Battery cover plate assembly and power battery

Abstract

The invention discloses a battery cover plate assembly and a power battery, two ends of a cover plate are provided with pole mounting holes, and the bottom of the cover plate is connected with lower plastic; an outer welding ring is arranged at the pole mounting hole, a conductive column is arranged on the inner side of the outer welding ring, the conductive column and the outer welding ring are insulated through upper plastic, and the peripheral side of the top of the upper plastic is clamped and matched with the inner side of the outer welding ring to prevent torsion; a sealing ring and an inner welding ring are sequentially arranged at the bottom of the conductive column; an opening is formed in the position, corresponding to the pole mounting hole, of the lower plastic, an annular protruding structure is arranged on the top face of the lower plastic, buckles are arranged on the circumferential side of the annular protruding structure, and the annular protruding structure is clamped and fixed to the inner side of the inner welding ring through the buckles; the top of the annular protruding structure is in compression joint with the inner side of the sealing ring. Through anti-torsion and corresponding sealing insulation design, the strength and sealing insulation performance of the cover plate assembly are improved, and the stability of the battery is improved.

Description

Technical Field

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

[0002] Lithium-ion batteries are currently widely used in electric vehicles due to their safety, high efficiency, pollution-free, high specific energy, rich raw materials, and many recycling times. Therefore, the safety requirements for lithium-ion batteries are getting higher and higher. For lithium-ion power batteries, there are requirements for high-rate charging and discharging. Therefore, it is inevitable that the battery temperature will be too high. After long-term use, it will cause inevitable damage to the seals of the battery poles. There will be different degrees of leakage at the seals of the poles. In severe cases, it may even cause the electrolyte inside the battery to leak out, seriously affecting the safety of the battery and reducing the overall service life of the battery. In addition, the strength of the cover assembly will also indirectly affect the sealing performance of the cover assembly. During the driving process of the vehicle, the battery vibrates due to the vibration of the vehicle. If the strength of the cover assembly is reduced due to the vibration, there is a situation where the sealing performance of the cover assembly also decreases. With the rapid development of new energy vehicles, the battery cover assembly is the main structural component of the battery. The design of its strength and insulation seal is directly related to the safety performance of the battery.

[0003] The utility model patent with authorization announcement number CN207320177U discloses a new energy battery cover assembly, which has sealing rings installed at the bottom ends of the negative electrode column and the positive electrode column to increase the sealing of the negative electrode column and the positive electrode column; the sealing method of this solution is relatively simple and cannot achieve good sealing performance.

[0004] The invention patent with application publication number CN115347288A discloses a battery cover and a power battery. This solution replaces the existing sealing ring seal with a glue seal to increase the structural strength and ensure the sealing of the cover. However, this solution only considers the sealing problem and does not take the safety performance of the battery into consideration as a whole. Summary of the invention

[0005] In view of the deficiencies in the prior art, an object of the present invention is to provide a battery cover assembly and a power battery, which improves the strength and sealing and insulating performance of the cover assembly and improves the stability of the battery through anti-twisting and corresponding sealing and insulating designs.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] A battery cover plate assembly comprises a cover plate, wherein pole mounting holes are provided at both ends of the cover plate, and the bottom of the cover plate is connected to a lower plastic; an outer welding ring is provided at the pole mounting hole, a conductive column is provided on the inner side of the outer welding ring, and the conductive column and the outer welding ring are insulated by an upper plastic, and the top peripheral side of the upper plastic is snap-fitted with the inner side of the outer welding ring to prevent twisting; a sealing ring and an inner welding ring are sequentially provided at the bottom of the conductive column; the lower plastic is opened at the position corresponding to the pole mounting hole and an annular protrusion structure is provided on the top surface, a buckle is provided on the peripheral side of the annular protrusion structure, and the buckle is snap-fitted and fixed to the inner side of the negative electrode inner welding ring; the top of the annular protrusion structure is crimped with the inner side of the sealing ring.

