Cover structure and battery

Abstract

The present invention relates to the field of battery technology, and discloses a cover plate structure and a battery. The cover plate structure includes: a cover plate body, a pole assembly, an insulating assembly and a top cover patch. By arranging the insulating plate in a groove on the cover plate body, and the outer contour of the insulating plate being larger than the outer contour of the plastic body of the first plastic part located on the side of the insulating plate away from the bottom surface of the groove, direct contact between the plastic body and the first surface of the cover plate body is avoided. At the same time, by arranging the opening contour of the third through hole on the top cover patch to be smaller than the outer contour of the insulating plate, the edge area of ​​the top cover patch close to the third through hole is overlapped on the insulating plate, so that the gap between the top cover patch and the outer peripheral side of the first plastic part completely falls on the insulating plate, avoiding the partial area on the first surface of the cover plate body close to the outer peripheral side of the plastic body being exposed to the air, and avoiding the problem of short circuit between the cover plate body and the pole assembly caused by overlap between the cover plate body and the limiting part due to water droplets condensed on the first plastic part.

Description

Technical Field

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

[0002] The battery primarily consists of a housing, a cover structure, and a pole group. The cover structure includes the cover body, poles mounted on it, and plastic components. The first plastic component is located on the side of the cover body facing the exterior of the housing and between the cover body and the poles to ensure insulation between the poles and the cover body. A top cover patch, made of insulating material, is affixed to the side of the cover body facing the exterior of the housing to protect the cover body.

[0003] However, due to manufacturing tolerances for the top cover patch and equipment alignment tolerances, a certain gap exists between the top cover patch and the upper plastic, leaving the portion of the cover plate corresponding to this gap exposed to the air. For batteries used in environments with large temperature swings between day and night, water droplets will condense on the battery's external surface. When the battery is exposed to such conditions for extended periods, the condensed water droplets gradually accumulate. The water droplets accumulated on the outer surface of the first plastic part can connect the exposed portion of the cover plate to the surface of the terminal facing the outside of the housing, causing a short circuit between the terminal and the cover plate, posing a significant risk. Summary of the Invention

[0004] In view of this, the present invention provides a cover plate structure and a battery to solve the problem of short circuit between the pole and the cover plate body when the battery is used for a long time in an environment with a large temperature difference between day and night.

[0005] In a first aspect, the present invention provides a cover structure, comprising: a cover body, a first surface being formed along a first side in a thickness direction thereof, a groove being constructed on the first surface, and a pole through-hole being provided on the bottom surface of the groove; a pole assembly, comprising a column inserted into the pole through-hole and a limiting portion connected to the column, the outer contour of the limiting portion being larger than the outer contour of the column, and the limiting portion being located on the first side of the cover body; an insulating assembly, located between the cover body and the limiting portion, the insulating assembly comprising an insulating plate and a first plastic part, the insulating plate being arranged in the groove and having a first through-hole for the column to pass through, a plastic part body of the first plastic part being arranged between the insulating plate and the limiting portion and having a second through-hole for the column to pass through, the outer contour of the insulating plate being larger than the outer contour of the plastic part body; a top cover patch, affixed to the first surface, a third through-hole being provided on the top cover patch, the opening contour of the third through-hole being greater than or equal to the outer contour of the plastic part body and smaller than the outer contour of the insulating plate.

[0006] Beneficial effect: By arranging an insulating component between the cover body and the limiting part, the insulation between the limiting part and the cover body is ensured; by arranging the insulating plate in the groove and the outer contour of the insulating plate being larger than the outer contour of the plastic body of the first plastic part located on the side of the insulating plate away from the bottom surface of the groove, the orthographic projection of the insulating plate on the first surface is one circle larger than the orthographic projection of the plastic body on the first surface, thereby avoiding direct contact between the plastic body and the first surface of the cover body; at the same time, by arranging the opening contour of the third through hole on the top cover patch to be smaller than the outer contour of the insulating plate, the edge area of ​​the top cover patch close to the third through hole overlaps with the insulating plate, so that the gap between the top cover patch and the outer peripheral side of the first plastic part caused by manufacturing tolerance or equipment fitting and positioning tolerance falls completely on the insulating plate, avoiding partial area of ​​the outer peripheral side of the plastic body on the first surface of the cover body being exposed to the air, avoiding the problem of short circuit between the cover body and the pole assembly caused by overlapping of the cover body and the limiting part through water droplets condensed on the first plastic part, thereby improving the safety of the battery.

[0007] In an optional embodiment, the groove is a quadrilateral groove, the insulating plate and the plastic body are both quadrilaterals; the dimension of the insulating plate along the width direction of the cover body is W2, and the dimension of the plastic body along the width direction of the cover body is W3, wherein (W2-W3) / 2≥0.1mm, and 1<W2 / W3≤1.4.

[0008] Beneficial effects: On the one hand, it ensures that the insulating plate is sufficiently larger than the plastic body in the width direction, ensuring that the top cover patch can be overlapped on the insulating plate, and the portion of the insulating plate that is larger than the plastic body is sufficient to fill the gap between the top cover patch and the plastic body, avoiding the area on the first surface of the cover body close to the first plastic part being exposed to the air. On the other hand, it avoids the phenomenon of the edge of the insulating plate warping due to the portion of the insulating plate that is larger than the plastic body, thereby avoiding affecting the bonding strength of the overlapping portion of the top cover patch and the insulating plate, and avoiding the overlapping portion of the top cover patch and the insulating plate from warping and exposing the cover body. The combination of these two aspects ensures the insulation between the first plastic part and the cover body, and prevents short circuit between the pole assembly and the cover body.

[0009] In an optional embodiment, the dimension of the insulating plate along the length direction of the cover body is L2, and the dimension of the plastic body along the length direction of the cover body is L3, wherein (L2-L3) / 2≥0.1mm, and 1<L2 / L3≤1.6.

