical field of batteries, and discloses a battery cell and a battery module, the battery cell comprises a pole group, a shell, a cover plate and a pole column assembly, one side of the shell facing a first direction is provided with an opening, the inner edge of the shell at the opening is provided with a chamfer, the probability that the pole group and an insulating film are scratched can be reduced when the pole group is loaded into the shell from the opening, the cover plate covers the opening, and the cover plate covers the pole column assembly. The cover plate comprises a first plate body and a second plate body, the first plate body is perpendicular to the first direction, the second plate body comprises a first side and a second side which are oppositely arranged, the first side is connected with the first plate body and points to the second side from the first side, the second plate body inclines towards the second direction, and the second direction is opposite to the first direction. The pole assembly penetrates through and is fixed on the second plate body, and the first plate body protrudes out of the pole assembly in the first direction, so that the probability that the pole assembly is collided in the manufacturing process is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a battery cell and a battery module. BACKGROUND

[0002] The battery cell generally comprises a shell, a pole group and a cover plate, wherein the shell is provided with a receiving cavity and an opening communicating with the receiving cavity, the pole group is loaded into the receiving cavity through the opening, and the cover plate is arranged at the opening.

[0003] In the prior art, the inner edge of the shell at the opening is a right angle structure, and when the pole group is loaded into the receiving cavity, the right angle at the inner edge is easy to scratch the pole group and the insulating film wrapped outside the pole group, thereby reducing the safety and product yield of the battery cell. On the other hand, the existing cover plate is a flat plate structure, and the pole post on the cover plate is protruded on the surface of the side of the cover plate away from the shell. During the transportation and assembly process of the battery cell, the protruding pole post is easy to be knocked, thereby reducing the safety performance and appearance yield of the battery cell.

[0004] Therefore, it is urgent to provide a battery cell and a battery module to solve the above technical problems. SUMMARY

[0005] The first object of the present application is to provide a battery cell which can reduce the probability of scratching the pole group and the insulating film when the pole group is loaded into the shell through the opening, and can also reduce the probability of knocking the pole post assembly during the process.

[0006] To achieve this object, the present application adopts the following technical solutions:

[0007] The battery cell comprises:

[0008] a pole group;

[0009] a shell, one side of the shell towards a first direction is provided with an opening, an inner edge of the shell at the opening is provided with a chamfer, and the pole group can be loaded into the shell through the opening;

[0010] a cover plate, the cover plate is arranged at the opening, the cover plate comprises a first plate body and a second plate body, the first plate body is perpendicular to the first direction, the second plate body comprises oppositely arranged first and second sides, the first side is connected with the first plate body, the second plate body is inclined to a second direction from the direction pointing from the first side to the second side, and the second direction is opposite to the first direction;

[0011] a pole post assembly, the pole post assembly is arranged through and fixed to the second plate body, and the first plate body is protruded from the pole post assembly in the first direction.

[0012] Optionally, the shell comprises two oppositely arranged first wall bodies, the first wall bodies are provided with first protrusions on the side facing the first direction, the surface of the first protrusion on the side facing the first direction comprises a flat section and an inclined section, the flat section is connected with the inclined section, the first plate cover is arranged on the flat section of the two first wall bodies, and the second plate cover is arranged on the inclined section of the two first wall bodies.

[0013] Optionally, the number of the inclined sections and the second plates is two, the two inclined sections are symmetrically arranged about the flat section, and the two second plates are symmetrically arranged about the first plate.

[0014] Optionally, the number of the pole assembly is two, and the two pole assemblies correspond to the two second plates one by one.

[0015] Optionally, the acute angle between the flat section and the inclined section is N, N≥31°, and / or N≤63°.

[0016] Optionally, the size of the inclined section in the width direction is L, the size of the flat section in the width direction is W, the width direction is parallel to the surface of the first wall body, and the width direction is perpendicular to the first direction, L / (L+W)≥0.19, and / or L / (L+W)≤0.46.

[0017] Optionally, the first plate, the second plate and the first protrusions of the two first wall bodies form a capacity-increasing space in the shell, the pole group is arranged in the shell, the pole group is provided with a second protrusion on the side facing the first direction, and the second protrusion is located in the capacity-increasing space.

[0018] Optionally, the battery cell further comprises an explosion-proof valve, the explosion-proof valve is arranged on the shell, and the explosion-proof valve is located in the middle of the shell in the first direction.

[0019] And / or, the angle of the chamfer is 45°, the width of the chamfer is C, C≥0.05mm, and / or C≤0.17mm.

