A battery module

Abstract

The present application provides a battery module, which includes a cell assembly, wherein the cell in the cell assembly includes a cell body and a tab, and is characterized in that the battery module also includes: a first fixing belt, which surrounds the cell assembly along the thickness direction of the cell; a second fixing belt, which surrounds the cell assembly along the thickness direction of the cell; along the length direction of the cell, the distance between the projection position of the first fixing belt and the first end of the cell body is less than or equal to L / 4, and the distance between the projection position of the second fixing belt and the second end of the cell body is less than or equal to L / 4, where L is the length of the cell body.

Description

Technical Field

[0001] The present application relates to the field of new energy, and in particular to a battery module. Background Art

[0002] Battery modules are widely used in all aspects of life, and battery modules have a wide range of application scenarios. During the use of battery modules, the volume of the battery modules will expand with the charge and discharge cycle, resulting in reduced cycle performance of the battery modules. The commonly used solution in the industry is to pressurize the battery module, but the existing solution has the problem of pressurization balance. In the traditional pressurization method, after the battery module expands, the external pressure on its various parts is not balanced, and there is no precise pressure control, resulting in different pressure values ​​in different areas of the battery module, which has an adverse effect on the electrical cycle performance of the battery module. Existing solutions also have the problem of short-circuiting the battery cells, or failure due to the offset of the fixing device.

[0003] How to solve the above problems is what those skilled in the art need to consider. Summary of the invention

[0004] In order to solve the problems in the prior art. The present application provides a battery module, the battery module includes a battery cell assembly, the battery cell in the battery cell assembly includes a battery cell body and a tab, the battery module also includes: a first fixing belt, along the thickness direction of the battery cell, surrounding the battery cell assembly; a second fixing belt, along the thickness direction of the battery cell, surrounding the battery cell assembly; along the length direction of the battery cell, the distance between the projection position of the first fixing belt and the first end of the battery cell body is less than or equal to L / 4, and the distance between the projection position of the second fixing belt and the second end of the battery cell body is less than or equal to L / 4, where L is the length of the battery cell body.

[0005] By providing a fixing belt to apply pressure to the battery cell assembly, the expansion of the battery cell assembly during the charge and discharge cycle is restricted, which can improve the cycle performance of the battery module.

[0006] In a first possible implementation, in combination with the aforementioned battery module, the distance between the projection position of the first fixing belt and the first end of the battery cell body is greater than or equal to 2L / 25. By selecting this value, excessive pressure in the middle area of ​​the battery cell assembly can be avoided.

[0007] In combination with the first possible implementation manner, in a second possible implementation manner, a distance between a projection position of the second fixing belt and the second end of the battery cell main body is greater than or equal to 2L / 25.

[0008] In combination with the first and second possible implementations, in a third possible implementation, the battery module further includes a housing, the housing includes a shell, and the shell is disposed between the fixing belt and the battery cell assembly. By selecting the value of the preset area, excessive pressure on the outer area of ​​the battery cell assembly can be avoided.

[0009] In combination with the first to third possible implementations, in a fourth possible implementation, the battery module further includes an end plate, and along the stacking direction of the battery cells, the end plate is arranged between the outermost battery cell of the battery cell assembly and the fixing belt.

[0010] In combination with the first to fourth possible implementations, in a fifth possible implementation, a groove is provided on the outer surface of the shell, the shell includes a first surface and a second surface arranged opposite to each other, and the groove is formed on the first surface and the second surface.

[0011] In combination with the first to fifth possible implementations, in a sixth possible implementation, the portion of the fixing belt that contacts the housing is disposed in the groove. The groove can be used to limit the movement of the fixing belt to prevent the fixing belt from shifting due to expansion of the battery module.

[0012] In combination with the first to sixth possible implementations, in a seventh possible implementation, the number of the fixing belts is two, the two fixing belts are arranged at intervals, the groove includes a first sub-groove, a second sub-groove, a third sub-groove and a fourth sub-groove, the first sub-groove and the second sub-groove are formed on the first surface, the third sub-groove and the fourth sub-groove are formed on the second surface, one fixing belt is arranged in the first sub-groove and the third sub-groove, and the other fixing belt is arranged in the second sub-groove and the fourth sub-groove. The two fixing belts arranged at intervals can make the pressure applied to the battery cell assembly more balanced.

[0013] In combination with the first to seventh possible implementations, in an eighth possible implementation, the battery module further includes an end plate, which is disposed between the outermost cell of the cell assembly and the fixing belt along the stacking direction of the cell. An end plate is disposed between the fixing belt and the outer shell, and the end plate can enhance the pressure-bearing capacity of the outer shell to prevent the outer shell from being damaged due to excessive pressure.

[0014] In combination with the first to eighth possible implementations, in a ninth possible implementation, the housing further comprises a third surface and a fourth surface disposed opposite to each other, the end plate contacts the third surface and the fourth surface, the housing further comprises at least two receiving grooves, at least two of the receiving grooves are formed on the third surface and the fourth surface, and the end plate is disposed in the receiving grooves. The end plate is disposed in the receiving groove to prevent the end plate from being misaligned due to expansion of the battery module.

