Lower plastic member and top cover assembly of battery, and battery

Abstract

A lower plastic member (13) and a top cover assembly (10) of a battery (1), and a battery (1). The lower plastic member (13) of a battery (1) comprises a lower plastic body (131), a deformable body (132), and a surrounding body (133), wherein the deformable body (132) is connected to the lower plastic body (131), and a first recess (134) is provided therebetween; the surrounding body (133) is connected to the deformable body (132), and a second recess (135) is provided therebetween; the second recess (135) and the first recess (134) are spaced apart by the deformable body (132), and the surrounding body (133) defines a terminal post through hole (133a); and the deformable body (132) is deformable within a space between the second recess (135) and the first recess (134).

Description

A lower plastic part of a battery, a top cover assembly and a battery

[0001] The present application claims priority to the Chinese patent application No. 202421151020.4, filed on May 23, 2024, to the Chinese Patent Office, the whole content of the above application being incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the field of battery manufacturing, in particular to a lower plastic part of a battery, a top cover assembly and a battery. BACKGROUND

[0003] In the manufacturing process of lithium-ion batteries, the design and function of the battery cover plate are crucial to the overall performance and safety of the battery. In the design of the cover plate, the cooperation between the pole and the lower plastic is a key link. The pole is a component that connects the internal and external circuits of the battery, while the lower plastic is part of the top cover, usually made of plastic material, used to form an electrical connection with the metal pole of the battery shell; the gap between the two can ensure the performance and safety of the battery. TECHNICAL PROBLEM

[0004] In the related art, a sealing ring is installed in the gap between the pole and the lower plastic to achieve insulation and sealing between the pole and the lower plastic. However, due to the manufacturing tolerances of the diameter of the pole and the diameter of the pole through hole provided on the lower plastic, changes in these tolerances can cause instability in the gap size. If the gap is too large, it may cause the risk of high voltage breakdown; if the gap is too small, the sealing ring may be squeezed against the lower plastic due to excessive expansion, causing the lower plastic to deform, which in turn affects the structural integrity and performance of the battery. In addition, when the electrolyte flows inside the battery, if the gap is not properly controlled, negative electrode powder may accumulate in these areas, leading to unstable voltage and aluminum shell corrosion. TECHNICAL SOLUTION

[0005] In a first aspect, the present application provides a lower plastic part of a battery, comprising a lower plastic body, a deformation body and a surrounding body, the deformation body being connected to the lower plastic body and having a first groove between the deformation body and the lower plastic body; and the surrounding body being connected to the deformation body and having a second groove between the surrounding body and the deformation body, the second groove being spaced from the first groove by the deformation body, the surrounding body defining a pole through hole; wherein the deformation body is capable of deforming in the space between the second groove and the first groove.

[0006] In a second aspect, the present application also provides a top cover assembly of a battery, comprising a pole, a sealing ring and a lower plastic part of a battery; the sealing ring being sleeved on the outer wall of the pole; the pole and the sealing ring being arranged in the pole through hole; wherein in the case of expansion of the sealing ring, the sealing ring is capable of squeezing the surrounding body and the deformation body and causing the deformation body to deform.

[0007] In a third aspect, the application further provides a battery comprising the top cover assembly provided by the application. Advantages

[0008] The battery lower plastic part, the top cover assembly and the battery provided by the application have the following advantages: when the surrounding body of the lower plastic part is subjected to an external force such as the expansion force of the sealing ring sleeved on the pole, the surrounding body transmits the force to the deformation body connected thereto, and the deformation body can be deformed in the space between the second groove and the first groove, that is, the deformation body is allowed to deform freely in a certain space, thereby improving the adaptability and impact resistance of the lower plastic part to mechanical stress, maintaining the overall stability of the battery, especially the stability of the top cover assembly of the battery; at the same time, the design of the deformation body allows the size and position of the assembly to be fine-tuned during assembly, ensuring accurate fitting between the lower plastic part and other components of the battery, and improving the overall assembly accuracy.

