Battery cell

Abstract

The invention relates to the technical field of power batteries, and particularly discloses a battery cell which comprises a shell and a cover plate. The interior of the shell is hollow to form a containing cavity, one end of the shell is provided with an opening communicated with the containing cavity, the cover plate comprises a cover plate body and a guide part, the guide part is arranged on the side, facing the shell, of the cover plate body, the guide part comprises a conical guide face, and one end of the conical guide face is in transition connection with a straight matching face of the cover plate body. When the shell and the cover plate are subjected to press fitting, the conical guide face is matched with the shell, and the cover plate body penetrates through the opening to enter the containing cavity under the guide of the conical guide face, so that mechanical damage generated when the cover plate and the shell are assembled is reduced, the appearance of the shell is good, hemming or other mechanical damage does not occur, the assembly precision between the cover plate and the shell is high, and the assembly yield is high.

Description

Technical Field

[0001] The present invention relates to the technical field of power batteries, and particularly to an electric core. Background Art

[0002] With the increasing maturity of lithium-ion battery technology, lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage fields, and people's requirements for the use performance and safety of lithium-ion batteries are increasing day by day. Among them, the electric core is the core component of the lithium-ion battery pack, and its structural design is crucial for the safety of the lithium-ion battery pack. The electric core includes a pole group, an electric core, and a housing. The pole group is installed in the housing, and the electric core cooperates with the housing to realize the encapsulation of the pole group.

[0003] Generally, a guiding structure with a rounded corner is provided on the cell cover plate of the electric core to facilitate the press-fitting of the cell housing and the cell cover plate. However, due to the inappropriate selection of the matching dimensions and structure between the guiding structure with the rounded corner and the cell housing, mechanical damage of varying degrees often occurs at the edge where the cell housing and the cell cover plate are matched, the outer surface of the electric core is uneven, and the production yield and assembly accuracy of the electric core are poor. Summary of the Invention

[0004] The purpose of the present invention is to provide an electric core, in which the matching dimensions and structural design of the guiding portion provided on the cover plate and the housing are reasonable, which can reduce mechanical damage occurring during the assembly of the cover plate and the housing, is beneficial to improving the assembly accuracy between the cover plate and the housing, and has a high assembly yield.

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

[0006] The present invention provides an electric core, which includes:

[0007] A housing, which is hollow inside to form a receiving cavity, and at least one end of the housing is provided with an opening communicating with the receiving cavity;

[0008] A cover plate, including a cover plate body and a guiding portion. The guiding portion is provided on the side of the cover plate body facing the housing. The guiding portion includes a conical guiding surface. One end of the conical guiding surface is transitionally connected to the straight surface mating surface of the cover plate body. Under the guidance of the conical guiding surface, the cover plate body passes through the opening and enters the receiving cavity, and the straight surface mating surface of the cover plate body is attached to the inner wall surface of the housing;

[0009] Along a first direction, the distance between the end of the conical guiding surface departing from the cover plate body and the straight surface mating surface is A, and along a second direction, the distance between the end of the conical guiding surface departing from the cover plate body and the end of the conical guiding surface connecting the straight surface mating surface is C;

[0010] A and C satisfy: 0.3 ≤ A / C ≤ 1.4;

[0011] Among them, the value range of A is: 0.25mm<A≤0.6mm;

[0012] The value range of C is: 0.2mm≤C≤1.5mm.

[0013] Optionally, the cover plate further includes a lap portion, which is arranged on a side of the cover plate body opposite to the guide portion, and protrudes from the straight mating surface of the cover plate body along a first direction, and the lap portion abuts against an outer edge of an opening side of the shell.

[0014] Optionally, along the second direction, a distance between an end surface of the overlap portion facing the shell and an end of the conical guide surface connected to the cover body is E, and E and C satisfy: E+C≤1.5mm;

[0015] The value range of E is: 0.4mm<E≤1.2mm.

[0016] Optionally, along the second direction, the thickness of the overlapped portion is G1, the total thickness of the cover plate is T1, and the relationship between T1 and G1, E, and C is: T1=G1+E+C;

[0017] The value range of G1 is: 0.5mm≤G1≤1.0mm.

[0018] Optionally, along the first direction, the height of the outer wall surface of the shell protruding from the end surface of the overlapping portion on the side away from the cover body is H, and the value range of H is: 0.05mm≤H≤0.15mm.

[0019] Optionally, the shell includes a first side plate and a second side plate, and the first side plate and the second side plate surround the opening; along the first direction, an effective guiding distance of the conical guide surface to the first side plate is A1, and A1=A.

