Sodium battery spot welding equipment and spot welding method

Abstract

The present invention discloses a sodium battery spot welding device and a spot welding method thereof in the field of battery technology. The device comprises a base plate, a support column fixed to the top of one side of the base plate, an extension arm fixed to the top sidewall of the support column facing the base plate, a lifting connection plate provided at the bottom end of the extension arm away from the support column, and a mounting bracket fixed to the bottom end of the lifting connection plate. The beneficial effects of the present invention are as follows: a nickel-aluminum composite welding sheet acts as solder for welding the aluminum negative electrode of the sodium battery to the steel shell of the battery. The aluminum surface of the composite welding sheet is welded to the aluminum tabs of the positive and negative electrodes of the battery, and the nickel surface of the composite welding sheet is welded to the steel shell of the battery, completing the welding operation of the aluminum tabs of the sodium battery to the steel shell, thereby improving the strength of the weld and thereby increasing the service life of the sodium battery.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, in particular to a sodium battery spot welding device and a spot welding method thereof. Background Art

[0002] Sodium batteries, also known as sodium-ion batteries, are rechargeable secondary batteries that primarily rely on the movement of sodium ions between the positive and negative electrodes. Similar to lithium-ion batteries, sodium-ion batteries are manufactured using a steel casing, while the positive and negative current collectors are aluminum foil. However, welding the aluminum foil positive and negative electrodes to the steel casing is brittle and prone to cracking due to the significant difference in melting temperatures between aluminum and steel. Existing methods for welding aluminum to steel include: 1. Friction welding (primarily suitable for shafts); 2. Explosion welding (primarily suitable for welding aluminum to steel); 3. Brazing (primarily using a gas welding flame as a heat source to melt lead solder); and 4. For applications with less stringent weld requirements, aluminum welding rods can be used. This method is inexpensive, fast, and easy to use, but the welds lack impact resistance, and larger aluminum parts require preheating before welding. Existing welding methods are not suitable for welding the positive and negative electrodes of lithium batteries to the steel casing. This makes welding between the positive and negative electrodes of lithium batteries and the steel casing difficult and results in poor weld strength, which is detrimental to the use of sodium batteries. Therefore, this application document proposes a sodium battery spot welding device and spot welding method to solve the welding problem between the aluminum positive and negative electrodes of sodium batteries and the steel casing. Summary of the Invention

[0003] The purpose of the present invention is to provide a sodium battery spot welding machine and a spot welding method thereof, so as to solve the above-mentioned problem that the existing welding methods are not suitable for welding operations between the positive and negative electrodes of the lithium battery and the steel shell, resulting in great difficulty in welding the positive and negative electrodes of the lithium battery and the steel shell, poor welding strength, and being unfavorable for the use of the sodium battery.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a sodium battery spot welding machine device, comprising a base plate, a support column is fixed on the top of one side of the base plate, an extension arm is fixed to the top side wall of the support column facing the base plate, a lifting connecting plate is provided at the bottom end of the extension arm away from the support column, a mounting bracket is fixed at the bottom end of the lifting connecting plate, an electric welding head is detachably connected to the interior of the mounting bracket, the side wall of the support column located at the bottom end of the extension arm is movably connected to the support arm, a working groove is provided on the top of the support arm that matches the position of the electric welding head, a battery shell is provided inside the working groove, and the battery shell A battery filler is provided inside the shell, and a central cavity is opened inside the battery filler. A composite welding sheet is provided inside the bottom end of the central cavity. The composite welding sheet includes a nickel-faced solder and an aluminum-faced solder. The thickness of the nickel-faced solder is 0.08 mm, and the thickness of the aluminum-faced solder is 0.02 mm. The nickel-aluminum composite welding sheet acts as a welding object. When the sodium battery is welded, the aluminum surface of the nickel-aluminum composite welding sheet is welded to the negative electrode of the battery, and the nickel surface is welded to the steel shell, thereby increasing the welding strength between the aluminum pole pieces of the positive and negative poles of the battery and the steel shell, which is convenient for subsequent battery use.

