Cover plate assembly and battery

Abstract

The invention belongs to the technical field of batteries, and discloses a cover plate assembly and a battery, the cover plate assembly is connected with a tab, the cover plate assembly comprises a cover plate body, a pole, first plastic and a connecting piece, and the pole is arranged on the cover plate body; the first plastic is arranged on one side, facing the tab, of the cover plate body; the connecting piece is arranged on one side, in the third direction, of the first plastic, the connecting piece comprises a first welding part and a second welding part, the first welding part and the second welding part are arranged in the first direction, the first welding part is connected with the pole, and the second welding part is connected with the tab, so that the pole is electrically connected with the tab; in the second direction, the first plastic edge and the second welding part are arranged at intervals. Thus, a distance is reserved between the first plastic edge and the second welding part, assembly interference can be avoided, the influence of welding heat on the first plastic edge is reduced, hot melting deformation and cracking of the first plastic are avoided, the short circuit risk is reduced, and the safety performance and reliability of the battery cell are improved.

Description

Technical Field

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

[0002] Lithium-ion batteries are one of the high-performance batteries widely used at present due to their advantages such as high working voltage, high specific energy, large capacity, small self-discharge, good cycle performance, long service life, light weight, and small volume.

[0003] A long-core lithium-ion battery includes a cover plate, a housing, an electrode assembly, an electrolyte, etc. A connecting piece is connected to the cover plate. The electrode tab of the electrode assembly is welded to the connecting piece, and then welded to the electrode post base plate provided on the cover plate through the connecting piece, so as to be able to lead the current out of the housing and realize the electrical connection with the external circuit. After the cover plate and the housing are welded, a sealed space with a certain mechanical strength for protecting the electrode assembly can be formed.

[0004] In the prior art, due to the unreasonable size design of the connecting piece and the plastic, after the connecting piece is assembled to the plastic, the distance between the connecting piece and the edge of the plastic is relatively close. When the electrode tab is welded to the connecting piece, the high temperature generated may cause the plastic to melt and deform or even crack, thereby affecting the insulation performance of the plastic, posing a short-circuit risk, and affecting the safety performance of the battery cell. Summary of the Invention

[0005] The purpose of the present invention is to provide a cover plate assembly and a battery to solve the problem that the plastic is easily affected by the welding heat and causes melting deformation or even cracking.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] In a first aspect, a cover plate assembly is connected to an electrode tab. The cover plate assembly includes: a cover plate body and an electrode post, and the electrode post is provided on the cover plate body; a first plastic, and the first plastic is provided on a side of the cover plate body facing the electrode tab; a connecting piece, and the connecting piece is provided on one side of the first plastic in a third direction. The connecting piece includes a first welding portion and a second welding portion, and the first welding portion and the second welding portion are arranged side by side along a first direction. The first welding portion is connected to the electrode post, and the second welding portion is connected to the electrode tab to electrically connect the electrode post and the electrode tab; along a second direction, the edge of the first plastic is spaced from the second welding portion; the first direction is parallel to the length direction of the cover plate body, the second direction is parallel to the width direction of the cover plate body, and the third direction is parallel to the thickness direction of the cover plate body.

[0008] Preferably, along the third direction, the height difference between the second welding portion and the first plastic is A, and A≥1mm is satisfied.

[0009] Preferably, the first plastic is provided with a protruding portion which extends along the second direction and is disposed on the side of the second welding portion away from the first welding portion.

[0010] Preferably, along the first direction, the distance between the connecting piece and the protruding portion is B, and B≥2.5 mm is satisfied; and / or, along the second direction, the distance between the connecting piece and the edge of the first plastic is C, and C≥1.5 mm is satisfied.

[0011] Preferably, the first plastic further includes a separating rib which is disposed corresponding to the position of the second welding portion.

[0012] Preferably, along the third direction, the projection of the separating rib is located inside the projection of the corresponding second welding portion.

[0013] Preferably, the minimum distance between the separating rib and the edge of the second welding portion is greater than or equal to 2 mm.

[0014] Preferably, the thickness of the separating rib is H, and 0.1 mm≤H≤0.5 mm is satisfied.

[0015] Preferably, the separating rib extends along the first direction.

[0016] In a second aspect, a battery includes a pole group, a housing, and the cover plate assembly as described above. The cover plate body is connected to the housing, and the pole group is located inside the housing.

