Battery welding method and automobile

Abstract

The invention relates to the field of batteries, and particularly provides a battery welding method and an automobile, and the battery welding method comprises the following steps: S10: welding a positive tab and a negative tab on a first pole group and a second pole group; s20, stacking and fixing the first pole group, the partition plate and the second pole group; s30, welding the negative tab of the first pole group with the third pole column; s40, turning over the fixed first pole group, the partition plate and the second pole group, and welding a positive tab of the second pole group with a fourth pole column; s50, fixing the first shell, welding the positive lug of the first pole group with the first pole column, and rotating the first shell to cover the first pole group; s60, overturning the welded first pole group and the first shell, fixing the second shell, welding a negative tab of the second pole group with the second pole column, and rotating the second shell to cover the second pole group; and S70, sealing and welding the end parts of the first shell, the second shell and the partition plate to obtain the battery cell. By means of the welding method of the battery, the structural strength and the capacity density of the battery can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and particularly provides a welding method for a battery and an automobile. Background Art

[0002] With the increasing global attention to the control of fossil energy use and environmental pollution, the development of new energy has gradually accelerated in recent years and become the focus of people's attention. Among them, the research on new energy vehicles is the most popular in new energy. The battery part is an important component of new energy vehicles. Blade batteries have entered people's vision with their unique advantages, and the research on blade batteries has gradually deepened to obtain better and safer batteries.

[0003] In the prior art, the structure of a blade battery is to install a battery cell in a housing, and then the housing is welded and sealed. Then, several blade batteries are arranged to form a battery pack. At present, most of the blade batteries used in the market have a single-cell structure. After that, the encapsulated blade batteries are connected in series to form a power supply unit. However, the housing also occupies a certain volume in the battery pack. Therefore, there is still room for improvement in the volume energy density of the battery pack. At the same time, compared with traditional battery modules, blade batteries use themselves as a support structure. Therefore, while improving the volume energy density, the strength of the battery also needs to be considered. Then, the corresponding welding method for the housing also needs to be upgraded to meet the requirements of the strength and service life of the housing itself. At present, there is no good solution in the market.

[0004] Correspondingly, there is a need in the art for a new blade battery to solve the above problems. Summary of the Invention

[0005] The present invention aims to solve the above technical problems, that is, to solve the problem of how to improve the volume energy density of a blade battery in the prior art while maintaining the overall strength of the battery. For this purpose, the present invention provides a welding method for a battery, and the battery includes:

[0006] A first housing and a second housing, the first housing is provided with a first pole, and the second housing is provided with a second pole;

[0007] A first pole group and a second pole group, both the first pole group and the second pole group are provided with a positive electrode tab and a negative electrode tab;

[0008] A separator, the separator is provided with a third pole and a fourth pole, and the third pole and the fourth pole are located on both sides of the separator and are electrically connected;

[0009] The negative electrode tab of the first pole group is electrically connected to the third pole, and the positive electrode tab of the second pole group is electrically connected to the fourth pole;

[0010] The welding method includes the following steps:

[0011] S10: Weld a positive tab and a negative tab on the first electrode group and the second electrode group;

[0012] S20: Stack and fix the first electrode group, the separator, and the second electrode group, with the stacking direction being the first direction;

[0013] S30: Weld the negative tab of the first electrode group to the third terminal;

[0014] S40: Flip the fixed first electrode group, the separator, and the second electrode group, and weld the positive tab of the second electrode group to the fourth terminal;

[0015] S50: Fix the first housing with its opening perpendicular to the first direction, weld the positive tab of the first electrode group to the first terminal, and rotate and cover the first housing onto the first electrode group;

[0016] S60: Flip the welded first electrode group and the first housing, fix the second housing with its opening perpendicular to the first direction, weld the negative tab of the second electrode group to the second terminal, and rotate and cover the second housing onto the second electrode group;

[0017] S70: Seal and weld the ends of the first housing, the second housing, and the separator to obtain an electric core.

