End plate and battery

Abstract

The invention relates to the technical field of batteries, and particularly discloses an end plate and a battery, the end plate comprises a body, a first reinforcing plate and a second reinforcing plate, the body is of a frame structure, and the first reinforcing plate and the second reinforcing plate are respectively connected to two opposite side walls of the body along a first direction; the close end parts of the first reinforcing plate and the second reinforcing plate enclose a through hole with a gradually shrunk opening, the large opening end of the through hole faces the pole group, and a pole lug of the pole group penetrates through the through hole of the end plate. Due to the fact that the first reinforcing plate and the second reinforcing plate are arranged on the body of the end plate, the structural strength of the end plate is effectively improved, and the deformation problem of the end plate is reduced. And the first reinforcing plate and the second reinforcing plate are arranged at an included angle, so that the through hole is gradually shrunk along the direction deviating from the pole group, the root part of the tab is well gathered and shaped, and the shape of the tab in the battery is good. The invention also provides a battery which comprises the end plate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to an end plate and a battery. BACKGROUND

[0002] Lithium ion batteries are widely used due to their large capacity, high operating voltage, strong charge retention ability, long cycle life and other advantages. Generally, the structure of a lithium ion battery includes a cover plate, a shell, a pole group (including a tab), an end plate, a bare cell insulating sheet and other structural components. The cover plate and the shell are fixed by welding to form a sealed space that protects the pole group. The pole group is wrapped with a bare cell insulating sheet for protection, which prevents the pole group from contacting the shell and causing internal short circuit of the battery cell. The end plate is arranged between the pole group and the cover plate, and the tab can be fixed through the end plate, and a space is provided for protecting the tab. The tab, as a lug for leading out the current inside the battery, is usually made of copper foil / aluminum foil bonded together by ultrasonic welding. After ultrasonic welding, an insulating protective tape is pasted on both sides of the tab, and then the tab is passed through the end plate and welded with the pole column bottom plate integrated on the cover plate to lead out the current inside the battery to the outside of the battery.

[0003] At present, the wall thickness of the conventional end plate at the position where the tab is passed (avoidance groove) is relatively thin, and the end plate is easily deformed at the avoidance groove when the end plate is loaded by the equipment loading clamps. In addition, after the battery is assembled, the end plate is also easily deformed at the avoidance groove when it is pressed by the tab, which further causes misalignment gap at the contact position of the end plate and the lower plastic part of the cover plate, resulting in the risk of tab lapping the shell and greatly reducing the safety performance of the battery. SUMMARY

[0004] The purpose of the present application is to provide an end plate and a battery, which improves the structural strength of the end plate by providing a reinforcing structure on the end plate, and the end plate is not easily deformed, avoiding the problem of internal short circuit of the battery caused by lapping of the tab and the shell.

[0005] To achieve the above purpose, the present application adopts the following technical solutions:

[0006] On the one hand, the present application provides an end plate, which comprises:

[0007] a body, the body being a frame structure;

[0008] a first reinforcing plate and a second reinforcing plate, respectively connected to the two side walls of the body opposite in a first direction, the end portions of the first reinforcing plate and the second reinforcing plate facing each other to form a gradually tapered through hole, the large end of the through hole facing the pole group, and the tab of the pole group being passed through the through hole.

[0009] Optionally, the body comprises a first side plate and a second side plate oppositely arranged along a first direction, and a third side plate and a fourth side plate oppositely arranged along a second direction, the first side plate, the second side plate, the third side plate and the fourth side plate are connected to form the frame structure.

[0010] The first reinforcing plate is connected to the first side plate near one side of the pole group, the second reinforcing plate is connected to the second side plate near one side of the pole group, the first reinforcing plate and the second reinforcing plate extend towards each other, and the first reinforcing plate and the second reinforcing plate are arranged at an angle.

[0011] Optionally, along the first direction, the thickness of the first side plate is T1, and the thickness of the second side plate is T2; the value range of T1 is 0.9mm≤T1≤1.1mm, and the value range of T2 is 0.9mm≤T2≤1.1mm.

