Battery cell cover plate assembly, battery cell and battery pack

Abstract

The present invention relates to the technical field of batteries, and discloses a battery cell cover plate assembly, a battery cell and a battery pack, the battery cell cover plate assembly comprises a cover plate, and the cover plate is provided with a first through hole; the pole column is mounted in the first through hole, the pole column comprises a first sub-pole column, a second sub-pole column and a third sub-pole column, the first sub-pole column extends into the second sub-pole column and abuts against the second sub-pole column, and the third sub-pole column is arranged on the first sub-pole column in a sleeving manner and is mounted in the second sub-pole column; the second sub-pole is connected with the third sub-pole in a welding manner to form a welding seam; the sealing ring is arranged on the first sub-pole in a sleeving manner and is respectively propped against the first sub-pole, the second sub-pole, the third sub-pole and the cover plate, and the sealing ring covers the welding seam. The pole provided by the invention is simple to form, and the connection reliability between the sub-poles is high; the sealing ring is arranged on the first sub-pole in a sleeving manner, and the sealing ring covers the welding seam, so that the condition that the copper layer and the aluminum layer of the pole fall off due to corrosion of an aluminum material below the welding seam is prevented, and the electrical safety of the battery cell is improved.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a battery cover assembly, a battery cell and a battery pack. Background Art

[0002] As new energy battery technology becomes increasingly mature, new energy batteries are widely used as power batteries in electric vehicles and energy storage fields, and the performance requirements for new energy batteries are increasing.

[0003] In related technologies, new energy batteries are composed of multiple battery cells, and the battery cells generally include a cover assembly, an electrode group and a shell. Currently, the pole of the negative terminal in the cover assembly is complex to form, and the copper layer and the aluminum layer of the pole are easy to fall off, which makes the battery cell unable to be used normally. Summary of the Invention

[0004] In view of this, the present invention provides a battery cover assembly, a battery cell and a battery pack to solve the problem of easy detachment between the copper layer and the aluminum layer of the pole.

[0005] In a first aspect, the present invention provides a battery cell cover assembly, comprising:

[0006] a cover plate, wherein a first through hole is provided on the cover plate;

[0007] A pole, mounted in the first through hole, the pole comprising a first sub-pole, a second sub-pole, and a third sub-pole, the first sub-pole extending into the second sub-pole and abutting against the second sub-pole, the third sub-pole sleeved on the first sub-pole and mounted in the second sub-pole;

[0008] The second sub-pole is welded to the third sub-pole to form a weld;

[0009] The sealing ring is sleeved on the first sub-pole and respectively abuts the first sub-pole, the second sub-pole, the third sub-pole and the cover plate, and the sealing ring covers the weld.

[0010] Beneficial effect: By extending the first sub-pole into the second sub-pole, and sleeved the third sub-pole on the first sub-pole, and then installing the third sub-pole in the second sub-pole, the second sub-pole and the third sub-pole are welded to form a weld, so that the first sub-pole, the second sub-pole and the third sub-pole cooperate with each other to form a pole, and then the pole is installed in the first through hole on the cover plate, the reliability of the connection between the sub-poles can be effectively improved, and the sub-poles can be prevented from falling off. The sealing ring is further sleeved on the first sub-pole, so that the sealing ring is respectively in contact with the first sub-pole, the second sub-pole, the third sub-pole and the cover plate, and the sealing ring covers the weld to prevent the aluminum material under the weld from corroding and causing the copper layer and the aluminum layer of the pole to fall off, thereby improving the electrical safety of the battery cell; and the pole provided by the present invention is simple to form, which can effectively improve the forming efficiency of the pole.

[0011] In an optional embodiment, the distance c between the outer peripheral edge of the sealing ring and the weld satisfies 0.5 mm ≤ c ≤ 2 mm.

[0012] In an optional embodiment, the penetration depth of the weld is greater than the thickness of the third sub-pole, and the distance b by which the penetration depth of the weld exceeds the thickness of the third sub-pole satisfies 0.3 mm ≤ b ≤ 1 mm.

[0013] In an optional embodiment, the method further includes:

[0014] an upper plastic ring, sleeved on the first sub-pole, the upper plastic ring comprising a plastic ring body and a first ring body arranged on the outer periphery of the plastic ring body;

[0015] A connecting piece is abutted against the plastic ring body and is arranged in the first ring body. The connecting piece is connected to the first sub-pole.