[0020] Optionally, the guide portion further includes a clamping surface, and the end of the conical guide surface facing away from the cover plate body is transitionally connected to the clamping surface, a pole group and an insulating member are provided in the accommodating cavity, the clamping surface abuts against the insulating member, and the insulating member abuts against the pole group.

[0021] Optionally, the battery cell is a blade battery cell, the shell is provided with openings at both ends along the second direction, two cover plates are provided, and the two cover plates are respectively arranged at one of the openings, and two insulating members are also provided, and each insulating member is clamped between a cover plate and the pole group.

[0022] Optionally, a positive terminal is integrated on one of the cover plates, and the positive tab of the electrode group is electrically connected to the positive terminal after passing through one of the insulating members; a negative terminal is integrated on the other cover plate, and the negative tab of the electrode group is electrically connected to the negative terminal after passing through the other insulating member.

[0023] Optionally, the battery cell is a square shell battery cell, one end of the shell in the second direction is provided with the opening, there is one cover plate, the cover plate is arranged at the opening, and the insulating member is clamped between the cover plate and the electrode group;

[0024] A positive terminal and a negative terminal are integrated on the cover plate, the positive tab of the electrode group is electrically connected to the positive terminal after passing through the insulating member, and the negative tab of the electrode group is electrically connected to the negative terminal after passing through the insulating member.

[0025] The beneficial effects of the present invention are as follows:

[0026] The present invention provides a battery cell, including a shell and a cover plate. The interior of the shell is hollow to form a receiving cavity, one end of the shell is provided with an opening communicating with the receiving cavity, the cover plate includes a cover plate body and a guiding portion, the guiding portion is arranged on the side of the cover plate body facing the shell, the guiding portion includes a conical guiding surface, and one end of the conical guiding surface is in transitional connection with the straight surface mating surface of the cover plate body. When the shell and the cover plate are press-fitted, the conical guiding surface cooperates with the shell, and under the guidance of the conical guiding surface, the cover plate body passes through the opening and enters the receiving cavity, reducing the mechanical damage occurring during the assembly of the cover plate and the shell. The appearance of the shell is good, without curling or other mechanical damage, the assembly accuracy between the cover plate and the shell is relatively high, and the assembly yield is relatively high. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the content of the embodiments of the present invention and these drawings.

[0028] Figure 1 Schematic diagram of the battery cell (the electrode group is not shown) provided in the first embodiment of the present invention;

[0029] Figure 2 Partial enlarged view of the cover plate and the shell after assembly provided in the first embodiment of the present invention;

[0030] Figure 3 Partial enlarged view of the cover plate and the shell during assembly provided in the first embodiment of the present invention;

[0031] Figure 4It is a partial enlarged view after the cell cover plate and the cell housing are assembled in the traditional technical solution;

[0032] Figure 5 It is a partial enlarged view when the cell cover plate and the cell housing are assembled in the traditional technical solution;

[0033] Figure 6 It is a schematic structural diagram of the cell (the electrode group is not shown) provided in the second embodiment of the present invention.

[0034] In the figure:

[0035] 10’, cell housing; 20’, cell cover plate; 21’, cell cover plate body; 22’, guiding structure; 221’, arc surface; 23’, overlapping structure;

[0036] 100, housing; 101, opening; 110, bottom plate; 120, first side plate; 121, inner wall surface; 122, outer wall surface; 200, cover plate; 210, cover plate body; 211, straight surface mating surface; 220, guiding portion; 221, conical guiding surface; 222, pressing surface; 230, overlapping portion. Specific embodiments

[0037] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0038] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is 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 a limitation to 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 moreover, the first feature being "above", "above" and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "below", "below" and "under" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0039] In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" 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 an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, in which the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0041] Embodiment 1

[0042] As Figures 1-3 shown, this embodiment provides an electric core, which is a square shell electric core and includes a shell 100, a cover plate 200, and an electrode assembly. Among them, there is one cover plate 200. The interior of the shell 100 is hollow to form a receiving cavity. One end of the shell 100 is provided with an opening 101 communicating with the receiving cavity. The electrode assembly is installed into the receiving cavity of the shell 100 through the opening 101. The cover plate 200 is arranged at the opening 101 of the shell 100 and is used to block the opening 101 of the shell 100. The electrode assembly is encapsulated by the cover plate 200 and the shell 100 together.