[0010] Beneficial effects: on the one hand, it is ensured that the insulating plate is sufficiently larger than the plastic body along the length direction, so that the top cover patch can be overlapped on the insulating plate, and the portion of the insulating plate that is larger than the plastic body is sufficient to cover the gap between the top cover patch and the plastic body, avoiding the area on the first surface of the cover body close to the first plastic part being exposed to the air. On the other hand, it avoids the phenomenon that the edge of the insulating plate is warped due to the portion of the insulating plate that is larger than the plastic body, thereby avoiding affecting the bonding strength of the overlapping portion of the top cover patch and the insulating plate, and avoiding the overlapping portion of the top cover patch and the insulating plate from warping and exposing the cover body. The combination of these two aspects ensures the insulation between the first plastic part and the cover body, and prevents short circuit between the pole assembly and the cover body.

[0011] In an optional embodiment, the dimension W2 of the insulating plate along the width direction of the cover body is in the range of 8mm<W2≤28mm; the dimension W3 of the plastic part body along the width direction of the cover body is in the range of 8mm≤W3≤20mm.

[0012] Beneficial effect: While ensuring that the width of the insulating plate is greater than the width of the plastic body, the widths of the insulating plate and the plastic body are both within a reasonable range, which can not only ensure the overcurrent capacity of the pole assembly, but also reduce the risk of thermal warping of the outer ring edge of the insulating ring due to the influence of welding heat. The excess part of the insulating plate is sufficient to cover the gap between the top cover patch and the plastic body, thereby ensuring the insulation between the first plastic part and the cover body, and preventing the pole assembly and the cover body from short-circuiting.

[0013] In an optional embodiment, the dimension L2 of the insulating plate along the length direction of the cover body has a value range of 15mm<L2≤128mm; the dimension L3 of the plastic part body along the length direction of the cover body has a value range of 15mm≤L3≤80mm.

[0014] Beneficial effects: While ensuring that the length of the insulating plate is greater than the width of the plastic body, the lengths of the insulating plate and the plastic body are both within a reasonable range, which can not only ensure the overcurrent capacity of the pole assembly, but also save materials, avoid the edges of the insulating plate on both sides along the length direction from warping, and ensure the insulation between the first plastic part and the cover body, prevent short circuit between the pole assembly and the cover body, and improve safety.

[0015] In an optional embodiment, the dimension of the cover plate body along its width direction is W1, wherein (W1-W2) / 2≥1mm.

[0016] Beneficial effect: By setting (W1-W2) / 2≥1mm, the distance from the edge of the insulating plate to the edge of the cover body in the width direction is greater than or equal to mm, thereby preventing the insulating plate from being affected by the welding heat of the cover body shell and causing shrinkage, warping, burning and other problems, thereby ensuring the reliability of the insulating plate, ensuring the appearance and insulation performance of the insulating plate, and ensuring that the top cover patch can be well overlapped on the edge of the insulating plate, thereby ensuring the insulation between the cover body and the pole assembly.

[0017] In an optional embodiment, along the thickness direction of the cover plate body, the thickness of the insulating plate is equal to the depth of the groove.

[0018] Beneficial effect: By setting the thickness of the insulating plate to be equal to the groove depth of the groove, when the insulating plate is assembled on the cover body, the upper surface of the insulating plate is flush with the first surface of the cover body, which makes it easy for the top cover patch to be attached to the cover body and the insulating plate in a flat state, avoiding step-like wrinkles on the top cover patch due to the insulating plate and the first surface not being on the same plane, thereby ensuring that the top cover patch is completely fitted with the cover body and the insulating plate, ensuring sealing and insulation, and avoiding water droplets from entering the bottom of the top cover patch through the gap between the top cover patch and the insulating plate and contacting the first surface, thereby further avoiding the cover body and the pole assembly from overlapping due to accumulated water droplets, avoiding short circuits, and improving safety.

[0019] In an optional embodiment, a dimension of the cover plate body along its thickness direction is H1, and a dimension of the insulating plate along the thickness direction of the cover plate body is H2, wherein 0.15≤H2 / H1≤0.45.

[0020] Beneficial effects: It can ensure that the insulating plate has sufficient thickness, avoid cracking or warping of the insulating plate, thereby improving reliability and ensuring good insulation performance, and can also avoid the structural strength of the cover plate body being reduced due to the insulating plate being too thick and the groove being too deep, thereby ensuring the stability and reliability of the cover plate body.

[0021] In an optional embodiment, the dimension H1 of the cover plate body along its thickness direction has a value range of: 1.5 mm ≤ H1 ≤ 3 mm.

[0022] Beneficial effects: It can ensure that the cover body has sufficient strength and reliability, and ensure that the groove has sufficient groove depth, so that the insulation board has sufficient thickness, avoid cracking or edge warping of the insulation board, ensure insulation, and avoid the cover body being too thick, reduce weight and save costs.

[0023] In a second aspect, the present invention further provides a battery comprising: a housing having an open end; an electrode group disposed within the housing, the electrode group having a tab; and the aforementioned cover plate structure disposed over the open end of the housing, the electrode post assembly within the cover plate structure being electrically connected to the tab. Because the battery includes the cover plate structure, it has the same effects as the cover plate structure and is not further described here. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 This is an exploded schematic diagram of a cover plate structure according to an embodiment of the present invention;

[0026] Figure 2 Schematic diagram of the positional relationship between the top cover patch and other components on the cover plate structure during the assembly process of the cover plate structure according to an embodiment of the present invention;

[0027] Figure 3 for Figure 1 The schematic diagram of the structure of the cover plate structure after assembly shown;

[0028] Figure 4 for Figure 3 A top view of the cover structure shown;

[0029] Figure 5 for Figure 4 Cross-sectional view in the AA direction;

[0030] Figure 6 for Figure 5 The cross-sectional view of the cover structure shown includes a partial enlarged schematic diagram of the pole assembly portion;

[0031] Figure 7 for Figure 4 Cross-sectional view in the middle BB direction;

[0032] Figure 8 Schematic diagram of the structure of the first plastic part of an embodiment of the present invention.