[0012] Optionally, along the first direction, the width of the body is W.

[0013] The value range of W is 12mm≤W≤45mm.

[0014] Optionally, the angle between the first reinforcing plate and the first side plate is β.

[0015] The value range of β is 60°≤β≤75°.

[0016] The angle between the second reinforcing plate (16) and the second side plate (12) is γ.

[0017] The value range of γ is 25°≤γ≤35°.

[0018] Optionally, the thickness of the first reinforcing plate is t1, and the thickness of the second reinforcing plate is t2.

[0019] The value range of t1 is 0.65mm≤t1≤1.0mm.

[0020] The value range of t2 is 0.65mm≤t2≤0.85mm.

[0021] Optionally, the length of the first reinforcing plate is A1, and the length of the second reinforcing plate is A2.

[0022] The value range of A1 is 5mm≤A1≤18mm.

[0023] The value range of A2 is 3mm≤A2≤8mm.

[0024] Optionally, the end plate further comprises a first support part and a second support part, the first support part and the second support part are connected to two ends of the body along the second direction respectively;

[0025] Wherein, along the third direction, the end faces of the first side plate, the second side plate, the third side plate and the fourth side plate away from the pole group are flush with the end faces of the first support part and the second support part away from the pole group;

[0026] The height of the first support part and the second support part along the third direction is equal, the height of the first side plate and the second side plate along the third direction is less than the height of the first support part along the third direction, and the height of the third side plate and the fourth side plate along the third direction is equal to the height of the first support part along the third direction.

[0027] Optionally, along the third direction, the distance between the end part of the first reinforcing plate connected with the first side plate and the end face of the first support part towards the pole group is h1;

[0028] The value range of h1 is: 0.2mm≤h1≤0.8mm;

[0029] Along the third direction, the distance between the end part of the second reinforcing plate connected with the second side plate and the end face of the first support part towards the pole group is h2;

[0030] The value range of h2 is: 0.2mm≤h2≤0.8mm.

[0031] In another aspect, the application provides a battery comprising the end plate in any of the above-mentioned schemes.

[0032] The application has the following beneficial effects:

[0033] The application provides an end plate, which comprises a body, a first reinforcing plate and a second reinforcing plate, the body is a frame structure, the first reinforcing plate and the second reinforcing plate are connected to two opposite side walls of the body along a first direction, the end parts of the first reinforcing plate and the second reinforcing plate close to each other form a gradually tapered through hole, the large end of the through hole faces the pole group, and the lug of the pole group passes through the through hole of the end plate. Since the first reinforcing plate and the second reinforcing plate are arranged on the body of the end plate, the structural strength of the end plate is effectively improved, and the problem of deformation of the end plate is reduced. Moreover, since the first reinforcing plate and the second reinforcing plate are arranged at an angle, the through hole has a gradually tapered trend in the direction away from the pole group, so that the root of the lug is well gathered and shaped, and the shape of the lug in the battery is good.

[0034] The application further provides a battery comprising the end plate, which can effectively support and limit the tab, is not prone to deformation, has high structural strength, ensures the gathering and shaping of the root of the tab, has good shape after bending, and improves the safety and reliability of the battery. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments of the present application will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of the contents of the embodiments of the present application and the drawings.

[0036] Figure 1 is a structural schematic view of the end plate provided in the embodiments of the present application;

[0037] Figure 2 is a top view of the end plate provided in the embodiments of the present application;

[0038] Figure 3 is a sectional view of A-A in Figure 2

[0039] Figure 4 is a sectional view of the end plate and the cover plate assembly, the shell and the pole assembly after assembly in the embodiments of the present application;

[0040] Figure 5 is a structural schematic view of the battery in the embodiments of the present application.

