Battery cover plate assembly and battery

Abstract

The invention relates to the technical field of batteries, and particularly discloses a battery cover plate assembly and a battery, and the battery cover plate assembly comprises a cover plate body, a first plastic part, a second plastic part and a pole. A first mounting hole is formed in the cover plate body, a first through hole is formed in the first plastic part, a second through hole is formed in the second plastic part, and a pole lug of the pole group penetrates through the second through hole, the first mounting hole and the first through hole and then is connected with the pole column. The pole is arranged on the side, deviating from the cover plate body, of the first plastic part and does not occupy the internal space of the shell, the arrangement space of the pole group is increased, and the energy density of the battery is high. Besides, a connecting flange is arranged on the second plastic part or the cover plate body, the connecting flange is in interference fit with the first mounting hole / the second through hole, the second plastic part and the cover plate body are stably and firmly connected, the insulation between the tab and the cover plate body is good, and the safety of the battery is high. The invention also provides a battery which comprises the battery cover plate assembly.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery cover assembly and a battery. Background Art

[0002] In lithium-ion batteries, the battery cover assembly is one of the key accessories. It is connected to the shell through the battery cover assembly to encapsulate the electrode group in the shell. At the same time, the pole on the battery cover assembly can lead out the pole ear of the electrode group to connect the external circuit.

[0003] The existing battery cover assembly generally includes a rivet block, an upper plastic part, a pole, a cover body, a lower plastic part and a sealing ring. The sealing ring is sleeved on the outside of the pole. The column part of the pole passes through the lower plastic part, the cover body, and the upper plastic part from one side of the cover body in sequence and is connected to the rivet block. The plate part of the pole is pressed against the lower plastic part. After the battery cover assembly is installed with the shell, the plate part of the pole and the lower plastic part are located in the shell and are clamped between the cover body and the pole group. Since the plate part of the pole and the lower plastic part have a certain height, they occupy the internal space of the shell, resulting in a reduction in the layout space of the pole group, which is not conducive to the rational use of space and the energy density of the battery is low. In addition, there is usually no connection structure between the existing upper plastic part, the lower plastic part and the cover body. The upper plastic part and the lower plastic part are only pressed against the cover body by the riveted poles. When the battery is shaken or bumped, the upper plastic part or the lower plastic part may shift, thereby causing insulation failure and low battery safety. Summary of the invention

[0004] The object of the present invention is to provide a battery cover plate assembly and a battery, wherein the pole does not need to occupy the internal space of the shell, the volume of the pole group is increased, the space utilization rate is high, and the energy density of the battery is high. A connecting structure is provided between the second plastic part and the cover plate body, the connection between the two is stable and firm, and the battery is highly safe.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] In one aspect, the present invention provides a battery cover assembly, comprising:

[0007] The cover body is provided with a first mounting hole;

[0008] A first plastic part, disposed on one side of the cover body, wherein the first plastic part is provided with a first through hole;

[0009] A second plastic part is arranged on the other side of the cover body, the second plastic part is provided with a second through hole, and the central axes of the second through hole, the first through hole and the first mounting hole are coaxial;

[0010] A pole, which is arranged on a side of the first plastic part away from the cover body, and the pole lug of the pole group is connected to the pole after passing through the second through hole, the first mounting hole and the first through hole;

[0011] A connecting flange, wherein the connecting flange is arranged on the second plastic part, the connecting flange extends into the first mounting hole and has an interference fit with the inner wall of the first mounting hole; or the connecting flange is arranged on the cover body, the connecting flange extends into the second through hole and has an interference fit with the inner wall of the second through hole.

[0012] Optionally, the connecting flange includes a connecting flange body and a first interference rib, the connecting flange body is arranged on the second plastic part, the first interference rib is arranged on the connecting flange body, there is a gap between the connecting flange body and the inner wall of the first mounting hole, and the first interference rib is interference fit with the inner wall of the first mounting hole.

[0013] Optionally, the first interference ribs are provided in plurality and are in strip shape, the extension direction of the first interference ribs is the same as the extension direction of the connecting flange body, and the plurality of first interference ribs are evenly spaced in the circumferential direction of the connecting flange body;

[0014] Alternatively, at least one first interference rib is provided and the first interference rib is annular, and the first interference rib is arranged around the circumference of the connecting flange body.

[0015] Optionally, a guide structure is provided at the end of the first interference rib inserted into the first mounting hole.

[0016] Optionally, the interference between the first interference rib and the inner wall of the first mounting hole is h;

[0017] The value range of h satisfies: 0.05mm≤h≤0.5mm.

[0018] Optionally, a second interference rib is provided on the inner wall of the first mounting hole, and the second interference rib is interference-fitted with the connecting flange body.

