Batteries and battery packs

Abstract

This invention relates to the field of battery technology and discloses a battery and a battery pack. The battery includes a casing, an electrode assembly, and a negative electrode cover. The electrode assembly is disposed within the casing; the negative electrode cover is disposed at one end of the casing, and the negative electrode cover includes a negative electrode cover body and a first recess disposed on the body and facing the electrode assembly. The negative electrode cover body and the first recess are connected by an elastic rib. The negative electrode cover body is connected to the casing, and the first recess is electrically connected to the negative electrode of the electrode assembly. This invention utilizes the battery provided by this invention. Because the negative electrode cover has a first recess, and the first recess is electrically connected to the negative electrode of the electrode assembly, the negative electrode connecting piece is eliminated, reducing the number of parts, greatly saving product costs, simplifying assembly processes, improving production efficiency, and making it sufficiently competitive in the market.

Description

Technical Field

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

[0002] As lithium-ion battery technology becomes increasingly mature, power batteries are widely used in electric vehicles as a new type of battery, and the performance and safety requirements of power batteries are increasing.

[0003] The electrode structure of cylindrical batteries currently on the market includes upper plastic, lower plastic, pole, sealing ring, positive electrode connecting plate, negative electrode connecting plate, negative electrode cover, sealing cover and sealing nails, etc., which have the following disadvantages: more parts, higher cost, complicated assembly process, especially more welding steps, which can easily lead to poor performance and cause quality problems. Summary of the invention

[0004] In view of this, the present invention provides a battery and a battery pack to solve at least one of the following technical problems: the battery has many parts and components, the cost is high, the assembly process is complicated, and the production efficiency is low.

[0005] In a first aspect, the present invention provides a battery, comprising a housing, an electrode group and a negative electrode cover. The electrode group is arranged in the housing; the negative electrode cover is arranged at one end of the housing, the negative electrode cover comprises a negative electrode cover body and a first recessed portion arranged on the body and facing the electrode group, the negative electrode cover body and the first recessed portion are connected by elastic ribs, the negative electrode cover body is connected to the housing, and the first recessed portion is electrically connected to the negative electrode of the electrode group.

[0006] With the battery provided by the present invention, since the negative electrode cover is provided with the first recessed portion, and the first recessed portion is electrically connected to the negative electrode of the electrode group, the negative electrode connecting sheet is eliminated, the number of parts is reduced, the product cost is greatly saved, the assembly process is simplified, the production efficiency is improved, and it has sufficient market competitiveness. The first recessed portion and the negative electrode cover body are connected by elastic ribs, so that the first recessed portion has elasticity, so as to better fit with the bottom surface of the electrode group, and ensure the connection effect between the negative electrode cover and the electrode group.

[0007] In an optional embodiment, the first recessed portion and the pole group are penetrated and welded.

[0008] Compared with the existing method of welding the negative electrode cover plate and the negative electrode connecting piece to the periphery of the shell, the top direct welding is changed to the first recessed portion and the electrode group through welding, which simplifies the welding process, optimizes the assembly process, improves the manufacturability of the product, increases the welding area, improves the reliability of the connection between the negative electrode cover plate and the electrode group, and improves the product performance.

[0009] In an optional embodiment, the thickness of the first recessed portion is 0.5 to 0.8 times the thickness of the housing wall.

[0010] The thickness of the first recessed portion is controlled within the range of 0.5 to 0.8 times the thickness of the shell wall, so that the first recessed portion has flexibility, so as to better fit the electrode group welding surface and ensure the welding effect. When the thickness of the first recessed portion exceeds this range, if it is too small, the strength is insufficient, and if it is too large, the flexibility is reduced. Preferably, the thickness of the first recessed portion is 0.65 times the thickness of the shell wall.

[0011] In an optional embodiment, the depth of the first recessed portion in the negative electrode cover body is 2.5 to 6 times the thickness of the shell wall.