[0009] In actual use, the pole and the sealing ring sleeved on the pole can be arranged in the pole through hole of the lower plastic part, and the sealing ring is pressed against the lower plastic part during expansion, and the deformation body is deformed in the space between the first groove and the second groove, thereby avoiding the gap size being too large or too small due to unstable manufacturing tolerance. BRIEF DESCRIPTION OF DRAWINGS

[0010] Fig. 1 is a structural schematic diagram of a battery provided by the application;

[0011] Fig. 2 is an assembly schematic diagram of a top cover assembly provided by the application;

[0012] Fig. 3 is a structural exploded view of two lower plastic parts provided by the application;

[0013] Fig. 4 is a perspective view of a top cover assembly provided by the application;

[0014] Fig. 5 is a structural exploded view of a top cover assembly provided by the application;

[0015] Fig. 6 is a structural schematic diagram of a top cover assembly provided by the application;

[0016] Fig. 7 is a sectional view along the AA' section line in Fig. 6;

[0017] Fig. 8 is an enlarged view of part B in Fig. 1;

[0018] Fig. 9 is a structural schematic diagram of a top cover assembly provided by the application;

[0019] Fig. 10 is a sectional view along the CC' section line in Fig. 9;

[0020] Fig. 11 is an enlarged view of part D in Fig. 10.

[0021] BRIEF DESCRIPTION OF DRAWINGS

[0022] 1, battery; 10, top cover assembly; 11, pole; 12, sealing ring; 121, first sealing part; 122, second sealing part; 13, lower plastic part; 131, lower plastic body; 132, deformation body; 133, surrounding body; 133a, pole through hole; 134, first groove; 135, second groove. 20, top cover assembly; 21, pole; 22, sealing ring; 23, lower plastic part; 231, lower plastic body; 232, deformation body; 2321, first deformation part; 2322, second deformation part; 233, surrounding body; 233a, pole through hole; 234, first groove; 235, second groove; 236, third groove. Embodiments of the present application

[0023] Referring to FIG. 1, the present application provides a battery 1, which is an energy storage device capable of converting chemical energy into electrical energy. The basic components of the battery 1 include a top cover assembly 10, an electric core and a transition sheet, wherein the top cover assembly 10 is a part of the packaging of the battery 1, which covers the top of the battery 1 and plays a role in closing and protecting the internal structure of the battery 1.

[0024] Referring to FIGS. 2, 3, 4 and 5, in an implementation manner of the present application, the top cover assembly 10 includes a pole 11, a sealing ring 12 and a lower plastic part 13. Among them, the top cover assembly 10 can be provided with one or more lower plastic parts 13, and the number of lower plastic parts 13 can be flexibly adjusted according to the needs and specifications of the battery 1, so as to adapt to different battery 1 designs and application scenarios.

[0025] For example, the lower plastic part 13 is an insulating lower plastic part 13, which can provide an insulating barrier between the pole 11 of the battery 1 and the shell of the battery 1, prevent short circuit and arc generation, and ensure the safe operation of the battery 1.

[0026] For example, the lower plastic part 13 is provided with a pole through hole 133a, and the pole 11 is arranged in the pole through hole 133a. The design of the pole through hole 133a provides a stable mechanical support point for the pole 11, preventing the pole 11 from moving or deflecting inside the battery 1. The sealing ring 12 is at least partially arranged in the pole through hole 133a, and the sealing ring 12 is sleeved on the outer wall of the pole 11. The sealing ring 12 is arranged in the accommodation gap between the outer wall of the pole 11 and the inner wall of the pole through hole 133a, which can effectively prevent electrolyte leakage and external contaminants from entering the inside of the battery 1, thereby improving the sealing performance and protection level of the battery 1.

[0027] In other embodiments, the top cover assembly 10 further comprises a cover plate abutting against the pole 11 and the sealing ring 12 and extruding the sealing ring 12 to ensure the sealing performance of the battery 1. After being extruded, the sealing ring 12 expands and tightly adheres to the outer wall of the pole 11 and the lower plastic part 13. However, in actual applications, the sealing ring 12 will deform, such as expand, after being extruded to exert force on the lower plastic part 13. In order to release the force from the sealing ring 12 and ensure the performance of the top cover assembly 10, the lower plastic part 13 in the embodiments of the present application can at least partially deform to release the force from the sealing ring 12.