[0017] Advantages of the present invention:

[0018] A cover plate assembly is connected to a pole ear. The cover plate assembly includes a cover plate body, a pole column, a first plastic, and a connecting piece. The pole column is disposed on the cover plate body; the first plastic is disposed on the side of the cover plate body facing the pole ear; the connecting piece is disposed on one side of the first plastic in the third direction. The connecting piece includes a first welding portion and a second welding portion. The first welding portion and the second welding portion are arranged along the first direction. The first welding portion is connected to the pole column, and the second welding portion is connected to the pole ear so that the pole column is electrically connected to the pole ear; along the second direction, the edge of the first plastic is spaced from the second welding portion; the first direction is parallel to the length direction of the cover plate body, the second direction is parallel to the width direction of the cover plate body, and the third direction is parallel to the thickness direction of the cover plate body.

[0019] In this way, the first plastic edge and the second welding part are arranged at intervals, which can avoid the assembly interference caused by the too close distance between the connecting piece and the first plastic edge. When the second welding part is welded to the tab and generates heat, the first plastic is not easily affected by the heat and melted and deformed or even cracked, maintaining the structural integrity of the first plastic, avoiding the influence on the insulation performance of the first plastic due to the deformation of the first plastic, reducing the short - circuit risk, and improving the safety performance and reliability of the battery cell. Brief Description of the Drawings

[0020] Figure 1 is the front view of the cover plate assembly in an embodiment of the present invention;

[0021] Figure 2 is the side view of the cover plate assembly in an embodiment of the present invention;

[0022] Figure 3 is the partial front view of the cover plate assembly in an embodiment of the present invention;

[0023] Figure 4 is the partial structural schematic diagram of the cover plate assembly in an embodiment of the present invention.

[0024] In the figure:

[0025] 1, cover plate body; 2, pole column; 3, first plastic; 31, protruding part; 32, reinforcing rib; 33, isolation rib; 4, connecting piece; 41, first welding part; 42, second welding part; X, first direction; Y, second direction; Z, third direction. Detailed Description of the Embodiment

[0026] The present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that for the convenience of description, only the parts related to the present invention are shown in the drawings, rather than all the structures.

[0027] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between 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 situations.

[0028] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicating that the horizontal height of the first feature is less than that of the second feature.

[0029] In the description of this embodiment, the orientation or positional relationships such as "up", "down", "right", etc. are based on the orientation or positional relationship shown in the drawings. It is only for the convenience of description and simplifying the operation, 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. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0030] Referring to Figure 1 , the present invention provides a cover plate assembly, which is connected to a tab (not shown in the figure). The cover plate assembly includes a cover plate body 1, a terminal post 2, a first plastic 3 and a connecting piece 4. The terminal post 2 is arranged on the cover plate body 1; the first plastic 3 is arranged on one side of the cover plate body 1 facing the tab; the connecting piece 4 is arranged on one side of the first plastic 3 in the third direction Z. The connecting piece 4 includes a first welding portion 41 and a second welding portion 42. The first welding portion 41 and the second welding portion 42 are arranged side by side along the first direction X. The first welding portion 41 is connected to the terminal post 2, and the second welding portion 42 is connected to the tab, so that the terminal post 2 is electrically connected to the tab; along the second direction Y, the edge of the first plastic 3 is spaced from the second welding portion 42; the first direction X is parallel to the length direction of the cover plate body 1, the second direction Y is parallel to the width direction of the cover plate body 1, and the third direction Z is parallel to the thickness direction of the cover plate body 1.

[0031] In this embodiment, the terminal post 2 is fixedly connected to the cover plate body 1. The first welding portion 41 and the second welding portion 42 are integrally formed. And one connecting piece 4 is provided with one first welding portion 41 and two second welding portions 42. The second welding portions 42 are arranged in one-to-one correspondence with the tabs. The two second welding portions 42 on the same connecting piece 4 are respectively arranged on both sides of the symmetry axis of the first welding portion 41 in the first direction X. The terminal post 2 and the first welding portion 41 are fixedly connected by welding, and the tab and the second welding portion 42 are fixedly connected by welding, so that the terminal post 2 and the tab are electrically connected and the relative positions of the terminal post 2 and the tab on the cover plate body 1 are restricted.