[0033] Description of reference numerals:

[0034] 1. Cover plate body; 101. Groove; 102. Pole through hole; 103. Explosion-proof valve hole; 110. First surface; 2. Pole assembly; 201. Column; 202. Limiting portion; 3. Insulating plate; 301. First through hole; 4. First plastic part; 401. Plastic part body; 402. Extended edge; 403. Second through hole; 5. Top cover patch; 501. Third through hole; 502. Fourth through hole; 6. Sealing ring; 7. Second plastic part; 8. Explosion-proof valve; 801. Explosion-proof valve patch. DETAILED DESCRIPTION

[0035] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0036] The following combination Figures 1 to 8 , describing embodiments of the present invention.

[0037] According to an embodiment of the present invention, on the one hand, a cover structure is provided, comprising: a cover body 1, a pole assembly 2, an insulating assembly and a top cover patch 5. The cover body 1 forms a first surface 110 along the first side in the thickness direction thereof, and a groove 101 is constructed on the first surface 110, and a pole through-hole 102 is provided on the bottom surface of the groove 101; the pole assembly 2 comprises a column 201 passing through the pole through-hole 102 and a limiting portion 202 connected to the column 201, the outer contour of the limiting portion 202 being larger than the outer contour of the column 201, and the limiting portion 202 is located on the first side of the cover body 1; the insulating assembly is located between the cover body 1 and the limiting portion 202, and the insulating assembly comprises an insulating plate 3 and a first plastic part 4. The insulating plate 3 is arranged in the groove 101 and has a first through hole 301 for the column 201 to pass through. The plastic body 401 of the first plastic part 4 is arranged between the insulating plate 3 and the limiting portion 202 and has a second through hole 403 for the column 201 to pass through. The outer contour of the insulating plate 3 is larger than the outer contour of the plastic body 401. The top cover patch 5 is attached to the first surface 110 and has a third through hole 501 formed on the top cover patch 5. The opening contour of the third through hole 501 is greater than or equal to the outer contour of the plastic body 401 and smaller than the outer contour of the insulating plate 3.

[0038] The first side of the cover body 1 refers to the side of the cover body 1 along the Figure 1 and Figures 5 to 7The side in the direction of "up" indicated by the arrow in the middle; the first surface 110 is the surface on the first side of the cover body 1. Specifically, when the cover structure is assembled with the battery shell, the first surface 110 is the surface facing the outside of the shell; the groove 101 is formed by a downward depression of a part of the area on the first surface 110, and the pole through hole 102 is along Figure 1 and Figures 5 to 7 The “up and down” direction indicated by the middle arrow passes through the cover body 1 .

[0039] In the cover structure of this embodiment, an insulating component is provided between the cover body 1 and the limiting portion 202 to ensure insulation between the limiting portion 202 and the cover body 1. The insulating plate 3 is provided in the groove 101, and the outer contour of the insulating plate 3 is larger than the outer contour of the plastic body 401 of the first plastic part 4 located on the side of the insulating plate 3 away from the bottom surface of the groove 101, so that the orthographic projection of the insulating plate 3 on the first surface 110 is larger than the orthographic projection of the plastic body 401 on the first surface 110, thereby avoiding direct contact between the plastic body 401 and the first surface of the cover body 1. At the same time, by providing the first plastic part 401 on the top cover patch 5, the insulating plate 3 is provided in the groove 101. The opening contour of the three through holes 501 is smaller than the outer contour of the insulating plate 3, so that the edge area of ​​the top cover patch 5 near the third through hole 501 overlaps the insulating plate 3, so that the gap between the top cover patch 5 and the outer peripheral side of the first plastic part 4 caused by manufacturing tolerance or equipment fitting positioning tolerance falls completely on the insulating plate 3, avoiding the partial area of ​​the outer peripheral side of the plastic part main body 401 on the first surface 110 of the cover body 1 from being exposed to the air, and avoiding the problem of short circuit between the cover body 1 and the pole assembly 2 caused by overlapping of the cover body 1 and the limiting part 202 due to water droplets condensed on the first plastic part 4, thereby improving the safety of the battery.

[0040] It should be noted that the outer contour of the orthographic projection of the insulating plate 3 on the first surface 110 is larger than the outer contour of the orthographic projection of the plastic component body 401 on the first surface 110; the opening contour of the third through hole 501 is greater than or equal to the outer contour of the plastic component body 401 on the first surface 110 and smaller than the outer contour of the orthographic projection of the insulating plate 3 on the first surface 110; wherein, the opening contour of the third through hole 501 is greater than or equal to the outer contour of the plastic component body 401, which can ensure that the plastic component body 401 can smoothly pass through the third through hole 501, thereby ensuring the smooth assembly of the cover structure. The pole through-hole 102 passes through the bottom surface of the groove 101, thereby passing through the cover body 1. The column 201 in the pole assembly 2 is arranged in the pole through-hole 102 and the limiting portion 202 is located on the first side of the cover body 1. The column 201 passes through the pole through-hole 102 on the cover body 1, the first through-hole 301 on the insulating plate 3, and the second through-hole 403 on the first plastic part 4 from the bottom of the cover body 1, and is fixedly connected to the limiting portion 202. The limiting portion 202 presses the insulating plate 3 and the first plastic part 4 on the cover body 1.

[0041] Optionally, the cover body 1 is made of aluminum, the insulating plate 3 is made of plastic materials such as PP and PPS, and the insulating plate 3 can be formed by punching, injection molding, and other processes.

[0042] In one embodiment, the limiting portion 202 is a riveted block, the column 201 is riveted to the riveted block, and presses the cover body 1, the insulating plate 3 and the first plastic part 4, thereby achieving relative fixation of the pole assembly 2 and the cover body 1, the insulating plate 3 and the first plastic part 4.

