Cover plate structure and battery

Abstract

The invention relates to the technical field of batteries, and discloses a cover plate structure and a battery. The cover plate structure comprises a cover plate body, a pole and a connecting sheet. The boss is arranged at the bottom of the pole, the mounting hole is formed in the connecting piece, the boss is inserted into the mounting hole, so that the pole and the connecting piece can be assembled, the edge of the lower end of the boss is constructed into the first chamfer, a guiding effect is provided for the boss to be assembled into the mounting hole, and the assembly yield is improved; meanwhile, the welding process parameters of the connecting piece and the pole are defined, so that the welding mark can wrap the first chamfer, welding burst points are avoided, the welding strength is ensured, the welding yield is improved, the overcurrent capacity between the connecting piece and the pole after welding is ensured, the quality reliability of the battery in the using process is improved, and the service life of the battery is prolonged. And resource waste caused by too large welding power can be avoided, and the production cost can be saved.

Description

Technical Field

[0001] This invention relates to the field of battery technology, specifically to a cover plate structure and a battery. Background Technology

[0002] A battery generally consists of an internal structure and an external structure. The internal structure mainly includes electrode arrays and connecting tabs, while the external structure mainly includes a cover plate and a casing. The casing provides space for the electrode arrays, and the positive and negative terminals of the electrode arrays are connected to the positive and negative terminals on the cover plate via connecting tabs. Charging and discharging are achieved through the positive and negative terminals of the external battery. The connecting tabs and terminals are assembled and welded to achieve electrical connection. However, in the current production process, poor assembly and welding of the connecting tabs and terminals often occur, affecting production efficiency and costs, and consequently impacting the safety of the battery during subsequent use. Summary of the Invention

[0003] This invention provides a cover plate structure and a battery to solve the problems of poor assembly and welding between the connecting piece and the terminal post.

[0004] In a first aspect, the present invention provides a cover plate structure, comprising: a cover plate body having an electrode post hole along the Z direction; an electrode post including a column body and a base plate, the column body passing through the electrode post hole, the base plate being located on the lower side of the cover plate body along the Z direction, the base plate including a plate body and a boss, the boss being connected to the lower surface of the plate body along the Z direction, the lower edge of the boss along the Z direction having a first chamfer, the orthographic projection of the first chamfer along the Z direction in the XY plane being annular with a width of C1; a connecting piece disposed on the lower side of the plate body along the Z direction, the connecting piece having an installation hole, the boss passing through the installation hole, the connecting piece and the boss being welded circumferentially along the installation hole to form a weld mark, the portion of the weld mark on the boss having a weld width of W1 in the XY plane, and the portion of the weld mark on the connecting piece having a weld width of W2 in the XY plane; wherein, the value of W1 is in the range of: C1+0.1 mm≤W1≤3. mm; the range of W2 is: C1+0.1 mm≤W2≤3 mm.

[0005] Beneficial effects: By setting a boss at the bottom of the terminal post and opening mounting holes on the connecting piece, the terminal post and connecting piece can be assembled by inserting the boss into the mounting holes. By constructing the lower edge of the boss as a first chamfer, the chamfer provides a guiding function for the boss to be assembled into the mounting holes, facilitating smooth assembly and improving assembly yield. At the same time, by limiting the weld width of the portion of the solder stamp on the boss and the portion of the solder stamp on the connecting piece to be within the range of the first chamfer plus 0.1 mm to 3 mm, the welding process parameters of the connecting piece and the terminal post are effectively defined. This ensures that the solder stamp can cover the first chamfer, thereby avoiding welding explosions, ensuring welding strength, improving welding yield, and ensuring the overcurrent capacity between the connecting piece and the terminal post after welding, improving the quality and reliability of the battery during use. It also avoids excessive welding power and resource waste, thus helping to save production costs.

[0006] In one optional embodiment, the weld width W1 of the portion of the solder mark located on the boss in the XY plane is in the range of: 0.25 mm ≤ W1 ≤ 3 mm; And / or, the weld width W2 of the portion of the solder mark located on the connecting piece in the XY plane is in the range of: 0.25 mm ≤ W2 ≤ 3 mm; And / or, the value range of C1 is: C1≥0.15 mm.

[0007] Beneficial effects: By limiting W1 to a value between 0.25 mm and 3 mm, the weld stamp can have sufficient strength, avoid weld stamp cracking, thereby improving the welding yield and ensuring welding reliability. At the same time, it can avoid excessive welding power and waste of resources, thereby saving production costs. And / or, by limiting W2 to a value between 0.25 mm and 3 mm, the solder stamp can have sufficient strength to avoid cracking, thereby improving the welding yield and ensuring welding reliability. At the same time, it can avoid excessive welding power and waste of resources, thereby saving production costs. And / or, by limiting C1 to not less than 0.15 mm, it can be ensured that the first chamfer can effectively play a guiding role and ensure the smooth assembly of the pole and the connecting piece.

[0008] In one alternative embodiment, the upper side of the connecting piece has a second chamfer around the circumferential edge of the mounting hole.