[0041] In the drawings:

[0042] 10, end plate; 11, first side plate; 12, second side plate; 13, third side plate; 14, fourth side plate; 15, first reinforcing plate; 16, second reinforcing plate; 1501, through hole; 17, first support part; 18, second support part; 1801, air hole;

[0043] 20, pole assembly; 21, tab; 211, first extension section; 212, first bending section; 213, second extension section; 214, second bending section;

[0044] 30, cover plate assembly; 31, cover plate body; 32, first plastic part; 33, pole; 34, second plastic part; 35, connecting block; 40, shell; 50, explosion-proof valve. DETAILED DESCRIPTION

[0045] ​The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0046] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", etc. are only for the purpose of description, 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 "above", "above" and "above" of the first feature on the second feature include the first feature directly above and obliquely above the second feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The "below", "below" and "below" of the first feature below the second feature include the first feature directly below and obliquely below the second feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0047] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0048] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the drawings, wherein 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 application, and cannot be understood as limiting the present application.

[0049] As Figures 1-4 shown, the present embodiment provides an end plate 10, which, after being assembled with a cover plate assembly 30, a shell 40 and a pole group 20, forms a battery.

[0050] The end plate 10 comprises a body, a first reinforcing plate 15 and a second reinforcing plate 16, the body is a frame structure, the first reinforcing plate 15 and the second reinforcing plate 16 are respectively connected to the two side walls opposite to each other along the first direction of the body, the end portions of the first reinforcing plate 15 and the second reinforcing plate 16 close to each other form a gradually tapered through hole 1501, the large end of the through hole 1501 is directed to the pole group 20, the lug 21 of the pole group 20 is electrically connected to the pole column 33 on the cover plate assembly 30 after passing through the through hole 1501 of the end plate 10, and then the lug 21 is bent to weld the cover plate body 31 of the cover plate assembly 30 to the shell 40, the pole group 20 can be pressed in the shell 40 through the end plate 10 to realize the fixation of the pole group 20 in the shell 40. The first reinforcing plate 15 and the second reinforcing plate 16 jointly constitute the reinforcing structure of the body of the end plate 10, effectively improve the structural strength of the end plate 10, reduce the problem of deformation of the end plate 10, and avoid the risk of short circuit caused by the overlap of the lug 21 and the shell 40 as much as possible.

[0051] Optionally, the body comprises a first side plate 11 and a second side plate 12 arranged opposite to each other along the first direction, and a third side plate 13 and a fourth side plate 14 arranged opposite to each other along the second direction, the first side plate 11, the second side plate 12, the third side plate 13 and the fourth side plate 14 are connected to each other to form a frame structure. The first reinforcing plate 15 is connected to one side of the first side plate 11 close to the pole group 20, the second reinforcing plate 16 is connected to one side of the second side plate 12 close to the pole group 20, and the first reinforcing plate 15 and the second reinforcing plate 16 are respectively located on the side walls of the first side plate 11 and the second side plate 12 close to each other. The first reinforcing plate 15 and the second reinforcing plate 16 extend in the direction close to each other, and the first reinforcing plate 15 and the second reinforcing plate 16 are arranged at an angle. The first direction is the Y-axis direction shown in Figure 1 Figure 1 The second direction is the X-axis direction shown in

[0052] Since the first reinforcing plate 15 and the second reinforcing plate 16 are arranged at an angle, the through hole 1501 has a gradually tapered trend in the direction away from the pole group 20, thereby playing a good gathering and shaping role on the root of the lug 21; in addition, when the end plate 10 is assembled with the cover plate assembly 30, the shell 40 and the pole group 20, the lug 21 is first bent in the direction of the first reinforcing plate 15 after passing through the end plate 10, and the lug 21 is lifted by the first reinforcing plate 15, and then the lug 21 is continuously bent to form a state similar to "S", the lug 21 has a good form inside the battery, avoiding the risk of short circuit caused by the lug 21 being pressed and inserted into the pole group 20, which is beneficial to ensure the safety performance of the battery and is not easy to cause insulation failure.