[0019] Optionally, the first plastic part includes a first plastic part body and an overlap portion, the first through hole is provided on the first plastic part body, the overlap portion is located in the circumferential direction of the first plastic part body, a sink groove is provided on the end surface of the cover plate body on the side away from the second plastic part, the overlap portion is embedded in the sink groove and fits with the bottom wall of the sink groove;

[0020] Wherein, along the first direction, the width of the overlap portion is c;

[0021] The value range of c satisfies: 0mm≤c≤10mm;

[0022] And / or, along the second direction, the thickness of the cover plate body is H, and the distance between the end surface of the overlapping portion facing away from the second plastic part and the end surface of the cover plate body facing away from the second plastic part is b;

[0023] The value range of b satisfies: -1mm≤b≤0.5H;

[0024] The value range of H satisfies: 1mm≤H≤3mm.

[0025] Optionally, a limiting flange and a connecting rib are provided on the side of the first plastic body facing away from the cover body, the limiting flange is arranged in the circumference of the first through hole, the limiting flange, the connecting rib and the first plastic body form a mounting groove, and at least part of the pole is embedded in the mounting groove.

[0026] Optionally, one of the first plastic part and the cover body is provided with a fusion column, and the other of the first plastic part and the cover body is provided with a fixing groove, and the fusion column is fixed to the fixing groove by hot melting.

[0027] On the other hand, the present invention provides a battery, comprising a shell, a pole group, and a battery cover assembly in any of the above schemes, wherein the battery cover assembly is encapsulated at an opening of the shell, and the pole group is arranged in the shell.

[0028] The beneficial effects of the present invention are:

[0029] The present invention provides a battery cover assembly, comprising a cover body, a first plastic part, a second plastic part and a pole. The first plastic part and the second plastic part are respectively arranged on both sides of the cover body, and the pole is arranged on the side of the first plastic part away from the cover body. A first mounting hole is provided on the cover body, a first through hole is provided on the first plastic part, and a second through hole is provided on the second plastic part. The pole lug of the pole group is connected to the pole after passing through the second through hole, the first mounting hole and the first through hole. Since the pole is arranged on the side of the first plastic part away from the cover body, it will not occupy the space inside the shell, the arrangement space of the pole group in the shell is increased, the space utilization rate is high, and it is helpful to improve the energy density of the battery. In addition, a connecting flange is provided on the second plastic part, and the connecting flange is interference fit with the inner wall of the first mounting hole. Or a connecting flange is provided on the cover body, and the connecting flange is interference fit with the inner wall of the second through hole. As a result, the positioning between the second plastic part and the cover body is accurate, and the assembly accuracy of the battery cover assembly is high; at the same time, the connection between the second plastic part and the cover body is stable and firm, and the second plastic part is not easy to detach from the cover body, ensuring good insulation between the tab and the cover body and high battery safety.

[0030] The present invention also provides a battery, including a shell, a pole group, and the above-mentioned battery cover assembly. An opening is provided on one side of the shell, and the pole group is loaded into the shell through the opening. The battery cover assembly is arranged at the opening of the shell and is welded to the shell. The battery cover assembly and the shell form a closed accommodation space to enclose the pole group in the accommodation space. By adopting the above-mentioned battery cover assembly, the pole column is arranged outside the shell and does not occupy the internal space of the shell, so that the volume of the pole group can be increased, and the energy density of the battery is large. In addition, a connecting flange is provided on the second plastic part or the cover body, and the second plastic part and the cover body are accurately positioned and stably and firmly connected. The insulation performance between the pole ear and the cover body is better, and the battery has high safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0032] Figure 1 This is a schematic diagram of the structure of the battery cover assembly provided in the first embodiment of the present invention;

[0033] Figure 2 An exploded view of the battery cover assembly provided in Embodiment 1 of the present invention;

[0034] Figure 3 An exploded view of the battery cover assembly provided in the first embodiment of the present invention from another perspective;

[0035] Figure 4 A front view of a battery cover assembly provided in Embodiment 1 of the present invention;

[0036] Figure 5 for Figure 4 Sectional view of the AA section;

[0037] Figure 6 for Figure 5 A partial enlarged view of point B in the middle;

[0038] Figure 7 for Figure 5 Sectional view of the CC section;

[0039] Figure 8 for Figure 7 A partial enlarged view of point D in the middle;

[0040] Fig. 9 This is a schematic structural diagram of a first plastic part provided in Embodiment 1 of the present invention;

[0041] Fig.10 This is a schematic structural diagram of a second plastic part provided in Embodiment 1 of the present invention;

[0042] Fig.11 for Fig.10 A partial enlarged view of point E in the middle.

[0043] In the figure:

[0044] 100, cover body; 110, first mounting hole; 120, sink; 130, fixing groove; 140, second mounting hole; 150, supporting rib; 160, first injection hole;

[0045] 200, first plastic part; 210, first plastic part body; 211, first through hole; 220, overlapping part; 230, limiting flange; 240, connecting rib; 241, mounting groove; 250, melting column;

[0046] 300, second plastic part; 310, second plastic part body; 311, second through hole; 320, connecting flange; 321, connecting flange body; 322, first interference rib; 3221, guide structure; 330, vent hole; 340, second injection hole;

[0047] 400. Explosion-proof valve. DETAILED DESCRIPTION

[0048] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and the first feature "above", "above" and "above" the second feature include the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature "below", "below" and "below" the second feature include the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0050] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0052] Embodiment 1

[0053] like Figure 1-Figure 3 As shown, a battery cover assembly is provided in this embodiment, and the battery cover assembly includes a cover body 100, a first plastic part 200, a second plastic part 300 and a pole.