[0009] Beneficial effects: The second chamfer matches the first chamfer at the lower end of the boss, further facilitating the insertion of the boss into the mounting hole, ensuring smooth assembly of the connecting piece and the pole, and improving assembly accuracy and efficiency.

[0010] In one optional embodiment, along the Z direction, the lower surface of the boss is not lower than the lower surface of the connecting piece, and the distance between the lower surface of the connecting piece and the lower surface of the boss along the Z direction is g1; along the Z direction, the penetration depth of the solder on the boss is h, the thickness of the connecting piece is T, and the dimension of the second chamfer is C2; wherein, the value range of h satisfies: 0.3 mm ≤ h ≤ T-C2-g1.

[0011] Beneficial effects: By linking the weld penetration depth with the structure and dimensions of the boss and connecting piece, welding explosions are avoided, and the weld penetration depth is ensured to be sufficient, thereby improving welding strength and quality, preventing the weld position from breaking during battery use, thus ensuring the stability of the connection between the connecting piece and the terminal post, and ensuring the safety and reliability of the cover plate structure and the battery.

[0012] In one alternative embodiment, along the Z direction, the weld penetration depth h on the boss ranges from 0.3 mm to 1.5 mm.

[0013] Beneficial effects: It can ensure that the weld has sufficient penetration depth, thereby ensuring welding strength, avoiding weld cracking, improving welding yield, and ensuring welding reliability. It can also avoid excessive welding power and waste of resources, thereby saving production costs.

[0014] In one optional implementation, the thickness T of the connecting piece along the Z direction ranges from 0.5 mm to T ≤ 3 mm. And / or, along the Z direction, the value range of the second chamfer dimension C2 is: C2≤2 mm; And / or, the distance g1 between the lower surface of the connecting piece and the lower surface of the boss along the Z direction is in the range of 0 mm ≤ g1 ≤ 1 mm.

[0015] Beneficial effects: By limiting T to a value within the range of 0.5 mm to 3 mm, it is possible to ensure that the connecting piece itself has sufficient structural strength and that the connecting piece can provide sufficient welding space for the solder mark along the Z direction, ensuring that the solder mark has sufficient effective penetration depth, thereby improving welding strength and ensuring stable connection between the connecting piece and the terminal post. It is also possible to avoid the connecting piece occupying too much internal space of the battery, which is conducive to improving the battery energy density. And / or, by limiting the dimension C2 of the second chamfer 3011 along the Z direction to no more than 2 mm, the excessive thickness of the connecting piece 3 and the boss 222 can be avoided, thereby avoiding material waste and saving costs; And / or, by limiting g1 to a value between 0 mm and 1 mm, the height difference between the lower surface of the boss and the lower surface of the connecting piece is avoided to prevent welding spalls, improve welding quality, ensure welding strength, and thus ensure the stability of the connection between the connecting piece and the pole.

[0016] In one optional implementation, the distance between the upper end of the first chamfer and the lower end of the second chamfer along the Z direction is H, wherein the value of H is in the range of 0.2 mm ≤ H ≤ 5 mm.

[0017] Beneficial effects: It can prevent metal shavings or wires from getting caught in the assembly process of the boss and connecting piece, thus preventing the metal shavings or wires from getting into the battery and causing a short circuit, ensuring battery safety, and also avoids material waste and saves costs.

[0018] In one optional embodiment, the distance between the wall of the mounting hole and the boss in the XY plane is g2, wherein the value of g2 is in the range of 0 mm ≤ g2 ≤ 0.8 mm.

[0019] Beneficial effects: Ensures smooth assembly of the boss on the pole and the mounting hole of the connecting piece, and avoids welding defects such as spalls during the welding process, thereby ensuring welding quality.

[0020] In one optional embodiment, the connecting piece includes a first connecting area and a second connecting area. The first connecting area has the mounting hole along the Z direction, and the upper surface of the first connecting area is in contact with the lower surface of the plate. The second connecting area is connected along the X direction to the side of the first connecting area near the center of the cover plate body. Along the X direction, the distance between the edge of the first connecting area away from the second connecting area and the mounting hole is D, where the value of D is in the range of: D≤30 mm; and / or, the distance between the edge of the first connecting area and the second connecting area connected to the mounting hole and the mounting hole is F, where the value of F is in the range of: F≥3 mm.

[0021] Beneficial effects: By limiting D to no more than 30 mm, the size of the first connecting area along the X direction can be avoided from being too large, thus avoiding material waste and saving costs; and / or, by limiting F to no less than 3 mm, it can be ensured that the area of ​​the first connecting area between the mounting hole and the second connecting area has sufficient overlap space with the base plate, avoiding the phenomenon of insufficient space for pressing the connecting piece around the perimeter during welding, thereby ensuring the flatness of the connecting piece and the base plate assembly and ensuring welding quality.