[0015] In combination with the first to ninth possible implementations, in a tenth possible implementation, the shell further includes a first subshell and a second subshell, the first subshell and the second subshell are buckled together to form the shell, the first subshell is provided with a first surface, the second subshell is provided with a second surface, the shell further includes a fifth surface and a sixth surface, the buckled surface of the first subshell and the second subshell divides the third surface, the fourth surface, the fifth surface and the sixth surface, the accommodating groove includes a first sub-groove and a second sub-groove, the first sub-groove is provided in the first subshell, and the second sub-groove is provided in the second subshell. The buckled first subshell and the second subshell can make the shell and the battery cell assembly more convenient during installation.

[0016] In combination with the first to tenth possible implementations, in an eleventh possible implementation, the fixing belt includes at least one pressure adjustment unit, and the pressure adjustment unit is used to adjust the pressure of the fixing belt pressing the housing. By providing the pressure adjustment unit, precise fine-tuning of the pressure of the fixing belt on the battery cell assembly can be achieved.

[0017] In combination with the first to eleventh possible implementations, in a twelfth possible implementation, the pressure regulating unit includes a screw and a nut, and the torque borne by the screw is greater than or equal to 1.5 NM.

[0018] In combination with the first to twelfth possible implementations, in the thirteenth possible implementation, the fixing belt is in the shape of a strip, and the fixing belt includes a first adjustment part and a second adjustment part that are spaced apart, the pressure adjustment unit is movably connected to the first adjustment part and the second adjustment part, and the pressure adjustment unit adjusts the pressure of the fixing belt on the shell by adjusting the distance between the first adjustment part and the second adjustment part.

[0019] In combination with the first to thirteenth possible implementations, in the fourteenth possible implementation, the pressure value of the fixing belt on the shell ranges from 0kgf to 100kgf, so that the pressure on the battery cell assembly is within a reasonable range, which can effectively improve the cycle performance of the battery module.

[0020] In combination with the first to fourteenth possible implementations, in a fifteenth possible implementation, the sum of the cross-sectional areas of the fixing belt is greater than or equal to 60 mm 2 , which can ensure that the fixing belt has sufficient strength.

[0021] In combination with the first to fifteenth possible implementations, in a sixteenth possible implementation, the housing further includes a front cover and a control circuit, the front cover is buckled onto one end of the shell, and the control circuit is disposed between the end plate and the front cover.

[0022] In combination with the first to sixteenth possible implementations, in a seventeenth possible implementation, a mounting groove is provided inside the shell, and at least a portion of the battery cell assembly is disposed in the mounting groove.

[0023] Compared with the prior art, the battery module of the present application applies pressure to the battery cell assembly by setting a surrounding fixing belt on the outside of the battery cell assembly, so that the expansion of the battery cell assembly during the charge and discharge cycle is limited, thereby improving the cycle performance of the battery module. Further, along the length direction of the battery cell, at least part of the fixing belt is set in a preset area, and the preset area includes one end of the battery cell body to L / 4 away from one end of the battery cell body, so that the pressure on the battery module is more balanced, and the battery module The cycle performance is further improved. Further, a shell is provided between the battery cell assembly and the fixing belt to avoid damage or short circuit that may be caused by direct contact between the fixing belt and the battery cell assembly. Further, an end plate is provided between the fixing belt and the shell, and the end plate can enhance the pressure-bearing capacity of the shell and prevent the shell from being damaged due to excessive pressure. Further, the fixing belt can be set in a groove of the shell to prevent the fixing belt from shifting due to the expansion of the battery module. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a three-dimensional schematic diagram of a battery module according to an embodiment of the present application.

[0025] Figure 2 It is a three-dimensional schematic diagram of a battery module according to an embodiment of the present application.

[0026] Figure 3 It is a schematic three-dimensional exploded view of a battery module according to an embodiment of the present application.

[0027] Figure 4 It is a partial three-dimensional schematic diagram of a battery module according to an embodiment of the present application.

[0028] Figure 5 It is a partial exploded schematic diagram of a battery module according to an embodiment of the present application.

[0029] Figure 6 It is a partial enlarged schematic diagram of a battery module according to an embodiment of the present application.

[0030] Figure 7 It is a partial enlarged schematic diagram of a battery module according to an embodiment of the present application.

[0031] Figure 8 It is a perspective schematic diagram of a battery module according to an embodiment of the present application.

[0032] Fig. 9This is a schematic diagram of the deformation degree distribution of the end plate when the projection distance of the first fixing belt of the battery module of an embodiment of the present application along the length direction of the battery cell is greater than L / 4 at the first end and the projection distance of the second fixing belt along the length direction of the battery cell is greater than L / 4 at the second end.

[0033] Fig.10 This is a schematic diagram of the deformation degree distribution of the end plate when the projection distance of the first fixing band of the battery module along the length direction of the battery cell at the first end is less than and the distance of the second fixing band adjacent to the second end can be less than 2L / 25 at the second end of the projection distance of the second fixing band along the length direction of the battery cell.