[0028] In one way, the surface of the lower plastic part 13, such as the lower plastic part 13, is designed to be not completely attached to the sealing ring 12. During the extrusion of the sealing ring 12 on the lower plastic part 13, the part attached to the sealing ring 12 can deform to release a part of the force from the sealing ring 12 to a certain extent. However, in actual applications, the sealing ring 12 is a flexible component. During the deformation, such as expansion, of the sealing ring 12 under the action of force, the sealing ring 12 and the lower plastic part 13 may not have good contact, thereby causing uneven force and poor release of the force.

[0029] As shown in FIGS. 6, 7 and 8, in one implementation of the embodiments of the present application, the lower plastic part 13 comprises a lower plastic body 131, a deformation body 132 and a surrounding body 133. The deformation body 132 is connected to the lower plastic body 131 and has a first groove 134 between the deformation body 132 and the lower plastic body 131. The surrounding body 133 is connected to the deformation body 132 and has a second groove 135 between the surrounding body 133 and the deformation body 132. The second groove 135 is spaced from the first groove 134 by the deformation body 132. The surrounding body 133 defines a pole through hole 133a. The deformation body 132 can deform in the space between the second groove 135 and the first groove 134, such as the surrounding body 133 under the action of force, which can be transmitted to the deformation body 132, so that the deformation body 132 deforms in the space between the second groove 135 and the first groove 134.

[0030] In the embodiments of the present application, when the surrounding body 133 of the lower plastic part 13 is subjected to external forces, such as the expansion force of the sealing ring 12 fitted on the pole 11, the surrounding body 133 transmits the force to the deformation body 132 connected thereto. The deformation body 132 can deform in the space between the second groove 135 and the first groove 134, that is, allow the deformation body 132 to freely deform in a certain space, thereby improving the adaptability and impact resistance of the lower plastic part 13 to mechanical stress, maintaining the overall stability of the battery 1, especially the stability of the top cover assembly 10 of the battery 1.

[0031] The design of the deformation body 132 allows fine-tuning of the size and position of the assembly during assembly, ensuring accurate fit between the lower plastic part 13 and other components of the battery 1, improving the overall assembly accuracy.

[0032] The surrounding body 133 defines a pole passage hole 133a, which helps to form a tight fit with other components of the top cover assembly 10 (such as the pole 11 and the sealing ring 12), thereby improving the sealing performance of the battery 1.

[0033] For example, the pole passage hole 133a is defined by the surrounding body 133, i.e. the distance between the lower plastic body 131, the deformation body 132 and the surrounding body 133 and the pole passage hole 133a decreases in turn, and the lower plastic body 131 is farthest from the pole passage hole 133a, which can provide stable base support, and the design of the deformation body 132 and the surrounding body 133 gradually decreasing the distance from the pole passage hole 133a helps to form a structure that transitions from stable to flexible, maintaining the overall stability of the lower plastic part 13 while allowing necessary local deformation.

[0034] For example, the sealing ring 12 disclosed in the embodiment is installed in the accommodation gap and abuts against the surrounding body 133, which can more effectively transmit the external force from the surrounding body 133 to the deformation body 132 when the sealing ring 12 is subjected to an external force, and the distance between the deformation body 132 and the pole passage hole 133a is less than the distance between the lower plastic body 131 and the pole passage hole 133a, which can ensure that deformation mainly occurs on the deformation body 132 when subjected to force, rather than on the entire lower plastic part 13. More precise control of local deformation avoids unnecessary overall deformation and protects the internal structure of the battery 1 from damage.