[0054] The cover body 100 is provided with a first mounting hole 110, the first plastic part 200 is arranged on one side of the cover body 100, the second plastic part 300 is arranged on the other side of the cover body 100, and the pole is arranged on the side of the first plastic part 200 away from the cover body 100. The first plastic part 200 is provided with a first through hole 211, the second plastic part 300 is provided with a second through hole 311, the central axes of the second through hole 311, the first through hole 211 and the first mounting hole 110 are coaxial, and the pole group is arranged on the side of the second plastic part 300 away from the cover body 100.

[0055] After the battery cover assembly is assembled, the pole lug of the pole group passes through the second through hole 311, the first mounting hole 110 and the first through hole 211 and is connected to the pole. The cover body 100 is connected to the battery shell, and the second plastic part 300 and the pole group are located in the shell. Since the pole is arranged on the side of the first plastic part 200 away from the cover body 100, that is, the pole is arranged outside the shell, the pole will not occupy the space inside the shell, and the arrangement space of the pole group in the shell is increased, and the space utilization rate is high, which helps to improve the energy density of the battery. In addition, the second plastic part 300 in this embodiment is generally flat, and its Figure 1-Figure 3 The thickness in the Z-axis direction shown in the figure is relatively thin, which can further reduce the occupied space, increase the arrangement space of the pole group, and increase the energy density of the battery. Figure 1-Figure 3 The thickness in the Z-axis direction shown in the figure is also relatively thin, so the size of the entire battery cover assembly along the Z-axis direction is relatively small. When the battery with the battery cover assembly is arranged in a whole battery pack, the space utilization rate is high and the energy density is high.

[0056] Furthermore, in this embodiment, the first plastic part 200 and the second plastic part 300 are both made of insulating materials, and the pole column is insulated from the cover body 100 by the first plastic part 200, and the pole group is insulated from the cover body 100 by the second plastic part 300. The second plastic part 300 includes a second plastic part body 310 and a connecting flange 320, and the connecting flange 320 is arranged in the circumference of the second through hole 311 and extends into the first mounting hole 110 of the cover body 100. The connecting flange 320 is interference-fitted with the inner wall of the first mounting hole 110, and is radially (i.e., radially) in the first mounting hole 110. Figure 1-Figure 3The pole ear is located on the side of the connecting flange 320 away from the cover body 100, and the connecting flange 320 can insulate the pole ear from the cover body 100. The connecting flange 320 and the inner wall of the first mounting hole 110 are interferingly fitted. On the one hand, the accurate positioning between the second plastic part 300 and the cover body 100 is ensured, which helps to improve the assembly accuracy of the battery cover assembly; on the other hand, the connection strength between the second plastic part 300 and the cover body 100 is improved, and the connection between the two is stable and firm. The second plastic part 300 is not easy to detach from the cover body 100, which ensures that the insulation between the pole ear and the cover body 100 is good, and the battery is highly safe.

[0057] See also Figure 4-Figure 6 In this embodiment, the connecting flange 320 includes a connecting flange body 321 and a first interference rib 322. The connecting flange body 321 is disposed on the second plastic part 300. The connecting flange body 321 is annular and is disposed around the circumference of the second through hole 311. There is a gap between the outer peripheral wall of the connecting flange body 321 (i.e., the side wall close to the first mounting hole 110) and the inner wall of the first mounting hole 110. The first interference rib 322 is disposed on the outer peripheral wall of the connecting flange body 321 and is interference-fitted with the inner wall of the first mounting hole 110.

[0058] Alternatively, see Figure 6 , Fig.10 and Fig.11 The first interference ribs 322 are provided in plurality and are in a strip shape. For example, the first interference ribs 322 can be provided in a straight line shape, a wave shape, etc. The plurality of first interference ribs 322 are provided along the axial direction of the first mounting hole 110 ( Figure 1-Figure 3 The first interference ribs 322 extend in the Z-axis direction shown in the figure or are arranged obliquely in the axial direction deviating from the first mounting hole 110. A plurality of first interference ribs 322 are evenly spaced in the circumferential direction of the connecting flange body 321. The cross section (along the Z-axis direction) of each first interference rib 322 is Figure 1-Figure 3 The cross section of the XY plane shown in FIG is a triangle, one side wall of the first interference rib 322 is connected to the connecting flange body 321, and the edge opposite to the side wall is interference fit with the inner wall of the first mounting hole 110. Further, the edge opposite to the side wall on the first interference rib 322 can be smoothly transitioned by an arc surface, so as to prevent the first interference rib 322 from scratching the inner wall of the first mounting hole 110.

[0059] Furthermore, a guide structure 3221 is further provided at the end of the first interference rib 322 facing the cover body 100, and the guide structure 3221 can make it easier for the connecting flange body 321 to be installed in the first mounting hole 110, so as to facilitate assembly. Exemplarily, the guide structure 3221 can be an inclined surface provided at the end of the first interference rib 322, and the side of the inclined surface away from the second through hole 311 is inclined in a direction away from the cover body 100. Of course, in some embodiments, the guide structure 3221 can also be an arc surface at the end of the first interference rib 322.