[0022] Secondly, the present invention also provides a battery, comprising: a housing having an open end; an electrode assembly disposed within the inner cavity of the housing; and the aforementioned cover structure covering the open end of the housing. Since the battery includes the cover structure and has the same effect as the cover structure, it will not be described further here. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a top view of a cover plate structure according to an embodiment of the present invention; Figure 2 for Figure 1 A cross-sectional view along the AA direction; Figure 3 for Figure 2 A magnified view of part B in the diagram; Figure 4 for Figure 3 A magnified view of part of J; Figure 5 for Figure 4 A schematic diagram of the structure before solder marks are formed; Figure 6 for Figure 2 A magnified view of part of E in the diagram; Figure 7 for Figure 1 The bottom view of the cover plate structure shown.

[0025] Explanation of reference numerals in the attached figures: 1. Cover plate body; 11. Pole post hole; 2. Pole post; 21. Post body; 22. Base plate; 221. Plate body; 222. Boss; 2221. First chamfer; 3. Connecting piece; 301. Mounting hole; 3011. Second chamfer; 31. First connection area; 32. Second connection area; 4. Weld mark; 5. Riveting block; 6. First insulating component; 7. Second insulating component. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] A battery generally consists of an internal structure and an external structure. The internal structure mainly includes electrode arrays and connecting tabs, while the external structure mainly includes a cover plate and a casing. The casing provides space for the electrode arrays, and the positive and negative electrodes are connected to the positive and negative terminals on the cover plate via connecting tabs. Charging and discharging are achieved through the positive and negative terminals of the external battery. The connecting tabs and terminals are assembled and welded to achieve electrical connection. However, current production lines lack effective definitions for the assembly and welding process parameters of the connecting tabs and terminals. This leads to frequent assembly and welding defects during production, affecting production efficiency and costs. Consequently, a series of safety issues may arise during subsequent battery use, such as: insufficient solder strength leading to solder cracking; insufficient overcurrent area leading to excessive heat generation and thermal runaway; and residual metal wires causing internal short circuits.

[0028] The following is combined Figures 1 to 7 The following describes embodiments of the present invention.

[0029] According to an embodiment of the present invention, a cover plate structure is provided, comprising: a cover plate body 1, an electrode post 2, and a connecting piece 3. The cover plate body 1 has an electrode post hole 11 along the Z direction; the electrode post 2 includes a column body 21 and a base plate 22, the column body 21 passing through the electrode post hole 11, and the base plate 22 located on the lower side of the cover plate body 1 along the Z direction. The base plate 22 includes a plate body 221 and a boss 222, the boss 222 being connected to the lower surface of the plate body 221 along the Z direction. The lower edge of the boss 222 along the Z direction has a first chamfer 2221, the first chamfer 2221 having an annular orthographic projection in the XY plane along the Z direction. The ring width is C1; the connecting piece 3 is located on the lower side of the plate 221 along the Z direction, and the connecting piece 3 has a mounting hole 301. The boss 222 passes through the mounting hole 301. The connecting piece 3 and the boss 222 are welded around the mounting hole 301 to form a weld mark 4. The weld mark 4 located on the boss 222 has a weld width of W1 in the XY plane, and the weld mark 4 located on the connecting piece 3 has a weld width of W2 in the XY plane. The value range of W1 is: C1+0.1 mm≤W1≤3 mm; the value range of W2 is: C1+0.1 mm≤W2≤3 mm.

[0030] It should be noted that the cover plate structure has intersecting X, Y, and Z directions, such as... Figures 1 to 7 As shown, the X, Y, and Z directions form a rectangular coordinate system, and the X and Y directions intersect to form the XY plane; the cover plate structure has upper and lower sides arranged opposite to each other along the Z direction. When the cover plate structure is assembled with the shell, the side of the cover plate structure away from the shell along the Z direction is the upper side, and the side of the cover plate structure facing the shell along the Z direction is the lower side.

[0031] It should be noted that after the connecting piece 3 is fitted onto the boss 222 of the pole post 2 through the mounting hole 301, the welding equipment performs welding from below the connecting piece 3. The welding position is located in the gap between the boss 222 and the hole wall of the mounting hole 301. The welding trajectory surrounds the boss 222 around the circumference of the mounting hole 301. The weld mark 4 is formed at the lower end of the boss 222. Part of the weld mark 4 is located on the boss 222 and the other part is located on the connecting piece 3, thereby realizing the welding of the boss 222 and the connecting piece 3.

[0032] Wherein, the orthographic projection of the weld mark 4 along the Z direction in the XY plane is annular, W1 refers to the annular width of the portion of the weld mark 4 located on the boss 222 along the Z direction in the XY plane, and W2 refers to the annular width of the portion of the weld mark 4 located on the connecting piece 3 along the Z direction in the XY plane. W1 and W2 can be equal or unequal. In the actual welding process, the welding equipment welds from the gap between the connecting piece 3 and the boss 222, and the weld widths of the weld marks formed on the connecting piece 3 and the boss 222 tend to be equal; the first chamfer 2221 is set around the lower edge of the boss 222, and C1 is equal to the annular width of the portion cut off from the lower end face of the boss 222 in the plane where the lower end face of the boss 222 is located; if W1 is less than C1+0.1 If the weld mark 4 is less than 3 mm, it will not be able to cover the first chamfer 2221, which will cause the weld between the connecting piece 3 and the boss 222 to explode, resulting in poor welding and affecting the current carrying capacity between the connecting piece 3 and the boss 222. In addition, since the part of the weld mark 4 on the connecting piece 3 and the part of the weld mark 4 on the boss 222 are formed at the same time and are nearly symmetrical, the lower limit of W2 is limited to the same as the lower limit of W1. If W1 is greater than 3 mm, the welding power will be too high, resulting in waste of resources and increased cost.