[0043] The cover plate 200 includes a cover plate body 210 and a guiding portion 220. The guiding portion 220 is arranged on the side of the cover plate body 210 facing the shell 100. The guiding portion 220 includes a conical guiding surface 221. One end of the conical guiding surface 221 is in transitional connection with the straight surface mating surface 211 of the cover plate body 210. Among them, the straight surface mating surface 211 of the cover plate body 210 is the side wall in its length direction, and the length direction of the cover plate body 210 is Figure 1 the Y-axis direction shown in

[0044] Further, along the first direction, that is Figure 1In the Y-axis direction shown in the figure, the distance between the end of the conical guiding surface 221 facing away from the cover plate body 210 and the straight surface mating surface 211 is A, that is, the thickness of the guiding portion 220 in the second direction is A. In the second direction, that is, Figure 1 In the X-axis direction shown in the figure, the distance between the end of the conical guiding surface 221 facing away from the cover plate body 210 and the end of the conical guiding surface 221 connecting the straight surface mating surface 211 is C. The relationship between A and C satisfies: 0.3 ≤ A / C ≤ 1.4. For example, the value of A / C can be 0.3, 0.5, 0.8, 1.0, 1.2 or 1.4, etc. Among them, the value range of A is: 0.25 mm < A ≤ 0.6 mm, and the value range of C is: 0.2 mm ≤ C ≤ 1.5 mm.

[0045] By controlling the value of A / C within the above range, it can ensure that the conical guiding surface 221 has a better guiding effect on the housing 100, so that the cover plate body 210 can smoothly enter the housing 100. Otherwise, when the value of A / C is too small, the effective guiding distance of the conical guiding surface 221 is small, and the cover plate body 210 is likely to rub against the housing 100, which may damage one end of the housing 100 provided with the opening 101, causing deformation of the housing 100 and low assembly yield. The value of A / C should not be too large either, otherwise it will increase the total thickness of the cover plate 200 in the second direction, making the cover plate 200 relatively thick and heavy, which is not conducive to the lightweight design of the battery cell, and both the cost and weight are relatively large.

[0046] As an alternative technical solution, the housing 100 in this embodiment includes a bottom plate 110, two first side plates 120 and two second side plates. Among them, the two first side plates 120 are arranged at both ends of the bottom plate 110 in the first direction, and the two second side plates are arranged at both ends of the bottom plate 110 in the third direction, and the third direction is perpendicular to the first direction and the second direction. The two first side plates 120 and the two second side plates enclose the opening 101 of the housing 100, and the bottom plate 110 is arranged on the opposite side of the opening 101. The conical guiding surface 221 of the cover plate 200 cooperates with the first side plate 120 to realize the guiding function when the cover plate 200 is press-fitted with the housing 100. After press-fitting, the straight surface mating surface 211 of the cover plate body 210 fits with the inner wall surface 121 of the first side plate 120.

[0047] Furthermore, the cover plate 200 in this embodiment further includes a lapping portion 230. The lapping portion 230 is arranged on the side of the cover plate body 210 opposite to the guiding portion 220, and in the first direction, the lapping portion 230 protrudes from the straight surface mating surface 211 of the cover plate body 210, and the lapping portion 230 abuts against the outer edge of the side of the housing 100 provided with the opening 101. Optionally, Figure 1 、 Figure 2Taking the example that the lapping part 230 abuts against the first side plate 120 of the housing 100, the positioning between the cover plate 200 and the housing 100 is realized through the cooperation of the lapping part 230 and the first side plate 120, ensuring that the two are assembled in place and at the same time avoiding the cover plate 200 from damaging the electrode group.

[0048] Of course, the lapping part 230 protrudes from the side wall of the cover plate body 210 in the width direction of the cover plate body 210, and the lapping part 230 abuts against the second side plate of the housing 100. The width direction of the cover plate 200 is the third direction, which is perpendicular to both the Figure 1 and Figure 2 X-axis direction and Y-axis direction shown in

[0049] Continue to refer to Figure 2 , along the second direction, the distance between the end face of the lapping part 230 facing the housing 100 and the end of the conical guide surface 221 connecting the cover plate body 210 is E, that is, the thickness of the cover plate body 210 along the second direction is E, and E and C satisfy: E + C ≤ 1.5 mm. The value range of E is: 0.4 mm < E ≤ 1.2 mm. For example, when the value of E is 0.4 mm, the value of C can be 0.2 mm, 0.4 mm, 0.8 mm or 1.1 mm. When the value of E is 1.2 mm, the value of C can be 0.2 mm, 0.25 or 0.3 mm, etc. By controlling the sum of E and C to be less than 1.5 mm, it is ensured that the size of the cover plate 200 extending into the accommodation cavity of the housing 100 is not too large, thereby avoiding the cover plate 200 from damaging the electrode group and being beneficial to protecting the electrode group from damage.