[0012] The depth of the first recessed portion in the negative electrode cover body is controlled within the range of 2.5 to 6 times the shell wall thickness, which can ensure the elasticity of the elastic rib and the space utilization rate. When it exceeds this range, the depth of the first recessed portion in the negative electrode cover body is too small, and the elasticity of the elastic rib is insufficient. When the depth of the first recessed portion in the negative electrode cover body is too large, the strength is weak and the space utilization rate is low. Preferably, the depth of the first recessed portion in the negative electrode cover body is 4 times the shell wall thickness.

[0013] In an optional embodiment, the thickness of the elastic rib is 0.35 times to 0.6 times the thickness of the shell wall.

[0014] The thickness of the elastic rib is controlled within the range of 0.35 to 0.6 times the shell wall thickness, which can ensure the structural strength of the elastic rib and make the elastic rib have a certain elasticity. When the thickness of the elastic rib exceeds this range, if it is too small, the strength of the elastic rib is weak and difficult to manufacture, and if it is too large, the elasticity of the elastic rib is poor. Preferably, the thickness of the elastic rib is 0.45 times the shell wall thickness.

[0015] In an optional embodiment, the elastic rib and the negative electrode cover body are integrally formed; and / or the negative electrode cover and the shell are integrally formed. In this configuration, the elastic rib and the negative electrode cover body are made of the same material and are integrally formed, which simplifies the assembly process of the battery and reduces production costs.

[0016] In an optional embodiment, the shell is cylindrical, the negative electrode cover is circular and matches the shell, and the first recess is annular. This arrangement is suitable for cylindrical batteries.

[0017] In an optional embodiment, it also includes a positive cover plate, which includes a positive cover plate body and a second recessed portion arranged in the middle of the positive cover plate body and facing the electrode group. The periphery of the positive cover plate body and the periphery of the other end of the shell are welded, and the second recessed portion is provided with a mounting hole, and the mounting hole is connected to a pole via an insulating seal, and the pole post and the positive electrode of the pole group are electrically connected.

[0018] Compared with the existing seals and insulating parts which are independent components, the battery in the embodiment of the present invention integrates the seals and insulating parts into one structural part, which not only improves the sealing and insulation performance, but also reduces the number of parts, simplifies the assembly process, greatly saves battery costs, and improves the competitiveness of the product.

[0019] In an optional embodiment, the positive electrode cover plate also includes a protrusion arranged toward the electrode group, the protrusion is arranged around the second recessed portion, the inner circle of the protrusion is connected to the second recessed portion, and the outer circle of the protrusion is connected to the positive electrode cover plate body; the protrusion is provided with an explosion-proof valve; and the negative electrode cover plate is provided with a liquid injection hole.

[0020] The explosion-proof valve is arranged on the raised part, the injection hole is arranged on the negative electrode cover plate, and the explosion-proof valve and the injection hole are separately arranged on different end faces. When the explosion-proof valve leaks due to breakdown, the injection hole is prevented from being contaminated, thereby improving the assembly yield of the product and saving product costs.

[0021] In a second aspect, the present invention further provides a battery pack comprising at least two batteries of any one of the above technical solutions.

[0022] Because the battery pack includes the battery provided in the first aspect of the present invention, it has the same technical effects as the battery and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A three-dimensional diagram of a battery housing according to an embodiment of the present invention;

[0025] Figure 2 for Figure 1 A cross-sectional view along the axial direction;

[0026] Figure 3 for Figure 1 A is a partial enlarged schematic diagram;

[0027] Figure 4 A three-dimensional diagram of a positive electrode cover plate of a battery according to an embodiment of the present invention;

[0028] Figure 5 for Figure 4 A top view of

[0029] Figure 6 for Figure 5Cross-sectional view along the middle line BB;

[0030] Figure 7 for Figure 6 A partial enlarged schematic diagram of point C in the middle;

[0031] Figure 8 is a three-dimensional diagram of a battery according to an embodiment of the present invention;

[0032] Fig. 9 for Figure 8 A cross-sectional view of

[0033] Fig.10 for Fig. 9 A partial enlarged schematic diagram of the positive terminal;

[0034] Fig.11 for Fig. 9 A partial enlarged schematic diagram of the middle negative terminal.