[0032] In this way, the edge of the first plastic member 3 is spaced apart from the second welding portion 42. This not only avoids assembly interference caused by the close distance between the connecting piece 4 and the edge of the first plastic member 3, improving the assembly efficiency, but also reduces the influence of welding heat on the edge of the first plastic member 3 when the second welding portion 42 is welded to the tab. It can prevent the first plastic member 3 from melting and deforming or even cracking under the action of high temperature, maintaining the structural integrity of the first plastic member 3, improving the insulation performance of the first plastic member 3, reducing the short-circuit risk caused by the damage of the first plastic member 3, and enhancing the safety performance and reliability of the battery cell.

[0033] Referring to Figure 1 and Figure 2 , in some embodiments, along the third direction Z, the height difference between the second welding portion 42 and the first plastic member 3 is A, and A≥1 mm is satisfied. That is, the distance between the surface of the second welding portion 42 facing away from the first plastic member 3 and the surface of the first plastic member 3 facing the second welding portion 42. Exemplarily, the height difference A between the connecting piece 4 and the first plastic member 3 can be 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm. In this embodiment, the second welding portion 42 is spaced apart from the first plastic member 3.

[0034] In this way, when the tab is welded to the second welding portion 42, it can block the conduction of welding heat to the first plastic member 3, preventing the first plastic member 3 from melting, deforming or even cracking due to heat reaching the thermal deformation temperature, improving the insulation performance of the first plastic member 3, and ensuring the structural integrity of the first plastic member 3 while ensuring the stable connection between the tab and the second welding portion 42.

[0035] It can be understood that the height difference A between the second welding portion 42 and the first plastic member 3 cannot be too small. Otherwise, the welding heat is likely to directly act on the first plastic member 3 and cause the first plastic member 3 to melt and deform. The height difference A between the second welding portion 42 and the first plastic member 3 can be adjusted according to actual needs and will not be listed in detail here.

[0036] Referring to Figure 1 and Figure 3 , in some embodiments, the first plastic member 3 is provided with a protruding portion 31. The protruding portion 31 extends along the second direction Y and is provided on the side of the second welding portion 42 facing away from the first welding portion 41.

[0037] In this embodiment, two pole columns 2 and two connecting pieces 4 corresponding to and connected to the pole columns 2 are provided on the cover body 1. The second welding portions 42 of the two connecting pieces 4 are arranged oppositely. The protruding portion 31 is integrally formed with the first plastic member 3 and is provided between the two connecting pieces 4 for abutting against the pole group (not shown in the figure) and pressing the pole group. Along the first direction X, the connecting piece 4 connected to one of the pole columns 2, the protruding portion 31, and the connecting piece 4 connected to the other pole column 2 are sequentially spaced apart.

[0038] In this way, the protruding portion 31 can enhance the structural strength of the first plastic 3 and provide stable support for the electrode group. The protruding portion 31 is arranged between the two connecting pieces 4, which can effectively utilize the space on the side of the first plastic 3 facing the tab. The two connecting pieces 4 are both arranged at intervals with the protruding portion 31, which can reduce the influence of the welding heat on the protruding portion 31 when the second welding portion 42 is welded to the tab, and avoid the protruding portion 31 being melted and deformed by heat and causing crushing or scratching to other structures.

[0039] It can be understood that the setting position of the protruding portion 31 can be adjusted according to the setting positions of the pole column 2 and the connecting piece 4, which will not be elaborated here.

[0040] Refer to Figure 1 , in some embodiments, along the first direction X, the distance between the connecting piece 4 and the protruding portion 31 is B, and B≥2.5 mm is satisfied. Along the second direction Y, the distance between the connecting piece 4 and the edge of the first plastic 3 is C, and C≥1.5 mm is satisfied.

[0041] In this embodiment, the distance B between the connecting piece 4 and the protruding portion 31 is also the distance between the side of the second welding portion 42 facing away from the first welding portion 41 and the protruding portion 31. The edge of the first plastic 3 is provided with a reinforcing rib 32. The distance C between the connecting piece 4 and the edge of the first plastic 3 is also the distance between the side of the second welding portion 42 facing the edge of the first plastic 3 and the reinforcing rib 32 on the side edge of the first plastic 3. Exemplarily, the distance B between the connecting piece 4 and the protruding portion 31 can be 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, etc.; the distance C between the connecting piece 4 and the edge of the first plastic 3 can be 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, etc.