[0020] The second object of the application is to provide a battery module with high safety and high yield.

[0021] To achieve this object, the application adopts the following technical solutions:

[0022] The battery module comprises a connecting sheet and the battery cell.

[0023] Optionally, the connecting sheet is connected to the side of the pole assembly away from the second plate, and the first plate protrudes from the connecting sheet in the first direction.

[0024] The application has the following beneficial effects:

[0025] The inner edge of the shell at the opening is provided with a chamfer, when the pole group is loaded into the shell through the opening, the chamfer can protect the pole group and the insulating film wrapped outside the pole group, reduce the probability of scratching the pole group and the insulating film, and be beneficial to improving the safety of the battery cell and the product yield.

[0026] In another aspect, the cover plate comprises a first plate body and a second plate body, wherein the first plate body is perpendicular to the first direction, the first side of the second plate body is connected with the first plate body, the second plate body is inclined to the second direction from the direction of the first side to the second side, the pole column assembly is arranged and fixed on the second plate body, and the first plate body protrudes from the pole column assembly in the first direction, so that the first plate body can protect the pole column assembly, reduce the probability of the pole column assembly being bumped in the process of transportation and assembly, and be beneficial to improving the safety of the battery cell and the product yield. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a first structural schematic diagram of a battery cell provided by the application;

[0028] Figure 2 is a second structural schematic diagram of a battery cell provided by the application;

[0029] Figure 3 is Figure 2 is a local enlarged view of E in FIG.

[0030] Figure 4 is a structural schematic diagram of a cover plate provided by the application;

[0031] Figure 5 is a first structural schematic diagram of a shell provided by the application;

[0032] Figure 6 is a local sectional structural schematic diagram of a battery cell provided by the application;

[0033] Figure 7 is Figure 6 is a local enlarged view of F in FIG.

[0034] Figure 8 is a local structural enlarged view of a shell provided by the application;

[0035] Figure 9 is a second structural schematic diagram of a shell provided by the application;

[0036] Figure 10 is an assembly structural schematic diagram of a pole column assembly and a connecting sheet provided by the application.

[0037] In the drawings:

[0038] D1, first direction; D2, second direction;

[0039] 1, pole group; 11, second protrusion; 2, shell; 21, opening; 211, chamfer; 22, first wall body; 221, first protrusion; 2211, flat section; 2212, slope section; 2212a, first end; 2212b, second end; 23, capacity-increasing space; 24, second wall body; 241, reinforcing rib; 3, cover plate; 31, first plate body; 32, second plate body; 321, first side; 322, second side; 4, pole post assembly; 41, plastic piece; 42, riveting block; 431, base; 432, post body; 5, explosion-proof valve; 6, insulating piece; 7, connecting sheet. DETAILED DESCRIPTION

[0040] The application will be further described below in conjunction with the drawings and examples. It should be understood that the specific examples described herein are intended to be merely illustrative of the application and not in limitation thereof. It should also be noted that, for the purpose of clarity, only those structures directly related to the application are shown in the drawings.

[0041] In the description of the application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0042] In the present application, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include the direct contact of the first and second features, or the indirect contact of the first and second features through another feature between them. Moreover, the "upper", "upper" and "upper" of the first feature to the second feature include the vertical direction of the first feature above and oblique above the second feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The "lower", "lower" and "lower" of the first feature to the second feature include the vertical direction of the first feature below and oblique below the second feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0043] In the description of the present embodiment, the terms "upper", "lower", "right", and other orientation or position relationship are based on the orientation or position relationship shown in the drawings, which is only for the convenience of description and simplification of operation, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the application. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0044] The electric core provided by the embodiment can reduce the probability of scratching the pole group and the insulating film when the pole group is loaded into the shell through the opening, and can also reduce the probability of knocking the pole assembly in the process.

[0045] Specifically, as shown in the figure, Figures 1 to 6 The electric core comprises a pole group 1, a shell 2, a cover plate 3, and a pole assembly 4. The shell 2 is provided with an internal cavity, and one side of the shell 2 towards a first direction D1 is provided with an opening 21 which is in communication with the cavity. The pole group 1 can be loaded into the cavity in the shell 2 through the opening 21. The shell 2 is formed with an inner edge towards the cavity and an outer edge away from the cavity at the opening 21. The inner edge of the shell 2 at the opening 21 is provided with a chamfer 211. The cover plate 3 is arranged at the opening 21. The cover plate 3 comprises a first plate body 31 and a second plate body 32. The first plate body 31 is perpendicular to the first direction D1. The second plate body 32 comprises a first side 321 and a second side 322 which are oppositely arranged. The first side 321 is connected with the first plate body 31. The second plate body 32 is inclined to a second direction D2 from the direction pointing from the first side 321 to the second side 322. The second direction D2 is opposite to the first direction D1. The pole assembly 4 is arranged through and fixed to the second plate body 32. The first plate body 31 protrudes from the pole assembly 4 in the first direction D1.