[0035] Compared to designing a deformation structure on the side of the surrounding body 133 that is in contact with the sealing ring 12 to relieve the force from the sealing ring 12, the deformation body 132 disclosed in the embodiment is arranged on the side of the surrounding body 133 away from the sealing ring 12, which can more evenly transmit the force applied by the sealing ring 12 to the deformation body 132 through the surrounding body 133 as an intermediate layer, reducing stress concentration that may be caused by directly designing a deformation structure on the surrounding body 133; and the direct and tight contact between the surrounding body 133 and the sealing ring 12 can provide a more stable sealing interface and reduce the gap between the surrounding body 133 and the sealing ring 12.

[0036] Exemplarily, the first groove 134 is arranged between the lower plastic body 131 and the deformation body 132, and the second groove 135 is arranged between the surrounding body 133 and the deformation body 132. If only one groove is arranged, the stress will be concentrated at one point, causing excessive deformation and increasing the risk of damage to the lower plastic part 13. Arranging two grooves can disperse and relieve the force received by the outside of the lower plastic part 13, so that the stress is more evenly distributed on the deformation body 132, improving the durability of the lower plastic part 13.

[0037] It should be noted that the deformation body 132 can be one structural part or at least two structural parts. For example, the deformation body 132 is one structural part in the embodiment of the present application.

[0038] Exemplarily, the surrounding body 133 can conduct the force to the deformation body 132, so that the deformation body 132 deforms in the space between the second groove 135 and the first groove 134. The arrangement of the first groove 134 and the second groove 135 provides a predetermined deformation space for the deformation body 132, thereby ensuring the sealing performance and overall performance of the battery 1 cover plate.

[0039] Exemplarily, the first groove 134 can be provided with at least one, and the at least one first groove 134 is arranged between the deformation body 132 and the lower plastic body 131. The at least one first groove 134 provides more deformation points, so that the deformation body 132 can more flexibly adapt and absorb the force when the force is received, thereby improving the deformation adaptability of the overall structure. Exemplarily, the deformation body 132 and the lower plastic body 131 have one first groove 134, and one first groove 134 of the embodiment of the present application is beneficial to simplify the design and manufacturing process of the overall structure. It should be understood that the first groove 134 of the embodiment of the present application is exemplified as one, and the number of the first groove 134 can also be designed as two or three, which will not be repeated here.

[0040] Exemplarily, the second groove 135 can be provided with at least one, and the at least one second groove 135 is arranged between the deformation body 132 and the surrounding body 133. The design of the at least one second groove 135 provides more design parameters, which can be adjusted according to the requirements and application conditions of the battery 1 to meet specific performance targets. Exemplarily, the surrounding body 133 and the deformation body 132 have one second groove 135, and one second groove 135 of the embodiment of the present application is beneficial to simplify the design and manufacturing process of the overall structure. It should be understood that the second groove 135 of the embodiment of the present application is exemplified as one, and the number of the second groove 135 can also be designed as two or three, which will not be repeated here.

[0041] Exemplarily, the space accommodating the gap is smaller than the theoretical expansion volume of the sealing ring 12 after being subjected to external force, so that the sealing ring 12 can extrude the surrounding body 133 and be transmitted to the deformation body 132 in the direction towards the lower plastic body 131 when being subjected to the force to expand, so as to completely fill the sealing ring 12 in the accommodating gap.

[0042] Exemplarily, the lower plastic body 131, the deformation body 132 and the surrounding body 133 are integrally formed, which ensures that there is no joint between each part of the lower plastic part 13, reduces the need for separate processing and subsequent assembly of multiple components and errors that may occur during the assembly process; and the upper surface and the lower surface of the lower plastic body 131, the deformation body 132 and the surrounding body 133 are flush with each other, so that the three still remain flat in the axial direction of the pole through hole 133a after the surrounding body 133 extrudes the deformation body 132, thereby improving stability.

[0043] Please continue to refer to FIG. 8, in an implementation manner of the embodiment of the application, the sealing ring 12 includes the first sealing part 121 and the second sealing part 122 connected with each other, one side of the first sealing part 121 away from the second sealing part 122 is attached to one side of the surrounding body 133 away from the deformation body 132, the attachment of the first sealing part 121 and the surrounding body 133 can be used as a stress buffer zone, one side of the second sealing part 122 away from the first sealing part 121 is sleeved on the outer wall of the pole 11, the second sealing part 122 provides additional fixation and support for the pole 11, and enhances the overall structural stability of the top cover assembly 10.