[0033] Using the cover plate structure of this embodiment, by providing a boss 222 at the bottom of the pole post 2 and opening a mounting hole 301 on the connecting piece 3, the pole post 2 and the connecting piece 3 can be assembled by inserting the boss 222 into the mounting hole 301. By constructing the lower edge of the boss 222 as a first chamfer 2221, the chamfer provides a guiding function for the assembly of the boss 222 into the mounting hole 301, facilitating smooth assembly and improving the assembly yield. At the same time, by limiting the weld width of the portion of the solder mark 4 located on the boss 222 and the weld width of the portion of the solder mark 4 located on the connecting piece 3 to both the size of the first chamfer 2221 plus 0.1 mm to 3 mm, the assembly yield is improved. The values ​​are taken within the range of mm to effectively define the welding process parameters of the connecting piece 3 and the electrode post 2. This can ensure that the weld mark 4 can cover the first chamfer 2221, thereby avoiding welding explosions, ensuring welding strength, improving welding yield, and ensuring the overcurrent capacity between the connecting piece 3 and the electrode post 2 after welding, thus improving the quality and reliability of the battery during use. It can also avoid excessive welding power and waste of resources, thereby helping to save production costs.

[0034] It should be noted that the pole hole 11 is a through hole that penetrates the cover plate body 1 along the Z direction, and the mounting hole 301 is a through hole that penetrates the connecting piece 3 along the Z direction.

[0035] In one embodiment, the weld width W1 of the portion of the weld mark 4 located on the boss 222 in the XY plane ranges from 0.25 mm to 3 mm. If W1 is less than 0.25 mm, the weld width is too small, resulting in insufficient weld strength and a tendency to crack; if W1 is greater than 3 mm, the weld width is too large, leading to excessive welding power. Therefore, by limiting W1 to a value between 0.25 mm and 3 mm, the weld mark 4 can have sufficient strength, preventing weld cracking and thus improving welding yield and reliability. Simultaneously, excessive welding power can be avoided, preventing resource waste and saving production costs.

[0036] Optionally, the value of W1 is any one of 0.25 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, or a value between any two of these values.

[0037] In one embodiment, the weld width W2 of the portion of the weld stamp 4 located on the connecting piece 3 in the XY plane ranges from 0.25 mm to 3 mm. Similarly, if W2 is less than 0.25 mm, the weld width of the portion of the weld stamp 4 located on the connecting piece 3 is too small, resulting in insufficient welding strength and a tendency to crack; if W2 is greater than 3 mm, the weld width is too large, leading to excessive welding power. Therefore, by limiting W2 to a value between 0.25 mm and 3 mm, the weld stamp 4 can have sufficient strength, preventing weld cracking and thus improving welding yield and ensuring welding reliability. Simultaneously, it avoids excessive welding power and resource waste, thereby saving production costs.

[0038] Optionally, the value of W2 is any one of 0.25 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, or a value between any two of these values.

[0039] In one embodiment, the value of C1 ranges from C1 ≥ 0.15 mm. Further combining... Figure 5 As shown, the size of the first chamfer 2221 includes its dimension along the XY plane and its dimension along the Z direction. C1 represents the dimension of the first chamfer 2221 along the XY plane. Preferably, the first chamfer 2221 is a 45° chamfer, and the dimension of the first chamfer 2221 along the XY plane and its dimension along the Z direction are equal. If C1 is too small (0.15 mm), the first chamfer 2221 will be too small and will not play a guiding role, which will not be conducive to the smooth insertion of the boss 222 of the pole post 2 into the mounting hole 301 of the connecting piece 3. Therefore, by limiting C1 to not less than 0.15 mm, it can be ensured that the first chamfer 2221 can effectively play a guiding role and ensure the smooth assembly of the pole post 2 and the connecting piece 3.

[0040] In one embodiment, the upper side of the connecting piece 3 is provided with a second chamfer 3011 around the circumferential edge of the mounting hole 301. It should be noted that the connecting piece 3 is sleeved on the boss 222 from bottom to top. By constructing the second chamfer 3011 on the circumferential edge at the upper end of the mounting hole 301, the second chamfer 3011 cooperates with the first chamfer 2221 at the lower end of the boss 222, which further facilitates guiding the boss 222 into the mounting hole 301, ensuring the smooth assembly of the connecting piece 3 and the pole post 2, and improving assembly accuracy and assembly efficiency.