[0018] In the specific embodiment of the above welding method for a battery, in steps S40 and S60, the angle by which the fixed first electrode group, the separator, and the second electrode group are flipped is 180 degrees, and / or the angle by which the welded first electrode group and the first housing are flipped is 180 degrees.

[0019] In the specific embodiment of the above welding method for a battery, in steps S50 and S60, the angle by which the first housing and / or the second housing rotates is 90 degrees.

[0020] In the specific embodiment of the above welding method for a battery, the welding method further includes:

[0021] Before step S20, hot-press the first electrode group and the second electrode group, and / or wrap the first electrode group and the second electrode group with an insulating film.

[0022] In the specific embodiment of the above welding method for a battery, the materials of the first housing, the second housing, and the separator are all aluminum.

[0023] In the specific embodiment of the welding method with a battery, in the steps S50 and S60, the welding angle between the positive tab of the first electrode group and the first pole column is inclined to the opening direction of the first housing and the first direction, and / or the welding angle between the negative tab of the second electrode group and the second pole column is inclined to the opening direction of the first housing and the first direction.

[0024] In the specific embodiment of the welding method with a battery, the welding method further includes:

[0025] In the step S10, positive tabs and negative tabs are welded to the first electrode group and the second electrode group by ultrasonic welding; and / or

[0026] In the steps S50 and S60, the positive tab of the first electrode group is welded to the first pole column and the negative tab of the second electrode group is welded to the second pole column of the second housing by laser welding; and / or

[0027] In the step S70, the first housing, the second housing and the separator are welded by laser penetration welding, laser sealing welding or laser brazing.

[0028] In the specific embodiment of the welding method with a battery, the separator is located between the first electrode group and the second electrode group, and a receiving space is formed between the separator and the first housing or between the separator and the second housing.

[0029] In the specific embodiment of the welding method with a battery, the first electrode group and the second electrode group are respectively arranged in the receiving space. The first electrode group is connected to the first pole column and the third pole column in series, and the second electrode group is connected to the second pole column and the fourth pole column in series.

[0030] An automobile includes a battery, and the battery is a battery produced by using the above welding method.

[0031] In the case of adopting the above technical solution, the present invention can realize two or even more pole groups inside an assembly housing to form a series-connected blade battery through a series structure. For the series-connected blade battery, in the same volume, the housing of the battery of the present invention occupies a smaller volume, and the pole groups inside adopt a series connection method. The battery produced by the battery welding method of the present invention has a higher energy density than a single-core blade battery, and a partition is adopted inside the housing to separate the pole groups, and the overall explosion-proof and pressure-resistant strength of the battery can also be improved. On the basis of the existing technology, for the welding method of the pole group and the housing, while obtaining a battery with a higher energy density, the process flow can be simplified, the performance of the battery can be further improved, and the production efficiency can be improved, thereby solving the problem of how to improve the volume energy density and reduce the cost while maintaining the overall strength of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings, in which:

[0033] Figure 1 is a schematic diagram of the internal structure of the battery of the present invention, which shows the internal pole group connection structure and the laser penetration welding structure;

[0034] Figure 2 is a main step flow chart of the welding method of the present invention;

[0035] Figure 3 is a schematic diagram of the pole group structure of the present invention;

[0036] Figure 4 is a schematic diagram of the partition structure of the present invention;

[0037] Figure 5 is a schematic diagram of the welding of the pole group and the partition of the present invention;

[0038] Figure 6 is a schematic diagram of the welding of the pole group and the partition welded together with the housing of the present invention;

[0039] Figure 7 is a schematic diagram of the welding of the pole group and the partition welded together with the other side housing of the present invention;

[0040] Figure 8 is a schematic diagram of the internal structure of the battery after press-fitting and encapsulation of the present invention.