[0016] In an optional embodiment, the first sub-pole includes a column, a first connecting portion provided at the top of the column, and a second connecting portion provided at the bottom of the column;

[0017] The first connecting portion is provided with a first flange, the connecting member is provided with a limiting step, and the first flange abuts against the limiting step.

[0018] In an optional embodiment, the second sub-pole includes a second sub-pole body and a second ring body arranged on the outer periphery of the second sub-pole body, and the second connecting portion and the third sub-pole are both arranged in the second ring body;

[0019] The upper surface of the second connecting portion abuts against the lower surface of the third sub-pole, and the lower surface of the second connecting portion abuts against the upper surface of the second sub-pole body.

[0020] In an optional embodiment, the thickness a of the second sub-pole body satisfies 0.6 mm ≤ a ≤ 1.5 mm.

[0021] In an optional embodiment, an insulating member is further included, which abuts between the cover plate and the second sub-pole; a second through hole corresponding to the first through hole is provided on the insulating member, and the pole is installed in the second through hole.

[0022] In a second aspect, the present invention further provides a battery cell, comprising:

[0023] The battery cell cover assembly as described above;

[0024] A housing having a receiving cavity and an opening communicating with the receiving cavity, wherein the cell cover assembly covers the opening;

[0025] The pole group is arranged in the accommodating cavity, and the pole group is provided with a pole ear, and the pole ear is electrically connected to the pole column.

[0026] Beneficial effects: The battery cell shell and the battery cell cover assembly form a closed space that can effectively protect the electrode group and other internal components from external physical damage, such as collisions and extrusions. It can also prevent dust, moisture, and other impurities from entering the accommodating cavity, avoiding affecting the normal operation of the battery cell and reducing the probability of faults such as short circuits and corrosion. The electrode group is placed in the accommodating cavity and then sealed with the cover assembly. This assembly method is simple and efficient, and the cover can be opened relatively conveniently for maintenance or replacement of internal components. By electrically connecting the tabs to the poles, the intermediate links and resistance of current transmission are reduced, allowing current to flow more quickly and efficiently between the electrode group and the external circuit, thereby improving the charge and discharge performance of the battery cell.

[0027] In a third aspect, the present invention further provides a battery pack comprising: a plurality of battery cells as described above.

[0028] Beneficial effects: Since the battery pack includes battery cells, it has the same effects as the battery cells and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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.

[0030] Figure 1 This is a three-dimensional diagram of a battery cover assembly according to an embodiment of the present invention;

[0031] Figure 2 for Figure 1 A top view of the cell cover assembly shown;

[0032] Figure 3 for Figure 2 Cross-sectional view along AA direction;

[0033] Figure 4 for Figure 3 A partial enlarged schematic diagram of B in the middle;

[0034] Figure 5 This is an exploded view of a battery cell cover assembly according to an embodiment of the present invention;

[0035] Figure 6 This is a partial schematic diagram of a battery cell cover assembly according to another embodiment of the present invention;

[0036] Figure 7 This is a three-dimensional diagram of a battery cell cover assembly according to another embodiment of the present invention.

[0037] Description of reference numerals:

[0038] 100. Battery cell cover assembly; 110. Cover; 111. First through hole; 120. First sub-pole; 121. Column; 122. First connecting portion; 1221. First flange; 123. Second connecting portion; 130. Second sub-pole; 131. Second sub-pole body; 132. Second coil; 140. Third sub-pole; 150. Sealing ring; 160. Insulating member; 161. Second through hole; 170. Upper plastic ring; 171. Plastic ring body; 172. First coil; 173. Third through hole; 180. Connector; 181. Limiting step; 190. Weld. DETAILED DESCRIPTION

[0039] 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.

[0040] The following combination Figures 1 to 7 , describing embodiments of the present invention.

[0041] According to an embodiment of the present invention, on the one hand, referring to Figures 1 to 5, provides a battery cell cover assembly 100, including: a cover 110, a first through hole 111 is provided on the cover 110; a pole, installed in the first through hole 111, the pole including a first sub-pole 120, a second sub-pole 130 and a third sub-pole 140, the first sub-pole 120 extends into the second sub-pole 130 and abuts against the second sub-pole 130, the third sub-pole 140 is sleeved on the first sub-pole 120 and installed in the second sub-pole 130; the second sub-pole 130 and the third sub-pole 140 are welded to form a weld 190; a sealing ring 150, sleeved on the first sub-pole 120, and the first sub-pole 120, the second sub-pole 130, the third sub-pole 140 and the cover 110 abut respectively, and the sealing ring 150 covers the weld 190.