[0050] Along the second direction, the thickness of the lapping part 230 is G1, and the value range of G1 is: 0.5 mm ≤ G1 ≤ 1.0 mm. For example, the value of G1 can be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm or 1.0 mm, etc. By controlling the value of G1 within the above range, on the one hand, it is ensured that the lapping part 230 has sufficient mechanical strength to meet the welding requirements of the lapping part 230 and the housing 100; on the other hand, the weight reduction of the cover plate 200 is ensured as much as possible, avoiding the cover plate 200 from being designed too thick and heavy, increasing the cost and weight.

[0051] Furthermore, along the second direction, the total thickness of the cover plate 200 is T1, and the relationship between T1, G1, E and C is: T1 = G1 + E + C. That is to say, the sum of the thickness of the lapping part 230 along the second direction, the thickness of the cover plate body 210 along the second direction and the thickness of the guide part 220 along the second direction is the total thickness of the cover plate 200.

[0052] Along the first direction, the height of the outer wall surface 122 of the shell 100 protruding from the end surface of the lap joint 230 away from the cover plate body 210 is H, that is, the height difference between the end surface of the lap joint 230 away from the cover plate body 210 and the outer wall surface 122 of the first side plate 120 is H, and the value range of H is: 0.05mm≤H≤0.15mm. For example, the value of H can be 0.05mm, 0.08mm, 0.10mm, 0.12mm or 0.15mm, etc. By limiting the value of H within the above range, it is ensured that the assembly accuracy of the cover plate 200 and the shell 100 after press-fitting is high, which facilitates the subsequent welding of the lap joint 230 and the shell 100, and the welding strength and welding quality are high, ensuring that the connection strength between the cover plate 200 and the shell 100 after welding is high, and the outer surface of the battery cell is relatively smooth and has a good appearance.

[0053] Continue to see Figure 3 According to the value of A / C, the angle β between the conical guide surface 221 and the inner wall surface 121 of the first side plate 120 can be calculated using the inverse trigonometric function arctan(x), and the value range of β is: 16.7°≤β≤54.4°. For example, the value of β can be 16.7°, 20.0°, 30.0°, 35.0°, 45.0°, 50.0° or 54.4°. The entire wall surface of the conical guide surface 221 can provide good guidance for the first side plate 120, that is, along the first direction, the effective guiding distance of the conical guide surface 221 of the cover plate 200 is A1, A1=A. In this way, it can be ensured that the conical guide surface 221 has a better guiding effect on the shell 100, and the cover plate 200 can be smoothly inserted into the shell, with high assembly accuracy and assembly yield.

[0054] Furthermore, the guide portion 220 also includes a pressing surface 222, and one end of the conical guide surface 221 away from the cover body 210 is transitionally connected to the pressing surface 222. The housing cavity of the shell 100 is provided with a pole group (not shown in the figure) and an insulating member (not shown in the figure), and the pressing surface 222 of the guide portion 220 abuts against the insulating member, and the insulating member abuts against the pole group. The insulating member is sandwiched between the cover 200 and the pole group along the second direction. The pole group is fixed in the shell 100 by the cover 200 and the insulating member, and the insulating member insulates the cover 200 from the pole group. The positive pole column and the negative pole column are integrated on the cover 200. The positive pole ear of the pole group passes through the insulating member and is electrically connected to the positive pole column, and the negative pole ear of the pole group passes through the insulating member and is electrically connected to the negative pole column. In this way, the conduction between the pole group and the external circuit is achieved, and the pole group can be charged and discharged.

[0055] The following samples in some specific implementation schemes are used to verify the values ​​of relevant parameters A, E, C, A / C, and E+C of the cover plate 200 in this embodiment to explore whether the conical guide surface 221 of the cover plate 200 can provide a better guiding effect on the shell 100. Details are shown in Table 1.

[0056] Table 1

[0057]

[0058] From the above results, it can be obtained that among Samples 1 to 5, the values of parameters A, E, C, A / C, and E + C of each cover plate 200 all meet the restrictions of their corresponding dimensional ranges. The cover plate 200 can smoothly enter the shell under the guidance of the conical guiding surface 221, and the guiding effect is obvious. The cover plate 200 is well assembled with the shell 100, and there are no problems such as the cover plate 200 popping out, the shell 100 being damaged by pressure, and the cover plate 200 rubbing against the shell 100. The assembled battery cell product is good.