[0053] Continuing to refer to Figure 3 ​In the first direction, the thickness of the first side plate 11 is T1, and T1 is in the range of 0.9mm≤T1≤1.1mm. For example, T1 can be 0.9mm, 1.0mm or 1.1mm, etc. In the first direction, the thickness of the second side plate 12 is T2, and T2 is in the range of 0.9mm≤T2≤1.1mm. For example, T2 can be 0.9mm, 1.0mm or 1.1mm, etc. In some embodiments, the thickness of the first side plate 11 is equal to the thickness of the second side plate 12. Of course, in other embodiments, the thickness of the first side plate 11 can also be different from the thickness of the second side plate 12. By limiting the value of T1 and T2 in the above range, the thickness of the first side plate 11 and the second side plate 12 is large, the mechanical strength of the first side plate 11 and the second side plate 12 is high, which can provide sufficient support for the first reinforcing plate 15 and the second reinforcing plate 16, and the structural strength of the end plate 10 is improved.

[0054] Further, in the first direction, the width of the body is W, that is, the distance between the side walls of the first side plate 11 and the second side plate 12 is W. W is in the range of 12mm≤W≤45mm. For example, W can be 12mm, 15mm, 20mm, 30mm, 40mm or 45mm, etc. It should be noted that the value of W should not be too large, otherwise it is not conducive to the miniaturization and ultra-thin of the battery; of course, the value of W should not be too small, otherwise the space between the first side plate 11 and the second side plate 12 is small, which is not conducive to arranging the first reinforcing plate 15 and the second reinforcing plate 16, and the width of the through hole 1501 is small, which is easy to interfere with the end plate 10 when the tab 21 passes through the end plate 10, and the assembly yield and assembly efficiency of the tab 21 and the end plate 10 are reduced.

[0055] In the first direction, the width of the small end of the through hole 1501 is W1, that is, the distance between the end portions of the first reinforcing plate 15 and the second reinforcing plate 16 is W1, and W1 is in the range of 3mm≤W1≤5.5mm. For example, W1 can be 3mm, 4mm, 5mm or 5.5mm, etc. It should be noted that the value of W1 should not be too large, otherwise the end plate 10 has poor effect on gathering the root of the tab 21, and the tab 21 has poor shape when bending; of course, the value of W1 should not be too small, otherwise the tab 21 is easy to interfere with the end plate 10 when passing through the end plate 10.

[0056] Continuing to refer to Figure 3 and Figure 4The included angle between the first reinforcing plate 15 and the first side plate 11 is β, and the value of β is in the range of 60°≤β≤75°. For example, the value of β can be 60°, 65°, 70°, 72°, 74° or 75°. The included angle between the second reinforcing plate 16 and the second side plate 12 is γ, and the value of γ is in the range of 25°≤γ≤35°. For example, the value of γ can be 25°, 28°, 30°, 32°, 34° or 35°, etc. By limiting the values of β and γ within the above range, the inclination angles of the first reinforcing plate 15 and the second reinforcing plate 16 are appropriate, and the shape when the tab 21 is bent is more suitable, which is beneficial to ensure that the shape of the tab 21 after bending is good. Otherwise, when the values of β and γ are too large, the end plate 10 is easy to crush the root of the tab 21, and the risk of the tab 21 being inserted into the pole group 20 is easy to occur. Of course, the values of β and γ should not be too small, otherwise the gathering and shaping effect of the tab 21 is not good, and the tab 21 is easy to contact and short circuit with the shell 40.

[0057] After the tab 21 passes through the end plate 10 and is bent, the shape of the tab 21 inside the battery is in the shape of “S”, and the tab 21 includes a first extension section 211, a first bending section 212, a second extension section 213 and a second bending section 214 connected in sequence, wherein the first extension section 211 is connected with the pole group 20, that is, the first extension section 211 is at the root of the tab 21, and the second bending section 214 is connected with the pole column 33 integrated on the cover plate assembly 30. In the cross section perpendicular to the second direction, the second extension section 213 is parallel to and spaced apart from the first side plate 11, the first reinforcing plate 15 is used to support and limit the first bending section 212, and the second reinforcing plate 16 is used to support and limit the first extension section 211. The first reinforcing plate 15 and the second reinforcing plate 16 make the tab 21 gather and shape, avoiding the risk of the tab 21 being inserted into the pole group 20 or contacting and short circuiting with the shell 40.