[0041] In one embodiment, further combination Figures 4 to 5 As shown, along the Z-direction, the lower surface of the boss 222 is not lower than the lower surface of the connecting piece 3, and the distance between the lower surface of the connecting piece 3 and the lower surface of the boss 222 along the Z-direction is g1; along the Z-direction, the penetration depth of the solder mark 4 on the boss 222 is h, the thickness of the connecting piece 3 is T, and the dimension of the second chamfer 3011 is C2; where h is in the range of 0.3 mm ≤ h ≤ T - C2 - g1. The "lower surface" mentioned refers to the lower surface along the Z-direction. Specifically, the lower surface of the connecting piece 3 refers to the surface of the connecting piece 3 facing away from the cover plate body 1 along the Z-direction, and the lower surface of the boss 222 refers to the surface of the boss 222 facing away from the cover plate body 1 along the Z-direction.

[0042] It should be noted that the lower surface of the boss 222 is located above or flush with the lower surface of the connecting piece 3, and g1 is the height difference along the Z direction between the lower surface of the boss 222 and the lower surface of the connecting piece 3; the portion of the solder mark 4 on the boss 222 extends upward from the plane containing the lower surface of the boss 222, and the portion of the solder mark 4 on the connecting piece 3 extends upward from the plane containing the lower surface of the connecting piece 3. Since the lower surface of the boss 222 is not lower than the lower surface of the connecting piece 3, the penetration depth of the portion of the solder mark 4 on the boss 222 is not greater than the penetration depth of the portion of the solder mark 4 on the connecting piece 3; T-C2-g1 This indicates the distance along the Z direction between the lower surface of the boss 222 and the lower end of the second chamfer 3011. The welding depth of the weld mark 4 needs to be a certain distance from the second chamfer 3011 to avoid affecting the welding quality and welding strength. The part of the weld mark 4 located between the second chamfer 3011 and the first chamfer 2221 is the effective penetration depth of the weld mark. If h is greater than T-C2-g1, the weld mark 4 extends to the second chamfer 3011, which is prone to welding explosions, affecting the welding quality. Moreover, the effective penetration depth of the weld mark may be insufficient, resulting in poor welding strength. The welding position is prone to failure during battery use, causing the connecting piece 3 to fall off. If h is less than 0.3 mm, the penetration depth of the weld mark 4 on the boss 222 is too small, which also has the problem of insufficient welding strength.

[0043] Therefore, by limiting the penetration depth h of the solder mark 4 on the boss 222 to not less than 0.3 mm, and ensuring that the thickness T of the connecting piece 3, the dimension C2 of the second chamfer 3011 along the Z direction, and the height difference g1 between the lower surface of the boss 222 and the lower surface of the connecting piece 3 along the Z direction satisfy the relationship h≤T-C2-g1, the penetration depth of the solder mark is linked to the structure and dimensions of the boss 222 and the connecting piece 3. This avoids welding explosions and ensures that the solder mark 4 has sufficient effective penetration depth, improving welding strength and welding quality, preventing the welding position from breaking during battery use, thereby ensuring the stability of the connection between the connecting piece 3 and the terminal post 2, and ensuring the safety and reliability of the cover structure and the battery.

[0044] In one embodiment, along the Z-direction, the penetration depth h of the weld mark 4 on the boss 222 ranges from 0.3 mm to 1.5 mm. If h is less than 0.3 mm, the penetration depth of the weld mark 4 on the boss 222 is too small, resulting in insufficient welding strength and a tendency to crack. If h is greater than 1.5 mm, the penetration depth of the weld mark 4 on the boss 222 is too large, leading to excessive welding power. Therefore, by limiting h to the range of 0.3 mm to 1.5 mm, it is possible to ensure that the weld mark 4 has sufficient penetration depth, thereby guaranteeing welding strength, preventing weld mark cracking, improving welding yield, and ensuring welding reliability. Simultaneously, it is possible to avoid excessive welding power and resource waste, thereby saving production costs.

[0045] Optionally, the value of h is any one of 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, or a value between any two of these values.

[0046] In one embodiment, the thickness T of the connecting piece 3 along the Z-direction ranges from 0.5 mm to 3 mm. If T is less than 0.5 mm, the thickness of the connecting piece 3 is too small, resulting in insufficient structural strength and poor stability. This also leads to insufficient effective penetration of the solder joint 4, affecting welding strength and consequently the connection stability between the connecting piece 3 and the terminal post 2. If T is greater than 3 mm, the connecting piece 3 is too thick, occupying too much internal space in the battery casing, which is detrimental to improving the battery's energy density. Therefore, by limiting T to a range of 0.5 mm to 3 mm, it is possible to ensure that the connecting piece 3 itself has sufficient structural strength and provides sufficient welding space for the solder joint 4 along the Z-direction, ensuring sufficient effective penetration of the solder joint 4, thereby improving welding strength and ensuring a stable connection between the connecting piece 3 and the terminal post 2. Simultaneously, it avoids the connecting piece 3 occupying excessive internal battery space, thus contributing to improved battery energy density.

[0047] Optionally, the value of T is any one of 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, or a value between any two of these values.