[0042] In this way, there is a certain distance between the connecting piece 4 and the protruding portion 31 and the edge of the first plastic 3, which can make the heat generated when the connecting piece 4 is welded to the pole column 2 and the tab not easily affect the protruding portion 31 and the edge of the first plastic 3, avoid the first plastic 3 and the protruding portion 31 from being melted and deformed, resulting in problems such as poor insulation performance and assembly interference with other components, reduce the short-circuit risk, and improve the safety performance and reliability of the battery cell.

[0043] It can be understood that the distance B between the connecting piece 4 and the protruding portion 31 cannot be too small. If it is too small, the edge of the protruding portion 31 facing the second welding portion 42 will be affected by the welding heat, increasing the risk of deformation and cracking of the protruding portion 31. The distance C between the connecting piece 4 and the edge of the first plastic 3 cannot be too small. If it is too small, the outer edge of the first plastic 3 will be deformed after being melted, affecting the structural integrity of the first plastic 3, making it difficult for the first plastic 3 to be tightly connected to the cover body 1 and the housing, affecting the insulation performance, and increasing the short-circuit risk.

[0044] Refer to Figure 2 and Figure 4, in some embodiments, the first plastic 3 further includes a spacer rib 33, and the spacer rib 33 is disposed corresponding to the position of the second welding portion 42.

[0045] In this embodiment, the spacer rib 33 is disposed in the area where the second welding portion 42 is welded to the tab, and the edge of the spacer rib 33 is spaced from the edge of the second welding portion 42.

[0046] In this way, the spacer rib 33 can increase the overall structure thickness and absorb the concentrated heat generated during the tab welding process, avoiding local heat concentration and causing local deformation of the first plastic 3. By providing the spacer rib 33, the first plastic 3 can be isolated from the second welding portion 42, and the heat dissipation effect of the connecting piece 4 can be improved, making the battery cell have better safety performance and reliability; leaving a distance between the spacer rib 33 and the edge of the second welding portion 42 can not only facilitate the assembly of the connecting piece 4 to the first plastic 3 and avoid assembly interference between the spacer rib 33 and the connecting piece 4, but also improve the structural strength of the first plastic 3 and enhance the anti-bending and anti-deformation capabilities of the connecting piece 4.

[0047] It can be understood that the setting position of the spacer rib 33 can be adjusted according to the area where the tab is welded to the second welding portion 42, as long as it can achieve the improvement of the heat dissipation effect of the connecting piece 4, and no more examples are listed here.

[0048] Refer to Figure 2 , in some embodiments, along the third direction Z, the projection of the spacer rib 33 is located inside the projection of its corresponding second welding portion 42.

[0049] In this embodiment, the spacer rib 33 is disposed on the side of the second welding portion 42 facing the edge of the first plastic 3.

[0050] In this way, the spacer rib 33 does not protrude from the second welding portion 42, which can not only facilitate coincidence with the welding area of the tab, but also avoid assembly interference with the edge of the first plastic 3, improving the overall stability of the cover assembly. The spacer rib 33 can cover the area where the second welding portion 42 is welded to the tab and maintain an appropriate distance from the edge of the first plastic 3 and the protruding portion 31, achieving the blocking of welding heat, avoiding deformation and cracking of the first plastic 3 due to high temperature, reducing the short-circuit risk, and improving the safety performance and reliability of the battery cell.

[0051] Refer to Figure 1 , in some embodiments, the minimum distance between the spacer rib 33 and the edge of the second welding portion 42 is greater than or equal to 2 mm.

[0052] In this embodiment, the distance between the isolation rib 33 and the side wall of the second welding part 42 facing the edge of the first plastic 3 is D, the distance between the isolation rib 33 and the second welding part 42 away from the edge of the first plastic 3 is F, and the distances between the isolation rib 33 and the two side walls of the second welding part 42 along the first direction X are both E, and D≥2mm, E≥2mm, F≥2mm are satisfied. Exemplarily, the distance D between the isolation rib 33 and the side wall of the second welding part 42 facing the edge of the first plastic 3 can be 2mm, 2.5mm, 3mm, 3.5mm, 4mm, etc., the distances E between the isolation rib 33 and the two side walls of the second welding part 42 along the first direction X can be 2mm, 2.5mm, 3mm, 3.5mm, 4mm, etc., and the distance F between the isolation rib 33 and the second welding part 42 away from the edge of the first plastic 3 can be 2mm, 2.5mm, 3mm, 3.5mm, 4mm, etc.; the distance D between the isolation rib 33 and the side wall of the second welding part 42 facing the edge of the first plastic 3, the distances E between the isolation rib 33 and the two side walls of the second welding part 42 along the first direction X, and the distance F between the isolation rib 33 and the second welding part 42 away from the edge of the first plastic 3 are equal.