[0058] Further, the first reinforcing plate 15 has a thickness t1, and the value of t1 is in a range of 0.65mm≤t1≤1.0mm. For example, the value of t1 can be 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.9mm or 1.0mm, etc. The second reinforcing plate 16 has a thickness t2, and the value of t2 is in a range of 0.65mm≤t2≤0.85mm. For example, the value of t2 can be 0.65mm, 0.7mm, 0.75mm, 0.8mm or 0.85mm, etc. By limiting the value of t1 and t2 in the above range, the mechanical strength of the first reinforcing plate 15 and the second reinforcing plate 16 is ensured to be high, which can effectively strengthen the body of the end plate 10, avoid deformation of the end plate 10, and provide good support for the tab 21, so that the tab 21 has a good shape in the shell 40 and is not prone to problems such as reverse insertion or short circuit. It should be noted that the value of t1 and t2 should not be too small, otherwise the mechanical strength of the first reinforcing plate 15 and the second reinforcing plate 16 will be weak; and the value of t1 and t2 should not be too large, otherwise the first reinforcing plate 15 and the second reinforcing plate 16 will be too thick and heavy, and the body cannot provide good fixation and support for the first reinforcing plate 15 and the second reinforcing plate 16.

[0059] Continuing to refer to Figure 3 , the length of the first reinforcing plate 15 is A1, and the value of A1 is in a range of 5mm≤A1≤18mm. For example, the value of A1 can be 5mm, 8mm, 10mm, 15mm or 18mm, etc. The length of the second reinforcing plate 16 is A2, and the value of A2 is in a range of 3mm≤A2≤8mm. For example, the value of A2 can be 3mm, 4mm, 5mm, 6mm, 7mm or 8mm, etc. By comprehensively setting the angle β at which the first reinforcing plate 15 is inclined and the angle γ at which the second reinforcing plate 16 is inclined, the width W1 of the small opening end of the through hole 1501 in the first direction is controlled to be in a predetermined range, so that the end plate 10 can effectively gather the root of the tab 21, and the tab 21 is easy to pass through the end plate 10, thereby improving the assembly yield.

[0060] Continuing to refer to Figures 1-3 , the end plate 10 further comprises a first support portion 17 and a second support portion 18, and the first support portion 17 and the second support portion 18 are respectively connected to the two ends of the body along the second direction. Specifically, the first support portion 17 is connected to the side of the body provided with the third side plate 13, and the second support portion 18 is connected to the side of the body provided with the fourth side plate 14. In the third direction, the end face of the first side plate 11, the second side plate 12, the third side plate 13 and the fourth side plate 14 away from the pole group 20 is flush with the end face of the first support portion 17 and the second support portion 18 away from the pole group 20. The above-mentioned third direction is Figure 1The first support portion 17 and the second support portion 18 have equal heights along the third direction, the first side plate 11 and the second side plate 12 have smaller heights along the third direction than the first support portion 17, and the third side plate 13 and the fourth side plate 14 have equal heights along the third direction to the first support portion 17.

[0061] Optionally, along the third direction, the distance between the end of the first reinforcing plate 15 connected with the first side plate 11 and the end surface of the first support portion 17 on the side facing the pole group 20 is h1, and the value of h1 is in the range of 0.2mm≤h1≤0.8mm. For example, the value of h1 can be 0.2mm, 0.4mm, 0.6mm or 0.8mm, etc. Along the third direction, the distance between the end of the second reinforcing plate 16 connected with the second side plate 12 and the end surface of the first support portion 17 on the side facing the pole group 20 is h2, and the value of h2 is in the range of 0.2mm≤h2≤0.8mm. For example, the value of h2 can be 0.2mm, 0.4mm, 0.6mm or 0.8mm, etc. In some embodiments, the value of h1 is equal to the value of h2. By limiting the values of h1 and h2 within the above range, the side of the first reinforcing plate 15, the first side plate 11, and the side of the second reinforcing plate 16, the second side plate 12 close to the pole group 20 are all spaced apart from the end surface of the pole group 20 on the side facing the cover plate assembly 30, thereby preventing the first reinforcing plate 15 and the second reinforcing plate 16 from pressing the pole group 20 and / or the root of the pole tab 21.