[0048] In one embodiment, the value range of the dimension C2 of the second chamfer 3011 along the Z direction is: C2 ≤ 2 mm. If C2 is greater than 2 mm, the second chamfer 3011 is too large. To ensure the relationship T - C2 - g1 ≥ h, the thickness T of the connecting piece 3 needs to be increased. Correspondingly, the thickness of the boss 222 along the Z direction also needs to be increased, which would result in the connecting piece 3 and the boss 222 being too thick, wasting materials and increasing costs. Therefore, by limiting the dimension C2 of the second chamfer 3011 along the Z direction to no more than 2 mm, the excessive thickness of the connecting piece 3 and the boss 222 can be avoided, thereby avoiding material waste and saving costs.

[0049] It should be noted that the second chamfer 3011 has a dimension along the XY plane and a dimension along the Z direction. C2 represents the dimension of the second chamfer 3011 along the Z direction. Preferably, the second chamfer 3011 is a 45° chamfer. The dimensions of the second chamfer 3011 along the XY plane and the dimensions along the Z direction are equal, which facilitates processing.

[0050] In one embodiment, the distance g1 along the Z direction between the lower surface of the connecting piece 3 and the lower surface of the boss 222 is in the range of 0 mm ≤ g1 ≤ 1 mm. It should be noted that when g1 equals 0 mm, it means that the lower surface of the connecting piece 3 is flush with the lower surface of the boss 222 before connection. If g1 is greater than 1 mm, the height difference between the boss 222 and the connecting piece 3 is too large, leading to poor welding results. Therefore, by limiting g1 to a value between 0 mm and 1 mm, an excessive height difference between the lower surface of the boss 222 and the lower surface of the connecting piece 3 is avoided, thereby preventing welding defects, improving welding quality, ensuring welding strength, and thus ensuring the stability of the connection between the connecting piece 3 and the pole post 2.

[0051] Optionally, the value of g1 is any one of 0 mm, 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, 1 mm, or a value between any two of these values.

[0052] In one embodiment, further combination Figure 5 As shown, along the Z-direction, the distance between the upper end of the first chamfer 2221 and the lower end of the second chamfer 3011 is H, where the value of H ranges from 0.2 mm to 5 mm. The term "upper end" refers to the upper end along the Z-direction, and the term "lower end" refers to the lower end along the Z-direction. Specifically, the upper end of the first chamfer 2221 is the end of the first chamfer 2221 along the Z-direction closer to the cover plate body 1, and the lower end of the second chamfer 3011 is the end of the second chamfer 3011 along the Z-direction away from the cover plate body 1.

[0053] It should be noted that the distance along the Z-direction between the upper end of the first chamfer 2221 and the lower end of the second chamfer 3011 is the height of the overlapping area between the boss 222 and the connecting piece 3. If H is less than 0.2 mm, the overlapping area is too small, and metal shavings or wires are easily caught during the assembly of the boss 222 and the connecting piece 3. If these metal shavings or wires are left on the production line, they will be mixed in during battery production, causing short circuits in the battery. If H is greater than 5 mm, the overlapping area is too large, and both the connecting piece 3 and the boss 222 are too thick along the Z-direction, wasting materials and increasing costs. Therefore, by limiting H to a value between 0.2 mm and 5 mm, it is possible to avoid metal shavings or wires being caught during the assembly of the boss 222 and the connecting piece 3, thereby preventing these metal shavings or wires from being mixed into the battery and causing a short circuit, ensuring battery safety, and also avoiding material waste and saving costs.

[0054] Optionally, the value of H is any one of 0.2 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, or a value between any two of these values.

[0055] In one embodiment, further combination Figures 3 to 4 As shown, the distance between the wall of the mounting hole 301 and the outer peripheral surface of the boss 222 in the XY plane is g2, where the value of g2 is in the range of 0 mm ≤ g2 ≤ 0.8 mm. It should be noted that the boss 222 passes through the mounting hole 301. When g2 equals 0 mm, the outer peripheral wall of the boss 222 fits snugly against the wall of the mounting hole 301. g2 cannot be less than 0 mm; otherwise, interference will occur between the boss 222 and the wall of the mounting hole 301, and the boss 222 cannot be installed into the mounting hole 301. When g2 is greater than 0, the boss 222 and the mounting hole 301 have a clearance fit, and part of the weld mark 4 is located within this clearance. If g2 is greater than 0.8 mm, the clearance between the wall of the mounting hole 301 and the outer peripheral surface of the boss 222 will be too large, leading to poor weld breakage. Therefore, by limiting g2 to a value within the range of 0 mm to 0.8 mm, it is possible to ensure the smooth assembly of the boss 222 of the pole post 2 and the mounting hole 301 of the connecting piece 3, and to avoid welding defects such as blasting during the welding process, thereby ensuring the welding quality.

[0056] Optionally, the value of g2 is any one of 0 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, or a value between any two of these values.

[0057] In one embodiment, further combination Figures 6 to 7 As shown, the connecting piece 3 includes a first connecting area 31 and a second connecting area 32. A mounting hole 301 is formed on the first connecting area 31 along the Z direction, and the upper surface of the first connecting area 31 is in contact with the lower surface of the plate 221. The second connecting area 32 is connected along the X direction to the side of the first connecting area 31 closest to the center of the cover plate body 1. Along the X direction, the distance between the edge of the first connecting area 31 away from the second connecting area 32 and the mounting hole 301 is D, where D ≤ 30 mm. The upper surface of the first connecting area 31 refers to the upper surface of the first connecting area 31 along the Z direction, the lower surface of the plate 221 refers to the lower surface of the plate 221 along the Z direction, and the X direction refers to... Figures 1 to 7 The direction of the "X" indicated by the middle arrow.