[0059] On the contrary, in Samples 6 and 7, the value of the parameter A / C of the cover plate 200 is less than the minimum value of 0.3 ≤ A / C ≤ 1.4. When the cover plate 200 is assembled with the shell 100, there is no problem of the cover plate 200 popping out. However, when the cover plate 200 enters the shell under the guidance of the conical guiding surface 221, it rubs against the shell 100, and the shell 100 is damaged by pressure and curled. The appearance of the assembled battery cell product is poor and does not meet the product requirements.

[0060] In Samples 8 and 9, the value of the parameter A of the cover plate 200 is less than the minimum value of 0.25 mm < A ≤ 0.6 mm. When the cover plate 200 is assembled with the shell 100, there is no problem of the cover plate 200 popping out. However, when the cover plate 200 enters the shell under the guidance of the conical guiding surface 221, it seriously rubs against the shell 100, and the shell 100 is damaged by pressure and curled. The appearance of the assembled battery cell product is poor and does not meet the product requirements.

[0061] In Sample 10, the value of the parameter E + C of the cover plate 200 is greater than 1.5 mm, which does not meet the dimensional restriction of E + C ≤ 1.5 mm. The remaining parameters meet the restrictions of their corresponding dimensional ranges. When the cover plate 200 is assembled with the shell 100, there is no problem of the cover plate 200 popping out, and the cover plate 200 can smoothly enter the shell under the guidance of the conical guiding surface 221. However, the size of the cover plate 200 extending into the accommodating cavity of the shell 100 is relatively large, occupying the space of the electrode group, resulting in a decrease in the energy density of the battery cell. At the same time, the total thickness of the cover plate 200 increases, resulting in a larger cost and weight, and the battery cell product is poor and does not meet the product requirements.

[0062] Furthermore, in this embodiment, the guiding portion 220 of the cover plate 200 adopts the structural form of the conical guiding surface 221, which has a more excellent guiding effect compared to the battery cell cover plate 20' in the traditional technical solution with the same thickness dimension.

[0063] See Figure 4 and Figure 5, which shows the schematic structural diagrams of the cell cover plate 20' and the cell housing 10' after and during assembly in the traditional technical solution. The cell cover plate 20' includes a cell cover plate body 21', a guiding structure 22' and a lapping structure 23'. The guiding structure 22' is arranged on one side of the cell cover plate body 21' close to the cell housing 10', and the lapping structure 23' is arranged on one side of the cell cover plate body 21' far from the cell housing 10'. The guiding structure 22' includes an arc surface 221'. The arc surface 221' cooperates with the cell housing 10'. Under the guidance of the arc surface 221', the cell cover plate body 21' is inserted into the cell housing 10', and the lapping structure 23' abuts against the end of the cell housing 10'.

[0064] Wherein, the distance between the end of the arc surface 221' deviating from the cell cover plate body 21' and the side wall of the cell cover plate body 21' is B, the radius of the arc surface 221' is D, the distance between the end face of the lapping structure 23' facing the cell housing 10' and the end of the arc surface 221' connecting the cell cover plate body 21' is F, the center of the arc surface 221' is O, the contact point between the cell housing 10' and the arc surface 221' is e, and the central angle opposite the end point (f point) of the arc surface 221' deviating from the cell cover plate body 21' at the e point is V. Only when V≥45°, the arc surface 221' can play a guiding role. When V<45°, the cell cover plate 20' cannot be inserted into the housing, that is, the effective guiding distance of the arc surface 221' is B1, and B1<B. In this embodiment, the effective guiding distance of the conical guiding surface 221 of the cover plate 200 is A1, and A1 = A (see Figure 3 ). When the dimension of the guiding part 220 of the cover plate 200 in this embodiment along the first direction is the same as that of the guiding structure 22' of the cell cover plate 20' in the traditional technical solution, that is, A = B, the effective guiding distance of the conical guiding surface 221 in this embodiment is larger, and its guiding performance is better than that of the guiding structure 22' with the arc surface 221' in the traditional technical solution.