[0005] As a further solution of the present invention: a lifting cylinder is fixed to the top of the extension arm away from the support column, and the output end of the lifting cylinder is set toward the bottom end. The output end of the lifting cylinder is movably connected with the extension arm. The output end of the lifting cylinder passes through the extension arm and is detachably connected to the top of the lifting connecting plate. The lifting cylinder can drive the lifting connecting plate to perform lifting movement, thereby driving the electric welding head to perform lifting movement to complete the spot welding operation.

[0006] As a further solution of the present invention: the support arm is provided with an installation cavity inside one end of the working groove, a limiting electric push rod is fixed in the installation cavity, the output end of the limiting electric push rod is arranged toward one end of the working groove, a limiting plate is arranged inside the working groove toward the side of the limiting electric push rod, and the limiting plate is fixedly connected to the output end of the limiting electric push rod close to one end of the limiting electric push rod, and the battery casing in the working groove can be squeezed and limited by the limiting electric push rod and the limiting plate, thereby ensuring the accuracy of the spot welding position.

[0007] As a further solution of the present invention: a grounding plate is provided at one end of the base plate, a distribution box is fixed to the top side wall of one end of the support column, grounding is achieved through the grounding plate, and power is provided to the equipment through the distribution box.

[0008] As a further solution of the present invention: the top of the support column is detachably connected to an air pump, the output end of the air pump is fixedly connected to the input end of the lifting cylinder, and the air pump provides the lifting cylinder with the gas required for movement to ensure that the lifting cylinder can operate normally.

[0009] As a further solution of the present invention: a lifting electric push rod is fixed to the side wall of the support column located at the bottom end of the support arm, the output end of the lifting electric push rod is set toward the top, and the output end of the lifting electric push rod is fixedly connected to the bottom of the support arm. By starting the lifting electric push rod, the support arm can be driven to perform lifting movements, thereby driving the battery housing to move closer to the welding head.

[0010] A sodium battery spot welding method includes the above-mentioned spot welding machine and the following steps:

[0011] S100: Place the battery and welding piece, put the empty battery shell into the welding position, and

[0012] The composite welding sheet is placed in the gap between the front and back sides of the battery;

[0013] S200: Preliminary spot welding, welding the aluminum surface of the composite welding sheet to the aluminum foil in the gap on the negative electrode of the battery, with the nickel surface of the composite welding sheet facing outward;

[0014] S300: Folding the tabs, winding the composite welding sheets at both ends of the negative electrode, after folding the weight, the nickel surface of the middle tab faces inward, and the nickel surface of the outer tab faces outward;

[0015] S400: After winding, insert a hollow tube into the middle hollow part;

[0016] S500: Insert the welding needle into the hollow tube in the middle of the positive electrode of the battery, press it against the negative electrode ear, make it contact the steel shell, and weld the negative electrode to the steel shell using a spot welding machine.

[0017] As a further solution of the present invention: before performing the sodium battery welding operation, the step S100 needs to check the orientation of the nickel surface and the aluminum surface of the composite welding sheet to avoid welding to the wrong nickel surface and the wrong aluminum surface.

[0018] As a further solution of the present invention: during the welding operation in step S500, the negative electrode tab needs to be welded to the steel shell. During the welding operation, the aluminum surface of the composite welding sheet is welded to the negative electrode tab of the battery, and the nickel surface is welded to the steel shell.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. In the present invention, a nickel-aluminum composite welding sheet is used as the solder for welding the aluminum negative electrode of the sodium battery and the battery steel shell. The aluminum surface of the composite welding sheet is welded to the aluminum tabs of the positive and negative electrodes of the battery, and the nickel surface of the composite welding sheet is welded to the battery steel shell. The welding operation of the aluminum tabs and the steel shell of the sodium battery is completed, the strength of the weld is improved, and thus the service life of the sodium battery is increased.

[0021] 2. In the present invention, through the double-sided composite solder design, when welding the sodium battery tab and the steel shell, welding between different materials on both sides can be completed, thereby improving welding accuracy, reducing the welding process of the sodium battery tab, and improving welding efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the main structure of the present invention;

[0023] Figure 2 For the present invention Figure 1 A schematic diagram of the structure at center A;

[0024] Figure 3 For the present invention Figure 1 A magnified schematic diagram of the structure at B in the middle;

[0025] Figure 4 It is an enlarged schematic diagram of the cross-sectional structure of the battery housing in the present invention;

[0026] Figure 5 For the present invention Figure 4 A magnified schematic diagram of the structure at C in the middle;

[0027] Figure 6 Schematic diagram of the structure of the composite welding sheet of the present invention;

[0028] Figure 7 Schematic diagram of the cross-sectional structure of welding in the present invention;

[0029] Figure 8 Schematic diagram of the welding method of the present invention.