[0042] In this embodiment, the cover plate 110 can be a plain aluminum plate, and a first through hole 111 is provided in the middle of the plain aluminum plate, wherein the shape of the first through hole 111 can be circular. By reasonably setting the position of the first through hole 111, during the process of assembling the components on the cover plate 110, the operator can more clearly distinguish the purpose of the through holes in different positions, thereby improving the assembly efficiency. It can also facilitate the operator to quickly locate and deal with problems related to specific through holes during maintenance, and can also maintain the structural strength of the cover plate 110 to the greatest extent while ensuring the functions of other components on the cover plate 110. The pole is a conductive interface connecting the battery cell to the external circuit, which is responsible for the input or output of current. The negative pole and the positive pole together constitute the external electrical interface of the battery cell. The pole in this embodiment can be a negative pole, which is a conductive connection terminal of the negative pole of the battery cell, responsible for conducting the current inside the battery cell to the external circuit. The negative electrode post is installed in the first through hole 111. The shape of the post is a circular body that matches the shape of the first through hole 111. The shapes of the first through hole 111 and the post can be any shape and are not limited to circular. The specific shape can be selected according to actual usage requirements.

[0043] Furthermore, the pole includes a first sub-pole 120, a second sub-pole 130 and a third sub-pole 140, wherein the first sub-pole 120 can be made of aluminum, the second sub-pole 130 and the third sub-pole 140 can be made of copper, and the first sub-pole 120, the second sub-pole 130 and the third sub-pole 140 can all be formed by stamping or piercing. The first sub-pole 120 is extended into the second sub-pole 130 so that the first sub-pole 120 abuts against the second sub-pole 130; the third sub-pole 140 is sleeved on the first sub-pole 120, and then the third sub-pole 140 is installed in the second sub-pole 130 so that the third sub-pole 140 abuts against the second sub-pole 130; the abutting portion of the second sub-pole 130 and the third sub-pole 140 is welded to form a weld 190, so that the first sub-pole 120, the second sub-pole 130 and the third sub-pole 140 cooperate with each other to form a pole, and then the pole is installed in the first through hole 111 on the cover plate 110, which can effectively improve the reliability of the connection between the sub-poles and prevent the sub-poles from falling off. The weld refers to the joint formed by solidifying molten metal at the parent material connection through the welding process; that is, the joint formed by solidifying molten metal at the connection between the second sub-pole 130 and the third sub-pole 140 in this embodiment.

[0044] Furthermore, the sealing ring 150 is sleeved on the first sub-pole 120 so that the sealing ring 150 abuts against the first sub-pole 120, the second sub-pole 130, the third sub-pole 140 and the cover plate 110 respectively; the sealing ring 150 can fill the tiny gap between the pole and the cover plate 110, effectively preventing external dust, moisture and other impurities from entering the battery cell, avoiding short circuits or corrosion inside the battery cell, and ensuring the normal operation and service life of the battery cell. It can also further play a buffering role during the operation of the battery cell, and reduce direct collision and wear between the pole and the cover plate 110, reducing the risk of loose connection or damage due to vibration. By covering the weld 190 with the sealing ring 150, the aluminum material under the weld 190 can be prevented from corroding and causing the copper layer and aluminum layer of the pole to fall off, thereby improving the electrical safety of the battery cell; and the pole provided by the present invention is simple to form, which can effectively improve the forming efficiency of the pole.

[0045] In other possible implementations, the sealing ring may be a rubber sealing ring, a fluororubber sealing ring, a silicone rubber sealing ring, etc., and the specific selection may be based on actual usage requirements.

[0046] like Figure 7As shown, in other possible implementations, the cover plate 110 is provided with two first through holes 111, which are respectively provided at both ends of the cover plate 110, and the positive electrode post and the negative electrode post are respectively installed in the two first through holes 111. It is understandable that the number of through holes provided on the cover plate 110 can be set according to needs.

[0047] When there is a cold weld or broken area between the second sub-pole 130 and the third sub-pole 140, the aluminum material under the weld 190 area will be exposed. Under the action of the electrolyte, a primary battery will be formed between the copper and aluminum, and electrochemical corrosion will occur. The aluminum material with low potential will be corroded, causing the pole to break.