[0046] Based on the above design, the inner edge of the shell 2 at the opening 21 is provided with the chamfer 211. When the pole group 1 is loaded into the shell 2 through the opening 21, the chamfer 211 can protect the pole group 1 and the insulating film wrapped outside the pole group 1, thereby reducing the probability of scratching the pole group 1 and the insulating film, and improving the safety of the electric core and the product yield.

[0047] On the other hand, the cover plate 3 comprises the first plate body 31 and the second plate body 32. The first plate body 31 is perpendicular to the first direction D1. The first side 321 of the second plate body 32 is connected with the first plate body 31. The second plate body 32 is inclined to the second direction D2 from the direction pointing from the first side 321 to the second side 322. The pole assembly 4 is arranged through and fixed to the second plate body 32. The first plate body 31 protrudes from the pole assembly 4 in the first direction D1. Therefore, the first plate body 31 can protect the pole assembly 4, thereby reducing the probability of knocking the pole assembly 4 in the process such as transportation and assembly, and improving the safety of the electric core and the product yield.

[0048] As shown in the figure, Figure 7As shown, in this embodiment, the pole assembly 4 includes a plastic part 41, a riveting block 42, and a pole. Both the plastic part 41 and the riveting block 42 are located on the side of the second plate 32 facing away from the housing 2, with the plastic part 41 sandwiched between the second plate 32 and the riveting block 42. The pole includes a base 431 and a column 432. The base 431 is located on the side of the second plate 32 facing the housing 2. One end of the column 432 is connected to the base 431, and the other end of the column 432 passes through the second plate 32, the plastic part 41, and the riveting block 42, and is riveted to the riveting block 42 for fixation. The statement that the first plate 31 protrudes from the pole assembly 4 in the first direction D1 means that the first plate 31 protrudes from the riveting block 42 in the first direction D1, thereby reducing the probability of the riveting block 42 being bumped during the manufacturing process.

[0049] Furthermore, the side of the rivet block 42 facing away from the second plate 32 is parallel to the surface of the second plate 32, so as to further reduce the probability of the rivet block 42 being bumped during the manufacturing process.

[0050] Optionally, such as Figure 3 As shown, the chamfer 211 has an angle of 45° and a bevel width of C, where C ≥ 0.05 mm. For example, C can be 0.05 mm, 0.06 mm, 0.07 mm, or 0.08 mm, with C ≥ 0.06 mm being preferred. If C < 0.05 mm, the inner edge of the opening 21 of the housing 2 will be relatively sharp, and when the electrode assembly 1 is inserted into the housing 2 through the opening 21, the electrode assembly 1 and the insulating film are more likely to be scratched by the inner edge.

[0051] Optionally, C ≤ 0.17 mm. For example, C can be 0.17 mm, 0.15 mm, 0.12 mm, or 0.09 mm, with C ≤ 0.15 mm being preferred. If C > 0.17 mm, the thickness at the opening 21 of the housing 2 will be too small, which will reduce the structural strength at the opening 21 of the housing 2. When welding the cover plate 3 to the opening 21 of the housing 2, it will not only increase the welding difficulty, but also easily cause problems such as explosion points due to insufficient molten pool size.

[0052] Optionally, such as Figure 5As shown, the shell 2 comprises two oppositely arranged first wall bodies 22, and each first wall body 22 is provided with a first protruding portion 221 on the side facing the first direction D1, and the surface of the first protruding portion 221 on the side facing the first direction D1 comprises a planar section 2211 and a sloping section 2212, the planar section 2211 is perpendicular to the first direction D1, and the first plate body 31 is arranged on the planar section 2211 of the two first wall bodies 22; the sloping section 2212 comprises a first end 2212a and a second end 2212b arranged oppositely, the first end 2212a is connected with the planar section 2211, and the sloping section 2212 is inclined to the second direction D2 from the first end 2212a to the second end 2212b, and the sloping section 2212 is parallel to the second plate body 32, and the second plate body 32 is arranged on the sloping section 2212 of the two first wall bodies 22, so as to realize that the cover plate 3 is arranged at the opening 21 of the shell 2.