[0008] As a further implementation method, a circular opening is provided in the center of the outer welding ring to facilitate the upper plastic and the conductive column to extend to the circular opening, and a plurality of anti-twist grooves extend outward from the inner side of the circular opening for clamping with the peripheral side of the top of the upper plastic.

[0009] As a further implementation method, the upper plastic is an annular structure, which completely fills the gap between the outer welding ring, the conductive column, the sealing ring and the inner welding ring to achieve insulating sealing. Its structure is arranged so that the top extends inwardly for a set distance and then forms a circular ring body upward. A plurality of anti-twist bosses are provided on the circumference of the circular ring body, and the anti-twist bosses are used to engage with the anti-twist groove.

[0010] As a further implementation, the outer side surface of the upper plastic body is a first insulating portion, and the top surface is a second insulating portion, which is used to cooperate with the inner side surface of the outer welding ring.

[0011] As a further implementation method, the buckle is arranged at the middle height of the annular protrusion, and the top surface of the annular protrusion abuts against the lower bottom surface of the conductive column.

[0012] As a further implementation, an inner welding ring step is provided on the inner side of the inner welding ring.

[0013] As a further implementation, the cross-section of the outer side surface of the annular protrusion that is higher than the buckle is an inclined surface, and is in compression contact with the sealing ring through the inclined surface.

[0014] As a further implementation method, the sealing ring is compressed between the conductive column and the inner welding ring, and the inner side of the sealing ring is provided with a step structure, which provides space for the compression and expansion of the sealing ring by the conductive column and the inner welding ring in this direction, and on the other hand, provides space for the expansion generated by the lower plastic compressing the sealing ring.

[0015] As a further implementation method, the edge portion of the top surface of the inner welding ring contacts the bottom surface of the outer welding ring close to the inner side, the outer diameter of the inner welding ring is smaller than the outer diameter of the outer welding ring, the conductive column is an integrated structure, the positive electrode column is a conductive aluminum column; the negative electrode column is a copper-aluminum composite structure, including a conductive aluminum column, and the bottom of the conductive aluminum column is a conductive copper column.

[0016] In a second aspect, a power battery is provided, the power battery comprising any of the battery cover plate assemblies described above.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1. The inner side of the outer welding ring of the present invention is provided with a conductive column, and the conductive column and the outer welding ring are insulated and sealed by the upper plastic. The lower plastic is provided with a buckle, which is buckled and fixed with the positive inner welding ring and is in compression contact with the sealing ring. The sealing ring is used to achieve sealing, which can prevent the electrolyte from penetrating between the conductive column and the inner welding ring, causing high voltage or low voltage of the shell; the anti-torsion clamping structure is set to improve the anti-torsion strength of the positive and negative poles, increase the torque, and improve the safety of the battery during vibration or vehicle driving. The anti-torsion design and the compression seal of the lower plastic and the sealing ring improve the strength and sealing performance of the cover assembly and the stability of the battery.

[0019] 2. The upper plastic of the present invention is injection molded between various metal structures, and an upper plastic insulating part located between the outer welding ring, the conductive column and the inner welding ring is formed by injection molding. The insulating part is located between various metal structures to achieve insulation and sealing between various metals.

[0020] 3. The inner side of the sealing ring of the present invention is provided with a step structure. The step design provides space for the compression and expansion of the sealing ring by the conductive terminal and the inner welding ring in this direction, and also provides space for the expansion of the lower plastic when compressing the sealing ring.