[0065] Furthermore, the total thickness of the cover plate 200 in this embodiment along the second direction is T1, and the total thickness of the cell cover plate 20' in the traditional technical solution along the second direction is T2. If the thickness G2 of the lapping structure 23' of the cell cover plate 20' in the traditional technical solution along the second direction is equal to the thickness G1 of the lapping part 230 of the cover plate 200 in this embodiment, and the guiding structure 22' of the cell cover plate 20' in the traditional technical solution wants to achieve the same technical effect as the guiding part 220 of the cover plate 200 in this embodiment, it is necessary to satisfy A1 = B1. At this time, B>A. In the case where E is equal to F and C is equal to D, the following conclusions can be drawn:

[0066]

[0067] The total thickness T2 of the cell cover plate 20' in the traditional technical solution along the second direction is less than the total thickness T1 of the cover plate 200 in this embodiment along the second direction, and the mechanical strength is weak.

[0068] The following uses samples in some specific implementation solutions to verify the above conclusions. The details are shown in Table 2.

[0069] Table 2

[0070]

[0071] It can be obtained from the above results that the values of A / C in samples 1 to 6 of the cover plate 200 in this embodiment satisfy the corresponding value range of 0.3 ≤ A / C ≤ 1.4. There is no abnormality in the assembly of the cover plate 200 and the housing 100. The guiding part 220 on the cover plate 200 has a good guiding effect on the housing 100, and the assembly of the cover plate 200 and the housing 100 is qualified. On the contrary, in samples 7 to 10 of the cell cover plate 20' in the traditional technical solution, when the cell cover plate 20' is assembled with the cell housing 10', the cell housing 10' is easily bruised and deformed, and the assembly is unqualified.

[0072] Specifically, comparing sample 1 and sample 7, the value of A / (E + C) in sample 1 is equal to the value of B / (F + D) in sample 6, and the value of A / C is equal to the value of B / D. At this time, there is no abnormality in the assembly of the cover plate 200 and the housing 100 in this embodiment. The guiding part 220 on the cover plate 200 has a good guiding effect on the housing 100, and the assembly of the cover plate 200 and the housing 100 is qualified. When the cell cover plate 20' in the traditional technical solution is assembled with the cell housing 10', the cell housing 10' is significantly bruised, and the port of the cell housing 10' is severely deformed, and the assembly is unqualified.

[0073] Comparing sample 2 and sample 8, the value of A / (E + C) is equal to the value of B / (F + D), and the value of A / C is equal to the value of B / D. At this time, there is no abnormality in the assembly of the cover plate 200 and the housing 100 in this embodiment. The guiding part 220 on the cover plate 200 has a good guiding effect on the housing 100, is easy to assemble, and the assembly is qualified. When the cell cover plate 20' in the traditional technical solution is assembled with the cell housing 10', the cell housing 10' is significantly bruised, and the port of the cell housing 10' is severely deformed, and the assembly is unqualified.

[0074] Comparing Sample 3 and Sample 9, the value of A / (E + C) is equal to the value of B / (F + D), and the value of A / C is equal to the value of B / D. At this time, the cover plate 200 and the housing 100 in this embodiment are assembled without abnormality. The guiding portion 220 on the cover plate 200 has a good guiding effect on the housing 100, is easy to assemble, and the assembly is qualified. When the battery cell cover plate 20' and the battery cell housing 10' in the traditional technical solution are assembled, the guiding structure 22' on the battery cell cover plate 20' has a poor guiding effect on the battery cell housing 10'. There are bruises on the battery cell housing 10', and the port of the battery cell housing 10' is deformed, and the assembly is unqualified.

[0075] Comparing Sample 4 and Sample 10, the value of A / (E + C) is equal to the value of B / (F + D), and the value of A / C is equal to the value of B / D. At this time, the cover plate 200 and the housing 100 in this embodiment are assembled without abnormality. The guiding portion 220 on the cover plate 200 has a good guiding effect on the housing 100, is easy to assemble, and the assembly is qualified. When the battery cell cover plate 20' and the battery cell housing 10' in the traditional technical solution are assembled, the guiding structure 22' on the battery cell cover plate 20' has a poor guiding effect on the battery cell housing 10'. There are scratches on the battery cell housing 10', and the port of the battery cell housing 10' is deformed, and the assembly is unqualified.

[0076] Comparing Sample 5 and Sample 11, the value of A / (E + C) is equal to the value of B / (F + D), and the value of A / C is equal to the value of B / D. At this time, the cover plate 200 and the housing 100 in this embodiment are assembled without abnormality. The guiding portion 220 on the cover plate 200 has a good guiding effect on the housing 100, is easy to assemble, and the assembly is qualified. When the battery cell cover plate 20' and the battery cell housing 10' in the traditional technical solution are assembled, the guiding structure 22' on the battery cell cover plate 20' has a fair guiding effect on the battery cell housing 10'. The battery cell housing 10' and the battery cell cover plate 20' are successfully assembled, and the assembly is qualified.