[0043] In one embodiment, the first plastic part 4 further includes an extended edge 402, which extends from the outer edge of the plastic body 401 in a direction away from the cover body 1. The rivet block is located in a groove formed by the plastic body 401 and the extended edge 402 of the first plastic part 4. By providing the first plastic part 4 with the plastic body 401 and the extended edge 402 connected to the outer edge of the plastic body 401, the first plastic part 4 is formed as a whole into a groove. By embedding the rivet block of the pole assembly 2 into the groove formed by the first plastic part 4, the plastic body 401 is positioned between the rivet block and the cover body 1. The extended edge 402 surrounds the circumferential surface of the rivet block, further improving the insulation protection of the rivet block. While ensuring electrical connection between the rivet block and the electrode assembly within the battery through the column 201, the rivet block and the cover body 1 are also insulated, thereby improving battery safety.

[0044] It should be noted that the insulating plate 3 is added before the cover structure is riveted, and the insulating plate 3 and the cover body 1 are integrally riveted. After riveting, the insulating plate 3 is subjected to stress, which may cause warping around the edges. Therefore, further restrictions are required to prevent warping at the edges of the insulating plate 3. Specifically, the insulating plate 3 and the first plastic part 4 are assembled with the cover body 1 one by one. Each component has a relatively simple structure, is easy to process, is convenient to replace, and has good versatility.

[0045] In one embodiment, the groove 101 is a quadrilateral groove, the insulating plate 3 and the plastic body 401 are both quadrilaterals; the dimension of the insulating plate 3 along the width direction of the cover body 1 is W2, and the dimension of the plastic body 401 along the width direction of the cover body 1 is W3, wherein (W2-W3) / 2≥0.1mm, and 1<W2 / W3≤1.4. The width direction refers to Figure 4 and Figure 7 The arrow in the middle indicates the "width direction". W2 is the width dimension of the insulating plate 3, and W3 is the width dimension of the plastic body 401. Since the outer contour of the insulating plate 3 is larger than the outer contour of the plastic body 401, along the width direction, the width dimension W2 of the insulating plate 3 and the width dimension W3 of the plastic body 401 satisfy W2>W3, that is, W2 / W3>1. W3 is also the width dimension of the overlapping area of ​​the plastic body 401 and the insulating plate 3.

[0046] It should be noted that the center point of the plastic body 401 coincides with the center point of the insulating plate 3, and the plastic body 401 is symmetrical about a straight line passing through the center point of the upper surface of the insulating plate 3 and parallel to the length direction of the cover body 1. Then, on both sides along the width direction, the size of the portion of the insulating plate 3 that is more than the plastic body 401 is the same, both are (W2-W3) / 2. If (W2-W3) / 2 is less than 0.1mm, the size of the portion of the insulating plate 3 that is more than the plastic body 401 along the width direction is too small, and there may be a situation where the top cover patch 5 cannot be overlapped with the insulating plate 3. The portion of the insulating plate 3 that is more than the plastic body 401 is not enough to fill the gap between the top cover patch 5 and the plastic body 401, making it difficult to ensure the insulation between the first plastic part 4 and the cover body 1. If W2 / W3 is less than or equal to 1, the limiting condition that the outer contour of the insulating plate 3 is larger than the outer contour of the plastic body 401 cannot be met. As a result, the plastic body 401 may directly contact the first surface of the cover body 1, or the plastic body 401 may be exactly aligned with the insulating plate 3 along the width direction. As a result, the edge area of ​​the top cover patch 5 near the third through hole 501 cannot overlap the insulating plate 3 along the width direction. The gap between the top cover patch 5 and the outer periphery of the first plastic part 4 exposes a portion of the outer periphery of the cover body 1 near the plastic body 401 to the air. There is still the problem of overlapping of the cover body 1 and the limiting portion 202 due to water droplets condensed on the first plastic part 4, resulting in a short circuit between the cover body 1 and the terminal assembly 2. The larger the value of W2 / W3 is, the larger the width dimension W2 of the insulating plate 3 is relative to the width dimension W3 of the plastic body 401, that is, the larger the dimension of the portion of the insulating plate 3 that is larger than the plastic body 401 in the width direction is. If W2 / W3 is greater than 1.4, W2 is too large relative to W3, and the dimension of the insulating plate 3 extending relative to the plastic body 401 is too large. After the battery is assembled, the insulating plate 3 is subjected to pressure from the first plastic part 4 and the limiting portion 202. The insulating plate 3 is prone to warping at the edges under pressure. After the top cover patch 5 is attached, the bonding strength of the overlapping portion of the top cover patch 5 and the insulating plate 3 is low, and it is also prone to warping, exposing the cover body 1, thereby failing to ensure the insulation between the cover body 1 and the first plastic part 4.

[0047] Therefore, by limiting the width dimension W2 of the insulating plate 3 and the width dimension W3 of the plastic body 401 to satisfy the relationship (W2-W3) / 2≥0.1mm and 1<W2 / W3≤1.4, on the one hand, it is ensured that the insulating plate 3 is larger than the plastic body 401 in the width direction, so that the top cover patch 5 can be overlapped on the insulating plate 3, and the excess portion of the insulating plate 3 is sufficient to fill the gap between the top cover patch 5 and the plastic body 401, thereby avoiding the cover body 1 from being blocked. The area on the surface 110 close to the first plastic part 4 is exposed to the air. On the other hand, the phenomenon of the edge of the insulating plate 3 being warped due to the excess size of the insulating plate 3 compared to the plastic part main body 401 is avoided, thereby avoiding affecting the bonding strength of the overlapping portion of the top cover patch 5 and the insulating plate 3, and avoiding the overlapping portion of the top cover patch 5 and the insulating plate 3 being warped and exposing the cover plate body 1. The combination of these two aspects ensures the insulation between the first plastic part 4 and the cover plate body 1, and prevents a short circuit between the pole assembly 2 and the cover plate body 1.