[0060] Alternatively, in some embodiments, the first interference rib 322 may be provided as one or more, and the first interference rib 322 is spirally arranged around the circumference of the connecting flange body 321 along the axial direction of the first mounting hole 110. Alternatively, in other embodiments, a plurality of first interference ribs 322 are provided, and the plurality of first interference ribs 322 are annular, each of the first interference ribs 322 surrounds the circumference of the connecting flange body 321, and the plurality of first interference ribs 322 are sequentially arranged at intervals along the axial direction of the first mounting hole 110. Of course, in the above two solutions, a guide structure 3221 may also be provided on the side of the first interference rib 322 facing the cover plate body 100.

[0061] Continue to see Figure 6 , the interference between the first interference rib 322 and the inner wall of the first mounting hole 110 is h, and the value range of h satisfies: 0.05mm≤h≤0.5mm. For example, the value of h can be 0.05mm, 0.10mm, 0.15mm, 0.20mm, 0.25mm, 0.30mm, 0.40mm or 0.50mm. It should be noted that the value of h should not be too small, otherwise the connection strength between the second plastic part 300 and the cover body 100 is low, the connection between the two is not firm, and the second plastic part 300 may be detached from the cover body 100, posing a safety risk; the value of h should not be too large, otherwise the assembly between the second plastic part 300 and the cover body 100 is difficult, which is not conducive to installation, and may also cause deformation of the cover body 100, and the flatness of the battery cover assembly is not good.

[0062] Optionally, in some embodiments, a second interference rib (not shown) is provided on the inner wall of the first mounting hole 110, and the second interference rib is interference-fitted with the outer peripheral wall of the connecting flange body 321. The structure of the second interference rib is the same as that of the first interference rib 322. The interference amount between the second interference rib and the outer peripheral wall of the connecting flange body 321 is also h, and the value range of h satisfies: 0.05mm≤h≤0.5mm. For example, the value of h can be 0.05mm, 0.10mm, 0.15mm, 0.20mm, 0.25mm, 0.30mm, 0.40mm or 0.50mm.

[0063] The following is a trial assembly of samples of battery cover assemblies in some specific implementation schemes to explore the influence of the value of the parameter h on the assembly results of the cover body 100 and the second plastic part 300. The results are shown in Table 1.

[0064] Table 1

[0065]

[0066] From the trial assembly results, it is known that in sample 1, the value of h is smaller than the minimum value of its set range of 0.05mm≤h≤0.5mm, the cover body 100 and the second plastic part 300 cannot be fixedly connected, the second plastic part 300 will fall from the cover body 100, the battery cover assembly cannot be connected as a whole, and the battery cover assembly is a defective product.

[0067] In Sample 2, Sample 3, Sample 4, Sample 5, Sample 6, Sample 7, Sample 8, Sample 9, Sample 10 and Sample 11, the value of h is within its set range of 0.05mm≤h≤0.5mm, the cover body 100 and the second plastic part 300 are easy to assemble, and after assembly, the cover body 100 and the second plastic part 300 are stably connected, the second plastic part 300 is not easy to fall from the cover body 100, the second plastic part 300 is stably fixed on the cover body 100 and is not easy to shake, the reliability of the connection between the cover body 100 and the second plastic part 300 is high, the battery cover assembly is successfully assembled into one, and the battery cover assembly product is good.

[0068] In sample 12, the value of h is greater than the maximum value of its setting range of 0.05mm≤h≤0.5mm, and the cover body 100 and the second plastic part 300 are difficult to assemble. During assembly, metal wires may be generated on the inner wall of the first mounting hole 110 on the cover body 100, causing the electrode group to have a short circuit risk and resulting in a defective battery cover assembly.

[0069] See also Figure 7-Figure 9 In this embodiment, the first plastic part 200 includes a first plastic part body 210 and a lap part 220. The first through hole 211 is provided on the first plastic part body 210. The lap part 220 is located in the circumferential direction of the first plastic part body 210. A sink groove 120 is provided on the end surface of the cover plate body 100 away from the second plastic part 300. The lap part 220 is embedded in the sink groove 120 and fits with the bottom wall of the sink groove 120. On the one hand, the lap part 220 can be arranged along the axial direction ( Figure 1On the other hand, by setting the sink groove 120, part of the first plastic component body 210 can be embedded in the cover body 100, further reducing the size of the battery cover assembly along the axial direction of the first mounting hole 110, thereby improving the space utilization rate of the entire battery pack and increasing the energy density.