[0044] Exemplarily, the first sealing part 121 and the second sealing part 122 have a stepped structure, and the axial height of the second sealing part 122 along the pole through hole 133a is greater than the axial height of the first sealing part 121 along the pole through hole 133a, one side of the second sealing part 122 away from the first sealing part 121 abuts against the outer wall of the pole 11, and one side of the first sealing part 121 away from the second sealing part 122 abuts against the surrounding body 133, so that the second sealing part 122 can provide a wider contact area in the axial direction, and abut against the outer wall of the pole 11 more closely, thereby enhancing the sealing effect and effectively preventing the leakage of electrolyte or the invasion of other external contaminants.

[0045] The upper surface of the first sealing portion 121 and the upper surface of the surrounding body 133 are substantially flush, and the lower surface of the first sealing portion 121 and the lower surface of the surrounding body 133 are substantially flush, which ensures that the first sealing portion 121 uniformly extrudes the surrounding body 133, ensures the close fit between the first sealing portion 121 and the surrounding body 133, and forms a continuous sealing interface after extrusion, thereby improving the overall assembly quality. That is, the height of the first sealing portion 121 and the height of the surrounding body 133 are substantially equal, or the thickness of the first sealing portion 121 and the thickness of the surrounding body 133 are substantially equal. It should be noted that the size relationship between the first sealing portion 121 and the surrounding body 133 is not limited to this, such as the height of the first sealing portion 121 can be slightly greater than the height of the surrounding body 133.

[0046] For example, the side of the first sealing portion 121 away from the second sealing portion 122 abuts against the side of the surrounding body 133 away from the deformation body 132, which can maximize the contact area and uniformly distribute the force on the contact surface, reduce local stress concentration, and provide more reliable sealing abutment effect.

[0047] In an implementation manner of the embodiment of the present application, the opening direction of the first groove 134 is opposite to the opening direction of the second groove 135, so that when the surrounding body 133 is subjected to an external force, the first groove 134 and the second groove 135 with opposite opening directions can better guide the distribution of the force, and in the extrusion process, the groove space in the first groove 134 and the second groove 135 is eliminated, so that the contact surface between the surrounding body 133 and the sealing ring 12 can still be kept flat after extrusion, which helps to maintain good sealing abutment.

[0048] In an implementation manner of the embodiment of the present application, the deformation body 132 is arranged obliquely relative to the surrounding body 133 and the lower plastic body 131, and the oblique angle of the deformation body 132 relative to the surrounding body 133 is equal to the oblique angle of the deformation body 132 relative to the lower plastic body 131, that is, the longitudinal section of the lower plastic body 131, the deformation body 132 and the surrounding body 133 is in N shape or reverse N shape. The design of the same oblique angle makes the deformation body 132 produce expected deformation when extruded, and will not be deformed excessively or damaged. The longitudinal section design in N shape or reverse N shape helps the deformation body 132 to be in close contact with the surrounding body 133 and the lower plastic body 131 when subjected to force, and reduces the accumulation of negative pole powder in the first groove 134 and the second groove 135 during the flow of electrolyte.

[0049] It should be noted that it is also feasible that the oblique angle of the deformation body 132 relative to the surrounding body 133 is not equal to the oblique angle of the deformation body 132 relative to the lower plastic body 131.

[0050] For example, in an implementation form of the embodiment, the deformation body 132 is arranged in an arc shape or a curved segment shape relative to the surrounding body 133 and the lower plastic body 131, and the designer can flexibly adjust the inclination angle and shape of the deformation body 132, which will not be described here again.