[0058] It should be noted that the connecting piece 3 is a metal conductor. The first connecting area 31 and the second connecting area 32 are connected along the X direction. The second connecting area 32 and the first connecting area 31 are connected in a stepped manner. The lower surface of the second connecting area 32 is lower than the lower surface of the first connecting area 31. The first connecting area 31 is connected to the base plate 22 of the pole post 2. The second connecting area 32 is used to connect with the pole tab of the pole group, thereby realizing the electrical connection between the pole group and the pole post 2 through the connecting piece 3. The dimension of the first connecting area 31 along the X direction is less than or equal to the dimension of the plate 221 along the X direction. D is the dimension of the area of ​​the first connecting area 31 along the X direction located on the side away from the second connecting area 32 of the mounting hole 301. This area overlaps with the base plate 22. If D is greater than 30 mm, the dimension of the area of ​​the first connecting area 31 along the X direction located on the side away from the second connecting area 32 of the mounting hole 301 along the X direction is too large, exceeding the range of the base plate 22, and wasting material. Therefore, by limiting D to no more than 30 mm, the size of the first connection area 31 along the X direction can be avoided from being too large, thus avoiding material waste and saving costs.

[0059] In one embodiment, further combination Figure 6 As shown, along the X direction, the distance between the edge connecting the first connecting area 31 and the second connecting area 32 and the mounting hole 301 is F, where F ≥ 3 mm. It should be noted that F is the dimension along the X direction of the area on the first connecting area 31 located between the mounting hole 301 and the second connecting area 32. This area overlaps with a portion of the plate 221. If F is less than 3 mm, there will be insufficient space for the connecting piece to press against the base plate during welding, making it impossible to ensure the flatness of the connecting piece 3 and the base plate 22, resulting in poor welding. Therefore, by limiting F to no less than 3 mm, sufficient overlap space between the area of ​​the first connecting area 31 located between the mounting hole 301 and the second connecting area 32 and the base plate 22 can be ensured, avoiding the phenomenon of insufficient space for the connecting piece to press against the base plate during welding, thereby ensuring the flatness of the connecting piece 3 and the base plate 22 and guaranteeing welding quality.

[0060] In one embodiment, the cover plate structure further includes a riveting block 5, which is disposed on the side of the cover plate body 1 facing away from the bottom plate 22 along the Z direction, and the riveting block 5 is riveted to the column 21 of the pole post 2.

[0061] In one embodiment, the cover plate structure further includes a first insulating member 6 and a second insulating member 7. The first insulating member 6 is disposed between the riveting block 5 and the cover plate body 1 to ensure insulation between the riveting block 5 and the cover plate body 1. The second insulating member 7 is disposed on the side of the cover plate body 1 away from the riveting block 5 along the Z direction to ensure insulation between the cover plate body 1 and the electrode assembly. Specifically, the first insulating member 6 is an upper plastic and the second insulating member 7 is a lower plastic.

[0062] The cover plate structure of this embodiment effectively defines the assembly and welding process parameters of the connecting piece 3 and the terminal post 2, improves the assembly and welding yield between the terminal post 2 and the connecting piece 3, ensures the welding strength and overcurrent performance, and improves the quality problems during battery use.

[0063] According to an embodiment of the present invention, in another aspect, a battery is also provided, comprising: a housing, an electrode assembly, and the aforementioned cover structure. The housing has an open end; the electrode assembly is disposed in the inner cavity of the housing; the cover structure covers the open end of the housing. An electrode tab extends from the side of the electrode assembly facing the cover structure, and the electrode tab is electrically connected to the second connection area 32 of the connecting piece 3 in the cover structure. Optionally, the battery is a lithium-ion power battery.

[0064] The following examples and comparative examples verify the impact of different parameter values ​​on the battery. The parameter settings for the examples and comparative examples are shown in Table 1, and the corresponding verification results are shown in Table 2. In Tables 1 and 2, W represents W1 and W2, meaning that the values ​​of W1 and W2 are taken from the values ​​of W in Table 1.

[0065] Table 1

[0066] Table 2

[0067] As can be seen from Tables 1 to 2, for the batteries of Examples 1 to 5, all parameters are within the range defined in this application, the batteries do not fail and have good performance.

[0068] For the battery in Comparative Example 1, the value of W is 0.38 mm, and C1+0.1 is 0.40 mm. W is less than C1+0.1, that is, W1 is not within the range of C1+0.1 mm≤W1≤3 mm as defined in this application, and W2 is not within the range of C2+0.1 mm≤W1≤3 mm as defined in this application. During the manufacturing process, the welding point between the connecting piece and the base plate explodes, and the solder stamp cannot cover the first chamfer, so the welding yield cannot be guaranteed.