[0048] In one embodiment, the dimension of the insulating plate 3 along the length direction of the cover body 1 is L2, and the dimension of the plastic body 401 along the length direction of the cover body 1 is L3, wherein (L2-L3) / 2≥0.1mm, and 1<L2 / L3≤1.6. Figure 4 and Figures 5 and 6 The arrow in the middle indicates the "length direction." L2 is the length of the insulating plate 3, and L3 is the length of the plastic body 401. Since the outer contour of the insulating plate 3 is larger than that of the plastic body 401, along the length direction, the length L2 of the insulating plate 3 and the length L3 of the plastic body 401 satisfy L2>L3, that is, L2 / L3>1. L2 is also the length dimension of the overlapping area of ​​the plastic body 401 and the insulating plate 3.

[0049] It should be noted that the plastic part main body 401 is symmetrical about a straight line passing through the center point of the upper surface of the insulating plate 3 and parallel to the width direction of the cover plate main body 1. Then, on both sides along the length direction, the size of the portion of the insulating plate 3 that is more than the plastic part main body 401 is the same, both are (L2-L3) / 2. If (L2-L3) / 2 is less than 0.1mm, the size of the portion of the insulating plate 3 that is more than the plastic part main body 401 along the length direction is too small, and there may be a situation where the top cover patch 5 cannot be overlapped with the insulating plate 3. The portion of the insulating plate 3 that is more than the plastic part main body 401 is not enough to fill the gap between the top cover patch 5 and the plastic part main body 401, making it difficult to ensure the insulation between the first plastic part 4 and the cover plate main body 1. If L2 / L3 is less than or equal to 1, the limiting condition that the outer contour of the insulating plate 3 is larger than the outer contour of the plastic body 401 cannot be met, and the plastic body 401 will be in direct contact with the first surface of the cover body 1 or the plastic body 401 will be exactly aligned with the insulating plate 3 along the length direction. As a result, along the length direction, the edge area of ​​the top cover patch 5 near the third through hole 501 cannot be overlapped on the insulating plate 3. The gap between the top cover patch 5 and the outer peripheral side of the first plastic part 4 makes part of the outer peripheral area of ​​the cover body 1 near the plastic body 401 exposed to the air. There is still a problem of overlap between the cover body 1 and the limiting portion 202 due to water droplets condensed on the first plastic part 4, which causes the cover body 1 to be The problem of short circuit with the pole assembly 2; the larger the value of L2 / L3, the larger the length dimension L2 of the insulating plate 3 is relative to the length dimension L3 of the plastic body 401, that is, the larger the length dimension of the portion of the insulating plate 3 that is longer than the plastic body 401. If L2 / L3 is greater than 1.6, L2 is too large relative to L3, and the dimension of the insulating plate 3 extending relative to the plastic body 401 is too large. When the insulating plate 3 is under pressure, it is easy for the edges on both sides along the length direction to warp. After the top cover patch 5 is affixed, the bonding strength of the overlapping portion of the top cover patch 5 and the insulating plate 3 is low, and it is also easy to warp, exposing the cover body 1, thereby failing to ensure the insulation between the cover body 1 and the first plastic part 4.

[0050] Therefore, by limiting the length dimension L2 of the insulating plate 3 and the length dimension L3 of the plastic body 401 to satisfy the relationship (L2-L3) / 2≥0.1mm, L2 / L3≤1.6, on the one hand, it is ensured that the insulating plate 3 is sufficiently larger than the plastic body 401 in the length direction to ensure that the top cover patch 5 can overlap on the insulating plate 3. The excess portion of the insulating plate 3 over the plastic body 401 is sufficient to cover the gap between the top cover patch 5 and the plastic body 401, thereby preventing the area on the first surface 110 of the cover body 1 near the first plastic part 4 from being exposed to the air. On the other hand, the phenomenon of the edge of the insulating plate 3 being warped due to the excess portion of the insulating plate 3 over the plastic body 401 is avoided, thereby avoiding affecting the bonding strength of the overlapping portion of the top cover patch 5 and the insulating plate 3, and avoiding the overlapping portion of the top cover patch 5 and the insulating plate 3 from warping and exposing the cover body 1. The combination of these two aspects ensures the insulation between the first plastic part 4 and the cover body 1, and prevents a short circuit between the pole assembly 2 and the cover body 1.

[0051] In one embodiment, the value range of the dimension W2 of the insulating plate 3 along the width direction of the cover body 1 is: 8mm<W2≤28mm; the value range of the dimension W3 of the plastic body 401 along the width direction of the cover body 1 is: 8mm≤W3≤20mm. If W2 is less than or equal to 8mm or W3 is less than 8mm, the width of the insulating plate 3 and the plastic body 401 is too small, resulting in the limitation portion 202 in the pole assembly surrounded by the first plastic part 4 being too small in the width direction, thereby affecting the flow area of ​​the pole assembly 2 and the busbar, thereby affecting the flow capacity of the battery. When W2 is equal to 8mm, there is a situation where W2 and W3 are equal, the insulating plate 3 and the plastic body 401 have the same width, the top cover patch 5 cannot overlap the insulating plate 3 in the width direction, and the gap between the top cover patch 5 and the plastic body 401 will cause part of the area of ​​the cover body 1 near the first plastic part 4 to be exposed, and there is a gap between the cover body 1 and the pole. The risk of short circuit of the column assembly 2; when the edge of the cover body 1 is welded to the shell, if W2 is greater than 28mm, the insulating plate 3 is too close to the side edges of the cover body 1 on both sides in the width direction. During the welding process of the cover body 1 and the shell, the outer edge of the insulating plate 3 will be affected by the thermal deformation of welding, resulting in the risk of thermal warping of the outer edge of the insulating plate 3; if W3 is greater than 20mm, the plastic body 401 is too close to the edge of the insulating plate 3 in the width direction, and the excess size of the insulating plate 3 is insufficient. The excess size of the insulating plate 3 is insufficient to fill the gap between the top cover patch 5 and the plastic body 401, making it difficult to ensure the insulation between the first plastic part 4 and the cover body 1. Among them, the bus is a metal part connected to the side of the limit part 202 away from the cover body 1, which is used for electrical connection between different batteries or between batteries and external devices.