[0053] In another embodiment, the cover plate 3 further comprises two extension plates corresponding to the two first wall bodies 22, the extension plates are parallel to the first direction D1, and the side wall of the extension plate is connected with the side of the first plate body 31 facing the second direction D2, and the first plate body 31 is arranged at the opening 21 of the shell 2 through the two extension plates, so as to eliminate the first protruding portion 221 of the first wall body 22 facing the first direction D1.

[0054] Further, the number of the sloping section 2212 and the second plate body 32 is two, the two sloping sections 2212 are symmetrically arranged about the planar section 2211, and the two second plate bodies 32 are symmetrically arranged about the first plate body 31, that is, the shell 2 and the cover plate 3 are both symmetrical structures, and such symmetrical structure is beneficial to reduce the assembly difficulty of the shell 2 and the cover plate 3, and has the effects of reducing production cost and improving production efficiency.

[0055] Further, the number of the pole assembly 4 is two, and the two pole assemblies 4 correspond to the two second plate bodies 32, that is, the two pole assemblies 4 are respectively arranged on the corresponding second plate body 32, so that the overall stress of the cover plate 3 is more uniform, which is beneficial to reduce the probability of deformation of the cover plate 3 due to uneven stress.

[0056] Further, the shell 2 further comprises two oppositely arranged second wall bodies 24, and the two second wall bodies 24 are respectively connected to the two sides of the first wall body 22, so that the two second wall bodies 24 and the two first wall bodies 22 form a cavity of the shell 2, and the two second plate bodies 32 of the cover plate 3 correspond to the two second wall bodies 24, and the second side 322 of the second plate body 32 is arranged on the side of the second wall body 24 facing the first direction D1.

[0057] It should be noted that in the embodiment, the inner edge of the shell 2 at the opening 21 is provided with a chamfer 211, the inner edge of the flat section 2211, the inner edge of the slope section 2212, and the inner edge of the second wall body 24 towards the first direction D1 are all provided with a chamfer 211, that is, the chamfers 211 are distributed along the circumference of the opening 21, so as to avoid the problem of scratching the pole group 1 and the insulating film when the pole group 1 enters the shell. In addition, the inner edge of the connection position of the flat section 2211 and the slope section 2212 is provided with a chamfer 211, which can reduce the probability of metal wires and metal debris at the connection position of the flat section 2211 and the slope section 2212, thereby reducing the probability of metal wires and metal debris falling into the shell 2 to damage the pole group 1.

[0058] Optionally, as shown in Figure 5 , the battery cell further comprises an explosion-proof valve 5, the explosion-proof valve 5 is arranged on the second wall body 24, and the explosion-proof valve 5 is located at the middle of the second wall body 24 in the first direction D1. When the battery cell is abnormal and the explosion-proof valve 5 blows off gas, this structure can shorten the exhaust path of the high-pressure gas inside the shell 2, achieve the effect of rapid exhaust, and thereby facilitate to improve the safety of the battery cell. Of course, in other embodiments, the explosion-proof valve 5 can also be arranged at the middle of the first wall body 22 in the first direction D1, which can be determined according to the actual use requirement.

[0059] Further, the second wall body 24 is further provided with two reinforcing ribs 241, and the two reinforcing ribs 241 are respectively located on both sides of the explosion-proof valve 5 in the first direction D1, so as to improve the structural strength of the second wall body 24 in the circumference of the explosion-proof valve 5. In actual production, the explosion-proof hole needs to be first formed on the second wall body 24, and then the explosion-proof valve 5 is welded at the explosion-proof hole. The setting of the reinforcing rib 241 improves the structural strength of the second wall body 24 at the edge area of the explosion-proof hole, thereby reducing the probability of deformation of the second wall body 24 in the circumference of the explosion-proof hole when the explosion-proof valve 5 is welded at the explosion-proof hole, facilitating to improve the welding yield of the explosion-proof valve 5, and also facilitating to reduce the probability of deformation of the explosion-proof valve 5 after the explosion-proof valve 5 is welded, thereby reducing the risk of failure of the explosion-proof valve 5 due to deformation.