[0034] Fig.11 This is a schematic diagram of the deformation degree distribution of the end plate when the distance from the first end of the projection of the first fixing belt along the length direction of the battery cell of an embodiment of the present application is greater than or equal to 2L / 25 and less than or equal to L / 4, and the distance from the second end of the projection of the second fixing belt along the length direction of the battery cell is greater than or equal to 2L / 25 and less than or equal to L / 4.

[0035] Main component symbols

[0036] Battery module 1

[0037] Housing 10

[0038] Housing 11

[0039] First surface 111

[0040] Second surface 112

[0041] The third surface 113

[0042] Fourth surface 114

[0043] Fifth surface 115

[0044] Sixth surface 116

[0045] Buckle surface 117

[0046] First subshell 118

[0047] Second subshell 119

[0048] Fixed belt 12

[0049] The first fixing belt 121

[0050] Second fixing belt 122

[0051] Belt 120

[0052] The first adjustment unit 125

[0053] The second adjustment unit 126

[0054] Pressure regulating unit 123

[0055] End plate 13

[0056] Front cover 14

[0057] Control circuit 15

[0058] Groove 16

[0059] First subslot 161

[0060] Second subslot 162

[0061] The third subslot 163

[0062] Fourth subslot 164

[0063] Mounting slot 17

[0064] Accommodation groove 18

[0065] The first sub-slot 181

[0066] Second sub-slot 182

[0067] Battery Cell Components 19

[0068] Battery Cell 190

[0069] Battery cell main body 191

[0070] First End 193

[0071] Second end 194

[0072] Tab 192

[0073] The first deformation zone 211

[0074] The second deformation zone 212

[0075] The third deformation zone 213

[0076] Fourth deformation zone 221

[0077] Fifth deformation zone 222

[0078] Sixth deformation zone 223

[0079] Seventh deformation zone 231

[0080] Eighth deformation zone 232

[0081] Ninth Deformation Zone 233

[0082] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0083] The following description will refer to the accompanying drawings to more fully describe the content of the present application. Shown in the accompanying drawings are exemplary embodiments of the present application. However, the present application can be implemented in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein. These exemplary embodiments are provided to make the present application thorough and complete, and to fully convey the scope of the present application to those skilled in the art. Similar reference numerals represent identical or similar components.

[0084] The terms used herein are only used for the purpose of describing specific exemplary embodiments and are not intended to limit the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. In addition, when used herein, "includes" and / or "comprising" or "including" and / or "including" or "having" and / or "having", integers, steps, operations, components and / or components, but do not exclude the presence or addition of one or more other features, regions, integers, steps, operations, components, components and / or groups thereof.

[0085] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this application belongs. In addition, unless explicitly defined herein, terms such as those defined in general dictionaries should be interpreted as having a meaning consistent with their meaning in the relevant technology and the content of this application, and will not be interpreted as an idealized or overly formal meaning.

[0086] The following will describe exemplary embodiments in conjunction with the accompanying drawings. It should be noted that the components depicted in the reference drawings are not necessarily shown to scale; and the same or similar components will be given the same or similar reference numerals or similar technical terms.

[0087] The specific implementation methods of the present application are further described in detail below with reference to the accompanying drawings.

[0088] like Figures 1 to 8 As shown, the present application provides a battery module 1 , and the battery module 1 includes a battery cell assembly 19 .

[0089] like Figure 3As shown, the battery cell assembly 19 includes a plurality of stacked battery cells 190, each battery cell 190 includes a sheet-shaped battery cell body 191 and a tab 192, and the plurality of battery cell bodies 191 are stacked in the thickness direction of the battery cell body 191. In one embodiment, foam may be disposed between each battery cell 190; two battery cell assemblies 19 may be stacked to form a battery cell with a larger capacity, and a pressurized foam may be disposed between two adjacent battery cell assemblies 19.

[0090] In one embodiment, the battery module 1 also includes a fixing belt 12, which surrounds the battery cell assembly 19 along the thickness direction of the battery cell 190. In this embodiment, the fixing belt 12 may also include an insulating structure, which is at least arranged between the fixing belt 12 and the battery cell assembly 19 to prevent the fixing belt 12 from causing a short circuit in the battery cell assembly 19 during the pressurization process.

[0091] In one embodiment, if Figures 1 to 3 As shown, the battery module 1 further includes a housing 10 , which includes a shell 11 , an end plate 13 , a front cover 14 and a control circuit 15 . The shell 11 is disposed between the fixing belt 12 and the battery cell assembly 19 .

[0092] In one embodiment, the housing 10 may be formed by combining multiple units, and the housing 11 is connected to the front cover 14. In one embodiment, the housing 11 may be an integral structure; in other embodiments, the housing 11 may also be composed of multiple brackets stacked. In this embodiment, the housing 10 is formed by combining multiple units, and the housing 11 is connected to the front cover 14, and the housing 11 may be an integral structure.

[0093] The battery cell assembly 19 is arranged inside the shell 11, the fixing belt 12 is arranged around the outside of the shell 11, the end plate 13 is arranged on the outer surface of the shell 11, the front cover 14 is buckled on the outside of the shell 11, and the control circuit 15 is arranged between the shell 11 and the front cover 14.