[0051] It should be noted that the longitudinal section of the lower plastic body 131, the deformation body 132 and the surrounding body 133 can be in the shape of N, inverted N, M, W or curve, and the designer can adjust the inclination angle and size of the deformation body 132 relative to the lower plastic body 131 and the surrounding body 133 according to the needs, so as to adapt to different specifications and performance requirements of the battery 1 and provide greater design flexibility. Different structural forms of the deformation body 132 and different connection relationships between the deformation body 132, the lower plastic body 131 and the surrounding body 133 will be described below in combination with other drawings.

[0052] For example, in an implementation form of the embodiment, the thickness of the surrounding body 133 along the radial direction of the pole post through hole 133a is greater than the thickness of the deformation body 132 along the radial direction of the pole post through hole 133a, that is, the deformation body 132 is a deformation weak point. When the surrounding body 133 is subjected to external force, the deformation body 132 is more likely to deform in the preset first groove 134 and second groove 135 due to its thin thickness, thereby maintaining good sealing performance of the overall structure.

[0053] In an implementation form of the embodiment, the thickness of the deformation body 132 along the radial direction of the pole post through hole 133a is a, and a satisfies: 0.2mm≤a≤1.0mm. On the one hand, the thickness of the deformation body 132 in this range can ensure that it has sufficient strength to withstand certain mechanical stress and has certain toughness to adapt to deformation, thereby maintaining stability when the battery 1 is running and the external environment changes. On the other hand, during the charging and discharging process of the battery 1, the deformation body 132 may be affected by thermal expansion. The appropriate thickness can ensure that the deformation body 132 maintains stable performance under temperature changes, preventing deformation or damage caused by thermal expansion.

[0054] In an implementation form of the embodiment, the thickness of the surrounding body 133 along the radial direction of the pole post through hole 133a is b, and b satisfies: 0.6mm≤b≤2.0mm. The surrounding body 133 can maintain good structural strength and toughness, thereby maintaining stability when subjected to mechanical stress and extrusion, reducing the risk of damage, and the thickness of the surrounding body 133 directly affects its cooperation with the deformation body 132 and the lower plastic body 131. The appropriate thickness helps to improve the sealing performance of the battery 1 cover plate, preventing electrolyte leakage and other potential safety risks.

[0055] In an implementation form of the embodiment of the application, the difference between the thickness of the surrounding body 133 along the radial direction of the pole post through hole 133a and the thickness of the deformation body 132 along the radial direction of the pole post through hole 133a is c, and c satisfies: 0.2mm≤c≤1.8mm. By setting the thickness difference between the surrounding body 133 and the deformation body 132, it can be ensured that the deformation body 132 is more likely to produce the expected deformation when subjected to force, so that the deformation body 132 can be more closely attached to the lower plastic body 131 and the surrounding body 133 as a deformation weak point in the structure.

[0056] In an implementation form of the embodiment of the application, the first groove 134 and the second groove 135 are both arranged around the circumference of the pole post through hole 133a, that is, the first groove 134 is a first annular groove, and the second groove 135 is a second annular groove; the sealing ring 12 is an annular sealing ring 12, which can ensure that when the annular sealing ring 12 is pressed in the circumferential direction around the surrounding body 133, a good sealing effect in all directions is achieved, and a consistent deformation effect is achieved, so that the contact between the annular sealing ring 12 and the surrounding body 133 is more closely, preventing the structure of the lower plastic part 13 from being damaged due to uneven deformation.

[0057] In an implementation form of the embodiment of the application, the first groove 134 and the second groove 135 are symmetrically arranged with respect to the deformation body 132. The symmetrically arranged first groove 134 and the second groove 135 help to produce uniform and balanced deformation when the deformation body 132 is subjected to force, avoiding structural damage or functional failure due to uneven deformation.

[0058] In an implementation form of the embodiment of the application, the width of any one or both of the first groove 134 and the second groove 135 gradually decreases from the opening to the bottom thereof. The gradual decrease of the groove width can reduce the stress concentration at the opening of the groove, while providing better support at the bottom of the groove to prevent excessive deformation or damage.