[0053] In this way, since there is a certain distance between the isolation rib 33 and the edge of the first plastic 3, the influence of the welding heat on the first plastic 3 can be reduced. When the first plastic 3 has a slight heat melting problem, the deformed part is not easily protruded from the cover body 1 and causes poor appearance. There is a certain distance between the isolation rib 33 and the side wall of the second welding part 42, which can improve the welding stability between the tab and the second welding part 42, and avoid welding defects such as tab tearing and false soldering due to the distance between the welding part and the edge of the second welding part 42 being too close.

[0054] It can be understood that the distance D between the isolation rib 33 and the side wall of the second welding part 42 facing the edge of the first plastic 3, the distances E between the isolation rib 33 and the two side walls of the second welding part 42 along the first direction X, and the distance F between the isolation rib 33 and the second welding part 42 away from the edge of the first plastic 3 cannot be too small. Being too small will cause the first plastic 3 to be affected by the welding heat and melt and deform, and make the structural strength of the connection part between the connecting piece 4 and the tab poor, and the force on the tab and the pole 2 is uneven after being assembled to the connecting piece 4; the distance D between the isolation rib 33 and the side wall of the second welding part 42 facing the edge of the first plastic 3, the distances E between the isolation rib 33 and the two side walls of the second welding part 42 along the first direction X, and the distance F between the isolation rib 33 and the second welding part 42 away from the edge of the first plastic 3 may also be unequal.

[0055] Refer to Figure 4 In some embodiments, the thickness of the isolation rib 33 is H, and 0.1mm≤H≤0.5mm is satisfied.

[0056] In this embodiment, the thickness H of the isolation rib 33 can be any value between 0.1 mm and 0.5 mm or the range between any two values, such as 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, etc.

[0057] In this way, the isolation rib 33 can have sufficient thickness to absorb the welding heat and block the transfer of the welding heat to the first plastic 3, preventing the first plastic 3 from deforming and cracking under the action of the welding heat, reducing the risk of short circuit. Moreover, the isolation rib 33 can enhance the structural strength of the welding joint between the tab and the second welding part 42, improve the connection stability between the tab and the second welding part 42, and enable the tab and the pole column 2 to achieve stable electrical connection, improving the safety performance and reliability of the battery cell.

[0058] It can be understood that the thickness H of the isolation rib 33 cannot be too large, as this will increase the overall thickness of the cover assembly and is not conducive to achieving structural lightweighting. Nor can the thickness H of the isolation rib 33 be too small, as this will make it easy for the welding heat to pass through the isolation rib 33 and increase the risk of thermal melting deformation of the first plastic 3. The thickness H of the isolation rib 33 can be adjusted according to actual needs and will not be listed in detail here.

[0059] Refer to Figure 4 In some embodiments, the isolation rib 33 extends along the first direction X. In this embodiment, the length direction of the isolation rib 33 is parallel to the length direction of the second welding part 42.

[0060] In this way, the space of the second welding part 42 along the first direction X can be effectively utilized, and the area of the isolation rib 33 can be increased as much as possible, improving the heat absorption efficiency, making the heat distribution in the welding area between the tab and the second welding part 42 more uniform, avoiding local heat concentration, avoiding problems such as thermal melting deformation and cracking of the first plastic 3 under the action of the welding heat, enabling the first plastic 3 to maintain good insulation performance, reducing the short circuit risk, and improving the safety performance of the battery cell.

[0061] It can be understood that the shape and size of the isolation rib 33 can be adjusted according to the shape and size of the second welding part 42, as long as it can increase the structural strength of the second welding part 42 and absorb the welding heat, and will not be elaborated here.

[0062] To verify the rationality of the height difference A range between the second welding part 42 and the first plastic 3, as shown in Table 1, this embodiment provides four groups of examples and four groups of comparative examples for illustration to verify the appearance of the first plastic 3 when the connecting piece 4 is welded to the tab.