[0094] like Figure 1 , Figure 2 , Figure 4As shown, in one embodiment, the housing 11 is substantially a hexahedral structure, and the housing 11 includes a first surface 111, a second surface 112, a third surface 113, a fourth surface 114, a fifth surface 115, and a sixth surface 116. The first surface 111 is disposed opposite to the second surface 112. The third surface 113 is disposed opposite to the fourth surface 114. The fifth surface 115 is disposed opposite to the sixth surface 116. The housing 11 also includes a first subshell 118 and a second subshell 119, and the first subshell 118 and the second subshell 119 are buckled to form the housing 11, and the buckling surface 117 of the first subshell 118 and the second subshell 119 divides the third surface 113, the fourth surface 114, the fifth surface 115, and the sixth surface 116. The first surface 111 is disposed on the first subshell 118, and the second surface 112 is disposed on the second subshell 119.

[0095] In one embodiment, the first surface 111 and the second surface 112 correspond to the surface enclosed by the length and height (thickness) of the battery cell body 191, the third surface 113 and the fourth surface 114 correspond to the surface enclosed by the length and width of the battery cell body 191, and the fifth surface 115 and the sixth surface 116 correspond to the surface enclosed by the width and height (thickness) of the battery cell body 191.

[0096] like Figure 5 and Figure 6 As shown, the outer surface of the housing 11 is formed with a groove 16, and the groove 16 is formed by the outer surface of the housing 11 being recessed toward the inside of the housing 11, as shown in FIG. Figure 2 and Figure 3 As shown, in one embodiment, the groove 16 is formed on the first surface 111 and the second surface 112. The groove 16 includes a first sub-groove 161, a second sub-groove 162, a third sub-groove 163 and a fourth sub-groove 164. The first sub-groove 161 and the second sub-groove 162 are formed on the first surface 111, and the third sub-groove 163 and the fourth sub-groove 164 are formed on the second surface 112.

[0097] The fixing belt 12 is disposed around the outer side of the shell 11 along the thickness direction of the battery body 191 (i.e., the stacking direction of the multiple battery cells 190). The fixing belt 12 fixes the shell 11 and the battery cell assembly 19 by applying pressure to the shell 11. At the same time, the fixing belt 12 does not contact the battery cell assembly 19 to avoid damage to the battery cell assembly 19 or short circuit of the battery cell assembly 19 during the pressurization process. The portion of the fixing belt 12 in contact with the shell 11 is disposed in the groove 16, which can limit the position of the fixing belt 12 to prevent the fixing belt 12 from shifting or falling off due to the expansion of the battery module 1.

[0098] In one embodiment, the fixing belt 12 may be a steel belt. In some cases, an insulating structure may be provided outside the steel belt, and the insulating structure may cover the surface of the steel belt.

[0099] like Figure 4 As shown, each fixing belt 12 includes a belt body 120 and at least one pressure regulating unit 123. The pressure regulating unit 123 is movably connected to the belt body 120 so that the belt body 120 forms an annular structure. The pressure regulating unit 123 is used to adjust the pressure of the fixing belt 12 pressing the shell 11. In this embodiment, the pressure regulating unit 123 can be a tension regulating unit in which a nut and a screw cooperate with each other. The initial pre-pressure of the fixing belt on the shell 11 can be adjusted by adjusting the torque when the screw is tightened. The screw can be selected from M5, M6, and M8 models. The torque on the screw during tightening is expected to be in the range of 1.5NM to 50NM. In this embodiment, the fixing belt 12 includes a steel belt.

[0100] In other embodiments, the pressure regulating unit 123 also includes other types of regulating units. In one embodiment, the torque range provided by the pressure regulating unit 123 to the fixing belt 12 can be 1.5NM to 50NM. Too small a torque (for example, less than 1.5NM) makes the fixing belt 12 relatively loose and unable to provide pressure after the battery cell assembly 19 expands. Too large a torque (for example, greater than 50NM) may damage the fastening structure of the fixing belt 12, thereby causing structural failure.

[0101] like Figure 7 As shown, in one embodiment, the fixing belt 12 may be in a strip shape, and the fixing belt 12 further includes a first adjustment portion 125 and a second adjustment portion 126 disposed at intervals, and the first adjustment portion 125 and the second adjustment portion 126 are located at two ends of the belt body 120. Figure 7 As shown, in one embodiment, the pressure regulating unit 123 is movably connected to the first regulating portion 125 and the second regulating portion 126, and the pressure regulating unit 123 adjusts the pressure of the fixing belt 12 on the housing 11 by adjusting the distance between the first regulating portion 125 and the second regulating portion 126. In other embodiments, a fixing belt 12 can also be formed by two independent sub-belts connected at both ends by two different pressure regulating units 123.