[0041] In the figure: 1. Pole group, 11. First pole group, 12. Second pole group, 2. Negative electrode tab, 3. Positive electrode tab, 4. Partition, 41. Third pole column, 42. Fourth pole column, 5. First housing, 51. First pole column, 52. First flange, 6. Second housing, 61. Second pole column, 62. Second flange. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings and in connection with the batteries of the bipolar group. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the present invention and are not used to limit the protection scope of the present invention. Those skilled in the art can make adjustments according to needs to adapt to specific application scenarios. For example, although the description in the specification is in connection with the batteries of the bipolar group, this is not restrictive, and those skilled in the art can apply the present invention to the batteries of the multi-polar group according to needs.

[0043] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the accompanying drawings. This is only for convenience of description and does not indicate or imply that the relevant devices or elements must be arranged in a specific orientation, constructed and operated in a specific orientation, so it cannot be understood as a limitation of the present invention. In addition, ordinal numbers such as "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0044] In addition, it should also be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0045] Furthermore, in order to more clearly show the core technical solution of the present invention, the description of the known structure of the blade battery is omitted below. However, this omission is only for convenience of description and does not mean that the blade battery can be without these structures.

[0046] As Figure 1 shown, the present invention provides a battery, which includes:

[0047] A first housing 5 and a second housing 6, both the first housing 5 and the second housing 6 are provided with external pole posts;

[0048] A pole group 1, and there are at least two pole groups 1;

[0049] A separator 4, the separator 4 is provided with connection pole posts, and the separator 4 is located between adjacent pole groups 1;

[0050] A receiving space is formed between the separator 4 and the first housing 5 or the second housing 6, the pole group 1 is arranged in the receiving space, and several pole groups 1 are connected to the external pole posts and the connection pole posts in series.

[0051] In this embodiment, it should be noted that the description is made in combination with the blade battery in which two pole groups 1 are connected in series. However, this does not limit the protection scope of the present invention. Specifically, the blade battery in which two pole groups 1 are connected in series and the blade battery in which multiple pole groups 1 are connected in series are both formed by buckling two outer shells to form a closed structure. Inside the shell, a partition 4 is used to divide the internal sealed space into two parts. There are two pole groups 1, which are respectively installed in the divided sealed spaces. The two pole groups 1 form a double-layer structure one above the other, and the position arrangement is as described above. The connection between the pole groups 1 is in series, so there are only two contact points outside the outer shell, and the inside is an integral whole. The internal electrical connection forms a series connection of the pole groups 1 in the two spaces through the partition 4. The partition 4 is preferably made of aluminum, and other plates that can conduct electricity and have a certain supportability can also be selected. There are connecting pole columns at both ends of the partition 4, and the connecting pole columns are connected to the pole groups 1. The connecting pole columns are arranged at one end in the length direction of the partition 4 and on both sides in the thickness direction of the partition 4, and the two-sided pole groups 1 achieve internal electrical connection through a series connection method. The shell protects the internal structure and realizes the overall support. The shell is divided into a first shell 5 and a second shell 6, and they are connected by a buckling method. There are also external connecting pole columns on the first shell 5 and the second shell 6. Inside, after the pole groups 1 and the partition 4 are connected in series, the other ends of the two pole groups 1 are respectively connected to the external connecting pole columns on the first shell 5 and the second shell 6. The materials of the first shell 5 and the second shell 6 are both aluminum, and other plates that can conduct electricity and have a certain supportability can also be selected. In this way, while realizing the internal electrical connection, the outside of the entire battery outputs electrical energy through the external connecting pole columns on the first shell 1 and the second shell 2. When in use, the above-mentioned blade battery is adopted, with an energy density > 2000 Wh / kg, a 50% improvement in charging capacity, and an anti-explosion and pressure-resistant strength ≥ 1.5 MPa, further improving the various performances of the blade battery.

[0052] Further, referring to Figure 3 , which is the specific implementation manner of the structure of the pole group 1;

[0053] In this embodiment, at both ends of the pole group 1, the ear-lead method is adopted for electrical connection. The negative ear 2 and the positive ear 3 are respectively arranged at both ends of the pole group 1. Those skilled in the art can adjust the specific form of the electrode output end of the pole group 1 according to actual needs, but this does not limit the protection scope of the present invention.