[0021] 4. The lower plastic of the present invention contacts and compresses the compression surface of the sealing ring through the inclined surface, thereby compressing and sealing the sealing ring, thereby achieving insulation and sealing between the conductive column and the inner welding ring, eliminating the problem of shell corrosion caused by low shell voltage caused by electrolyte infiltration between the two, or increased self-discharge caused by high shell voltage, thereby improving the safety performance of the battery cell and achieving the fixation of the lower plastic. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0023] Figure 1 It is a schematic diagram of the overall structure of a battery cover assembly provided in an embodiment of the present invention;

[0024] Figure 2 A schematic diagram of an exploded structure of a battery cover assembly provided in an embodiment of the present invention;

[0025] Figure 3 A schematic cross-sectional view of a battery cover assembly provided in an embodiment of the present invention;

[0026] Figure 4 A cross-sectional view showing the position of the negative electrode column of a battery provided in an embodiment of the present invention;

[0027] Figure 5 A schematic diagram of a negative electrode outer welding ring provided in an embodiment of the present invention;

[0028] Figure 6 A schematic diagram of the plastic on the negative electrode provided in an embodiment of the present invention;

[0029] Figure 7 A schematic diagram of the lower plastic provided in an embodiment of the present invention at the position of the negative electrode column;

[0030] Figure 8 A schematic diagram of a negative electrode inner welding ring provided in an embodiment of the present invention;

[0031] Fig. 9 Schematic diagram of a negative electrode sealing ring provided in an embodiment of the present invention.

[0032] In the figure: the distances or sizes between parts are exaggerated to show the positions of various parts, and the schematic diagram is for reference only.

[0033] Among them: 1. Battery cover assembly; 10. Negative pole, 20. Positive pole, 30. Bare cover, 40. Lower plastic; 101. Negative outer welding ring, 102. Negative upper plastic, 103. Negative conductive pole, 104. Negative sealing ring, 105. Negative inner welding ring; 106. Negative sealing ring expansion area, 107. Negative sealing ring compression area; 201. Positive outer welding ring, 202. Positive upper plastic, 203. Positive conductive pole, 204. Positive sealing ring , 205. positive electrode inner welding ring; 1011. outer welding ring anti-twist groove, 1012. flange, 1021. upper plastic anti-twist boss; 1022. first upper plastic insulating portion, 1023. second upper plastic insulating portion, 1024. third upper plastic insulating portion, 1025. annular ring; 1031. negative electrode conductive aluminum column, 1032. negative electrode conductive copper column, 1041. sealing ring compression surface, 1051. inner welding ring step; 401. buckle, 402. inclined surface. DETAILED DESCRIPTION

[0034] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0035] Embodiment 1

[0036] In a typical embodiment of the present invention, reference is made to Figure 1-Figure 9As shown, a battery cover assembly, the battery cover assembly 1 includes a light cover 30, pole mounting holes are provided at both ends of the cover, and the bottom of the cover is connected to the lower plastic 40; an explosion-proof valve is provided in the middle of the cover, and a liquid injection hole is also provided on the cover. The two pole mounting holes are respectively installed with the corresponding positive pole 20 and negative pole 10.

[0037] like Figure 2 and Figure 3 As shown, the positive electrode column includes a positive electrode conductive column 203, a positive electrode plastic 202, a positive electrode sealing ring 204, a positive electrode outer welding ring 201, and a positive electrode inner welding ring 205; the negative electrode column includes a negative electrode conductive column 103, a negative electrode plastic 102, a negative electrode sealing ring 104, a negative electrode outer welding ring 101, and a negative electrode inner welding ring 105. The positive electrode column and the negative electrode column have the same structural form.

[0038] like Figure 4 As shown, taking the negative pole as an example, a negative pole outer welding ring 101 is welded and fixed at the pole mounting hole, a negative pole conductive column 103 is arranged inside the negative pole outer welding ring 101, and the negative pole outer welding ring 101 and the negative pole conductive column 103 are insulated by the negative pole upper plastic 102.

[0039] The bottom of the negative electrode conductive column 103 is provided with a negative electrode sealing ring 104 and a negative electrode inner welding ring 105 in sequence. The outer side surface of the negative electrode inner welding ring is also welded to the inner side of the pole mounting hole, and the top surface of the negative electrode inner welding ring 105 near the edge is in contact with the bottom surface of the negative electrode outer welding ring 101 near the inner side. The outer diameter of the negative electrode inner welding ring is smaller than the outer diameter of the negative electrode outer welding ring. Therefore, the inner cross section of the pole mounting hole is in the form of a step, such as Figure 4 shown.