[0102] In one embodiment, the number of fixing belts 12 is two, and each fixing belt 12 is arranged around the first surface 111, the second surface 112, the third surface 113 and the fourth surface 114. The two fixing belts 12 are arranged at intervals, and the two fixing belts 12 can be respectively arranged on both sides of the battery module 1. This structure can provide more balanced pressure support for the battery module 1. One fixing belt 12 is arranged in the first sub-groove 161 and the third sub-groove 163, and the other fixing belt 12 is arranged in the second sub-groove 162 and the fourth sub-groove 164. In other embodiments, the number of fixing belts 12 can be greater than two, and multiple fixing belts 12 can be in contact, for example, cross, and further can be perpendicular to each other.

[0103] In one embodiment, the two fixing belts 12 are respectively a first fixing belt 121 and a second fixing belt 122, and the first fixing belt 121 and the second fixing belt 122 may have the same structure. The battery body 191 includes a first end 193 and a second end 194, and the first end 193 and the second end 194 are arranged on two opposite sides of the battery body 191, and the first end 193 and the second end 194 may correspond to the end faces corresponding to the thickness and width of the battery 190 respectively.

[0104] In one embodiment, when the battery module 1 is in an initial state, the initial state includes the state of the battery module 1 after it is manufactured and before it is put into actual use. In this state, the battery cell assembly 19 in the battery module 1 does not expand; the pressure value of the fixing belt 12 on the shell 11 ranges from 0kgf to 100kgf. The initial pressure of the fixing belt 12 on the shell 11 is small. When the battery cell assembly 19 in the battery module 1 starts the charge and discharge cycle, the battery module 1 expands, and the pressure of the fixing belt 12 on the shell 11 will increase accordingly, thereby enhancing the cycle performance of the battery cell. The overall cross-sectional area of ​​the fixing belt 12 is greater than or equal to 60mm 2 In one embodiment, the cross-section of the belt body 120 of the fixing belt 12 can be a rectangle with a length of 19 mm and a width of 0.8 mm, and the sum of the cross-sectional areas of the four fixing belts 12 is greater than 60 mm. 2 In other embodiments, the fixing belt 12 may also be in other shapes such as a cylinder.

[0105] In one embodiment, if Figure 8 As shown, the first fixing belt 121 is arranged near the first end 193, and the second fixing belt 122 is arranged near the second end 194. In the length direction of the battery cell 190, the first fixing belt 121 surrounding the battery cell assembly 19, the projection position in the length direction of the battery cell main body 191 is less than or equal to L / 4 from the first end 193 of the battery cell main body 191, and can further be greater than or equal to 2L / 25; the second fixing belt 122 surrounding the battery cell assembly 19, the projection position in the length direction of the battery cell main body 191 is less than or equal to L / 4 from the second end 194 of the battery cell main body 191, and can further be greater than or equal to 2L / 25. Wherein, L is the length of the battery cell main body 191. In one embodiment, the first fixing belt 121 and the second fixing belt 122 can be symmetrically arranged. Specifically, the first fixing belt 121 and the second fixing belt 122 can be symmetrically arranged based on the line connecting the midpoints of the sides corresponding to the lengths of multiple battery cells 190 located on the same side as the symmetry axis.

[0106] In one embodiment, the midpoint or midline or the side edge of the projection of the fixing belt 12 in the length direction of the battery cell body 191 can be selected as the base point or baseline for calculating the length of the projection from the first end 193 or the second end 194 of the battery cell body 191 .

[0107] In one embodiment, the groove 16 for accommodating the fixing belt 12 can be disposed correspondingly according to the placement position of the fixing belt 12 .

[0108] The end plate 13 is disposed between the fixing belt 12 and the battery cell assembly 19. When the projection distance of the fixing belt 12 from the first end 193 or the second end 194 along the length direction of the battery cell 190 is set at different positions, the battery cell assembly 19 expands due to the charge and discharge cycle, and the deformation degree distribution of the end plate 13 is shown as follows: Figures 9 to 11 shown.

[0109] like Fig. 9 As shown, it is a schematic diagram of the deformation degree distribution of the end plate 13 when the projection distance of the first fixing belt 121 of the battery module 1 along the length direction of the battery cell 190 from the first end 193 is greater than L / 4 and the projection distance of the second fixing belt 122 along the length direction of the battery cell 190 from the second end 194 is greater than L / 4. In this embodiment, the length of the projection distance of the first fixing belt 121 along the length direction of the battery cell 190 from the first end 193 can be, for example, L / 3, and the length of the projection distance of the second fixing belt 122 along the length direction of the battery cell 190 from the second end 194 can be, for example, L / 3. The end plate 13 can be roughly divided into three areas according to the degree of deformation. The second deformation zone 212 is distributed in the narrower area in the middle of the end plate 13 and the edges on both sides of the end plate 13. The fifth deformation zone 222 and the eighth deformation zone 232 are divided into two parts by the second deformation zone 212. The fifth deformation zone 222 and the eighth deformation zone 232 are gradually evolved and distributed toward the upper and lower outer edges of the end plate 13 and quickly become smaller. The deformation degree of the second deformation zone 212 is greater than that of the fifth deformation zone 222, and the deformation degree of the fifth deformation zone 222 is greater than that of the eighth deformation zone 232. Specifically, the thickness range of the battery cell 190 can be 9 to 20 mm (for example, 13 mm), the width range of the battery cell 190 can be 122 to 142 mm, and the length range of the battery cell 190 can be 265 to 360 mm (for example, 360 mm); along the thickness direction of the end plate 13, when the pressure load is 5 KN, the maximum deformation range of the second deformation zone 212 can be δ = 5 mm to 6 mm (the maximum deformation value at both ends can be δmax = 5.506 mm), the maximum deformation range of the fifth deformation zone 222 can be δ = 3 mm to 4 mm (specifically, δmax = 3.75 mm), and the maximum deformation range of the eighth deformation zone 232 can be δ = 1 mm to 2 mm (specifically, δmax = 1.875 mm). The deformation degree of the end plate 13 is unevenly distributed. The deformation degree of both ends of the end plate 13 is large, the pressure at both ends of the end plate 13 is large, the pressure distribution of the end plate 13 is uneven and warping occurs, and correspondingly, the pressure distribution of the battery cell assembly 19 is uneven.