[0054] Further, referring to Figure 4 and Figure 5 , which is the specific implementation manner of the assembly of the pole group 1 and the partition 4;

[0055] Based on the specific structure of the electrode group 1 in the above embodiment, in this embodiment, the electrode group 1 includes a first electrode group 11 and a second electrode group 12. Each of the first electrode group 11 and the second electrode group 12 is provided with a negative tab 2 and a positive tab 3. The separator 4 is provided with a third pole 41 and a fourth pole 42. The third pole 41 and the fourth pole 42 are located on both sides of the separator 4 and are electrically connected to each other. The negative tab 2 of the first electrode group 11 is welded and electrically connected to the third pole 41 of the separator 4, and the positive tab 3 of the second electrode group 12 is welded and electrically connected to the fourth pole 42 of the separator 4. The first electrode group 11 and the second electrode group 12 are located on both sides of the separator 4, and the first electrode group 11, the separator 4, and the second electrode group 12 are stacked together in sequence. The separator 4 is located between the first electrode group 11 and the second electrode group 12, and an accommodation space is formed between the separator 4 and the first housing 5 or between the separator 4 and the second housing 6. The first electrode group 11 and the second electrode group 12 are respectively arranged in the accommodation space.

[0056] Further, continue to refer to Figures 6 to 8 , and the specific implementation method is as follows:

[0057] Based on the structure of the connection between the electrode group 1 and the separator 4 in the above embodiment, the first electrode group 11 is connected to the housing 5. The first housing 5 has a first pole 51 located on its inner wall and a first flange 52 extending outward from the edge. The positive tab 3 of the first electrode group 11 is welded and electrically connected to the first pole 51, realizing the electrical connection between the first electrode group 11 and the external pole on the first housing 5. The first electrode group 11 is connected to the first pole 51 and the third pole 41 in series, and the second electrode group 12 is connected to the second pole 61 and the fourth pole 42 in series.

[0058] The second electrode group 12 is connected to the housing 6. The first housing 6 has a second pole 61 located on its inner wall and a second flange 62 extending outward from the edge. The negative tab 2 of the second electrode group 12 is welded and electrically connected to the second pole 61, realizing the electrical connection between the second electrode group 12 and the external pole on the second housing 6. Through the series electrical connection of the first electrode group 11 with the housing 5 and the separator 4 and the series electrical connection of the second electrode group 12 with the housing 6 and the separator 4, a series connection in the state of the internal partition space is formed in this way. The first housing 5 and the second housing 6 also take measures to achieve sealed connection, thereby providing protection for the internal environment of the blade battery and realizing the electrical conduction of the entire battery.

[0059] Based on the specific structure of the battery with the above structure, continue to refer to Figures 2 to 8 , and a welding method for the battery is proposed. The welding method includes:

[0060] S10: Weld the positive tab 3 and the negative tab 2 on the first electrode group 11 and the second electrode group 12;

[0061] S20: Stack and fix the first electrode group 11, the separator 4, and the second electrode group 12 in the stacking direction of the first direction;

[0062] S30: Weld the negative electrode tab 2 of the first electrode group 11 to the third electrode post 41;

[0063] S40: Flip the fixed first electrode group 11, separator 4, and second electrode group 12, and weld the positive electrode tab 3 of the second electrode group 12 to the fourth electrode post 42;

[0064] S50: Fix the first housing 5 with its opening perpendicular to the first direction, weld the positive electrode tab 3 of the first electrode group 11 to the first electrode post 51, and rotate and cover the first housing 5 onto the first electrode group 11;

[0065] S60: Flip the welded first electrode group 11 and first housing 5, fix the second housing 6 with its opening perpendicular to the first direction, weld the negative electrode tab 2 of the second electrode group 12 to the second electrode post 61, and rotate and cover the second housing 6 onto the second electrode group 12;

[0066] S70: Seal and weld the ends of the first housing 5, second housing 6, and separator 4 to obtain an electric core.