[0030] In the figure: 1. Base plate; 2. Support column; 3. Distribution box; 4. Air pump; 5. Lifting cylinder; 6. Support arm; 7. Grounding plate; 8. Lifting connecting plate; 9. Mounting frame; 10. Welding head; 11. Working tank; 12. Limiting electric push rod; 13. Limiting plate; 14. Battery shell; 15. Battery filler; 16. Central cavity; 17. Composite welding piece; 171. Nickel-faced solder; 172. Aluminum-faced solder; 18. Extension arm; 19. Lifting electric push rod. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only 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 ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] For example 1, please refer to Figure 1-7When using this device to weld batteries, one only needs to place the base plate 1 in the appropriate position, connect the ground plate 7 to the ground, and electrically connect the external power to the input terminal of the distribution box 3 to complete the internal power transmission. The air pump 4 is then started to produce gas, preparing for the operation of the lifting cylinder 5. A new welding head 10 is then replaced through the mounting bracket 9. After completing the preparations, the battery housing 14 is placed in the working groove 11, and the limit electric push rod 12 is started. The movement of the limit electric push rod 12 drives the movement of the limit plate 13, thereby clamping the battery housing 14 in the working groove 11 through the limit plate 13. The battery filling material and the composite welding sheet 17 are placed in the internal cavity of the battery housing 14. The lifting cylinder 5 is then started. The movement of the lifting cylinder 5 drives the lifting connecting plate 8 to move up and down, driving the welding head 10 to move downward, insert into the internal cavity of the battery housing 14, and perform welding operations on the internal battery and the composite welding sheet 17.

[0033] See also Figure 1 In this embodiment, a controller is further provided outside the distribution box 3, wherein the controller mainly controls the internal circuits and pneumatic components.

[0034] See also Figure 2 In this embodiment, the mounting frame 9 is provided in two halves, the outer diameters of the two mounting frames 9 are exactly the same, and the two mounting frames 9 are connected by two screws. A mounting hole is vertically penetrated at the connection point, and the welding head 10 is provided in the mounting hole. The welding head 10 is connected and limited by the mounting hole, and it is convenient to replace the new welding head 10.

[0035] See also Figure 2 In this embodiment, a power supply line is also connected to the top of the welding head 10, and a control box is fixed to the bottom end of the lifting connecting plate 8. The power supply line of the welding head 10 connects the control box and the welding head 10, thereby controlling the working state of the welding head 10.

[0036] For example 2, please refer to Figure 1 and Figure 8In the present invention, when using a spot welding machine to weld the positive and negative tabs of the sodium battery and the battery shell 14, it is only necessary to place the battery shell 14 into the working groove 11, start the limit electric push rod 12 to cooperate with the limit plate 13 to limit the battery shell 14, and then place the composite welding sheet 17 into the battery shell 14. When placing it, it is necessary to pay attention to the negative bipolar tab being welded to the gap between the front and back sides of the tabs respectively, and the aluminum surface of the composite strip being welded to the aluminum foil in the gap between the negative tabs. After the negative bipolar tabs are wound with the nickel surface facing outward and folded in the center, the nickel surface of the middle tab faces inward, and the nickel surface of the outer tabs faces outward. After winding, a hollow tube is inserted in the middle. After the battery is put into the shell, a welding needle is inserted from the middle hollow tube of the positive pole to press against the negative tab to contact the steel shell. The negative pole and the steel shell are welded by the spot bottom welding machine, thereby increasing the nickel content on the negative tab of the battery through the composite welding sheet 17 supported by the nickel-aluminum material, thereby increasing the welding strength between the battery and the battery shell 14.

[0037] See also Figure 6 In this embodiment, the bottom of the composite welding sheet 17 is nickel, and its thickness is 0.08 mm, and the top of the composite welding sheet 17 is aluminum, and its thickness is 0.02 mm.