[0110] like Fig.10 As shown, the fixing belt 12 of the battery module 1 is arranged near the battery cell main body 191 (see Figure 8 ) is a schematic diagram of the deformation degree distribution of the end plate 13 in the case where the first fixing belt 121 is close to the first end 193, the distance of the first fixing belt 121 near the first end 193 can be the projection distance of the first fixing belt 121 along the length direction of the battery cell 190 to the first end 193 is less than 2L / 25 (for example, it can be L / 28), and the distance of the second fixing belt 122 near the second end 194 can be the projection distance of the second fixing belt 122 along the length direction of the battery cell 190 to the second end 194 is less than 2L / 25 (for example, it can be L / 28). The end plate 13 can be roughly divided into three areas according to the degree of deformation. The third deformation zone 213 is distributed in the middle area of ​​the end plate 13, and the sixth deformation zone 223 and the ninth deformation zone 233 are gradually evolved and distributed from the third deformation zone 213 to the outer edge of the end plate 13. The deformation degree of the third deformation zone 213 is greater than the deformation degree of the sixth deformation zone 223, and the deformation degree of the sixth deformation zone 223 is greater than the deformation degree of the ninth deformation zone 233. Specifically, the thickness range of the battery cell 190 can be 9 to 20 mm (for example, 13 mm), the width range of the battery cell 190 can be 122 to 142 mm, and the length range of the battery cell 190 can be 265 to 360 mm (for example, 360 mm); along the thickness direction of the end plate 13, when the pressure load is 5KN, the maximum deformation range of the third deformation zone 213 can be δ=5mm~6mm (specifically, δmax=5.941mm), the maximum deformation range of the sixth deformation zone 223 can be δ=4mm~5mm (specifically, δmax=4.375mm), and the maximum deformation range of the ninth deformation zone 233 can be δ=3mm~4mm (specifically, δmax=3.125mm). The overall deformation degree of the end plate 13 gradually decreases from the middle area to the outer area, so that the deformation of the entire end plate 13 presents a roughly uniform change, and the change trend is relatively balanced. Correspondingly, the pressure distribution of the end plate 13 is relatively balanced. Compared with Fig. 9 The embodiment shown, Fig.10 In the embodiment shown, the pressure distribution on the end plate 13 is relatively balanced, and no edge warping or damage occurs. Correspondingly, the pressure distribution on the battery cell assembly 19 is relatively balanced.

[0111] In this embodiment, there are two fixing belts 12, and the two fixing belts 12 are respectively arranged on both sides. In other embodiments, there may be three fixing belts 12, of which two fixing belts 12 are arranged on both sides and one fixing belt 12 is arranged in the middle area, and further, the center point of the end plate 13 may be covered, so that the pressure distribution of the end plate 13 is more balanced.

[0112] like Fig.11As shown, it is a schematic diagram of the deformation degree distribution of the end plate 13 when the distance from the projection of the first fixing belt 121 of the battery module 1 along the length direction of the battery cell 190 to the first end 193 is greater than or equal to 2L / 25 and less than or equal to L / 4, and the distance from the projection of the second fixing belt 122 along the length direction of the battery cell 190 to the second end 194 is greater than or equal to 2L / 25 and less than or equal to L / 4. In this embodiment, the distance from the projection of the first fixing belt 121 along the length direction of the battery cell 190 to the first end 193 can be L / 6, and the distance from the projection of the second fixing belt 122 along the length direction of the battery cell 190 to the second end 194 can be L / 6. The end plate 13 can be roughly divided into three areas according to the degree of deformation. The first deformation area 211 is distributed in the middle area of ​​the end plate 13, and the fourth deformation area 221 and the seventh deformation area 231 are gradually distributed from the first deformation area 211 to the outer edge of the end plate 13. The deformation degree of the first deformation zone 211 is greater than that of the fourth deformation zone 221, and the deformation degree of the fourth deformation zone 221 is greater than that of the seventh deformation zone 231. Specifically, the thickness range of the battery cell 190 can be 9 to 20 mm (for example, 13 mm), the width range of the battery cell 190 can be 122 to 142 mm, and the length range of the battery cell 190 can be 265 to 360 mm (for example, 360 mm); along the thickness direction of the end plate 13, when the pressure load is 5KN, the maximum deformation range of the first deformation zone 211 can be δ=5mm~6mm (specifically, δmax=5.687mm), the maximum deformation range of the fourth deformation zone 221 can be δ=4mm~5mm (specifically, δmax=4.375mm), and the maximum deformation range of the seventh deformation zone 231 can be δ=3mm~4mm (specifically, δmax=3.75mm). Compared to Fig. 9 and Fig.10 The embodiment shown, Fig.11 In the illustrated embodiment, the deformation degree of the end plate 13 is more evenly distributed, that is, the pressure on the end plate 13 is more evenly distributed. Correspondingly, the pressure on the battery cell assembly 19 is evenly distributed.