[0067] In this embodiment, the welding method of the battery described in the above embodiment is described, but this does not affect the protection scope of the present invention. Specifically, first, the first electrode group 11 and the second electrode group 12 are ultrasonically welded to the negative electrode tab 2 and the positive electrode tab 3. Before pre-welding, the first electrode group 11 and the second electrode group 12 are hot-pressed, and the first electrode group 11 and the second electrode group 12 are coated with an insulating film to ensure the independent insulation of the electrode group 1 unit.

[0068] After the electrode group 1 is manufactured, then comes the middle part. The first electrode group 11, the second electrode group 12, and the separator 4 are welded. The first electrode group 11, the second electrode group 12, and the separator 4 are press-fitted and fixed using a fixture. In this embodiment, a single separator 4 is adopted. The negative electrode tab 2 of the first electrode group 11 is welded to the third electrode post 41 of the separator 4. After welding, the fixed first electrode group 11, second electrode group 12, and separator 4 are flipped by 180 degrees, and the positive electrode tab 3 of the second electrode group 12 is welded to the fourth electrode post 42 of the separator 4.

[0069] Next, the welding assembly of the housing and the tab is welded. The first housing 5 is placed vertically and fixed, and the opening direction of the first housing 5 is perpendicular to the first direction. The positive tab 3 of the first electrode group 11 is laser welded to the first terminal 51, and the welding laser is incident from the side, that is, the welding angle between the positive tab 3 of the first electrode group 11 and the first terminal 51 is inclined to the opening direction and the first direction of the first housing 5. Then, the first housing 5 is rotated 90 degrees to cover the first electrode group 11, and the insertion of the first electrode group 11 into the housing is completed. Next, the welded first electrode group 11 and the first housing 5 are flipped 180 degrees. The second housing 6 is fixed with its opening perpendicular to the first direction. The negative tab 2 of the second electrode group 12 is laser welded to the second terminal 61, and the welding laser is incident from the side, that is, the welding angle between the negative tab 2 of the second electrode group 12 and the second terminal 61 is inclined to the opening direction and the first direction of the second housing 6, and the second housing 6 is rotated 90 degrees to cover the second electrode group 12, and the insertion of the second electrode group 12 into the housing is completed.

[0070] Finally, the first housing 5 and the second housing 6 are pressed together. The internal electrode group 1 and the separator 4 contract and are fixed under the pressing of the first housing 5 and the second housing 6. The first housing 5, the second housing 6, and the separator 4 need to be sealed, and welding treatment is adopted. There are various welding treatment methods. In this embodiment, laser penetration welding is adopted. The outside of the first housing 5 and the second housing 6 is reserved with flanges for traditional welding. The first housing 5 has a first flange 52, the second housing 6 has a second flange 62, and the separator 4 is also between the first flange 52 and the second flange 62 and is fixed by penetration welding. Of course, laser penetration welding, laser sealing welding, or laser brazing can also be used. In this way, the first housing 5 and the second housing 6 do not need to reserve flanges, and the separator 4 only needs to be aligned inside.

[0071] The present invention can achieve two or even more electrode groups forming a series-connected blade battery through a series structure inside an assembly housing. For the series-connected blade battery, in the same volume, the housing of the battery of the present invention occupies a smaller volume, and the internal electrode groups are connected in series. The battery produced by the battery welding method of the present invention has a higher energy density than a single-core blade battery. Moreover, a separator is adopted inside the housing to separate the electrode groups, and the overall explosion-proof and pressure-resistant strength of the battery can also be improved. Based on the prior art, for the welding method of the electrode group and the housing, while obtaining a battery with a higher energy density, the process flow can be simplified, the performance of the battery can be further improved, and the production efficiency can be increased, thereby solving the problem of how to improve the volume energy density and reduce the cost while maintaining the overall strength of the battery. By adopting the above battery production process, the manufacturing cost is reduced by 25% (RMB / Wh); the investment in equipment and factory buildings is reduced by 50%, and the production efficiency is increased by 250%; the produced blade battery can meet the requirement that the sealing does not fail after 2500 cycle lives.