[0040] like Figure 5 As shown, the structure of the negative electrode outer welding ring 101 is similar to that of a bottle cap, and a flange 1012 is provided at the bottom, which contacts the negative electrode inner welding ring 105 through the flange 1012, and the outer side of the annular flange is fixed to the inner side of the pole mounting hole. A circular opening is provided in the center of the negative electrode outer welding ring, so that the upper plastic and the conductive column extend to the circular opening, and a plurality of outer welding ring anti-twist grooves 1011 extend outward from the inner side of the circular opening, which are used to clamp with the top peripheral side of the negative electrode upper plastic 102.

[0041] like Figure 6 As shown, since the negative electrode upper plastic 102 is located on the inner side of the negative electrode outer welding ring 101, the shape of the negative electrode upper plastic 102 is adapted to the shape of the inner side surface of the negative electrode outer welding ring 101, and the structure of the upper plastic 102 is formed by injection molding, so the space between the negative electrode conductive column 103 and the negative electrode outer welding ring 101 can be sealed.

[0042] like Figure 6As shown, correspondingly, the negative electrode upper plastic 102 is an annular structure as a whole, which completely fills the gaps between the negative electrode outer welding ring 101, the negative electrode conductive column 103, the negative electrode sealing ring 104 and the negative electrode inner welding ring 105 to achieve insulation sealing, and its structure is arranged so that the top extends inwardly for a set distance and then forms an annular body 1025 upward, and a plurality of upper plastic anti-twist bosses 1021 are arranged outwardly on the circumference of the annular body 1025, and the upper plastic anti-twist bosses 1021 are used to engage with the anti-twist groove 1011 of the outer welding ring.

[0043] The anti-twist bosses and anti-twist grooves of the positive and negative electrodes improve the anti-twist strength of the positive and negative electrodes, increase the torque, and improve the safety of the battery during vibration or vehicle driving. The anti-twist design and the compression seal of the lower plastic and the sealing ring improve the strength and sealing performance of the cover assembly and the stability of the battery.

[0044] The negative electrode upper plastic 102 is injection molded between various metal structures, and its structure is such that the outer side surface of the negative electrode upper plastic 102 body is the first upper plastic insulating portion 1022, and the top surface is the second upper plastic insulating portion 1023, which is used to cooperate with the inner side surface of the negative electrode outer welding ring 101. The top surface of the annular body 1025 is the third upper plastic insulating portion 1024, which is formed by injection molding to be located between the negative electrode outer welding ring, the negative electrode conductive column 103 and the negative electrode inner welding ring 105. The insulating portion is located between various metal structures to achieve insulation and sealing between various metals.

[0045] The negative electrode sealing ring 104 is compressed between the bottom of the negative electrode conductive column 103 and the negative electrode inner welding ring 105, wherein the outer diameter of the negative electrode sealing ring 104 is not larger than the outer diameter of the bottom end of the negative electrode conductive column 103, and the inner diameter of the negative electrode sealing ring 104 is adapted to the inner diameter of the negative electrode inner welding ring 105.

[0046] The negative electrode inner welding ring 105 and the negative electrode conductive column 103 are insulated by the negative electrode sealing ring 104 and the negative electrode upper plastic 102 . The negative electrode sealing ring 104 and the negative electrode upper plastic 102 separate the negative electrode inner welding ring 105 from the negative electrode conductive column 103 , and the negative electrode sealing ring 104 achieves sealing performance.

[0047] like Figure 7 As shown, the lower plastic 40 is opened at the position corresponding to the pole mounting hole and an annular protrusion structure is provided upward on the top surface of the opening. During installation, the axis of the annular protrusion is the same as the axis of the pole mounting hole.