[0035] Description of reference numerals:

[0036] 1. Shell; 2. Pole group; 3. Negative electrode cover; 301. Negative electrode cover body; 302. First recessed portion; 303. Elastic rib; 4. Positive electrode cover; 401. Positive electrode cover body; 402. Second recessed portion; 403. Protruding portion; 5. Explosion-proof valve; 6. Liquid injection hole; 7. Pole; 701. Pole body; 702. First convex edge; 703. Second convex edge; 8. Insulating seal; 801. First sealing section; 802. Second sealing section; 803. Third sealing section; 9. Positive electrode connecting piece. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the 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 creative work are within the scope of protection of the present invention.

[0038] In the related art, the electrode structure of the cylindrical battery includes upper plastic, lower plastic, pole, sealing ring, positive electrode connecting piece, negative electrode connecting piece, negative electrode cover, sealing cover and sealing nails and other components, among which the positive and negative electrode connecting pieces and pole groups, the positive electrode connecting piece and pole, the negative electrode connecting piece and shell, and the negative electrode cover and shell are all connected by welding; after the pole is assembled into the shell, the upper and lower plastics and the sealing ring are compacted by riveting to achieve a sealing and insulating effect; after the pole group is put into the shell, the negative pole and the negative electrode connecting piece are laser welded, the negative electrode connecting piece is laser welded to the shell, and then the negative electrode cover and the shell are laser welded. After the injection is completed, the sealing cover and the negative electrode cover are laser welded.

[0039] Combine the following Figures 1 to 11 , describing an embodiment of the present invention.

[0040] According to an embodiment of the present invention, on the one hand, a battery is provided, comprising a housing 1, an electrode group 2 and a negative electrode cover plate 3. The electrode group 2 is arranged in the housing 1; the negative electrode cover plate 3 is arranged at one end of the housing 1, and the negative electrode cover plate 3 comprises a negative electrode cover plate body 301 and a first recessed portion 302 arranged on the body and facing the electrode group 2, the negative electrode cover plate body 301 and the first recessed portion 302 are connected by elastic ribs 303, the negative electrode cover plate body 301 is connected to the housing 1, and the first recessed portion 302 is electrically connected to the negative electrode of the electrode group 2.

[0041] With the battery provided by the present invention, since the negative electrode cover plate 3 is provided with the first recessed portion 302, and the first recessed portion 302 is electrically connected to the negative electrode of the electrode group 2, the negative electrode connecting sheet is eliminated, the number of parts is reduced, the product cost is greatly saved, the assembly process is simplified, the production efficiency is improved, and the battery has sufficient market competitiveness.

[0042] Since the manufacturing error of the electrode group 2 in height is ±0.3mm, the elastic rib 303 is provided so that the first recessed portion 302 has the ability of elastic deformation in the height direction of the electrode group 2, and can compensate for the manufacturing error of the electrode group 2 in the height direction. For example, when the error of the electrode group 2 in the height direction is -0.3mm, the first recessed portion 302 is close to the stroke of 0.3mm deformation of the electrode group 2, so that the first recessed portion 302 and the electrode group 2 are tightly welded. Otherwise, there is a gap between the first recessed portion 302 and the electrode group 2, which is prone to large welding spots or weak welding, resulting in a weak connection between the negative electrode cover plate 3 and the electrode group 2, and a poor contact phenomenon; when the error of the electrode group 2 in the height direction is 0.3mm, the first recessed portion 302 is far away from the stroke of 0.3mm deformation of the electrode group 2, ensuring the welding performance between the electrode group 2 and the negative electrode cover plate 3.