[0070] Optionally, along the first direction, the width of the overlapped portion 220 disposed on both sides of the first plastic body 210 is c, and the value range of c satisfies: 0mm≤c≤10mm. The first direction refers to Figure 1-Figure 3 In the Y-axis direction. Exemplarily, the value of c can be 0mm, 1mm, 2mm, 5mm, 8mm or 10mm, etc. By controlling the width c of the overlap portion 220 within the above range, it is possible to ensure that the assembly structure between the first plastic part 200 and the cover body 100 is stable, and the weight of the first plastic part 200 can be relatively reduced, thereby reducing material costs. It should be noted that when the width c of the overlap portion 220 is 0, the circumferential edge of the first plastic part body 210 overlaps the cover body 100, and at this time, the successful assembly of the first plastic part 200 and the cover body 100 can also be ensured. In addition, when the width c of the overlap portion 220 is greater than 10mm, it may occupy more space in the sink 120, affecting the assembly between the cover body 100 and other structural parts.

[0071] Along the third direction ( Figure 1-Figure 3 The width of the overlapped portion 220 disposed on both sides of the first plastic body 210 is also c, and the value range of c also satisfies: 0mm≤c≤10mm. For example, along the third direction, the width c of the overlapped portion 220 can be 0mm, 1mm, 2mm, 5mm, 8mm or 10mm, etc.

[0072] Furthermore, along the second direction ( Figure 1-Figure 3In the Z-axis direction of the cover body 100, the thickness of the cover body 100 is H, the distance between the end face of the overlap portion 220 away from the second plastic part 300 and the end face of the cover body 100 away from the second plastic part 300 is b, and the value range of b satisfies: -1mm≤b≤0.5H, and the value range of H satisfies: 1mm≤H≤3mm. Wherein "-" indicates that the end face of the overlap portion 220 away from the second plastic part 300 exceeds the end face of the cover body 100 away from the second plastic part 300. Exemplarily, when H is 1mm, the value of b can be -1mm, -0.5mm, 0mm, 0.1mm, 0.3mm or 0.5mm. It should be noted that the value of b should not be too large. If the value of b is greater than 0.5H, the depth of the sink 120 is large, which affects the mechanical strength of the cover body 100. When the cover body 100 is bumped, it is easy to deform or rupture, resulting in battery failure. Of course, the value of b should not be too small. If the value of b is less than -1 mm, it means that the end surface of the overlap portion 220 that is away from the second plastic part 300 exceeds the sink 120 too much, which may affect the assembly between the first plastic part 200 and other structural parts. Of course, in other embodiments, the value of H can also be 2 mm, 2.5 mm or 3 mm, etc. The value of b is within the above range, and is not listed here one by one.

[0073] The following are some samples of battery cover assemblies, and the dimension design of the overlap portion 220 and the dimension design of the cover body 100 are subjected to pressure resistance test and thrust test to explore the influence of the above parameters H, b, c on the insulation performance and structural strength of the battery cover assembly.

[0074] The withstand voltage test refers to: using an AC withstand voltage tester to load a high voltage (for example, the high voltage may be 1500V) between the cover body 100 and the first plastic part 200 for 2 seconds, and detecting the leakage current value. When the leakage current value is less than 2mA and the first plastic part 200 is not broken down, the insulation performance of the battery cover assembly is good.

[0075] The thrust test refers to: fixing the cover body 100 and applying a thrust toward the cover body 100 to the first plastic part 200. When the thrust applied to the first plastic part 200 is greater than 1200N, and the deformation of the cover body 100 along the thrust direction is less than 0.5mm, the structural strength of the battery cover assembly is high and meets the product requirements.

[0076] The detailed dimensional parameters and test results of the battery cover assembly are shown in Table 3 below.

[0077] Table 3

[0078]

[0079] In sample 1, the value of b is -2.0mm, the value of H is 2.0mm, and the value of b is less than the minimum value of -1mm≤b≤0.5H. At this time, the end surface of the overlapping portion 220 that is away from the second plastic part 300 exceeds the end surface of the cover body 100 that is away from the second plastic part 300 by too much, which affects the height design of the pole along the second direction, is not conducive to improving the energy density of the battery, is not recommended for use, and the product is defective.

[0080] In sample 2, the value of c is -0.5mm, which is less than the minimum value of 0mm≤c≤10mm. Other parameters H and b meet their corresponding size range limits. At this time, the insulation performance between the first plastic part 200 and the cover body 100 cannot be guaranteed, the voltage test fails, and there is a risk of voltage failure. It is not recommended for use and the product is defective.

[0081] In Sample 3, Sample 4, Sample 5, Sample 6, Sample 7, Sample 8, Sample 9, Sample 10, Sample 11, Sample 12, Sample 13, Sample 14 and Sample 15, the values ​​of parameters H, b, and c all meet their corresponding size range limits. At this time, the insulation performance between the first plastic part 200 and the cover body 100 is good, the voltage test is passed, and the structural strength of the cover body 100 is high, and the thrust test is passed. It is recommended to use and the product is good.

[0082] In sample 16, the value of c is 13.0 mm, which is greater than the maximum value of 0 mm ≤ c ≤ 10 mm. Other parameters H and b meet their corresponding size range limits. At this time, the insulation performance between the first plastic part 200 and the cover body 100 is good, and the voltage test is passed. However, the width of the overlapping portion 220 of the first plastic part 200 is large, and the material used for the first plastic part 200 and the pole is increased, resulting in a high cost. It is not recommended for use, and the product is defective.