[0062] Further, the height of the first support portion 17 along the third direction is H, and the value of H is in the range of 15mm≤H≤20mm. For example, the value of H can be 15mm, 16mm, 17mm, 18mm, 19mm or 20mm. By ensuring that the value of H is within the above range, the end plate 10 can press the two ends of the pole group 20 along the second direction, and the pole group 20 is fixed well in the shell 40, and is not easy to shake and pull the pole tab 21, and the pole tab 21 is in good form inside the battery.

[0063] Optionally, referring to Figure 1 , the first support portion 17 and / or the second support portion 18 are provided in a hollow structure, which can reduce the material usage of the end plate 10, reduce the cost, and also facilitate weight reduction. In this embodiment, the first support portion 17 and the second support portion 18 are both provided in a hollow structure as an example for illustration.

[0064] The end face of the second support part 18 towards the pole group 20 is provided with a plurality of air holes 1801 arranged at intervals. The cover plate body 31 is provided with a mounting hole for mounting the explosion-proof valve 50. The projection of the air hole 1801 on the cover plate body 31 in the third direction at least partially coincides with the projection of the explosion-proof valve 50 on the cover plate body 31, so that the air hole 1801 can communicate the accommodating cavity of the battery with the explosion-proof valve 50. When the internal pressure of the battery is too high, the explosion-proof valve 50 can realize the pressure relief function, and the safety of the battery is higher. Of course, in other embodiments, the air hole 1801 can also be arranged at the first support part 17, as long as the air hole 1801 is opposite to the explosion-proof valve 50.

[0065] As shown in the drawings, Figure 5 The present embodiment also provides a battery, which comprises the cover plate assembly 30, the shell 40, the pole group 20, and the end plate 10 described above. The cover plate assembly 30 is connected with the shell 40 and surrounds an accommodating cavity. The pole group 20 and the end plate 10 are arranged in the accommodating cavity and the end plate 10 is clamped between the cover plate assembly 30 and the pole group 20. The pole group 20 leads out the tab 21 at the end close to the cover plate assembly 30, and the tab 21 is arranged through the perforation 1501 of the end plate 10. By adopting the end plate 10 in the present embodiment, the tab 21 can be effectively supported and limited, the end plate 10 is not easy to deform, the structural strength is higher, and meanwhile the root of the tab 21 is gathered and shaped, the form of the tab 21 in the shell 40 is good, and the safety and reliability of the battery are improved.

[0066] Specifically, the cover plate assembly 30 comprises a cover plate body 31, and the cover plate body 31 is integrated with a first plastic part 32, a second plastic part 34, and a pole 33. The first plastic part 32 is arranged on the side of the cover plate body 31 close to the pole group 20, and the second plastic part 34 is arranged on the side of the cover plate body 31 away from the pole group 20. The pole 33 is arranged through the first plastic part 32, the cover plate body 31, and the second plastic part 34, and the second bending section 214 is connected with the end of the pole 33 close to the pole group 20. The cover plate assembly 30 further comprises a connecting block 35, and the pole 33 comprises a plate body part and a column part. The column part is riveted with the connecting block 35 after penetrating through the first plastic part 32, the cover plate body 31, the second plastic part 34, and the connecting block 35, so as to fix the pole 33 on the cover plate body 31. In addition, the first plastic part 32 and the second plastic part 34 insulate the pole 33 from the cover plate body 31.

[0067] Optionally, the battery in this embodiment can be a blade battery, in which two openings are formed at both ends of the housing 40 along the third direction, and two cover plate assemblies 30 are provided, and the two cover plate assemblies 30 are respectively connected to one opening of the housing 40. One of the cover plate assemblies 30 is a positive electrode cover plate, and the other cover plate assembly 30 is a negative electrode cover plate. The electrode group 20 includes two pole ears 21, which are led out from both ends of the electrode group 20 along the third direction and are respectively conductively connected to the pole posts 33 integrated on the positive electrode cover plate and the negative electrode cover plate. In this case, two end plates 10 are also provided, respectively arranged at both ends of the electrode group 20 along the third direction, one end plate 10 abuts against the positive electrode cover plate, and the other end plate 10 abuts against the negative electrode cover plate.