[0048] Therefore, if Figures 2 to 4 As shown, in one embodiment, the distance c between the outer peripheral edge of the sealing ring 150 and the weld 190 satisfies 0.5 mm ≤ c ≤ 2 mm.

[0049] In this embodiment, while the sealing ring 150 covers the weld 190, the outer edge of the sealing ring 150 extends beyond the weld 190, so that the distance c from the outer edge of the sealing ring 150 to the weld 190 is greater than or equal to 0.5 mm. Specifically, it can be 0.5 mm, 0.8 mm, 1 mm, 1.3 mm, 1.5 mm, 1.8 mm, 2 mm, etc. The specific distance c can be set according to actual usage requirements and is not specifically limited. If the distance c from the outer edge of the sealing ring 150 to the weld 190 is too small, for example, less than 0.5 mm, the sealing ring 150 may not effectively cover the weld 190, resulting in the weld 190 being directly exposed to a corrosive environment. Under the action of the electrolyte, electrochemical corrosion occurs between the copper and aluminum, resulting in terminal fracture. If the distance c from the outer edge of the sealing ring 150 to the weld 190 is too large, for example, greater than 2 mm, the sealing ring 150 will occupy too much space, which is not conducive to the assembly of other components in the battery cell cover assembly 100. By setting a suitable distance c, the weld 190 can be effectively sealed to prevent the weld 190 from being directly exposed to a corrosive environment, thereby further preventing the pole from being broken.

[0050] In one embodiment, the penetration depth of the weld 190 is greater than the thickness of the third sub-pole 140 , and the distance b by which the penetration depth of the weld 190 exceeds the thickness of the third sub-pole 140 satisfies 0.3 mm ≤ b ≤ 1 mm.

[0051] In this embodiment, the penetration of weld 190 is the distance between the deepest point of the melted portion of the base metal and the base metal surface during welding. The base metal is the workpiece material being welded, i.e., the metal body to be joined. In this embodiment, the third sub-pole 140 is the base metal, and the penetration of weld 190 is the distance from the deepest point of the melted portion of the third sub-pole 140 to the upper surface of the third sub-pole 140. First, the penetration of weld 190 must be greater than the thickness of the third sub-pole 140 to ensure that weld 190 completely penetrates the third sub-pole 140, thereby forming a full penetration weld and ensuring the mechanical strength and airtightness of the connection between the second sub-pole 130 and the third sub-pole 140. If the penetration is less than the thickness of the third sub-pole 140, weld 190 may only bond the surfaces of the second and third sub-pole 130, 140, while not fully penetrating the interior. This may result in a weak connection between the second and third sub-pole 130, 140 and may be prone to cracking. Furthermore, it is also necessary to ensure that the distance b by which the penetration depth of the weld 190 exceeds the thickness of the third sub-pole 140 satisfies 0.3mm≤b, that is, the distance from the deepest point of the weld 190 to the lower surface of the third sub-pole 140 needs to be greater than or equal to 0.3mm, which can be specifically 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc., and can be set according to actual usage requirements without specific restrictions.

[0052] If b is too small, for example, less than 0.3 mm, the internal resistance between the first sub-pole 120 and the second sub-pole 130 will be too large, resulting in a large temperature rise in the battery cell. If b is too large, for example, greater than 1 mm, welding deformation may occur after the second sub-pole 130 and the third sub-pole 140 are welded, and it is easy for a hole to appear on the weld 190. That is, during the welding process, a hole-like defect such as a hole, air hole, or explosion pit formed on the surface or inside the weld will cause the connection between the first sub-pole 120 and the second sub-pole 130 to be discontinuous, thereby increasing the internal resistance of the poles. By setting an appropriate distance b, the weld 190 can be made to completely penetrate the thickness of the third sub-pole 140, while ensuring the reliability of the connection between the second sub-pole 130 and the third sub-pole 140, and the resistance between the first sub-pole 120 and the second sub-pole 130 and the third sub-pole 140 can be guaranteed.

[0053] In one embodiment, it further includes: an upper plastic ring 170, which is sleeved on the first sub-pole 120, and the upper plastic ring 170 includes a plastic ring body 171 and a first ring body 172 arranged on the outer periphery of the plastic ring body 171; a connecting member 180, which abuts on the plastic ring body 171 and is arranged in the first ring body 172, and the connecting member 180 is connected to the first sub-pole 120.