[0083] In sample 17, the value of b is 1.5mm, the value of H is 2.0mm, and the value of b is greater than 0.5H, which does not meet the size limit of -1mm≤b≤0.5H. At this time, the depth of the groove 120 on the cover body 100 is large, the structural strength of the cover body 100 is low, and the thrust test fails. It is not recommended for use and the product is defective.

[0084] Continue to see Figure 2 , Figure 3 and Fig. 9 In this embodiment, there are two pole groups, each pole group has a length direction ( Figure 2 , Figure 3 There are two first plastic parts 200 and two poles, and the two first plastic parts 200 are respectively arranged along the cover body 100. Figure 2 , Figure 3 At the two ends of the X-axis direction shown in the figure, the poles on the side of the two first plastic parts 200 away from the cover body 100 are respectively a positive pole and a negative pole, and each first plastic part body 210 is provided with two first through holes 211, and the two first through holes 211 are arranged along Figure 2 , Figure 3 The Y-axis spacing settings are shown in .

[0085] The second plastic part 300 and the cover plate body 100 are each provided with a second plastic part body 310 along Figure 2 , Figure 3 Two second through holes 311 are respectively provided at both ends of the X-axis direction as shown in FIG. Figure 2 , Figure 3 As shown in the figure, two first mounting holes 110 are respectively provided at both ends of the X-axis direction, that is, there are four second through holes 311 in total, and there are four first mounting holes 110 in total. The second through holes 311 correspond to the first mounting holes 110 and the first through holes 211 one by one. The connecting flange 320 in the circumferential direction of each second through hole 311 is assembled with the corresponding first mounting hole 110 on the cover body 100. The positive electrode ear of each electrode group passes through the second plastic body 310 along Figure 2 , Figure 3 The negative electrode ear of each electrode group passes through the second plastic body 311 along the X-axis direction. Figure 2 , Figure 3 The second through hole 311 at the other end in the X-axis direction shown in the figure and the first through hole 211 on the other first plastic body 210 are connected to the negative pole. Thus, the pole ears of the two pole groups are directly led out from the shell and connected to the poles on the outside of the shell, which does not occupy the internal space of the shell, has high space utilization, and has large volume energy of the pole group.

[0086] Furthermore, a limiting flange 230 and a connecting rib 240 are provided on the side of the first plastic body 210 away from the cover body 100. Two limiting flanges 230 and two connecting ribs 240 are provided. Each limiting flange 230 is arranged around a first through hole 211 on the first plastic body 210. Both ends of each connecting rib 240 are connected to a limiting flange 230 respectively. The limiting flange 230, the connecting rib 240 and the first plastic body 210 form a mounting groove 241. At least part of the pole is embedded in the mounting groove 241. Since the pole is in a flat plate shape as a whole and at least part of the pole is embedded in the mounting groove 241, the battery cover assembly is further reduced along the mounting groove 241. Figure 2 , Figure 3 The dimensions in the Z-axis direction shown in the figure are used to improve space utilization and the energy density of the entire battery pack.

[0087] Continue to see Figure 2 and Figure 3 , the first plastic part 200 and the cover body 100 can be fixed by hot melting. Specifically, one of the first plastic part 200 and the cover body 100 is provided with a fusion column 250, and the other of the first plastic part 200 and the cover body 100 is provided with a fixing groove 130, and the fusion column 250 is fixed to the fixing groove 130 by ultrasonic hot melting. On the one hand, the cooperation between the fusion column 250 and the fixing groove 130 ensures the accurate positioning between the first plastic part 200 and the cover body 100, which is conducive to improving the assembly accuracy of the battery cover assembly; on the other hand, the hot melting fixing method is adopted, so that the surface flatness of the first plastic part body 210 away from the cover body 100 is better, which is convenient for arranging the pole.

[0088] By way of example, in this embodiment, a molten column 250 is provided on the end surface of the first plastic part body 210 facing the cover plate body 100, and a fixing groove 130 is provided on the bottom of the groove 120 of the cover plate body 100 facing the first plastic part 200. The molten column 250 is inserted into the fixing groove 130, and one end of the molten column 250 inserted into the fixing groove 130 is connected to the inner wall of the fixing groove 130 after ultrasonic hot melting, thereby realizing the connection between the first plastic part 200 and the cover plate body 100. Optionally, the fixing groove 130 can be set as a trapezoidal groove or a stepped groove with a tapered entrance, so as to improve the connection strength between the molten column 250 and the fixing groove 130, and the connection reliability between the first plastic part 200 and the cover plate body 100 is higher.

[0089] In addition, the bottom wall of the sink 120 may be provided with a plurality of fixing grooves 130, and the plurality of fixing grooves 130 are provided along the bottom wall of the sink 120. Figure 2 , Figure 3 As shown in the figure, the first plastic body 210 is arranged at intervals in the X-axis direction, and accordingly, a plurality of melting pillars 250 are also provided on the first plastic body 210, and the fixing grooves 130 and the melting pillars 250 correspond to each other one by one, thereby further improving the connection strength between the melting pillars 250 and the fixing grooves 130, and also improving the uniformity of the force on the first plastic part 200. By way of example, in this embodiment, two melting pillars 250 are provided on the end surface of the first plastic body 210 facing the cover body 100, and two fixing grooves 130 are correspondingly provided in the sink 120. Of course, in other embodiments, the number and arrangement of the melting pillars 250 and the fixing grooves 130 can also be flexibly adjusted as needed, and this embodiment does not limit this.