[0059] In the implementation form, the widest part of the opening of the first groove 134 and the second groove 135 or one of the two is the upper surface and the lower surface of the lower plastic part 13. The wider part of the opening of the first groove 134 and the second groove 135 or one of the two will deform first, and as the deformation goes deeper into the first groove 134 and the second groove 135 or one of the two, the deformation is gradually limited, which can more accurately control the deformation process and range.

[0060] For example, the depth of the first groove 134 and the second groove 135 disclosed in the embodiment is less than the axial height of the deformation body 132 along the pole post through hole 133a. It can be understood that the first groove 134 and the second groove 135 are not arranged through, avoiding the negative pole powder accumulation to lap the pole post 11 and the cover plate, causing voltage failure and aluminum shell corrosion.

[0061] The battery 1 of the embodiments of the present application can be a lithium battery, which is a rechargeable battery 1 based on lithium and is widely used in portable electronic devices, power tools, electric vehicles, energy storage systems and other fields. The lithium battery has become the preferred power solution in modern electronic devices due to its high energy density, low self-discharge rate, long service life and good temperature adaptability. The lithium battery includes a top cover assembly 10, which is a key part in the structure of the lithium battery and is located at the top of the battery 1 to connect the internal and external circuits of the battery 1 and ensure the sealing and safety of the battery 1. It can be understood that the battery 1 of the embodiments of the present application is not limited to a lithium battery.

[0062] For example, as shown in FIGS. 9, 10 and 11, the difference between the top cover assembly 20 and the top cover assembly 10 of the embodiments of the present application at least includes that the lower plastic part 23 includes at least three grooves, such as the lower plastic part 23 including the first groove 234, the third groove 236 and the second groove 235 arranged in sequence.

[0063] The other structural parts of the top cover assembly 20 except the lower plastic part 23 can refer to the top cover assembly 10, such as the pole 21 and the sealing ring 22 of the top cover assembly 20, which can refer to the pole 11 and the sealing ring 12 respectively, and the embodiments of the present application will not be described here.

[0064] The first groove 234 is formed between the deformation body 232 and the lower plastic body 231 of the lower plastic part 23, and the second groove 235 is formed between the deformation body 232 and the surrounding body 233 of the lower plastic part 23. For example, the opening directions of the first groove 234 and the second groove 235 are the same.

[0065] The deformation body 232 includes at least one groove, such as the deformation body 232 including a third groove 236. For example, the deformation body 232 includes a first deformation part 2321 and a second deformation part 2322 connected in sequence, and the first deformation part 2321 and the second deformation part 2322 have the third groove 236 therebetween.

[0066] The opening direction of the third groove 236 is opposite to the opening directions of the first groove 234 and the second groove 235, and the deformation body 232 is arranged obliquely relative to the surrounding body 233 and the lower plastic body 231, that is, the longitudinal section of the lower plastic body 231, the deformation body 232 and the surrounding body 233 is in the shape of M or W. The first deformation part 2321 can be deformed in the first groove 234 and the third groove 236, and the second deformation part 2322 can be deformed in the third groove 236 and the second groove 235, which helps to accurately control the position and degree of deformation.

[0067] The structure of the lower plastic body 231 can refer to the lower plastic body 131, the structure of the surrounding body 233 can refer to 133, and the pole through hole 233a defined by the surrounding body 233 can refer to the pole through hole 133a. Details are not repeated here.

[0068] The shapes of the first deformed part 2321 and the second deformed part 2322 can be the same or different. Details of the first deformed part 2321 and the second deformed part 2322 can refer to the deformed body 132.

[0069] The difference between the lower plastic part 23 and the lower plastic part 13 includes that the first groove 234 and the second groove 235 are arranged in axial symmetry, and the first groove 134 and the second groove 135 are arranged in central symmetry.