[0043] Specifically, the structure of the housing 1 can be cylindrical, suitable for cylindrical batteries, or can be a cubic structure, suitable for square batteries. Figure 1 The housing 1 comprises a cylindrical housing body 1 having a cavity for accommodating the pole group 2 .

[0044] In an optional embodiment, the first recessed portion 302 and the pole group 2 are penetrated and welded.

[0045] Compared with the existing method of welding the negative electrode cover plate 3 and the negative electrode connecting piece to the periphery of the shell 1, the method is changed to direct welding on the top, and the first recessed portion 302 and the electrode group 2 are penetrated and welded, which simplifies the welding process, optimizes the assembly process, improves the manufacturability of the product, increases the welding area, improves the reliability of the connection between the negative electrode cover plate 3 and the electrode group 2, and improves the product performance.

[0046] In an optional implementation, the thickness of the first recessed portion 302 is 0.5 to 0.8 times the wall thickness of the housing 1 .

[0047] The thickness of the first recessed portion 302 is controlled within the range of 0.5 to 0.8 times the thickness of the shell 1 wall, so that the first recessed portion 302 has flexibility, so as to better fit the welding surface of the electrode group 2 and ensure the welding effect. When the thickness of the first recessed portion 302 exceeds this range, if it is too small, the strength is insufficient, and if it is too large, the flexibility is reduced. Preferably, the thickness of the first recessed portion 302 is 0.65 times the thickness of the shell 1 wall.

[0048] In an optional implementation, the depth of the first recessed portion 302 in the negative electrode cover plate body 301 is 2.5 to 6 times the wall thickness of the shell 1 .

[0049] The depth of the first recessed portion 302 in the negative electrode cover body 301 is controlled within the range of 2.5 to 6 times the wall thickness of the shell 1, which can ensure the elasticity and space utilization of the elastic rib 303. When it exceeds this range, the depth of the first recessed portion 302 in the negative electrode cover body 301 is too small, and the elasticity of the elastic rib 303 is insufficient. When the depth of the first recessed portion 302 in the negative electrode cover body 301 is too large, the strength is weak and the space utilization is low. Preferably, the depth of the first recessed portion 302 in the negative electrode cover body 301 is 4 times the wall thickness of the shell 1.

[0050] In an optional implementation, the thickness of the elastic rib 303 is 0.35 to 0.6 times the wall thickness of the shell 1 .

[0051] The thickness of the elastic rib 303 is controlled within the range of 0.35 to 0.6 times the thickness of the shell 1, which can ensure the structural strength of the elastic rib 303 and make the elastic rib 303 have a certain elasticity. When the thickness of the elastic rib 303 exceeds this range, if it is too small, the strength of the elastic rib 303 is weak and difficult to manufacture, and if it is too large, the elasticity of the elastic rib 303 is poor. Preferably, the thickness of the elastic rib 303 is 0.45 times the thickness of the shell 1.

[0052] In an optional implementation, the elastic ribs 303 are only provided on the outer circle of the first recessed portion 302, so that the first recessed portion 302 has elasticity, and it is helpful to reduce the processing steps.

[0053] In an optional embodiment, the elastic rib 303 and the negative electrode cover body 301 are integrally formed; and / or, the negative electrode cover and the shell are integrally formed. In this way, the material of the elastic rib 303 is the same as that of the negative electrode cover body 301, and they are integrally formed, which simplifies the assembly process of the battery and reduces production costs. Regardless of whether the negative electrode cover and the shell are integrally formed, the negative terminal of the battery has only one layer of structure, which greatly reduces the number of parts and simplifies the assembly process compared to the multi-layer structure of the negative electrode cover in the related art.

[0054] In an optional embodiment, the housing 1 is cylindrical, the negative electrode cover 3 is circular and matches the housing 1, and the first recessed portion 302 is annular. This arrangement is suitable for cylindrical batteries.