[0072] In this embodiment, the battery produced by adopting this process can be applied to an automobile to provide more durable endurance and reduce the production cost of the automobile.

[0073] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A welding method for a battery, the battery comprising: A first housing and a second housing, the first housing being provided with a first pole post, and the second housing being provided with a second pole post; A first electrode group and a second electrode group, both the first electrode group and the second electrode group being provided with a positive electrode tab and a negative electrode tab; A separator, the separator being provided with a third pole post and a fourth pole post, the third pole post and the fourth pole post being located on both sides of the separator and electrically connected; The negative electrode tab of the first electrode group is electrically connected to the third pole post, and the positive electrode tab of the second electrode group is electrically connected to the fourth pole post; Characterized in that the welding method comprises the following steps: S10: Weld the positive electrode tab and the negative electrode tab on the first electrode group and the second electrode group; S20: Stack and fix the first electrode group, the separator, and the second electrode group, and the stacking direction is the first direction; S30: Weld the negative electrode tab of the first electrode group to the third pole post; S40: Flip the fixed first electrode group, the separator, and the second electrode group, and weld the positive electrode tab of the second electrode group to the fourth pole post; S50: Fix the first housing in a manner that the opening is perpendicular to the first direction, weld the positive electrode tab of the first electrode group to the first pole post, and rotate the first housing to cover the first electrode group; S60: Flip the welded first electrode group and the first housing, fix the second housing in a manner that the opening is perpendicular to the first direction, weld the negative electrode tab of the second electrode group to the second pole post, and rotate the second housing to cover the second electrode group; S70: Perform sealing welding on the ends of the first housing, the second housing, and the separator to obtain an electric core.

2. The welding method of the battery according to claim 1, characterized in that, In the steps S40 and S60, the angle by which the fixed first electrode group, the separator, and the second electrode group are flipped is 180 degrees, and / or the angle by which the welded first electrode group and the first housing are flipped is 180 degrees.

3. The welding method of the battery according to claim 1, characterized in that, In the steps S50 and S60, the angle by which the first housing and / or the second housing rotates is 90 degrees.

4. The welding method of the battery according to claim 1, wherein The welding method further comprises: Before the step S20, perform hot pressing on the first electrode group and the second electrode group, and / or wrap the first electrode group and the second electrode group with an insulating film.

5. The welding method of the battery according to claim 1, wherein, The materials of the first housing, the second housing, and the separator are all aluminum.

6. The welding method of the battery according to claim 1, characterized in that, In the steps S50 and S60, the welding angle between the positive electrode tab of the first electrode group and the first pole post is inclined to the opening direction of the first housing and the first direction, and / or the welding angle between the negative electrode tab of the second electrode group and the second pole post is inclined to the opening direction of the first housing and the first direction.

7. The welding method of the battery according to any one of claims 1 to 6, characterized in that, The welding method further comprises: In the step S10, use ultrasonic welding to weld the positive electrode tab and the negative electrode tab on the first electrode group and the second electrode group; and / or In the steps S50 and S60, use laser welding to weld the positive electrode tab of the first electrode group to the first pole post and the negative electrode tab of the second electrode group to the second pole post of the second housing; and / or In the step S70, the first housing, the second housing and the separator are welded by means of laser penetration welding, laser sealing welding or laser brazing.

8. The welding method of the battery according to claim 1, characterized in that The separator is located between the first electrode group and the second electrode group, and an accommodation space is formed between the separator and the first housing or between the separator and the second housing.

9. The welding method of the battery according to claim 8, wherein, The first electrode group and the second electrode group are respectively arranged in the accommodation space. The first electrode group is connected to the first pole column and the third pole column in series, and the second electrode group is connected to the second pole column and the fourth pole column in series.

10. An automobile, the automobile comprising a battery, characterized in that, The battery is a battery produced by using the welding method according to any one of claims 1 to 9.

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