[0063] Serial Number A / mm B / mm C / mm D / E / F / mm H / mm Test Results Example 1 1 3 2 2.5 0.2 The proportion of the first plastic hot-melt deformation during tab welding is approximately 0.013%, with slight deformation and no impact on appearance Example 2 1.2 3 2 2.5 0.2 The proportion of the first plastic hot-melt deformation during tab welding is approximately 0.0103%, with slight deformation and no impact on appearance Example 3 1.4 3 2 2.5 0.2 The proportion of the first plastic hot-melt deformation during tab welding is approximately 0.011%, with slight deformation and no impact on appearance Example 4 1.6 3 2 2.5 0.2 The proportion of the first plastic hot-melt deformation during tab welding is approximately 0.013%, with slight deformation and no impact on appearance Comparative Example 1 0.2 3 2 2.5 0.2 The value of A is small. The proportion of the first plastic hot-melt deformation during tab welding is approximately 0.82%, affecting the appearance Comparative Example 2 0.4 3 2 2.5 0.2 The value of A is small. The proportion of the first plastic hot-melt deformation during tab welding is approximately 0.73%, affecting the appearance Comparative Example 3 0.6 3 2 2.5 0.2 The value of A is small. The proportion of the first plastic hot-melt deformation during tab welding is approximately 0.45%, affecting the appearance Comparative Example 4 0.8 3 2 2.5 0.2 The value of A is small. The proportion of the first plastic hot-melt deformation during tab welding is approximately 0.43%, affecting the appearance

[0064] As can be seen from Examples 1 to 4 in Table 1, after meeting the range limitations, there is sufficient distance between the second welding part 42 and the first plastic 3, so that the first plastic 3 is not easily affected by the welding heat and the appearance is not affected.

[0065] As can be seen from Comparative Examples 1 to 4 in Table 1, when the height difference A between the second welding part 42 and the first plastic 3 is too small, the first plastic 3 is easily affected by the welding heat and undergoes hot melt deformation, which affects the appearance.

[0066] To verify the rationality of the spacing B range between the connecting piece 4 and the protruding part 31, as shown in Table 2, five examples and three comparative examples are provided in this embodiment for illustration to verify the appearance of the first plastic 3 when the connecting piece 4 is welded to the tab.

[0067] Serial Number A / mm B / mm C / mm D / E / F / mm H / mm Test Results Example 1 1 2.5 2 2.5 0.2 The proportion of the first plastic hot-melt deformation at adjacent positions during tab welding is approximately 0.018%, with slight deformation and no impact on appearance Example 2 1 2.8 2 2.5 0.2 The proportion of the first plastic hot-melt deformation at adjacent positions during tab welding is approximately 0.012%, with slight deformation and no impact on appearance Example 3 1 3.0 2 2.5 0.2 The proportion of the first plastic hot-melt deformation at adjacent positions during tab welding is approximately 0.010%, with slight deformation and no impact on appearance Example 4 1 3.2 2 2.5 0.2 The proportion of the first plastic hot-melt deformation at adjacent positions during tab welding is approximately 0.011%, with slight deformation and no impact on appearance Example 5 1 3.5 2 2.5 0.2 The proportion of the first plastic hot-melt deformation at adjacent positions during tab welding is approximately 0.013%, with slight deformation and no impact on appearance Comparative Example 1 1 1.8 2 2.5 0.2 The value of B is small. Along the length direction of the cover plate, the proportion of adjacent first plastic hot-melt is 0.65%, affecting the appearance Comparative Example 2 1 2.0 2 2.5 0.2 The value of B is small. Along the length direction of the cover plate, the proportion of adjacent first plastic hot-melt is 0.48%, affecting the appearance Comparative Example 3 1 2.2 2 2.5 0.2 The value of B is small. Along the length direction of the cover plate, the proportion of adjacent first plastic hot-melt is 0.21%, affecting the appearance

[0068] As can be seen from Examples 1 to 5 in Table 2, after meeting the range limitations, the spacing B between the connecting piece 4 and the protruding part 31 can ensure that the welding heat is not easily affected by the protruding part 31, avoiding hot melt deformation and cracking of the protruding part 31 and not affecting the appearance.