[0113] The deformation degree of the end plate 13 is positively correlated with the pressure on the end plate 13, and the pressure on the end plate 13 is also positively correlated with the pressure on the battery cell assembly 19. Fig. 9It can be seen that when the projection distance of the first fixing belt 121 of the battery module 1 along the length direction of the battery cell 190 from the first end 193 is greater than L / 4 and the projection distance of the second fixing belt 122 along the length direction of the battery cell 190 from the second end 194 is greater than L / 4, the deformation degree of the narrower area in the middle of the end plate 13 and the edge areas on both sides of the end plate 13 is relatively large, the deformation degree of the edges on both sides of the end plate 13 is too large, and the deformation degree of the edges on the other two sides is too small, the overall pressure on the end plate 13 is obviously uneven, and the pressure distribution on the battery cell assembly 19 is obviously uneven. Fig.10 It can be seen that the fixing belt 12 is arranged near the battery cell main body 191 (see Figure 8 ), the distance between the first fixing belt 121 and the first end 193 can be less than 2L / 25 of the projection distance of the first fixing belt 121 along the length direction of the battery cell 190 from the first end 193, and the distance between the second fixing belt 122 and the second end 194 can be less than 2L / 25 of the projection distance of the second fixing belt 122 along the length direction of the battery cell 190 from the second end 194. The deformation degree of the middle area of ​​the end plate 13 is relatively moderate, and the deformation degree of the edge area is evenly distributed. The overall pressure on the end plate 13 is relatively balanced, and the pressure distribution on the battery cell assembly 19 is relatively balanced. Fig.11 It can be seen that when the distance between the projection of the first fixing belt 121 and the first end 193 along the length direction of the battery cell 190 is greater than or equal to 2L / 25 and less than or equal to L / 4, and the distance between the projection of the second fixing belt 122 and the second end 194 along the length direction of the battery cell 190 is greater than or equal to 2L / 25 and less than or equal to L / 4, the deformation degree of the middle part of the end plate 13 is high, and the area of ​​the high deformation region in the middle part of the end plate 13 is moderate, and the deformation degree of the end plate 13 gradually decreases from the middle part to the peripheral area. Fig.10 The embodiment shown, Fig.11 In the illustrated embodiment, the pressure on the end plate 13 is more balanced, and the pressure distribution on the battery cell assembly 19 is also more balanced.

[0114] In one embodiment, the end plate 13 may not be provided between the battery cell assembly 19 and the fixing belt 12. Figures 9 to 11 The deformation degree, pressure distribution and change trend shown correspond to the deformation degree, pressure distribution and change trend of the outermost battery cell 190 of the battery cell assembly 19. Fig. 9 and Fig.10 In the embodiment shown, the pressure distribution on the outermost battery cell 190 of the battery cell assembly 19 is relatively balanced, corresponding to Fig.11 In the illustrated embodiment, the pressure distribution on the outermost battery cell 190 of the battery cell assembly 19 is relatively balanced.

[0115] The end plate 13 is disposed between the fixing belt 12 and the outermost side of the housing 11 along the stacking direction of the battery cells 190 , and the end plate 13 is in contact with the third surface 113 and the fourth surface 114 .

[0116] In one embodiment, the material of the end plate 13 can be metal, such as aluminum, and the material of the shell 11 can be an insulating material, such as insulating plastic. The end plate 13 is arranged on one side of the shell 11 to prevent the fixing belt 12 from damaging the shell 11 during the pressurization process.

[0117] like Figure 3 As shown, the housing 11 further includes at least two accommodating grooves 18, and the at least two accommodating grooves 18 are formed on the third surface 113 and the fourth surface 114. In one embodiment, the accommodating grooves 18 are formed by the third surface 113 and the fourth surface 114 being recessed into the interior of the housing 11, respectively, and the end plate 13 is disposed in the accommodating grooves 18. The pressure regulating unit 123 is disposed on the side of the end plate 13 away from the housing 11.

[0118] In one embodiment, the receiving groove 18 includes a first sub-groove 181 and a second sub-groove 182 . The first sub-groove 181 is disposed in the first sub-shell 118 , and the second sub-groove 182 is disposed in the second sub-shell 119 .