[0052] Therefore, by setting the width dimension W2 of the insulating plate 3 to satisfy 8mm<W2≤28mm and the width dimension W3 of the plastic body 401 to satisfy 8mm≤W3≤20mm, it is ensured that W2 is greater than W3, that is, the width dimension of the insulating plate 3 is greater than the width dimension of the plastic body 401, while the width dimensions of the insulating plate 3 and the plastic body 401 are both within a reasonable range. This can not only ensure the overcurrent capacity of the pole assembly 2, but also reduce the risk of thermal warping of the outer ring edge of the insulating plate 3 due to the influence of welding heat. The portion of the insulating plate 3 that is more than the plastic body 401 can also be sufficient to cover the gap between the top cover patch 5 and the plastic body 401, thereby ensuring the insulation between the first plastic part 4 and the cover body 1, and preventing the pole assembly 2 and the cover body 1 from short circuiting.

[0053] Preferably, 8.4 mm ≤ W2 ≤ 28 mm.

[0054] In one embodiment, the value range of the dimension L2 of the insulating plate 3 along the length direction of the cover body 1 is: 15mm<L2≤128mm; the value range of the dimension L3 of the plastic body 401 along the length direction of the cover body 1 is: 15mm≤L3≤80mm. If L2 is less than or equal to 15mm or L3 is less than 15mm, the length dimension of the insulating plate 3 and the plastic body 401 is too small, resulting in the limitation portion 202 in the pole assembly surrounded by the first plastic part 4 being too small in the length direction, thereby affecting the flow capacity of the pole assembly 2, and when L2 is equal to 15mm, there is a situation where L2 and L3 are equal, and the top cover patch 5 cannot be overlapped on the insulating plate 3 in the length direction. Then the gap between the top cover patch 5 and the plastic body 401 will make part of the area of ​​the cover body 1 close to the first plastic part 4 exposed to the outside, having a cover body. 1 and the risk of short circuit between the pole assembly 2; if L2 is greater than 128mm, the length of the insulating plate 3 is too large, which wastes materials and has the risk of warping due to the edge along the length direction being too far away from the first plastic part 4; if L3 is greater than 80mm, the plastic body 401 is too close to the edge of the insulating plate 3 along the length direction, and the excess size of the insulating plate 3 is insufficient compared to the plastic body 401. The excess size of the insulating plate 3 is insufficient to fill the gap between the top cover patch 5 and the plastic body 401, making it difficult to ensure the insulation between the first plastic part 4 and the cover body 1.

[0055] Therefore, by setting the length dimension L2 of the insulating plate 3 to satisfy 15mm<L2≤128mm, and the length dimension L3 of the plastic body 401 to satisfy 15mm≤L3≤80mm, it is ensured that L2 is greater than L3, that is, the length dimension of the insulating plate 3 is greater than the width dimension of the plastic body 401, while the length dimensions of the insulating plate 3 and the plastic body 401 are both within a reasonable range. This can not only ensure the overcurrent capacity of the pole assembly 2, but also save materials, avoid the edges of the insulating plate 3 on both sides along the length direction from warping, and also ensure the insulation between the first plastic part 4 and the cover body 1, prevent the pole assembly 2 and the cover body 1 from short circuiting, and improve safety.

[0056] Preferably, 16.2 mm ≤ L2 ≤ 128 mm.

[0057] In one embodiment, the width dimension of the cover body 1 is W1, where (W1-W2) / 2 is ≥ 1 mm. W1 is the width dimension of the cover body 1, and (W1-W2) / 2 is the distance from the edge of the insulating plate 3 to the edge of the cover body 1 along the width direction. The edge of the cover body 1 is used for welding to the shell. If (W1-W2) / 2 is less than 1 mm, the insulating plate 3 is too close to the edge of the cover body 1 along the width direction, making it easily affected by welding heat, resulting in shrinkage, warping, and burning of the insulating plate 3, affecting the appearance and insulation performance. Therefore, by setting (W1-W2) / 2≥1mm, in the width direction, the distance from the edge of the insulating plate 3 to the edge of the cover body 1 is greater than or equal to 1mm, thereby avoiding the insulating plate 3 being affected by the welding heat of the cover body 1 shell and causing shrinkage, warping, burning and other problems, thereby ensuring the reliability of the insulating plate 3, ensuring the appearance and insulation performance of the insulating plate 3, and ensuring that the top cover patch 5 can be well overlapped on the edge of the insulating plate 3, thereby ensuring the insulation between the cover body 1 and the pole assembly 2.

[0058] In one embodiment, the thickness of the insulating plate 3 is equal to the depth of the groove 101 along the thickness direction of the cover body 1. Figures 5 and 6The "up and down" directions indicated by the middle arrows are in the same direction; the groove depth refers to the size of the groove 101 along the up and down directions. By setting the thickness of the insulating plate 3 to be equal to the groove depth of the groove 101, when the insulating plate 3 is assembled on the cover body 1, the upper surface of the insulating plate 3 is flush with the first surface 110 of the cover body 1, so that the top cover patch 5 can be attached to the cover body 1 and the insulating plate 3 in a flat state, avoiding step-like wrinkles on the top cover patch 5 caused by the insulating plate 3 and the first surface 110 not being on the same plane, thereby ensuring that the top cover patch 5 is completely fitted with the cover body 1 and the insulating plate 3, ensuring sealing and insulation, and preventing water droplets from entering the bottom of the top cover patch 5 through the gap between the top cover patch 5 and the insulating plate 3 and contacting the first surface 110, thereby further preventing the cover body 1 and the pole assembly 2 from overlapping due to accumulated water droplets, avoiding short circuits and improving safety. Among them, the upper surface refers to Figures 5 and 6 The surface in the "up" direction indicated by the arrow in the middle.