[0069] As can be seen from Comparative Examples 1 to 3 in Table 2, when the spacing B between the connecting piece 4 and the protruding part 31 is too small, along the length direction of the cover plate, the adjacent first plastics 3 (i.e., the protruding parts 31) have a large amount of hot melt deformation, which affects the appearance.

[0070] To verify the rationality of the spacing C range between the connecting piece 4 and the edge of the first plastic 3, as shown in Table 3, five groups of examples and three groups of comparative examples are provided in this embodiment for illustration to verify the appearance of the first plastic 3 when the connecting piece 4 is welded to the tab.

[0071] Table 3

[0072] Serial Number A / mm B / mm C / mm D / E / F / mm H / mm Test Results Example 1 1 2.5 1.5 2.5 0.2 The proportion of the first plastic hot-melt deformation at adjacent positions during tab welding is approximately 0.015%, with slight deformation and no impact on appearance Example 2 1 2.5 1.7 2.5 0.2 The proportion of the first plastic hot-melt deformation at adjacent positions during tab welding is approximately 0.012%, with slight deformation and no impact on appearance Example 3 1 2.5 1.9 2.5 0.2 The proportion of the first plastic hot-melt deformation at adjacent positions during tab welding is approximately 0.011%, with slight deformation and no impact on appearance Example 4 1 2.5 2.1 2.5 0.2 The proportion of the first plastic hot-melt deformation at adjacent positions during tab welding is approximately 0.014%, with slight deformation and no impact on appearance Example 5 1 2.5 2.3 2.5 0.2 The proportion of the first plastic hot-melt deformation at adjacent positions during tab welding is approximately 0.012%, with slight deformation and no impact on appearance Comparative Example 1 1 2.5 0.8 2.5 0.2 The C value is small. Along the width direction of the cover plate, the heat fusion ratio of the first plastic edge reinforcing rib is 0.65%, which affects the appearance. Comparative Example 2 1 2.5 1 2.5 0.2 The C value is small. Along the width direction of the cover plate, the heat fusion ratio of the first plastic edge reinforcing rib is 0.53%, which affects the appearance. Comparative Example 3 1 2.5 1.2 2.5 0.2 The C value is small. Along the width direction of the cover plate, the heat fusion ratio of the first plastic edge reinforcing rib is 0.35%, which affects the appearance.

[0073] As can be seen from Examples 1 to 5 in Table 3, after meeting the range limitations, the spacing C between the connecting piece 4 and the edge of the first plastic 3 can ensure that when the tab is welded to the second welding part 42, the reinforcing rib 32 at the edge of the first plastic 3 is not easily affected by the welding heat and the appearance is not affected.

[0074] As can be seen from Comparative Examples 1 to 3 in Table 3, too small a spacing C between the connecting piece 4 and the edge of the first plastic 3 will cause the reinforcing rib 32 at the edge of the first plastic 3 to undergo hot melt, affecting the appearance.

[0075] In order to verify the rationality of the ranges of the distance D between the isolation rib 33 and the side wall of the second welding part 42 facing the edge of the first plastic 3, the distance E between the isolation rib 33 and the two side walls of the second welding part 42 along the first direction X, and the distance F between the isolation rib 33 and the second welding part 42 away from the edge of the first plastic 3, as shown in Table 4, this embodiment provides four sets of examples and four sets of comparative examples for illustration to verify the appearance of the first plastic 3 when the connecting piece 4 is welded to the tab.

[0076] Table 4

[0077] Serial number A / mm B / mm C / mm D / E / F / mm H / mm Test results Example 1 1 2.5 1.5 2.0 0.2 The proportion of appearance abnormalities is very small, about 0.02%, with slight exposure, which is acceptable. Example 2 1 2.5 1.5 2.2 0.2 The proportion of appearance abnormalities is very small, about 0.016%, with slight exposure, which is acceptable. Example 3 1 2.5 1.5 2.4 0.2 The proportion of appearance abnormalities is very small, about 0.014%, with slight exposure, which is acceptable. Example 4 1 2.5 1.5 2.5 0.2 The proportion of appearance abnormalities is very small, about 0.012%, with slight exposure, which is acceptable. Comparative Example 1 1 2.5 1.5 1.2 0.2 The D value is small. The first plastic at the bottom is deformed by heat, with exposure. The defective rate of the appearance yield is 0.52%, which is unacceptable. Comparative Example 2 1 2.5 1.5 1.4 0.2 The D value is small. The first plastic at the bottom is deformed by heat, with exposure. The defective rate of the appearance yield is 0.38%, which is unacceptable. Comparative Example 3 1 2.5 1.5 1.6 0.2 The D value is small. The first plastic at the bottom is deformed by heat, with exposure. The defective rate of the appearance yield is 0.29%, which is unacceptable. Comparative Example 4 1 2.5 1.5 1.8 0.2 The D value is small. The first plastic at the bottom is deformed by heat, with exposure. The defective rate of the appearance yield is 0.22%, which is unacceptable.