[0060] Further, as shown in Figure 9 , the wall thickness of the first wall body 22 is T11, and the wall thickness of the second wall body 24 is T12, wherein T11 is less than T12, and the thickness of the second wall body 24 provided with the explosion-proof valve 5 is greater than the thickness of the first wall body 22, so as to improve the structural strength of the second wall body 24, and further reduce the probability of deformation of the second wall body 24 in the circumference of the explosion-proof hole when the explosion-proof valve 5 is welded.

[0061] Optionally, as shown in Figure 5 and Figure 6As shown, the first plate body 31, the second plate body 32 and the first protruding part 221 of the two first wall bodies 22 surround to form the capacity-increasing space 23 in the shell 2, the pole group 1 is arranged in the shell 2, the second protruding part 11 is arranged on the side of the pole group 1 facing the first direction D1, and the second protruding part 11 is located in the capacity-increasing space 23. On the one hand, the second protruding part 11 can increase the volume of the pole group 1, thereby improving the capacity of the pole group 1. On the other hand, arranging the second protruding part 11 in the capacity-increasing space 23 improves the utilization rate of the internal space of the shell 2, which is conducive to improving the energy density of the battery cell.

[0062] Optionally, as shown in Figure 8 The acute angle between the planar section 2211 and the slope section 2212 is N, and N≥31°. For example, N can be 31°, 35°, 42° or 50°, etc., and preferably N≥35°. Since the first plate body 31 is parallel to the planar section 2211 and the second plate body 32 is parallel to the slope section 2212, the acute angle between the second plate body 32 and the first plate body 31 is N. If N<31°, the size of the first plate body 31 protruding from the pole group assembly 4 in the first direction D1 will be reduced, thereby reducing the protection capability of the first plate body 31 to the pole group assembly 4 and increasing the probability of the pole group assembly 4 being bumped during the process.

[0063] Optionally, N≤63°. For example, N can be 63°, 60°, 55° or 40°, etc., and preferably N≤60°. If N>63°, the side of the first protruding part 221 facing the first direction D1 will be relatively narrow, which will reduce the structural strength of the first protruding part 221 and easily cause deformation of the first protruding part 221 during the process. On the other hand, it will increase the difficulty of forming the shell 2, which is not conducive to reducing the production cost. On the other hand, it will increase the assembly difficulty of the cover plate 3 and the shell 2, which is not conducive to improving the welding yield of the cover plate 3 and the shell 2. Secondly, when N>63°, the side of the capacity-increasing space 23 facing the first direction D1 will be relatively narrow, which will make the side of the second protruding part 11 facing the first direction D1 relatively narrow, which is not conducive to improving the capacity of the pole group 1.

[0064] Optionally, as shown in Figure 8 and Figure 10As shown, the slope section 2212 has a dimension L in the width direction, and the planar section 2211 has a dimension W in the width direction, the width direction is parallel to the surface of the first wall body 22, and the width direction is perpendicular to the first direction D1, L / (L+W)≥0.19, and exemplarily, L / (L+W) can be 0.19, 0.2, 0.25, or 0.3, etc., and preferably, L / (L+W)≥0.2. In the direction in which the two second plate bodies 32 point to each other, the first plate body 31 has a dimension J, and the second plate body 32 has a dimension K, since the first plate body 31 is parallel to the planar section 2211, and the second plate body 32 is parallel to the slope section 2212, thus, J is equal to W, and K is equal to L, if L / (L+W)<0.19, then K / (K+J)<0.19, which will greatly reduce the size of the first plate body 31 protruding to the pole piece assembly 4 in the first direction D1, and thus reduce the protection capability of the first cover plate 3 to the pole piece assembly 4, and increase the probability of the pole piece assembly 4 being bumped in the process.

[0065] Optionally, L / (L+W)≤0.46, and exemplarily, L / (L+W) can be 0.46, 0.45, 0.4, or 0.35, etc., and preferably, L / (L+W)≤0.45. If L / (L+W)>0.46, on the one hand, it will make the increased space 23 on the side of the first direction D1 be sharp-angled, and thus make the second protruding part 11 of the pole piece 1 on the side of the first direction D1 be sharp-angled, which will reduce the volume of the second protruding part 11, and is not conducive to increasing the capacity of the pole piece 1. On the other hand, when L / (L+W)>0.46, it will make the first protruding part 221 on the side of the first direction D1 be sharp-angled, which will reduce the structural strength of the first wall body 22 on the side of the first direction D1, not only increase the probability of the first protruding part 221 being deformed in the process, but also reduce the support capability of the first protruding part 221 to the cover plate 3.