[0069] For the battery in Comparative Example 2, the value of h is 0.71 mm, and the value of T-C2-g1 is 0.7 mm. Since h is greater than T-C2-g1, it does not meet the requirement of 0.3 mm ≤ h ≤ T-C2-g1 as defined in this application. Therefore, the effective penetration depth of the solder is insufficient, resulting in an open circuit and detachment of the connector after the battery vibration test. It is evident that when h is within the range defined in this application, sufficient effective penetration depth of the solder can be ensured, improving welding strength and quality, and preventing connector detachment.

[0070] For the battery in Comparative Example 3, the value of g1 is 1.03 mm, which is greater than the upper limit of g1 of this application (1 mm) and is outside the range defined in this application, resulting in poor soldering quality. Therefore, when g1 is within the range defined in this application, soldering quality can be guaranteed.

[0071] For the battery in Comparative Example 4, the value of g2 is 0.9 mm, which is greater than the upper limit of g2 of 0.8 mm defined in this application and is outside the range defined in this application, resulting in poor soldering quality. Therefore, when g2 is within the range defined in this application, soldering quality can be guaranteed.

[0072] Unless otherwise stated, the values ​​of all parameters mentioned in this application can be determined using testing methods commonly used in the art. Unless otherwise stated, the test temperature for all parameters is 25°C.

[0073] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A cover structure, characterized by include: The cover plate body has pole hole along the Z direction; The pole post includes a column body and a base plate. The column body passes through the pole post hole. The base plate is located on the lower side of the cover plate body along the Z direction. The base plate includes a plate body and a boss. The boss is connected to the lower surface of the plate body along the Z direction. The lower edge of the boss along the Z direction is provided with a first chamfer. The orthographic projection of the first chamfer along the Z direction in the XY plane is annular and the width of the annulus is C1. A connecting piece is disposed on the lower side of the plate along the Z direction. The connecting piece has a mounting hole. The boss passes through the mounting hole. The connecting piece and the boss are welded around the mounting hole to form a weld mark. The portion of the weld mark on the boss has a weld width of W1 in the XY plane, and the portion of the weld mark on the connecting piece has a weld width of W2 in the XY plane. The range of W1 is: C1+0.1 mm≤W1≤3 mm; the range of W2 is: C1+0.1 mm≤W2≤3 mm.

2. The cover plate structure according to claim 1, characterized by The weld width W1 of the portion of the solder mark located on the boss in the XY plane is in the range of: 0.25 mm ≤ W1 ≤ 3 mm; And / or, the weld width W2 of the portion of the solder mark located on the connecting piece in the XY plane is in the range of: 0.25mm≤W2≤3mm; And / or, the value range of C1 is: C1≥0.15 mm.

3. The cover plate structure according to claim 1, wherein The upper side of the connecting piece has a second chamfer around the circumferential edge of the mounting hole.

4. The cover plate structure according to claim 3, characterized in that, Along the Z direction, the lower surface of the boss is not lower than the lower surface of the connecting piece, and the distance between the lower surface of the connecting piece and the lower surface of the boss along the Z direction is g1; along the Z direction, the penetration depth of the solder on the boss is h, the thickness of the connecting piece is T, and the dimension of the second chamfer is C2; wherein, the value range of h satisfies: 0.3 mm ≤ h ≤ T-C2-g1.

5. The cover plate structure according to claim 4, characterized in that, Along the Z direction, the weld penetration depth h on the boss ranges from 0.3 mm to 1.5 mm.

6. The cover plate structure according to claim 4, characterized in that, Along the Z direction, the thickness T of the connecting piece ranges from 0.5 mm to 3 mm. And / or, along the Z direction, the value range of the second chamfer dimension C2 is: C2≤2 mm; And / or, the distance g1 between the lower surface of the connecting piece and the lower surface of the boss along the Z direction is in the range of 0 mm ≤ g1 ≤ 1 mm.

7. The cover plate structure according to claim 3, characterized in that, Along the Z direction, the distance between the upper end of the first chamfer and the lower end of the second chamfer is H, where the value of H is in the range of 0.2 mm ≤ H ≤ 5 mm.

8. The cover plate structure according to claim 1, characterized in that, The distance between the wall of the mounting hole and the boss in the XY plane is g2, where the value of g2 is in the range of 0 mm ≤ g2 ≤ 0.8 mm.

9. The cover plate structure according to any one of claims 1 to 8, characterized in that, The connecting piece includes a first connecting area and a second connecting area. The first connecting area has the mounting hole along the Z direction, and the upper surface of the first connecting area is in contact with the lower surface of the plate. The second connecting area is connected along the X direction to the side of the first connecting area near the center of the cover plate body. Along the X direction, the distance between the edge of the first connecting area away from the second connecting area and the mounting hole is D, where the value of D is in the range of: D≤30 mm; and / or, the distance between the edge of the first connecting area and the second connecting area connected to the mounting hole and the mounting hole is F, where the value of F is in the range of: F≥3 mm.

10. A battery, characterized in that, include: The shell has an open end; The electrode assembly is disposed within the inner cavity of the housing; The cover plate structure according to any one of claims 1 to 9 is provided over the opening end of the housing.

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