[0055] In an optional embodiment, it also includes a positive cover plate 4, which includes a positive cover plate body 401 and a second recessed portion 402 arranged in the middle of the positive cover plate body 401 and facing the electrode group 2. The periphery of the positive cover plate body 401 and the periphery of the other end of the shell 1 are welded, and a mounting hole is provided on the second recessed portion 402. The mounting hole is connected to the pole 7 through an insulating seal 8, and the pole 7 is electrically connected to the positive electrode of the electrode group 2.

[0056] Compared with the existing seals and insulating parts which are independent components, the battery in the embodiment of the present invention integrates the seals and insulating parts into one structural part, which not only improves the sealing and insulation performance, but also reduces the number of parts, simplifies the assembly process, greatly saves battery costs, and improves the competitiveness of the product.

[0057] In an optional embodiment, the positive electrode cover plate 4 also includes a protrusion 403 arranged toward away from the electrode group 2, the protrusion 403 is arranged around the second recessed portion 402, the inner circle of the protrusion 403 is connected to the second recessed portion 402, and the outer circle of the protrusion 403 is connected to the positive electrode cover plate body 401; the protrusion 403 is provided with an explosion-proof valve 5; and the negative electrode cover plate 3 is provided with a liquid injection hole 6.

[0058] Specifically, the end faces of the positive electrode cover plate body 401 , the second recessed portion 402 and the raised portion 403 are not flush with each other. This arrangement can improve the structural strength of the positive electrode cover plate 4 .

[0059] The explosion-proof valve 5 is arranged on the raised portion 403, and the injection hole 6 is arranged on the negative electrode cover plate 3. The explosion-proof valve 5 and the injection hole 6 are separately arranged on different end faces. When the explosion-proof valve 5 leaks due to breakdown, the injection hole 6 is prevented from being contaminated, thereby improving the assembly yield of the product and saving product costs.

[0060] In an optional embodiment, the edge of the positive electrode cover plate 4 is flush with the edge of the shell 1 , and the periphery of the positive electrode cover plate 4 and the periphery of the shell 1 are welded.

[0061] In an optional embodiment, a mounting hole is opened on the second recessed portion 402 of the positive electrode cover plate, and a pole 7 is connected to the mounting hole through an insulating seal 8 , and the pole 7 is electrically connected to the positive electrode of the electrode group 2 .

[0062] In an optional embodiment, the pole 7 includes a pole body 701, a first flange 702 provided at the outer end of the pole body 701 and extending in the radial direction, and a second flange 703 provided at the inner end of the pole body 701 and extending in the radial direction, the pole body 701 is sleeved in the mounting hole, the first flange 702 is provided on the outer end surface of the mounting hole, and the second flange 703 is provided on the inner end surface of the mounting hole. The insulating seal 8 includes a plurality of sealing segments, which are alternately arranged in the radial direction and the axial direction, and the plurality of sealing segments are respectively correspondingly provided between the first flange 702 and the outer end surface of the mounting hole, between the pole body 701 and the inner wall of the mounting hole, and between the second flange 703 and the inner end surface of the mounting hole.

[0063] In this arrangement, on the one hand, the multiple sealing segments are alternately arranged in the radial direction and the axial direction to form a circuitous labyrinth sealing structure with better sealing effect. On the other hand, the insulating seal 8 has two functions of insulating and sealing the pole 7 and the positive electrode cover 4, integrating the insulating parts and the sealing parts that exist independently in the related technology into one, which not only reduces the number of parts, but also simplifies the assembly process and improves the production efficiency of the battery.