[0066] The cover plate 3, the shell 2, and the pole piece assembly 4 provided by the embodiment have simple structures, and the cover plate 3 and the shell 2 can both adopt relatively common aluminum materials or stainless steel materials, etc., and can be made by stamping and extrusion processes, etc., can be sealed and fixed by welding processes, and can form plastic parts 41 on the cover plate 3 by injection molding processes, and the stamping process, the extrusion process, the welding process, and the injection molding process are all relatively common production processes in the field, and are conducive to realizing batch automatic production.

[0067] The following Table 1 provides six groups of embodiments and six groups of comparative examples, the shell 2 in the six groups of embodiments and the six groups of comparative examples all adopt three-series aluminum materials, the insulating films are all polypropylene (PP) films, the plastic parts 41 are all polyphenylene sulfide (PPS) materials, and the insulating parts 6 clamped between the bases 431 and the second plate bodies 32 are all PP materials.

[0068] The distance between the two first wall bodies 22 facing away from each other is T2.

[0069]

[0070] In Example 1, T11 is 0.5mm, T2 is 15mm, C is 0.06mm, W is 20mm, L is 16.5mm, L / (W+L) is 0.45, N is 35°, and the qualified rate of the battery cell is >98%; the problem of insufficient strength of the shell 2 does not occur; when the pole group 1 is loaded into the shell 2, the problem of scratching of the insulating film and the pole group 1 does not occur; the welding rate of the cover plate 3 and the shell 2 meets the rate index.

[0071] In Example 2, T11 is 0.6mm, T2 is 36mm, C is 0.08mm, W is 40mm, L is 23mm, L / (W+L) is 0.37, N is 40°, and the qualified rate of the battery cell is >98%; the problem of insufficient strength of the shell 2 does not occur; when the pole group 1 is loaded into the shell 2, the problem of scratching of the insulating film and the pole group 1 does not occur; the welding rate of the cover plate 3 and the shell 2 meets the rate index.

[0072] In Example 3, T11 is 0.7mm, T2 is 60mm, C is 0.09mm, W is 75mm, L is 28mm, L / (W+L) is 0.27, N is 45°, and the qualified rate of the battery cell is >98%; the problem of insufficient strength of the shell 2 does not occur; when the pole group 1 is loaded into the shell 2, the problem of scratching of the insulating film and the pole group 1 does not occur; the welding rate of the cover plate 3 and the shell 2 meets the rate index.

[0073] In Example 4, T11 is 0.8mm, T2 is 88mm, C is 0.1mm, W is 110mm, L is 36mm, L / (W+L) is 0.25, N is 50°, and the qualified rate of the battery cell is >98%; the problem of insufficient strength of the shell 2 does not occur; when the pole group 1 is loaded into the shell 2, the problem of scratching of the insulating film and the pole group 1 does not occur; the welding rate of the cover plate 3 and the shell 2 meets the rate index.

[0074] In Example 5, T11 is 0.9mm, T2 is 100mm, C is 0.13mm, W is 150mm, L is 45mm, L / (W+L) is 0.23, N is 55°, and the qualified rate of the battery cell is >98%; the problem of insufficient strength of the shell 2 does not occur; when the pole group 1 is loaded into the shell 2, the problem of scratching of the insulating film and the pole group 1 does not occur; the welding rate of the cover plate 3 and the shell 2 meets the rate index.

[0075] In Example 6, T11 is 1 mm, T2 is 118 mm, C is 0.15 mm, W is 200 mm, L is 50 mm, L / (W+L) is 0.2, N is 60°, and the qualified rate of the battery cell is >98%; the problem of insufficient strength of the shell 2 does not occur; when the pole group 1 is loaded into the shell 2, the problem of scratching of the insulation film and the pole group 1 does not occur; and the welding rate of the cover plate 3 and the shell 2 meets the rate index.

[0076] In Comparative Example 1, T11 is 0.7 mm, T2 is 36 mm, C is 0.04 mm, W is 40 mm, L is 23 mm, L / (W+L) is 0.37, N is 40°, and the qualified rate of the battery cell is <98%; the inner edge of the opening 21 of the shell 2 is relatively sharp, and when the pole group 1 is loaded into the shell 2 through the opening 21, the pole group 1 and the insulation film are scratched by the inner edge, and the insulation fails.