[0078] As can be seen from Examples 1 to 4 in Table 4, after the range is satisfied, when the tab is welded to the second welding part 42, slight exposure of the first plastic 3 occurs, which is acceptable.

[0079] As can be seen from Comparative Examples 1 to 4 in the table, the distance D between the isolation rib 33 and the side wall of the second welding part 42 facing the edge of the first plastic 3 is too small, which easily causes the first plastic 3 to be affected by the welding heat and undergo hot melt deformation, resulting in the exposure of the first plastic 3 outside the housing body, which is unacceptable.

[0080] Refer to Figure 1 , the present invention also provides a battery, including a pole group, a housing (not shown in the figure), and a cover plate assembly. The cover plate body 1 is connected to the housing, and the pole group is located inside the housing.

[0081] In this embodiment, the cover plate body 1 and the housing are hermetically and fixedly connected by welding so that the pole group is protected by the cover plate body 1 and the housing.

[0082] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments, and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions, 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 cover plate assembly, characterized in that, Connected with the tab, the cover plate assembly comprises: A cover plate body (1) and a pole (2), wherein the pole (2) is arranged on the cover plate body (1); A first plastic (3), the first plastic (3) being arranged on a side of the cover body (1) facing the tab; A connecting piece (4), the connecting piece (4) being arranged on one side of the first plastic (3) in a third direction (Z), the connecting piece (4) comprising a first welding portion (41) and a second welding portion (42), the first welding portion (41) and the second welding portion (42) being arranged in a row along a first direction (X), the first welding portion (41) being connected to the pole (2), and the second welding portion (42) being connected to the pole lug, so that the pole (2) and the pole lug are electrically connected; Along the second direction (Y), the edge of the first plastic (3) and the second welding portion (42) are spaced apart; The first direction (X) is parallel to the length direction of the cover plate body (1), the second direction (Y) is parallel to the width direction of the cover plate body (1), and the third direction (Z) is parallel to the thickness direction of the cover plate body (1).

2. The cover plate assembly according to claim 1, wherein, Along the third direction (Z), the height difference between the second welding portion (42) and the first plastic (3) is A, and A≥1mm.

3. The cover plate assembly according to claim 1, wherein The first plastic (3) is provided with a protruding portion (31), the protruding portion (31) extends along the second direction (Y), and the protruding portion (31) is provided on a side of the second welding portion (42) away from the first welding portion (41).

4. The cover plate assembly according to claim 3, wherein Along the first direction (X), the distance between the connecting piece (4) and the protruding portion (31) is B, and B≥2.5mm; and / or, along the second direction (Y), the distance between the connecting piece (4) and the edge of the first plastic (3) is C, and C≥1.5mm.

5. The cover plate assembly according to any one of claims 1-4, characterized in that, The first plastic (3) further comprises an isolation rib (33), and the isolation rib (33) is arranged at a position corresponding to the second welding portion (42).

6. The cover plate assembly according to claim 5, wherein Along the third direction (Z), the projection of the isolation rib (33) is located inside the projection of the corresponding second welding portion (42).

7. The cover plate assembly according to claim 5, characterized in that The minimum distance between the isolation rib (33) and the edge of the second welding portion (42) is greater than or equal to 2 mm.

8. The cover plate assembly according to claim 5, characterized in that, The thickness of the isolation rib (33) is H, and satisfies 0.1 mm ≤ H ≤ 0.5 mm.

9. The cover plate assembly according to claim 5, wherein, The isolation rib (33) extends along the first direction (X).

10. A battery, characterized in that, It comprises a pole group, a shell and a cover plate assembly as claimed in any one of claims 1 to 9, wherein the cover plate body (1) is connected to the shell, and the pole group is located inside the shell.

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