[0119] The housing 11 is provided with a mounting groove 17, and at least a portion of the battery cell assembly 19 is disposed in the mounting groove 17. In one embodiment, there are multiple mounting grooves 17, and one mounting groove 17 corresponds to one battery cell main body 191. The battery cell 190 can be fixed to the housing 11 by the adhesive disposed in the mounting groove 17.

[0120] In the above, the specific implementation of the present application is described with reference to the accompanying drawings. However, those skilled in the art will appreciate that various changes and substitutions may be made to the specific implementation of the present application without departing from the spirit and scope of the present application.

Claims

1. A battery module, the battery module comprising a battery cell assembly, wherein the battery cell in the battery cell assembly comprises a battery cell body and a tab, It is characterized in that The battery module also includes: A first fixing belt surrounds the battery cell assembly along the thickness direction of the battery cell; A second fixing belt surrounds the battery cell assembly along the thickness direction of the battery cell; and In the length direction of the battery cell, the distance between the projection position of the first fixing belt and the first end of the battery cell body is less than or equal to L / 4 and greater than or equal to 2L / 25, and the distance between the projection position of the second fixing belt and the second end of the battery cell body is less than or equal to L / 4 and greater than or equal to 2L / 25, where L is the length of the battery cell body; The battery module further includes an outer shell, which includes a shell, the battery cell assembly is arranged inside the shell, and the shell is arranged between the first fixing belt and the battery cell assembly, and between the second fixing belt and the battery cell assembly.

2. The battery module according to claim 1, It is characterized in that The battery module further includes an end plate, which is disposed between the outermost cell of the cell assembly and the first fixing belt and the second fixing belt along the stacking direction of the cell.

3. The battery module according to claim 1, It is characterized in that The outer surface of the shell is provided with a groove. The shell includes a first surface and a second surface which are arranged opposite to each other. The groove is formed on the first surface and the second surface.

4. The battery module according to claim 3, It is characterized in that The first fixing belt and the second fixing belt are each arranged in one of the grooves.

5. The battery module according to claim 4, It is characterized in that The first fixing belt and the second fixing belt are arranged at intervals, the groove includes a first sub-groove, a second sub-groove, a third sub-groove and a fourth sub-groove, the first sub-groove and the second sub-groove are formed on the first surface, the third sub-groove and the fourth sub-groove are formed on the second surface, the first fixing belt is arranged in the first sub-groove and the third sub-groove, and the second fixing belt is arranged in the second sub-groove and the fourth sub-groove.

6. The battery module according to claim 1, It is characterized in that The battery module further includes an end plate, which is disposed between the outermost cell of the cell assembly and the first fixing belt and the second fixing belt along the stacking direction of the cell.

7. The battery module according to claim 6, It is characterized in that The shell also includes a third surface and a fourth surface arranged opposite to each other, the end plate is in contact with the third surface and the fourth surface, and the shell also includes at least two accommodating grooves, at least two of the accommodating grooves are formed on the third surface and the fourth surface, and the end plate is arranged in the accommodating grooves.

8. The battery module according to claim 7, It is characterized in that The shell further includes a first sub-shell and a second sub-shell, the first sub-shell and the second sub-shell are buckled together to form the shell, the first sub-shell is provided with a first surface, the second sub-shell is provided with a second surface, the shell further includes a fifth surface and a sixth surface, the buckling surface of the first sub-shell and the second sub-shell divides the third surface, the fourth surface, the fifth surface and the sixth surface, the accommodating groove includes a first sub-groove and a second sub-groove, the first sub-groove is provided in the first sub-shell, and the second sub-groove is provided in the second sub-shell.

9. The battery module according to claim 1, It is characterized in that The first fixing belt and the second fixing belt each include at least one pressure regulating unit, and the pressure regulating unit is used to regulate the pressure with which the first fixing belt and the second fixing belt press the housing.

10. The battery module according to claim 9, It is characterized in that The pressure regulating unit comprises a screw and a nut, and the torque borne by the screw is greater than or equal to 1.5 NM.

11. The battery module according to claim 9, It is characterized in that The first fixing strap and the second fixing strap are both in strip shape, and both include a first adjusting portion and a second adjusting portion that are spaced apart, and the pressure adjusting unit is movably connected to the first adjusting portion and the second adjusting portion, and the pressure adjusting unit adjusts the pressure of the first fixing strap or the second fixing strap on the shell by adjusting the distance between the first adjusting portion and the second adjusting portion.

12. The battery module according to claim 1, It is characterized in that The pressure values ​​of the first fixing belt and the second fixing belt on the housing are both in the range of 0 kgf to 100 kgf.

13. The battery module according to claim 1, It is characterized in that The sum of the cross-sectional areas of the first fixing belt and the second fixing belt is greater than or equal to 60 mm 2 .

14. The battery module according to claim 6, It is characterized in that The housing further comprises a front cover and a control circuit. The front cover is buckled on one end of the housing, and the control circuit is arranged between the end plate and the front cover.

15. The battery module according to claim 1, It is characterized in that The shell is provided with a mounting groove inside, and at least a part of the battery cell assembly is arranged in the mounting groove.

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