[0064] In an optional embodiment, the first sealing section 801 and the second sealing section 802 of the insulating seal 8, the first sealing section 801 and the second sealing section 802 both extend in the axial direction, the first sealing section 801 is arranged on the outside of the mounting hole, and the second sealing section 802 is arranged on the inside of the mounting hole, the first sealing section 801 at least partially covers the first flange 702 in the radial direction, and the second sealing section 802 at least partially covers the second flange 703 in the radial direction. Such an arrangement can ensure the insulation between the pole 7 and the positive cover plate 4, and can increase the creepage distance. It should be noted that the above-mentioned "outer end" refers to the end away from the pole group 2, and the "outer side" refers to the side away from the pole group 2; similarly, the above-mentioned "inner end" refers to the end close to the pole group 2, and the "inner side" refers to the side close to the pole group 2.

[0065] In an optional embodiment, referring to Figure 1 Since the positive electrode cover plate 4 is provided with a protrusion 403 and the first sealing section is provided between the protrusion 403 and the first convex edge, the side wall of the protrusion 403 can limit the insulating seal 8 and improve the connection stability of the insulating seal 8.

[0066] In an optional embodiment, referring to Figure 1The insulating seal 8 includes a third sealing segment 803 extending in the radial direction. The third sealing segment 803 is connected to the first sealing segment 801 , and the third sealing segment 803 is pressed between the first protruding edge 702 and the second recessed portion 402 .

[0067] In an optional embodiment, the pole 7 is conductively connected to the positive terminal of the pole group 2 via the positive electrode connecting sheet 9 .

[0068] According to an embodiment of the present invention, on the other hand, a battery pack is provided, comprising a battery according to any one of at least two of the above technical solutions.

[0069] Because the battery pack includes the battery provided in the first aspect of the present invention, it has the same technical effects as the battery and will not be described in detail here.

[0070] Although the embodiments of the present invention have been described in conjunction with 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, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A battery, characterized in that: include: case; A pole group, arranged in the shell; A negative electrode cover plate, disposed at one end of the shell, the negative electrode cover plate comprises a negative electrode cover plate body and a first recessed portion disposed on the body and disposed toward the electrode group, the negative electrode cover plate body and the first recessed portion are connected by elastic ribs, the negative electrode cover plate body is connected to the shell, and the first recessed portion is electrically connected to the negative electrode of the electrode group; It also includes a positive electrode cover plate, which includes a positive electrode cover plate body and a second recessed portion arranged in the middle of the positive electrode cover plate body and facing close to the electrode group. The periphery of the positive electrode cover plate body and the periphery of the other end of the shell are welded, and the second recessed portion is provided with a mounting hole. The mounting hole is connected to a pole via an insulating seal, and the pole is electrically connected to the positive electrode of the pole group.

2. The battery according to claim 1, characterized in that The first recessed portion and the pole group are penetrated and welded.

3. The battery according to claim 1 or 2, characterized in that: The thickness of the first recessed portion is 0.5 to 0.8 times the thickness of the shell wall.

4. The battery according to claim 1 or 2, characterized in that: The depth of the first recessed portion in the negative electrode cover body is 2.5 to 6 times the thickness of the shell wall.

5. The battery according to claim 1 or 2, characterized in that: The thickness of the elastic rib is 0.35 to 0.6 times the thickness of the shell wall.

6. The battery according to claim 1 or 2, characterized in that: The elastic rib and the negative electrode cover plate body are integrally formed; and / or the negative electrode cover plate and the shell are integrally formed.

7. The battery according to claim 1 or 2, characterized in that: The shell is cylindrical, the negative electrode cover is circular and matches the shell, and the first recessed portion is annular.

8. The battery according to claim 7, characterized in that The positive electrode cover plate also includes a protrusion arranged toward away from the electrode group, the protrusion is arranged around the second recessed portion, the inner circle of the protrusion is connected to the second recessed portion, and the outer circle of the protrusion is connected to the positive electrode cover plate body; the protrusion is provided with an explosion-proof valve; and the negative electrode cover plate is provided with a liquid injection hole.

9. A battery pack, characterized in that: A battery comprising at least two batteries according to any one of claims 1 to 8.

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