[0077] In Comparative Example 2, T11 is 0.7 mm, T2 is 36 mm, C is 0.18 mm, W is 40 mm, L is 23 mm, L / (W+L) is 0.37, N is 40°, and the qualified rate of the battery cell is <98%; the thickness of the opening 21 of the shell 2 is too small, the structural strength of the opening 21 of the shell 2 is relatively small, the welding difficulty is large when the cover plate 3 is welded with the opening 21 of the shell 2, and problems such as insufficient size of the molten pool and spatter are prone to occur.

[0078] In Comparative Example 3, T11 is 0.7 mm, T2 is 36 mm, C is 0.1 mm, W is 20 mm, L is 18 mm, L / (W+L) is 0.47, N is 40°, and the qualified rate of the battery cell is <98%; the side of the capacity-increasing space 23 and the second protruding portion 11 facing the first direction D1 is in a sharp angle shape, which is not conducive to improving the capacity of the pole group 1; the side of the first protruding portion 221 facing the first direction D1 is in a sharp angle shape, the structural strength of the side of the first wall body 22 facing the first direction D1 is low, the first protruding portion 221 is prone to deformation in the process, and the supporting capacity of the first protruding portion 221 to the cover plate 3 is poor.

[0079] In Comparative Example 4, T11 is 0.7 mm, T2 is 36 mm, C is 0.1 mm, W is 200 mm, L is 45 mm, L / (W+L) is 0.18, N is 40°, and the qualified rate of the battery cell is <98%; the size of the first plate body 31 protruding from the pole assembly 4 in the first direction D1 is relatively small, the protection capacity of the first cover plate 3 to the pole assembly 4 is poor, and the pole assembly 4 is prone to be knocked in the process.

[0080] In the comparative example 5, T11 is 0.7 mm, T2 is 36 mm, C is 0.1 mm, W is 40 mm, L is 23 mm, L / (W+L) is 0.37, N is 30°, and the qualified rate of the battery cell is less than 98%: the first plate body 31 protrudes from the size of the pole assembly 4 in the first direction D1, the protection ability of the first plate body 31 to the pole assembly 4 is low, and the pole assembly 4 is easily bumped in the process.

[0081] In the comparative example 6, T11 is 0.7 mm, T2 is 36 mm, C is 0.1 mm, W is 40 mm, L is 23 mm, L / (W+L) is 0.37, N is 64°, and the qualified rate of the battery cell is less than 98%: the first protruding part 221 is relatively long on the side facing the first direction D1, the structural strength of the first protruding part 221 is low, the first protruding part is easily deformed, the shell 2 is difficult to form, the assembly of the cover plate 3 and the shell 2 is difficult, and the welding rate of the cover plate 3 and the shell 2 is low; the capacity-increasing space 23 and the second protruding part 11 are relatively long on the side facing the first direction D1, which is not conducive to improving the capacity of the pole group 1.

[0082] In summary, when the above parameters satisfy 0.05 mm≤C≤0.17 mm, 0.19≤L / (W+L)≤0.46, 31°≤N≤63°, 0.5 mm≤T11≤1 mm, and 15 mm≤T2≤118 mm, the probability that the pole group 1 and the insulating film are scratched when the pole group 1 is loaded into the shell 2 can be reduced, the probability that the pole assembly 4 is bumped in the process can be reduced, the capacity of the pole group 1 can be improved, and the welding rate of the cover plate 3 and the shell 2 can be ensured, so that the qualified rate of the battery cell is greater than 98%.

[0083] The embodiment also provides a battery module, which includes the connecting sheet 7 and at least two battery cells described above. For example, the number of battery cells can be two, three or more. The connecting sheet 7 is usually made of metal materials with conductive properties such as copper sheet or aluminum sheet. The pole assemblies 4 of every two battery cells are welded and fixed to the same connecting sheet 7 to realize the conductive connection (series or parallel) of the two battery cells. When the pole group 1 of the battery cell is loaded into the shell 2 through the opening 21, the chamfer 211 can play a protective role for the pole group 1 and the insulating film wrapped outside the pole group 1, thereby reducing the probability that the pole group 1 and the insulating film are scratched, achieving the effect of improving the safety and yield of the battery cell. In addition, the first plate body 31 of the battery cell protrudes from the pole assembly 4 in the first direction D1, so that the first plate body 31 can play a protective role for the pole assembly 4, thereby reducing the probability that the pole assembly 4 is bumped in the process such as transportation and assembly, achieving the effect of improving the safety and yield of the battery cell. The battery module provided by the embodiment adopts the battery cell described above, and has high safety and product yield.