[0048] A buckle 401 is provided around the annular protrusion structure, and the buckle 401 is provided at the middle height of the annular protrusion, and is used to be clamped and fixed with the inner side of the negative electrode inner welding ring 105 through the buckle 401; the top of the annular protrusion structure is crimped with the inner side of the negative electrode sealing ring 104.

[0049] like Figure 4 As shown, the top surface of the annular protrusion abuts against the bottom surface of the negative electrode conductive column 103. Figure 8 As shown, an inner welding ring step 1051 is provided on the inner side of the negative electrode inner welding ring, and the lower plastic is fixed by the inner welding ring step 1051 and the buckle 401 being clamped and fixed.

[0050] The cross section of the portion of the outer side of the annular protrusion that is higher than the buckle is an inclined surface 402, which is in compression contact with the negative electrode sealing ring 104 to prevent the electrolyte from penetrating between the negative electrode conductive column and the negative electrode inner welding ring, causing the low voltage of the shell.

[0051] Correspondingly, the positive electrode outer welding ring 201 and the positive electrode conductive column 203 are insulated by the positive electrode upper plastic 202, and the positive electrode inner welding ring 205 and the positive electrode conductive column 203 are insulated by the positive electrode sealing ring 204 and the positive electrode upper plastic 202, and the sealing performance is achieved by the positive electrode sealing ring 204. The lower plastic 40 is provided with a buckle 401, which is buckled and fixed with the positive electrode inner welding ring 205 and is in compression contact with the positive electrode sealing ring 204 to prevent the electrolyte from penetrating between the positive electrode conductive column 203 and the positive electrode inner welding ring 205, causing the high voltage of the shell.

[0052] like Fig. 9 As shown, the inner side of the negative electrode sealing ring 104 is provided with a step structure, and its cross section is L-shaped. This step design provides space for the compression and expansion of the sealing ring by the negative electrode conductive column 103 and the negative electrode inner welding ring 105 in this direction, and provides space for the expansion of the lower plastic compression sealing ring on the other hand.

[0053] The negative electrode sealing ring 104 is located between the negative electrode conductive column 103 and the negative electrode inner welding ring 105, and is compressed by the two. The expanded material in the compressed area 107 is filled in the negative electrode sealing ring expanded material area 106, and the unfilled area is filled with the plastic on the negative electrode, thereby eliminating the gap between the negative electrode conductive column 103 and the negative electrode inner welding ring 105, and ensuring the insulation performance.

[0054] The lower plastic inclined surface 402 contacts and compresses the negative electrode sealing ring compression surface 1041 to compress and seal the sealing ring, thereby achieving insulation and sealing between the conductive column and the inner welding ring, eliminating the problem of shell corrosion caused by low shell voltage or increased self-discharge caused by high shell voltage caused by electrolyte infiltration between the two, improving the safety performance of the battery cell, and achieving the fixation of the lower plastic; it can be understood that the negative electrode sealing ring compression surface 1041 is located at the innermost annular surface of the negative electrode sealing ring close to the bottom, such as Fig. 9 shown.

[0055] It can be understood that this embodiment improves the strength and sealing performance of the cover assembly and improves the stability of the battery through the anti-twisting design and the compression seal between the lower plastic and the sealing ring.

[0056] like Figure 4 As shown, it should be noted that the edge portion of the top surface of the negative electrode inner welding ring 105 is in contact with the inner side of the bottom surface of the outer welding ring, and the outer diameter of the inner welding ring is smaller than the outer diameter of the outer welding ring.

[0057] It should be noted that the negative electrode conductive column 103 includes a negative electrode conductive aluminum column 1031 and a negative electrode conductive copper column 1032, which are an integrated structure and are formed by a copper-aluminum composite plate. The bottom of the negative electrode conductive aluminum column 1031 is a negative electrode conductive copper column 1032. The positive electrode conductive column 203 is made of aluminum and is formed by a plate.