[0077] Furthermore, comparing Sample 6 and Sample 11, when G1 = G2, E = F, and C = D, the value of B / (F + D) must be greater than or equal to 0.48 to ensure that the guiding structure 22' on the battery cell cover plate 20' has a good guiding effect on the battery cell housing 10', and the battery cell cover plate 20' and the battery cell housing 10' are assembled without abnormality. When the value of A / (E + C) in Sample 6 is greater than or equal to 0.20, it can ensure that the guiding portion 220 on the cover plate 200 has a good guiding effect on the housing 100. At this time, the value of B in Sample 11 is greater than the value of A in Sample 6.

[0078] That is to say, in this embodiment, the cover plate 200 can play a good guiding role for the housing 100 when the value of A is small. The matching dimensions and structural design of the guiding portion 220 provided on the cover plate 200 and the housing 100 are reasonable, which can reduce the mechanical damage occurring during the assembly of the cover plate 200 and the housing 100. The assembly accuracy between the cover plate 200 and the housing 100 is relatively high, and the assembly yield is relatively high. Moreover, the guiding portion 220 is easy to process, and the product yield is relatively high.

[0079] Embodiment Two

[0080] This embodiment also provides an electric core, which is different from the electric core in Embodiment One in that: this electric core is a blade electric core. Refer to Figure 6 , this electric core includes a housing 100, a cover plate 200 and a pole group. Among them, two cover plates 200 are provided. The interior of the housing 100 is hollow to form a receiving cavity. Both ends of the housing 100 along the second direction ( Figure 6 the X-axis direction shown in are provided with openings 101 communicating with the receiving cavity. The pole group is installed into the receiving cavity of the housing 100 through the openings 101. The two cover plates 200 are respectively arranged at the openings 101 of a housing 100 and are used to block the openings 101 of the housing 100. The pole group is encapsulated by the two cover plates 200 and one housing 100 together.

[0081] The cover plate 200 includes a cover plate body 210 and a guiding portion 220. The guiding portion 220 is arranged on the side of the cover plate body 210 facing the housing 100. The guiding portion 220 includes a conical guiding surface 221. One end of the conical guiding surface 221 is in transitional connection with the straight surface mating surface 211 of the cover plate body 210. Among them, the straight surface mating surface 211 of the cover plate body 210 is the side wall in its length direction. The first direction is Figure 6 the Y-axis direction shown in , that is, the first direction. When the housing 100 and the cover plate 200 are press-fitted, under the guidance of the conical guiding surface 221, the cover plate body 210 passes through the opening 101 and enters the receiving cavity, reducing the mechanical damage occurring during the assembly of the cover plate 200 and the housing 100. The assembly accuracy between the cover plate 200 and the housing 100 is relatively high. After the housing 100 and the cover plate 200 are press-fitted, the straight surface mating surface 211 of the cover plate body 210 is attached to the inner wall surface 121 of the housing 100. The appearance of the end of the housing 100 provided with the opening 101 is good, without curling or other mechanical damage, and the assembly yield is relatively high.

[0082] Furthermore, along the first direction, that is, Figure 6 the Y-axis direction shown in , the distance between the end of the conical guiding surface 221 departing from the cover plate body 210 and the straight surface mating surface 211 is A, that is, the thickness of the guiding portion 220 along the second direction is A. Along the second direction, that is, Figure 6In the X-axis direction shown in the figure, the distance between the end of the conical guide surface 221 facing away from the cover body 210 and the end of the straight surface mating surface 211 of the conical guide surface 221 is C. The relationship between A and C satisfies: 0.3 ≤ A / C ≤ 1.4. For example, the value of A / C can be 0.3, 0.5, 0.8, 1.0, 1.2, 1.4, etc. Among them, the value range of A is: 0.25 mm < A ≤ 0.6 mm, and the value range of C is: 0.2 mm ≤ C ≤ 1.5 mm.

[0083] By controlling the value of A / C within the above range, it can ensure that the conical guide surface 221 has a better guiding effect on the housing 100, and then enables the cover body 210 to smoothly enter the housing 100. Otherwise, when the value of A / C is too small, the effective guiding distance of the conical guide surface 221 is small, and the cover body 210 is likely to rub against the housing 100, which may damage one end of the housing 100 provided with the opening 101, causing deformation of the housing 100 and a low assembly yield. The value of A / C should not be too large either, otherwise it will increase the total thickness of the cover 200 in the second direction, making the cover 200 relatively thick and heavy, which is not conducive to the lightweight design of the battery cell, and both the cost and weight are relatively large.