[0038] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A sodium battery spot welding machine device, comprising a base plate (1), characterized in that: A support column (2) is fixed to the top of one side of the base plate (1), an extension arm (18) is fixed to the top side wall of the support column (2) facing the base plate (1), a lifting connection plate (8) is provided at the bottom end of the extension arm (18) away from the support column (2), a mounting frame (9) is fixed to the bottom end of the lifting connection plate (8), an electric welding head (10) is detachably connected to the interior of the mounting frame (9), a support arm (6) is movably connected to the side wall of the support column (2) located at the bottom end of the extension arm (18), and the top opening of the support arm (6) matches the position of the electric welding head (10). A working tank (11) is provided, wherein a battery shell (14) is provided inside the working tank (111), a battery filler (15) is provided inside the battery shell (14), a central cavity (16) is provided inside the battery filler (15), a composite welding sheet (17) is provided inside the bottom end of the central cavity (16), and the composite welding sheet (17) includes a nickel surface solder (171) and an aluminum surface solder (172), wherein the thickness of the nickel surface solder (171) is 0.08 mm, and the thickness of the aluminum surface solder (172) is 0.02 mm.

2. A sodium battery spot welding machine according to claim 1, characterized in that: A lifting cylinder (5) is fixed to the top of the extension arm (18) away from the support column (2), and the output end of the lifting cylinder (5) is arranged toward the bottom end. The output end of the lifting cylinder (5) is movably connected to the extension arm (18). After passing through the extension arm (18), the output end of the lifting cylinder (5) is detachably connected to the top of the lifting connecting plate (8).

3. The sodium battery spot welding machine according to claim 1, characterized in that: An installation cavity is provided inside the support arm (6) toward one end of the working slot (11), a limit electric push rod (12) is fixed in the installation cavity, an output end of the limit electric push rod (12) is arranged toward one end of the working slot (11), a limit plate (13) is provided inside the working slot (11) toward one side of the limit electric push rod (12), and an end of the limit plate (13) close to the limit electric push rod (12) is fixedly connected to the output end of the limit electric push rod (12).

4. The sodium battery spot welding machine according to claim 1, characterized in that: One end of the base plate (1) is provided with a grounding plate (7), and a distribution box (3) is fixed to the top side wall of one end of the support column (2).

5. The sodium battery spot welding machine according to claim 1, characterized in that: The top of the support column (2) is detachably connected to an air pump (4), and the output end of the air pump (4) is fixedly connected to the input end of the lifting cylinder (5).

6. A sodium battery spot welding device and spot welding method according to claim 1, characterized in that: A lifting electric push rod (19) is fixed to the side wall of the support column (2) at the bottom end of the support arm (6), and the output end of the lifting electric push rod (19) is arranged toward the top, and the output end of the lifting electric push rod (19) is fixedly connected to the bottom of the support arm (6).

7. A sodium battery spot welding method, characterized in that: The method comprises the spot welding machine according to claim 1 to claim 6 and the following steps: S100: Place the battery and welding piece, place the empty battery shell into the welding position, and place the composite welding piece into the gap between the front and back sides of the battery; S200: Preliminary spot welding, welding the aluminum surface of the composite welding sheet to the aluminum foil in the gap on the negative electrode of the battery, with the nickel surface of the composite welding sheet facing outward; S300: Tab folding, composite welding sheets wound around both ends of the negative electrode, after folding the weight, The nickel surface of the middle tab faces inward, and the nickel surface of the outer tab faces outward; S400: After winding, insert a hollow tube into the middle hollow part; S500: Insert the welding needle into the hollow tube in the middle of the positive electrode of the battery, press it against the negative electrode ear, make it contact the steel shell, and weld the negative electrode to the steel shell using a spot welding machine.

8. A sodium battery spot welding method according to claim 7, characterized in that: In step S100, before performing the sodium battery welding operation, the orientation of the nickel surface and the aluminum surface of the composite welding sheet must be checked to avoid welding to the wrong nickel surface and the wrong aluminum surface.

9. A sodium battery spot welding method according to claim 7, characterized in that: During the welding operation in step S500, the negative electrode tab needs to be welded to the steel shell. During the welding operation, the aluminum surface of the composite welding sheet is welded to the negative electrode tab of the battery, and the nickel surface is welded to the steel shell.

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