[0059] It should be noted that the insulating plate 3 and the groove 101 are the same size and shape. The insulating plate 3 is just embedded in the groove 101, which is convenient for assembly and positioning. It has good stability after assembly and can ensure that the top cover patch 5 fits well with the first surface 110 of the cover body 1 and the overlapping part of the insulating plate 3 to ensure insulation.

[0060] In one embodiment, further combined Figure 7 As shown, the dimension of the cover plate body 1 along its thickness direction is H1, and the dimension of the insulating plate 3 along the thickness direction of the cover plate body 1 is H2, wherein 0.15≤H2 / H1≤0.45. It should be noted that H1 is the total thickness of the cover body 1, that is, the maximum thickness of the area on the cover body 1 where the groove 101 is not opened, H2 is the thickness of the insulating plate 3, and the thickness of the insulating plate 3 is equal to the groove depth of the groove 101, then H2 / H1 can represent the proportion of the groove depth of the groove 101 in the total thickness of the cover body 1. If H2 / H1 is greater than 0.45, the groove depth of the groove 101 is too large relative to the thickness of the cover body 1, and the groove depth is too large, resulting in the remaining solid part corresponding to the bottom surface of the groove 101 on the cover body 1 being too small in the up and down directions. After forming, the strength of the cover body 1 is low, does not meet the strength requirements, and has poor stability; if H2 / H1 is less than 0.15, the thickness of the insulating plate 3 is too small relative to the thickness of the cover body 1, the insulating plate 3 is too thin, and during the riveting of the pole assembly 2, the insulating plate 3 is prone to cracking, deformation and warping.

[0061] Therefore, by setting the ratio H2 / H1 between the thickness H2 of the insulating plate 3 and the thickness H1 of the cover plate body 1 to be within the range of 0.15 to 0.45, it is possible to ensure that the insulating plate 3 has sufficient thickness and avoid cracking or warping of the insulating plate 3, thereby improving reliability and ensuring good insulation. It is also possible to avoid a reduction in the structural strength of the cover plate body 1 due to excessive thickness of the insulating plate 3 and excessive depth of the groove 101, thereby ensuring the stability and reliability of the cover plate body 1.

[0062] In one embodiment, the dimension H1 of the cover body 1 along its thickness direction has a value range of: 1.5mm≤H1≤3mm. If H1 is less than 1.5mm, the thickness of the cover body 1 is too small, the structural strength is insufficient, and sufficient design space cannot be provided for the groove 101, which in turn leads to insufficient thickness of the insulating plate 3, and the insulating plate 3 is easily pressed and cracked or the edges are warped; if H1 is greater than 3mm, the thickness of the cover body 1 is too large, too much material is used, the weight is too large, and the cost is wasted. Therefore, by setting the thickness H1 of the cover body 1 to a value within the range of 1.5mm to 3mm, it can be ensured that the cover body 1 has sufficient strength and reliability, and that the groove 101 has a sufficient groove depth, so that the insulating plate 3 has sufficient thickness, avoids cracking or edge warping of the insulating plate 3, and ensures insulation, and avoids the cover body 1 being too thick, reducing weight and saving costs.

[0063] In one embodiment, the cover structure further includes: a sealing ring 6, which is sleeved on the column 201 to ensure insulation and sealing between the column 201 and the cover body 1; a second plastic part 7, which is arranged on the side of the cover body 1 away from the first surface 110 to ensure insulation between the cover body 1 and the pole group.

[0064] In one embodiment, an explosion-proof valve hole 103 is further provided on the cover body 1, and the explosion-proof valve hole 103 penetrates the cover body 1 along the thickness direction of the cover body 1; the cover structure also includes an explosion-proof valve 8, which is installed in the explosion-proof valve hole 103. The explosion-proof valve 8 is suitable for opening when the air pressure inside the battery is greater than a preset value to discharge the high-pressure gas inside the battery through the explosion-proof valve hole 103 to prevent the battery from exploding; an explosion-proof valve patch 801 is affixed to the explosion-proof valve 8 to protect the explosion-proof valve 8; a fourth through hole 502 corresponding to the explosion-proof valve 8 is also provided on the top cover patch 5 to facilitate the opening of the explosion-proof valve 8.

[0065] The pole assembly 2 on the cover structure with different parameter values ​​was subjected to an ultimate thrust test. The test results are recorded below to verify the impact of different parameter values ​​on the cover structure. It should be noted that the ultimate thrust test refers to applying a thrust from top to bottom to the pole assembly 2 in the direction of the cover body 1 until the pole assembly 2 leaks and the seal fails. In this case, the pole assembly 2 is judged to have failed. The ultimate thrust value F at this time is recorded, and it is determined whether it meets the basic requirement of F ≥ 1500N. The ultimate thrust value F is equal to the maximum strength that the cover structure can withstand.

[0066] Table 1 Test results of the implementation case of the cover structure

[0067]

[0068]

[0069] It can be seen from Table 1 that for the cover plate structures of Implementation Case 1 to Implementation Case 12, the thickness H2 of the insulating plate 3, the thickness H1 and H2 / H1 of the cover plate body 1, the width dimension W2 of the insulating plate 3, the width dimension W3 and W2 / W3 of the plastic part main body 401, the length dimension L2 of the insulating plate 3, and the length dimension L3 and L2 / L3 of the plastic part main body 401 are all within the range specified in this application. The insulating plate 3 does not warp, and F is greater than 1500N, which meets the strength requirements of the cover plate structure. At the same time, the insulating plate has no problems such as warping and passes the test.