[0054] In this embodiment, a third through-hole 173 is further defined in the plastic ring body 171 of the upper plastic ring 170. The upper plastic ring 170 is sleeved onto the first sub-pole 120, allowing the first sub-pole 120 to fit within the third through-hole 173 and allowing the plastic ring body 171 to abut against the top of the cover plate 110. A connector 180 is disposed within the first ring body 172, abutting against the plastic ring body 171 and the inner wall of the first ring body 172. The connector 180 can be connected to the first sub-pole 120. Through the mutual abutment between the connector 180 and the first sub-pole 120, the upper plastic ring 170 can be secured between the first sub-pole 120 and the cover plate 110 without the need for additional connectors, thereby improving space utilization within the battery cell. During operation, the battery cell may be subject to vibration or impact. The upper plastic ring 170 also acts as a buffer, reducing direct impact and wear between the first sub-pole 120 and the cover plate 110, and reducing the risk of loosening or damage to the connection due to vibration. Furthermore, the upper plastic ring 170 has excellent insulation properties, preventing accidental conductive contact between the first sub-pole 120 and the cover plate 110, thereby further improving the electrical safety of the battery cell.

[0055] In one embodiment, the first sub-pole 120 includes a column 121, a first connecting portion 122 arranged at the top of the column 121, and a second connecting portion 123 arranged at the bottom of the column 121; a first flange 1221 is provided on the first connecting portion 122, and a limiting step 181 is provided on the connecting member 180, and the first flange 1221 abuts against the limiting step 181.

[0056] In this embodiment, the first sub-pole 120 is composed of a column 121, a first connecting portion 122 disposed at the top of the column 121, and a second connecting portion 123 disposed at the bottom of the column 121. The diameter of the first connecting portion 122 is smaller than that of the column 121, and the diameter of the second connecting portion 123 is larger than that of the column 121. A first flange 1221 is provided at the top of the first connecting portion 122, and a limiting step 181 is provided on the connector 180. The first flange 1221 abuts against the limiting step 181, and the top of the column 121 abuts against the lower surface of the connector 180, thereby forming a riveted structure between the connector 180 and the first sub-pole 120, thereby fixing the connector 180 and the first sub-pole 120 to the cell cover assembly 100. Riveting the connector 180 to the first sub-pole 120 can effectively limit the movement of the first sub-pole 120 and prevent it from being displaced due to vibration or other external forces during operation, thereby ensuring the reliability of the connection of the first sub-pole 120.

[0057] like Figure 6As shown, in other possible implementations, the first sub-pole 120 in the cell cover assembly 100 includes a column 121 and a second connecting portion 123. A through-hole is provided in the connector 180, and the column 121 is disposed within the through-hole and abuts against the inner wall of the through-hole. Welding is then performed at the abutment between the column 121 and the inner wall of the through-hole to securely connect the first sub-pole 120 to the connector 180. The connection method between the first sub-pole 120 and the connector 180 can be selected based on actual usage requirements and is not specifically limited.

[0058] In one embodiment, the second sub-pole 130 includes a second sub-pole body 131 and a second ring body 132 arranged on the outer periphery of the second sub-pole body 131, and the second connecting portion 123 and the third sub-pole 140 are both arranged in the second ring body 132; the upper surface of the second connecting portion 123 abuts against the lower surface of the third sub-pole 140, and the lower surface of the second connecting portion 123 abuts against the upper surface of the second sub-pole body 131.

[0059] In this embodiment, the second sub-pole 130 is disposed below the first sub-pole 120 and comprises a second sub-pole body 131 and a second ring body 132 disposed around the outer periphery of the second sub-pole body 131. The second connecting portion 123 is disposed within the second ring body 132, with the lower surface of the second connecting portion 123 abutting against the upper surface of the second sub-pole body 131, and the outer periphery of the second connecting portion 123 abutting against the inner wall of the second ring body 132. The third sub-pole 140 is then positioned within the second ring body 132, abutting the inner wall of the second ring body 132 and with its lower surface abutting the upper surface of the second connecting portion 123. The third sub-pole 140 is then welded to the second sub-pole 130. A groove is formed between the third sub-pole 140 and the second sub-pole body 131, allowing the second connecting portion 123 to be retained within the groove. Thus, the first sub-pole 120, the second sub-pole 130, and the third sub-pole 140 cooperate to form a pole. This pole structure is simple to form and has high connection strength, effectively preventing the first sub-pole 120, the second sub-pole 130, and the third sub-pole 140 from easily falling off due to stress.