[0068] Of course, in other embodiments, the battery may also be a prismatic battery, with the housing 40 having an opening formed at one end along the third direction, and the cover assembly 30 connected to the opening of the housing 40. The cover assembly 30 integrates two poles 33, and the two tabs 21 of the electrode assembly 20 extend from the same end along the third direction and are electrically connected to the two poles 33, respectively. The two tabs 21 are respectively a positive tab and a negative tab.

[0069] The following examples are used to verify the values ​​of the relevant parameters of the battery middle end plate 10, explore the influence of the size selection of the above parameters on the battery assembly process and the position of the electrode group 20 and the tab 21 in the finished battery, and verify the rationality of the above parameter design. For details, see Table 1.

[0070] Table 1

[0071]

[0072] It can be seen from the above results that the values ​​of the parameters L1, L2, W1, β, γ, h1, h2, and L2-L1 in Examples 1 to 10 all meet their corresponding dimensional limitations. According to CT testing, during the battery assembly process (i.e., when the cover plate assembly 30, the end plate 10, and the electrode group 20 are inserted into the shell), the structure of the end plate 10 is stable and there is no deformation. In the assembled finished battery, the shape of the tab 21 in the shell 40 is good, and there is no problem of the tab 21 being inserted upside down into the electrode group 20 or the tab 21 contacting and short-circuiting with the shell 40. The assembly yield is high and the battery product is good.

[0073] The value of T1 in Comparative Example 1 exceeds the lower limit of its value range of 0.9mm≤T1≤1.1mm, and other parameters are normally within their value range. The thickness of the first side plate 11 is relatively thin, and the mechanical strength of the first side plate 11 itself is insufficient. The end plate 10 is deformed after being squeezed by the feeding clamp. After CT detection, after the battery is assembled, the end plate 10 has poor limiting and fixing effects on the tab 21, the assembly yield is low, and the battery product is defective.

[0074] The value of T2 in Comparative Example 2 exceeds the lower limit of the value range 0.9mm≤T2≤1.1mm, and other parameters are normally taken within the value range. The thickness of the second side plate 12 is relatively thin, and the mechanical strength of the second side plate 12 itself is insufficient. After the end plate 10 is extruded by the loading clamp, deformation occurs. After CT detection, the positioning and fixing effect of the end plate 10 on the tab 21 is poor after the battery is assembled, the assembly yield is low, and the battery product is defective.

[0075] In Comparative Example 3, the value of t1 exceeds the lower limit of the value range 0.65mm≤t1≤1.0mm, and other parameters are normally taken within the value range. The thickness of the first reinforcing plate 15 is relatively thin, and cannot play a better reinforcing role on the second side plate 12. The mechanical strength of the first reinforcing plate 15 itself is insufficient, and cannot well support and position the tab 21. The structural strength of the end plate 10 is insufficient, and deformation occurs after the end plate 10 is extruded by the loading clamp. After CT detection, the positioning and fixing effect of the end plate 10 on the tab 21 is poor after the battery is assembled, the assembly yield is low, and the battery product is defective.

[0076] In Comparative Example 4, the value of t1 exceeds the upper limit of the value range 0.65mm≤t1≤1.0mm, and other parameters are normally taken within the value range. The thickness of the first reinforcing plate 15 is too thick, and occupies a lot of space, which is not conducive to the space arrangement of the tab 21 after bending. After CT detection, the bending space of the tab 21 is insufficient after the battery is assembled, the form of the tab 21 in the shell 40 is poor, the tab 21 is prone to contact short circuit with the shell 40, and the battery product is defective.