[0090] Of course, in other embodiments, the melting column 250 may be disposed at the bottom of the sink 120 , and the fixing groove 130 may be disposed on the end surface of the first plastic body 210 facing the cover body 100 , which will not be described in detail here.

[0091] Optionally, the battery cover assembly in this embodiment further includes an explosion-proof valve 400. The cover body 100 is provided with a second mounting hole 140, and the explosion-proof valve 400 is disposed in the second mounting hole 140. A vent hole 330 is provided on the second plastic body 310 at a position corresponding to the second mounting hole 140. Figure 2 , Figure 3 In the Z-axis direction shown in , the projection of the vent hole 330 on the cover body 100 coincides with the projection of the explosion-proof valve 400 on the cover body 100. Therefore, when the pressure in the battery shell exceeds the valve opening pressure of the explosion-proof valve 400, high-temperature, high-pressure gas and liquid can be discharged from the battery through the vent hole 330 and the explosion-proof valve 400, avoiding the risk of explosion and having high safety. In addition, criss-crossing support ribs 150 are also provided in the second mounting hole 140, and the support ribs 150 can support the cover body 100 and improve the structural strength of the cover body 100 at the second mounting hole 140. Furthermore, a plurality of vent holes 330 on the second plastic body 310 can be arranged at intervals to increase the flow area, so that high-temperature, high-pressure gas and liquid can be discharged quickly and circulate smoothly.

[0092] Optionally, in some embodiments, the cover body 100 is further provided with a first injection hole 160, and the second plastic body 310 is provided with a second injection hole 340 at a position corresponding to the first injection hole 160. Figure 2 , Figure 3 In the Z-axis direction shown in , the projection of the first injection hole 160 on the cover body 100 coincides with the projection of the second injection hole 340 on the cover body 100. After the battery cover assembly is assembled with the shell, electrolyte can be injected into the shell through the first injection hole 160 and the second injection hole 340 so that the electrode group can be immersed in the electrolyte. After the injection is completed, an injection plug can be installed in the first injection hole 160 and / or the second injection hole 340 to seal the first injection hole 160 and / or the second injection hole 340 to prevent leakage of the electrolyte. Exemplarily, the injection plug is made of a material with elastic deformation ability such as rubber.

[0093] This embodiment also provides a battery, including a shell, a pole group, and the above-mentioned battery cover assembly. One side of the shell is provided with an opening, and the pole group is installed in the shell through the opening. The battery cover assembly is arranged at the opening of the shell and is welded to the shell. The battery cover assembly and the shell form a closed accommodation space to enclose the pole group in the accommodation space.

[0094] By adopting the battery cover assembly, the pole is arranged outside the shell, and will not occupy the internal space of the shell, and the second plastic part 300 is flat and thin, so that the volume of the pole group can be increased, and the energy density of the battery is high. A connecting flange 320 is provided between the second plastic part 300 and the cover body 100, and the second plastic part 300 and the cover body 100 are accurately positioned and stably and firmly connected, and the insulation performance between the pole ear and the cover body 100 is better, and the safety of the battery is high.

[0095] Embodiment 2

[0096] This embodiment provides a battery cover assembly, which differs from the battery cover assembly in the first embodiment in that: the connecting flange 320 in this embodiment is arranged on the cover body 100, and the connecting flange 320 extends into the second through hole 311 of the second plastic part 300 and is interference fit with the inner wall of the second through hole 311.

[0097] Exemplarily, the connecting flange 320 includes a connecting flange body 321 and a first interference rib 322. The connecting flange body 321 is disposed on the cover plate body 100 and is located in the circumference of the first mounting hole 110. The connecting flange body 321 extends into the second through hole 311 on the second plastic body 310, and there is a gap between the connecting flange body 321 and the inner wall of the second through hole 311. The first interference rib 322 is interference fit with the inner wall of the second through hole 311. The interference amount between the first interference rib 322 and the inner wall of the second through hole 311 is h, and the value range of h satisfies: 0.05mm≤h≤0.5mm. For example, the value of h can be 0.05mm, 0.10mm, 0.15mm, 0.20mm, 0.25mm, 0.30mm, 0.40mm or 0.50mm. It should be noted that the value of h should not be too small, otherwise the connection strength between the second plastic part 300 and the cover body 100 is low, the connection between the two is not firm, and the second plastic part 300 may be detached from the cover body 100, posing a safety risk; the value of h should not be too large, otherwise the assembly between the second plastic part 300 and the cover body 100 is difficult, which is not conducive to installation and may also cause the cover body 100 to be completely deformed and the flatness of the battery cover assembly is poor.