[0060] In one embodiment, the thickness a of the second sub-pole body 131 satisfies 0.6 mm ≤ a ≤ 1.5 mm.

[0061] In this embodiment, the thickness a of the second sub-pole body 131 can be specifically 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, etc., and can be set according to actual needs. The lower surface of the second sub-pole body 131 can be welded to the battery cell tab or connecting piece, so that the pole can be electrically connected to the battery cell tab or connecting piece. When the second sub-pole 130 is welded to the battery cell tab or connecting piece, the penetration depth generally fluctuates between 0.1mm-0.5mm. By reasonably setting the thickness a of the second sub-pole body 131, the second sub-pole body 131 can be effectively prevented from being welded through, thereby ensuring the electrical performance between the pole and the battery cell tab or connecting piece. The penetration depth is the vertical depth of the welding material melted into the second sub-pole body 131 when the second sub-pole body 131 is welded to the battery cell tab or connecting piece. If the thickness a of the second sub-pole body 131 is too small, for example, less than 0.6 mm, the second sub-pole body 131 may be welded through when the lower surface of the second sub-pole body 131 is welded to the battery cell tab or connecting piece, causing the weld to penetrate the first sub-pole 120, thereby corroding the first sub-pole 120 and causing the pole to break. If the thickness a of the second sub-pole body 131 is too large, for example, greater than 1.5 mm, the second sub-pole 130 will occupy too much height space in the battery cell, increasing material costs and making stamping difficult.

[0062] In one embodiment, an insulating member 160 is further included, which is in contact between the cover plate 110 and the second sub-pole 130 . A second through hole 161 corresponding to the first through hole 111 is provided on the insulating member 160 , and the pole is installed in the second through hole 161 .

[0063] In this embodiment, the upper surface of the insulating member 160 abuts the lower surface of the cover plate 110, and the lower surface of the insulating member 160 partially abuts the second sub-pole 130. Positioning the insulating member 160 between the cover plate 110 and the second sub-pole 130 prevents accidental conductive contact between the second sub-pole 130 and the cover plate 110, further improving the electrical safety of the battery cell. A second through-hole 161 corresponding to the first through-hole 111 is provided on the insulating member 160. The pole is installed in the second through-hole 161, facilitating the pole to pass through the first and second through-holes 111, 161, and then be fixedly connected to the connector 180.

[0064] The cell cover plate assembly 100 provided by the present invention was tested, as shown in Table 1:

[0065] Table 1

[0066]

[0067]

[0068] It can be seen from Table 1 that by reasonably setting the parameters of the distance c between the outer edge of the sealing ring 150 and the weld 190, the distance b at which the penetration depth of the weld 190 exceeds the thickness of the third sub-pole 140, and the thickness a of the second sub-pole body 131, the resistance between the first sub-pole 120 and the second sub-pole 130 can be effectively reduced, thereby preventing the battery cell from heating excessively; and the electrolyte can be effectively prevented from penetrating into the weld, thereby reducing the possibility of pole breakage.

[0069] In a second aspect, the present invention further provides a battery cell, comprising: a battery cell cover assembly 100; a shell having a receiving cavity and an opening connected to the receiving cavity, the battery cell cover assembly 100 sealing the opening; a pole group, disposed in the receiving cavity, with a pole ear on the pole group, the pole ear being electrically connected to the pole column.

[0070] In this embodiment, the shell of the battery cell and the battery cell cover assembly 100 form a closed space, which can effectively protect the electrode group and other internal components from external physical damage, such as collision, extrusion, etc.; it can also prevent dust, moisture and other impurities from entering the accommodating cavity, avoid affecting the normal operation of the battery cell, and reduce the probability of faults such as short circuits and corrosion. The electrode group is set in the accommodating cavity and then sealed with the cover 110 assembly. This assembly method is simple and efficient, and when maintenance or replacement of internal components is required, the cover 110 can also be opened relatively conveniently for operation. By electrically connecting the pole ear to the pole column, the intermediate links and resistance of current transmission are reduced, and the current can flow more quickly and efficiently between the pole group and the external circuit, thereby improving the charge and discharge performance of the battery cell.

[0071] In this embodiment, the battery cell may be a secondary battery cell. A secondary battery cell refers to a battery cell that can be recharged to activate active materials after being discharged and can be used continuously.