[0070] In an implementation of the embodiment, the deformed body further includes three deformed parts, and the deformed body can further include two grooves. For example, the deformed body includes a first deformed part, a second deformed part, and a third deformed part connected in sequence. The first deformed part and the second deformed part define a third groove therebetween, and the second deformed part and the third deformed part define a fourth groove therebetween. The deformed body and the surrounding body define a second groove therebetween, and the deformed body and the lower plastic body define a first groove therebetween. The first groove and the third groove are adjacent and have opposite opening directions. The second groove and the fourth groove are adjacent and have opposite opening directions. The third groove and the fourth groove are adjacent and have opposite opening directions. The grooves with different opening directions help to optimize the force transmission path, so that the force can be more evenly distributed, thereby improving the mechanical properties of the entire assembly.

[0071] The opening directions of the grooves of the lower plastic part 13 disclosed in the embodiment have a certain rule, such as the opening directions of adjacent grooves being opposite, which helps to simplify the mold design and manufacturing process, and reduces the production cost.

Claims

1. A lower plastic part of a battery, comprising: a lower plastic body; a deformation body connected to the lower plastic body, and having a first groove between the deformation body and the lower plastic body; and a surrounding body connected to the deformation body, and having a second groove between the surrounding body and the deformation body, the second groove being spaced from the first groove by the deformation body, the surrounding body defining a pole post through hole; wherein the deformation body is capable of deforming in the space between the second groove and the first groove. The opening direction of the first groove is opposite to the opening direction of the second groove.

2. The lower plastic piece of the battery according to claim 1, wherein, The deformation body comprises a first deformation part and a second deformation part connected to each other, and a third groove between the first deformation part and the second deformation part; 3. The lower plastic battery of claim 1, wherein, wherein the opening direction of the third groove is opposite to the opening direction of the first groove and the opening direction of the second groove, and the opening direction of the first groove is the same as the opening direction of the second groove. The thickness of the surrounding body along the radial direction of the pole post through hole is greater than the thickness of the deformation body along the radial direction of the pole post through hole.

4. The lower plastic part of the battery according to any one of claims 1 to 3, wherein, The thickness of the deformation body along the radial direction of the pole post through hole is a, the thickness of the surrounding body along the radial direction of the pole post through hole is b, the difference between the thickness of the surrounding body along the radial direction of the pole post through hole and the thickness of the deformation body along the radial direction of the pole post through hole is c, the a, b and c can satisfy any one or both of the following conditions: 0.2mm≤a≤1.0mm;0.6mm≤b≤2.0mm;0.2mm≤c≤1.8mm.

5. The lower plastic battery of claim 4, wherein, The deformation body is arranged obliquely relative to the surrounding body and the lower plastic body, and the oblique angle of the deformation body relative to the surrounding body is equal to the oblique angle of the deformation body relative to the lower plastic body.

6. The lower plastic battery component of any of claims 1-3, wherein, The first groove and the second groove can be arranged along the circumferential direction of the pole post through hole, can be symmetrically arranged relative to the deformation body, or can be a combination of the above two.

7. The lower plastic battery component of any of claims 1-3, wherein, The width of any one or both of the first groove and the second groove gradually decreases from the opening to the bottom thereof.

8. The lower plastic battery component of any of claims 1-3, wherein, 9.A top cover assembly of a battery, comprising: a pole post; a sealing ring sleeved on the outer wall of the pole post; and the lower plastic part of the battery according to any one of claims 1-8, the pole post and the sealing ring being sleeved in the pole post through hole; wherein the sealing ring is capable of extruding the surrounding body and the deformation body and causing the deformation body to deform when the sealing ring expands. The sealing ring comprises a first sealing part and a second sealing part connected to each other, the side of the first sealing part away from the second sealing part being attached to the side of the surrounding body away from the deformation body, and the side of the second sealing part away from the first sealing part being sleeved on the outer wall of the pole post. The axial height of the second sealing part along the pole post through hole is greater than the axial height of the first sealing part along the pole post through hole.

10. The top cover assembly of a battery as claimed in claim 9, wherein, ​ 11. The top cover assembly of a battery as claimed in claim 10, wherein, ​ An upper surface of the first sealing portion and an upper surface of the surround are substantially flush, and a lower surface of the first sealing portion and a lower surface of the surround are substantially flush.

12. A battery comprising the top cover assembly of any one of claims 9-11.

Images