[0077] In summary, when the values of W, T1, t1, A1, β, T2, t2, A2 and γ all meet the corresponding value range, the structural strength of the end plate 10 can be significantly improved, the problem of deformation of the end plate 10 after production loading or assembly in the battery process due to extrusion by the tab 21 can be avoided, the end plate 10 in the finished battery does not deform, the end plate 10 plays a good fixing effect on the tab 21 and the pole group 20, the form of the tab 21 in the shell 40 is good and the bending shape is regular, the assembly yield of the battery is high, and the safety and reliability are good.

[0078] Obviously, the above embodiments of the present application are only examples for clear illustration of the present application, and are not a limitation on the embodiments of the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, it is not necessary and impossible to exhaust all the embodiments. Any modification, equivalent replacement and improvement made within the spirit and principles of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. An end plate, characterized in that: The end plate comprises: The main body is a frame structure; The first reinforcing plate and the second reinforcing plate are respectively connected to the two side walls of the main body opposite to each other along the first direction. The ends of the first reinforcing plate and the second reinforcing plate close to each other form a through-hole with a gradually narrowing opening. The large end of the through-hole faces the pole group, and the pole ear of the pole group is passed through the through-hole.

2. The end plate according to claim 1, characterized in that The main body includes a first side plate and a second side plate arranged opposite to each other along a first direction, and a third side plate and a fourth side plate arranged opposite to each other along a second direction, the first side plate, the second side plate, the third side plate and the fourth side plate are interconnected to form the frame structure; the first reinforcing plate is connected to the side of the first side plate close to the pole group, the second reinforcing plate is connected to the side of the second side plate close to the pole group, the first reinforcing plate and the second reinforcing plate extend in a direction close to each other, and the first reinforcing plate and the second reinforcing plate are arranged at an angle.

3. The end plate according to claim 2, characterized in that Along the first direction, the thickness of the first side plate is T1, and the thickness of the second side plate is T2; The value range of T1 is: 0.9mm≤T1≤1.1mm; The value range of T2 is: 0.9mm≤T2≤1.1mm.

4. The end plate according to claim 3, characterized in that Along the first direction, the width of the body is W, and the value range of W is: 12mm≤W≤45mm.

5. The end plate according to claim 2, characterized in that The included angle between the first reinforcing plate and the first side plate is β, and the value range of β is: 60°≤β≤75°; The included angle between the second reinforcing plate and the second side plate is γ; The value range of γ is: 25°≤γ≤35°.

6. The end plate according to claim 1, characterized in that The thickness of the first reinforcing plate is t1, and the thickness of the second reinforcing plate is t2; The value range of t1 is: 0.65mm≤t1≤1.0mm; The value range of t2 is: 0.65mm≤t2≤0.85mm.

7. The end plate according to claim 1, wherein: The length of the first reinforcing plate is A1, and the length of the second reinforcing plate is A2; The value range of A1 is: 5mm≤A1≤18mm; The value range of A2 is: 3mm≤A2≤8mm.

8. The end plate according to claim 2, characterized in that The end plate further includes a first supporting portion and a second supporting portion, wherein the first supporting portion and the second supporting portion are respectively connected to two ends of the body along the second direction; Among them, along the third direction, the end surfaces of the first side plate, the second side plate, the third side plate and the fourth side plate facing away from the pole group are flush with the end surfaces of the first support part and the second support part facing away from the pole group; the heights of the first support part and the second support part along the third direction are equal, the heights of the first side plate and the second side plate along the third direction are less than the height of the first support part along the third direction, and the heights of the third side plate and the fourth side plate along the third direction are equal to the height of the first support part along the third direction.

9. The end plate according to claim 8, characterized in that Along the third direction, the distance between the end portion of the first reinforcing plate connected to the first side plate and the end surface of the first supporting portion facing the electrode group is h1; the value range of h1 is: 0.2mm≤h1≤0.8mm; Along the third direction, the distance between the end portion of the second reinforcing plate connected to the second side plate and the end surface of the first supporting portion facing the electrode group is h2; The value range of h2 is: 0.2mm≤h2≤0.8mm.

10. A battery, characterized in that: The end plate comprises the end plate according to any one of claims 1 to 9.

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