[0058] Taking the negative electrode column as an example, the processing method is to fix the negative electrode conductive column 103, the negative electrode sealing ring 104, and the negative electrode inner welding ring 105 with a clamp to ensure the compression of the negative electrode sealing ring 104, and then fix the negative electrode outer welding ring 101 to the corresponding position, and then perform injection molding of the plastic 102 on the negative electrode to completely fill the gaps between the negative electrode conductive column 103, the negative electrode outer welding ring 101, the negative electrode sealing ring 104, and the negative electrode inner welding ring 105, and fix and insulate the metal parts.

[0059] Embodiment 2

[0060] In a typical embodiment of the present invention, reference is made to Figure 1-Figure 9 As shown, a power battery includes a shell, and the battery cover assembly described in Example 1 is installed on the shell. The power battery has the advantages of Example 1 and ensures the stability of the battery.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A battery cover assembly, characterized in that: It comprises a light cover plate, pole mounting holes are arranged at both ends of the cover plate, and the bottom of the cover plate is connected to the lower plastic; an outer welding ring is arranged at the pole mounting hole, a conductive column is arranged on the inner side of the outer welding ring, and the conductive column and the outer welding ring are insulated by the upper plastic, and the top peripheral side of the upper plastic is snap-fitted with the inner side of the outer welding ring to prevent twisting; a sealing ring and a negative electrode inner welding ring are arranged at the bottom of the conductive column in sequence; the lower plastic is opened at the position corresponding to the pole mounting hole and an annular protrusion structure is arranged on the top surface, a buckle is arranged on the peripheral side of the annular protrusion structure, and it is snap-fitted and fixed with the inner side of the inner welding ring through the buckle; the top of the annular protrusion structure is crimped with the inner side of the sealing ring.

2. A battery cover assembly according to claim 1, characterized in that: A circular opening is provided in the center of the outer welding ring so that the upper plastic and the conductive column can extend to the circular opening. A plurality of anti-twist grooves extend outward from the inner side of the circular opening for clamping with the peripheral side of the top of the upper plastic.

3. A battery cover assembly according to claim 2, characterized in that: The upper plastic is an annular structure, which completely fills the gaps between the outer welding ring, the conductive column, the sealing ring and the inner welding ring to achieve insulating sealing. Its structure is arranged so that the top extends inwardly for a set distance and then forms a circular ring upward. A plurality of anti-twist bosses are arranged on the circumference of the circular ring, and the anti-twist bosses are used to engage with the anti-twist grooves.

4. A battery cover assembly according to claim 3, characterized in that: The outer side surface of the upper plastic body is a first insulating portion, and the top surface is a second insulating portion, which is used to cooperate with the inner side surface of the outer welding ring.

5. A battery cover assembly according to claim 1, characterized in that: The buckle is arranged at the middle height of the annular protrusion, and the top surface of the annular protrusion abuts against the bottom surface of the conductive column.

6. A battery cover assembly according to claim 5, characterized in that: An inner welding ring step is arranged on the inner side of the inner welding ring.

7. A battery cover assembly according to claim 5, characterized in that: The outer side cross-section of the portion of the annular protrusion that is higher than the buckle is an inclined surface, and is in compression contact with the sealing ring through the inclined surface.

8. A battery cover assembly according to claim 1, characterized in that: The sealing ring is compressed between the conductive column and the inner welding ring. The inner side of the sealing ring is provided with a step structure, which provides space for the conductive column and the inner welding ring to compress and expand the sealing ring in this direction, and on the other hand, provides space for the expansion of the lower plastic compressing the sealing ring.

9. A battery cover assembly according to claim 1, characterized in that: The edge portion of the top surface of the inner welding ring contacts the bottom surface of the outer welding ring close to the inner side, the outer diameter of the inner welding ring is smaller than the outer diameter of the outer welding ring, the conductive column is an integrated structure, the positive conductive column is a conductive aluminum column; the negative conductive column is a copper-aluminum composite structure, including a conductive aluminum column, and the bottom of the conductive aluminum column is a conductive copper column.

10. A power battery, characterized in that: The power battery comprises a battery cover assembly as described in any one of claims 1-9.

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