[0084] Further, as shown in FIG. 1, the battery module includes the shell 2, the cover plate 3, the connecting sheet 7, and at least two battery cells. Figure 10As shown, the connecting piece 7 is connected to the side of the pole assembly 4 away from the second plate body 32, and the first plate body 31 protrudes from the connecting piece 7 in the first direction D1, so that the first plate body 31 plays a protective role on the connecting piece 7, reducing the probability of the connecting piece 7 being bumped in the process. In addition, compared with the flat cover plate 3, under the condition that the length, width and height dimensions of the battery cell are the same, this structure can save the assembly space of the battery module, which is conducive to improving the grouping rate of the battery module, thereby being conducive to improving the energy density and performance of the battery module, and reducing the cost of the battery module.

[0085] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the scope of the present application. Here, it is not necessary and impossible to exhaust all the embodiments. Any modification, equivalent substitution and improvement within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. An electric cell, characterized by, The application relates to a battery pack, comprising: a pole group (1); a shell (2) provided with an opening (21) on one side thereof facing a first direction (D1), an inner side of the shell (2) at the opening (21) being provided with a chamfer (211), the pole group (1) being capable of being loaded into the shell (2) through the opening (21); a cover plate (3) covering the opening (21), the cover plate (3) comprising a first plate body (31) and a second plate body (32), the first plate body (31) being perpendicular to the first direction (D1), the second plate body (32) comprising oppositely arranged first and second sides (321, 322), the first side (321) being connected with the first plate body (31), a direction from the first side (321) to the second side (322) being inclined to a second direction (D2), the second direction (D2) being opposite to the first direction (D1); a pole column assembly (4) penetrating and fixed to the second plate body (32), the first plate body (31) protruding from the pole column assembly (4) in the first direction (D1).

2. The electric cell of claim 1, wherein, The shell (2) comprises two oppositely arranged first wall bodies (22), each of the first wall bodies (22) being provided with a first protruding part (221) on one side thereof facing the first direction (D1), a surface of the first protruding part (221) on one side thereof facing the first direction (D1) comprising a planar section (2211) and a sloping section (2212), the planar section (2211) being connected with the sloping section (2212), the first plate body (31) covering the planar sections (2211) of the two first wall bodies (22), and the second plate body (32) covering the sloping sections (2212) of the two first wall bodies (22).

3. The electric cell of claim 2, wherein, The number of the sloping sections (2212) and the number of the second plate body (32) are both two, the two sloping sections (2212) are symmetrically arranged about the planar section (2211), and the two second plate bodies (32) are symmetrically arranged about the first plate body (31).

4. The electric cell of claim 3, wherein, The number of the pole column assembly (4) is two, and the two pole column assemblies (4) correspond to the two second plate bodies (32) one by one.

5. The cell of any of claims 2-4, wherein, An acute angle between the planar section (2211) and the sloping section (2212) is N, N is greater than or equal to 31 degrees, and / or N is less than or equal to 63 degrees.

6. The cell of any of claims 2-4, wherein, A dimension of the sloping section (2212) in a width direction is L, a dimension of the planar section (2211) in the width direction is W, the width direction is parallel to a surface of the first wall body (22), and the width direction is perpendicular to the first direction (D1), L / (L+W) is greater than or equal to 0.19, and / or L / (L+W) is less than or equal to 0.

46.

7. The cell of any of claims 2-4, wherein, The first plate body (31), the second plate body (32) and the first protruding part (221) of the two first wall bodies (22) surround to form a capacity-increasing space (23) in the shell (2), the pole group (1) is arranged in the shell (2), and one side of the pole group (1) in the first direction (D1) is provided with a second protruding part (11), and the second protruding part (11) is located in the capacity-increasing space (23).

8. The cell of any of claims 1-4, wherein, The electric core further comprises an explosion-proof valve (5), the explosion-proof valve (5) is arranged on the shell (2), and the explosion-proof valve (5) is located at the middle part of the shell (2) in the first direction (D1); And / or, the angle of the chamfer (211) is 45°, the width of the inclined surface of the chamfer (211) is C, C≥0.05mm, and / or C≤0.17mm.

9. A battery module, characterized by The electric core comprises a connecting sheet (7) and the electric core of any one of claims 1-8, and the connecting sheet (7) is connected with the pole assembly (4).

10. The battery module of claim 9, wherein, The connecting sheet (7) is connected with the side of the pole assembly (4) away from the second plate body (32), and the first plate body (31) protrudes from the connecting sheet (7) in the first direction (D1).

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