[0084] Furthermore, in this embodiment, there are also two insulating parts, and each insulating part is clamped between a cover 200 and the electrode group. A positive electrode post is integrated on one of the covers 200, and the positive electrode tab of the electrode group is electrically connected to the positive electrode post after passing through one of the insulating parts; a negative electrode post is integrated on the other cover 200, and the negative electrode tab of the electrode group is electrically connected to the negative electrode post after passing through the other insulating part.

[0085] The rest of the structure of the battery cell in this embodiment is the same as that in Embodiment 1, and will not be elaborated here.

[0086] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill 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 implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A battery cell, characterized in that: include: A shell body, the interior of which is hollow to form a receiving cavity, and at least one end of the shell body is provided with an opening communicating with the receiving cavity; The cover plate comprises a cover plate body and a guide portion, wherein the guide portion is arranged on a side of the cover plate body facing the shell, the guide portion comprises a tapered guide surface, one end of the tapered guide surface is transitionally connected with a straight mating surface of the cover plate body, and under the guidance of the tapered guide surface, the cover plate body passes through the opening and enters the accommodating cavity, and the straight mating surface of the cover plate body is in contact with the inner wall surface of the shell; Along the first direction, the distance between the end of the tapered guide surface away from the cover body and the straight mating surface is A, and along the second direction, the distance between the end of the tapered guide surface away from the cover body and the end of the tapered guide surface connected to the straight mating surface is C; A and C satisfy: 0.3≤A / C≤1.4; Among them, the value range of A is: 0.25mm<A≤0.6mm; The value range of C is: 0.2mm≤C≤1.5mm.

2. The battery cell according to claim 1, characterized in that: The cover plate further comprises a lap portion, which is arranged on a side of the cover plate body opposite to the guide portion and protrudes from the straight mating surface of the cover plate body along a first direction, and abuts against an outer edge of an opening side of the shell.

3. The battery cell according to claim 2, characterized in that: Along the second direction, the distance between the end surface of the overlap portion facing the shell and the end of the conical guide surface connected to the cover body is E, and E and C satisfy: E+C≤1.5mm; The value range of E is: 0.4mm<E≤1.2mm.

4. The battery cell according to claim 2, characterized in that: Along the second direction, the thickness of the overlapped portion is G1, and the total thickness of the cover plate is T1; The relationship between T1 and G1, E, and C is: T1 = G1 + E + C; The value range of G1 is: 0.5mm≤G1≤1.0mm.

5. The battery cell according to claim 2, characterized in that: Along the first direction, the height of the outer wall surface of the shell protruding from the end surface of the overlapping portion away from the cover body is H; The value range of H is: 0.05mm≤H≤0.15mm.

6. The battery cell according to claim 1, characterized in that: The shell includes a first side plate and a second side plate, and the first side plate and the second side plate surround the opening; along the first direction, the effective guiding distance of the conical guide surface to the first side plate is A1, and A1=A.

7. The battery cell according to claim 1, characterized in that: The guide portion also includes a pressing surface, and the end of the conical guide surface away from the cover body is transitionally connected to the pressing surface. A pole group and an insulating member are arranged in the accommodating cavity, the pressing surface abuts against the insulating member, and the insulating member abuts against the pole group.

8. The battery cell according to claim 7, characterized in that: The battery cell is a blade battery cell, and the shell is provided with openings at both ends along the second direction. Two cover plates are provided, and the two cover plates are respectively arranged at one of the openings. Two insulating members are also provided, and each insulating member is clamped between a cover plate and the pole group.

9. The battery cell according to claim 8, characterized in that: A positive electrode column is integrated on one of the cover plates, and the positive electrode ear of the electrode group is electrically connected to the positive electrode column after passing through one of the insulating parts; a negative electrode column is integrated on the other cover plate, and the negative electrode ear of the electrode group is electrically connected to the negative electrode column after passing through the other insulating part.

10. The battery cell according to claim 7, characterized in that: The battery cell is a square shell battery cell, the shell is provided with the opening at one end along the second direction, the cover is provided with one, the cover is arranged at the opening, and the insulating member is sandwiched between the cover and the electrode group; The cover plate is integrated with a positive electrode column and a negative electrode column. The positive electrode tab of the electrode group is electrically connected to the positive electrode column after passing through the insulating member, and the negative electrode tab of the electrode group is electrically connected to the negative electrode column after passing through the insulating member.

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