[0070] Table 2 Comparative case test results of cover plate structure

[0071]

[0072] It can be seen from Table 2 that for the cover plate structures of Comparative Cases 1 to 2, the values ​​of H2 / H1 are all greater than 0.45, which are not within the range of 0.15≤H2 / H1≤0.45 specified in this application. Although the insulating plate 3 does not warp, F is less than 1500N, which does not meet the strength requirement of the cover plate structure; for the cover plate structures of Comparative Cases 3 to 4, the values ​​of H2 / H1 are all less than 0.15, which are not within the range specified in this application. Although F is greater than 1500N, which can meet the strength requirement of the cover plate structure, the problem of warping of the insulating plate 3 occurs, which cannot meet the requirement that the insulating plate 3 does not warp; In the cover plate structures of Comparative Cases 5 to 8, W2 / W3 is greater than 1.4, which is outside the range of W2 / W3≤1.4 specified in this application. Although F is greater than 1500N, which meets the cover plate structural strength requirements, the insulating plate 3 warps, and the requirement of insulating plate 3 not warping is not met. For Comparative Cases 9 to 12, L2 / L3 is greater than 1.6, which is outside the range of L2 / L3≤1.6 specified in this application. Although F is greater than 1500N, which meets the cover plate structural strength requirements, the insulating plate 3 warps, and the requirement of insulating plate 3 not warping is not met. In other words, the cover plate structures of Comparative Cases 1 to 12 cannot simultaneously meet the cover plate structural strength requirements and the insulating plate not warping requirements.

[0073] In summary, for the width dimension W2 of the insulating plate 3 and the width dimension W3 of the plastic body 401, if 1 < W2 / W3 ≤ 1.4, 8mm < W2 ≤ 28mm, and 8mm ≤ W3 ≤ 20mm are satisfied, the cover plate structure can simultaneously meet the requirements for cover plate structural strength and the requirement that the insulating plate does not warp. For the length dimension L2 of the insulating plate 3 and the length dimension L3 of the plastic body 401, if 1 < L2 / L3 ≤ 1.6, 15mm < L2 ≤ 128mm, and 15mm ≤ L3 ≤ 80mm are satisfied, the cover plate structure can simultaneously meet the requirements for cover plate structural strength and the requirement that the insulating plate does not warp. For the thickness H2 of the insulating plate 3 and the thickness H1 of the cover body 1, if 0.15 ≤ H2 / H1 ≤ 0.45 and 1.5mm ≤ H1 ≤ 3mm are satisfied, the cover plate structure can simultaneously meet the requirements for cover plate structural strength and the requirement that the insulating plate does not warp. The fact that the insulating plate 3 does not warp means that the flatness of the insulating plate 3 is less than 0.3mm.

[0074] According to another aspect of an embodiment of the present invention, a battery is provided, comprising: a housing, an electrode group, and the aforementioned cover structure. The housing has an open end; the electrode group is positioned within the housing and has a tab; the cover structure covers the open end of the housing, and the electrode post assembly 2 in the cover structure is electrically connected to the tab. Optionally, the battery is a lithium-ion battery.

[0075] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A cover plate structure, characterized in that: include: The cover body has a first surface formed along a first side in a thickness direction thereof, wherein a groove is configured on the first surface, and a pole through hole is formed on a bottom surface of the groove; A pole assembly, comprising a column inserted into the pole through-hole and a limiting portion connected to the column, wherein the outer contour of the limiting portion is larger than the outer contour of the column, and the limiting portion is located on the first side of the cover body; an insulating assembly located between the cover body and the limiting portion, the insulating assembly comprising an insulating plate and a first plastic part, the insulating plate being disposed in the groove and having a first through hole for the column to pass through, a plastic body of the first plastic part being disposed between the insulating plate and the limiting portion and having a second through hole for the column to pass through, the outer contour of the insulating plate being larger than the outer contour of the plastic body; A top cover patch is attached to the first surface, and a third through hole is formed on the top cover patch. The opening contour of the third through hole is greater than or equal to the outer contour of the plastic body and smaller than the outer contour of the insulating plate.

2. The cover plate structure according to claim 1, characterized in that: The groove is a quadrilateral groove, and the insulating plate and the plastic body are both quadrilateral; The dimension of the insulating plate along the width direction of the cover body is W2, and the dimension of the plastic component body along the width direction of the cover body is W3, wherein (W2-W3) / 2≥0.1mm, and 1<W2 / W3≤1.

4.

3. The cover plate structure according to claim 2, characterized in that: The dimension of the insulating plate along the length direction of the cover body is L2, and the dimension of the plastic component body along the length direction of the cover body is L3, wherein (L2-L3) / 2≥0.1mm, and 1<L2 / L3≤1.

6.

4. The cover plate structure according to claim 2, characterized in that: The dimension W2 of the insulating plate along the width direction of the cover plate body is in the range of 8 mm < W2 ≤ 28 mm; The dimension W3 of the plastic component body along the width direction of the cover body has a value range of 8 mm ≤ W3 ≤ 20 mm.

5. The cover plate structure according to claim 2, characterized in that: The dimension L2 of the insulating plate along the length direction of the cover plate body is in the range of 15 mm < L2 ≤ 128 mm; The dimension L3 of the plastic component body along the length direction of the cover body has a value range of: 15mm≤L3≤80mm.

6. The cover plate structure according to claim 2, characterized in that: The dimension of the cover plate body along its width direction is W1, wherein (W1-W2) / 2≥1mm.

7. The cover plate structure according to any one of claims 1 to 6, characterized in that: In the thickness direction of the cover plate body, the thickness of the insulating plate is equal to the depth of the groove.

8. The cover plate structure according to claim 7, characterized in that: The dimension of the cover plate body along the thickness direction thereof is H1, and the dimension of the insulating plate along the thickness direction of the cover plate body is H2, wherein 0.15≤H2 / H1≤0.

45.

9. The cover plate structure according to claim 8, characterized in that: The dimension H1 of the cover body along its thickness direction has a value range of: 1.5 mm ≤ H1 ≤ 3 mm.

10. A battery, characterized in that: include: a housing having an open end; A pole group is placed inside the shell, and the pole group has pole ears; The cover plate structure according to any one of claims 1 to 9 is provided on the open end of the shell, and the pole assembly in the cover plate structure is electrically connected to the pole tab.

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