[0098] Optionally, a second interference rib is provided on the inner wall of the second through hole 311, and the second interference rib is interference-fitted with the outer peripheral wall of the connecting flange body 321. The structure of the second interference rib is the same as that of the first interference rib 322. The interference amount between the second interference rib and the outer peripheral wall of the connecting flange body 321 is also h, and the value range of h satisfies: 0.05mm≤h≤0.5mm. For example, the value of h can be 0.05mm, 0.10mm, 0.15mm, 0.20mm, 0.25mm, 0.30mm, 0.40mm or 0.50mm.

[0099] This embodiment also provides a battery, including a shell, a pole group, and the above-mentioned battery cover assembly. One side of the shell is provided with an opening, and the pole group is installed in the shell through the opening. The battery cover assembly is arranged at the opening of the shell and is welded to the shell. The battery cover assembly and the shell form a closed accommodation space to enclose the pole group in the accommodation space.

[0100] By adopting the battery cover assembly, the pole is arranged outside the shell, and will not occupy the internal space of the shell, and the second plastic part 300 is flat and thin, so that the volume of the pole group can be increased, and the energy density of the battery is high. A connecting flange 320 is provided between the second plastic part 300 and the cover body 100, and the second plastic part 300 and the cover body 100 are accurately positioned and stably and firmly connected, and the insulation performance between the pole ear and the cover body 100 is better, and the safety of the battery is high.

[0101] The remaining structures in this embodiment are the same as those in the first embodiment and will not be described in detail here.

[0102] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A battery cover assembly, characterized in that: include: The cover body is provided with a first mounting hole; A first plastic part, disposed on one side of the cover body, wherein the first plastic part is provided with a first through hole; A second plastic part is arranged on the other side of the cover body, the second plastic part is provided with a second through hole, and the central axes of the second through hole, the first through hole and the first mounting hole are coaxial; A pole, which is arranged on a side of the first plastic part away from the cover body, and the pole lug of the pole group is connected to the pole after passing through the second through hole, the first mounting hole and the first through hole; A connecting flange, wherein the connecting flange is arranged on the second plastic part, the connecting flange extends into the first mounting hole and has an interference fit with the inner wall of the first mounting hole; or the connecting flange is arranged on the cover body, the connecting flange extends into the second through hole and has an interference fit with the inner wall of the second through hole.

2. The battery cover assembly according to claim 1, characterized in that: The connecting flange includes a connecting flange body and a first interference rib, the connecting flange body is arranged on the second plastic part, the first interference rib is arranged on the connecting flange body, there is a gap between the connecting flange body and the inner wall of the first mounting hole, and the first interference rib is interference fit with the inner wall of the first mounting hole.

3. The battery cover assembly according to claim 2, characterized in that: The first interference ribs are provided in plurality and are in strip shape. The extending direction of the first interference ribs is the same as the extending direction of the connecting flange body. The plurality of first interference ribs are evenly spaced in the circumferential direction of the connecting flange body. Alternatively, at least one first interference rib is provided and the first interference rib is annular, and the first interference rib is arranged around the circumference of the connecting flange body.

4. The battery cover assembly according to claim 3, characterized in that: A guide structure is provided at the end of the first interference rib inserted into the first mounting hole.

5. The battery cover assembly according to claim 3, characterized in that: The interference between the first interference rib and the inner wall of the first mounting hole is h; The value range of h satisfies: 0.05mm≤h≤0.5mm.

6. The battery cover assembly according to any one of claims 2 to 5, characterized in that: A second interference rib is provided on the inner wall of the first mounting hole, and the second interference rib is interference-fitted with the connecting flange body.

7. The battery cover assembly according to claim 1, characterized in that: The first plastic part comprises a first plastic part body and an overlapped portion, the first through hole is arranged on the first plastic part body, the overlapped portion is located in the circumferential direction of the first plastic part body, a sink groove is arranged on the end surface of the cover plate body on the side away from the second plastic part, the overlapped portion is embedded in the sink groove and fits with the bottom wall of the sink groove; Wherein, along the first direction, the width of the overlap portion is c; The value range of c satisfies: 0mm≤c≤10mm; And / or, along the second direction, the thickness of the cover plate body is H, and the distance between the end surface of the overlapping portion facing away from the second plastic part and the end surface of the cover plate body facing away from the second plastic part is b; The value range of b satisfies: -1mm≤b≤0.5H; The value range of H satisfies: 1mm≤H≤3mm.

8. The battery cover assembly according to claim 7, characterized in that: A limiting flange and a connecting rib are provided on the side of the first plastic body away from the cover body. The limiting flange is arranged in the circumference of the first through hole. The limiting flange, the connecting rib and the first plastic body form a mounting groove. At least part of the pole is embedded in the mounting groove.

9. The battery cover assembly according to claim 1, characterized in that: One of the first plastic part and the cover body is provided with a fusion column, and the other of the first plastic part and the cover body is provided with a fixing groove, and the fusion column is fixed in the fixing groove by hot melting.

10. A battery, characterized in that: It comprises a shell, a pole group, and a battery cover assembly according to any one of claims 1 to 9, wherein the battery cover assembly is encapsulated at an opening of the shell, and the pole group is arranged in the shell.

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