[0072] The battery cell can be a lithium ion battery cell, a sodium ion battery cell, a sodium lithium ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium sulfur battery cell, a magnesium ion battery cell, a nickel-hydrogen battery cell, a nickel-cadmium battery cell, a lead storage battery cell, etc., and the embodiment of the present invention is not limited to this.

[0073] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductive medium between the positive and negative electrodes. The present invention does not specifically limit the type of electrolyte, and the electrolyte can be selected based on needs. The electrolyte can be liquid, gel, or solid.

[0074] According to an embodiment of the present invention, on the other hand, a battery pack is provided, comprising: a plurality of battery cells as described above.

[0075] The battery packs described in the embodiments of the present invention may comprise one or more battery cells, providing a single physical module with higher voltage and capacity. When multiple battery cells are present, they are connected in series, parallel, or in parallel via a busbar. Multiple battery cells may be directly assembled into a battery pack, or they may be assembled into battery modules, which are then assembled into a battery pack.

[0076] The battery cells of the embodiments of the present invention may be cylindrical, prismatic, pouch, or other shaped cells. Prismatic cells may include square-shell, blade-shaped, or other polygonal cells, such as hexagonal or octagonal cells, but the embodiments of the present invention are not limited thereto.

[0077] In some embodiments, the battery pack further includes a box, in which the battery cells or battery modules are housed.

[0078] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0079] 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 battery cover assembly, characterized in that: include: a cover plate, wherein a first through hole is provided on the cover plate; A pole, mounted in the first through hole, the pole comprising a first sub-pole, a second sub-pole, and a third sub-pole, the first sub-pole extending into the second sub-pole and abutting against the second sub-pole, the third sub-pole sleeved on the first sub-pole and mounted in the second sub-pole; The second sub-pole is welded to the third sub-pole to form a weld; The sealing ring is sleeved on the first sub-pole and respectively abuts the first sub-pole, the second sub-pole, the third sub-pole and the cover plate, and the sealing ring covers the weld.

2. The battery cover assembly according to claim 1, characterized in that: The distance c between the outer peripheral edge of the sealing ring and the welding seam satisfies 0.5 mm ≤ c ≤ 2 mm.

3. The battery cover assembly according to claim 1, characterized in that: The penetration depth of the weld is greater than the thickness of the third sub-pole, and a distance b by which the penetration depth of the weld exceeds the thickness of the third sub-pole satisfies 0.3 mm ≤ b ≤ 1 mm.

4. The battery cover assembly according to claim 1, characterized in that: Also includes: an upper plastic ring, sleeved on the first sub-pole, the upper plastic ring comprising a plastic ring body and a first ring body arranged on the outer periphery of the plastic ring body; A connecting piece is abutted against the plastic ring body and is arranged in the first ring body. The connecting piece is connected to the first sub-pole.

5. The battery cover assembly according to claim 4, characterized in that: The first sub-pole comprises a column, a first connecting portion provided at the top of the column, and a second connecting portion provided at the bottom of the column; The first connecting portion is provided with a first flange, the connecting member is provided with a limiting step, and the first flange abuts against the limiting step.

6. The battery cover assembly according to claim 5, characterized in that: The second sub-pole comprises a second sub-pole body and a second ring body arranged on the outer periphery of the second sub-pole body, and the second connecting portion and the third sub-pole are both arranged in the second ring body; The upper surface of the second connecting portion abuts against the lower surface of the third sub-pole, and the lower surface of the second connecting portion abuts against the upper surface of the second sub-pole body.

7. The battery cover assembly according to claim 6, characterized in that: The thickness a of the second sub-pole body satisfies 0.6 mm ≤ a ≤ 1.5 mm.

8. The battery cell cover assembly according to any one of claims 1 to 7, characterized in that: It also includes an insulating member abutting between the cover plate and the second sub-pole; the insulating member is provided with a second through hole corresponding to the first through hole, and the pole is installed in the second through hole.

9. A battery cell, characterized in that: include: The battery cell cover assembly according to any one of claims 1 to 8; A housing having a receiving cavity and an opening communicating with the receiving cavity, wherein the cell cover assembly covers the opening; The pole group is arranged in the accommodating cavity, and the pole group is provided with a pole ear, and the pole ear is electrically connected to the pole column.

10. A battery pack, characterized in that: include: A plurality of battery cells according to claim 9.

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