Auxiliary welding tool for improving fracture of ceramic layer of positive plate of soft package battery

Abstract

The utility model belongs to the technical field of manufacturing of soft package batteries, and discloses an auxiliary welding tool for improving fracture of a ceramic layer of a positive plate of a soft package battery, which comprises a tab pressing plate arranged above a welding seat between a welding head and a battery cell and used for pressing tab foil on the welding seat through the tab pressing plate. And the tab foil between the tab pressing plate and the battery cell is bent into a bent section capable of buffering the pulling force. During welding, the lower end of the tab pressing plate is propped against the tab foil, so that the tab foil positioned between the tab pressing plate and a battery cell can be bent into a bent section, such as an S-shaped bent section, capable of buffering pulling force, so that the tab foil can have a certain deformation space, the pulling force of a welding head on the foil is reduced, and the welding quality of the tab foil is improved. The problems that the foil and the pole piece are pulled and the mutual soluble area of the ceramic layer and the black material is easy to break in the welding process are avoided, and the safety performance of the battery is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of soft-pack battery manufacturing, and in particular relates to a welding auxiliary tool for improving the fracture of a ceramic layer of a positive electrode sheet of a soft-pack battery. Background Art

[0002] Lithium-ion soft-pack batteries are widely used in the market because of their high energy density. The production demand is increasing day by day. However, the production and manufacturing difficulty and cost of lithium-ion soft-pack power batteries are also high. The structural properties of lithium-ion soft-pack batteries determine that some of its technical problems need to be improved and solved. As we all know, soft-pack batteries are mainly composed of positive electrode sheets, negative electrode sheets, diaphragms, electrolytes and aluminum-plastic film outer packaging. Due to safety design, the alignment of positive and negative electrode sheets and diaphragms will be controlled. The diaphragm size is required to be larger than the negative electrode size, and the negative electrode size is required to be larger than the positive electrode size. The diaphragm is larger than the negative electrode to ensure that the diaphragm can separate the positive and negative electrode sheets. The negative electrode size is larger than the positive electrode to ensure that the lithium ions released from the positive electrode have enough space to be embedded in the negative electrode, so as to ensure that there is no lithium precipitation, and no lithium dendrites are formed to pierce the diaphragm and form an internal short circuit. Since the safety risk of the negative electrode material area contacting the aluminum foil is the greatest, in order to avoid direct contact between the negative electrode material area and the aluminum foil, a ceramic layer is designed to be coated on the edge of the positive electrode sheet area. However, due to the design of the ceramic layer, there is an overlap between the ceramic layer and the positive electrode material area, about 0-1mm, and the ceramic layer is on top and the positive electrode material area is on the bottom. As a result, the positive electrode sheet can be divided into three parts, including the positive electrode material area, the overlapping part of the ceramic layer and the material area, and the ceramic layer area. The junction between the ceramic and the material area is the dividing point for the extension of the foil (after rolling when the material area is thick, the foil is extended; when the ceramic area is thin, the foil has very little extension); when the tab is subjected to force, the ceramic area can disperse the internal stress through the ceramic layer, and the material area can disperse the internal stress through the black material. However, due to the mutual dissolution of ceramic and black material at the junction, it is an independent stress dispersion area, and the stress is concentrated in the area. During the welding process, the battery cell will be loaded into the welding turntable through the welding carrier for pre-welding, tab cutting, and final welding. When welding, the welding pressure drops to a certain position, and then drops together with the welding head, pressing onto the core package tab foil. During welding, the welding pressure plate presses the tab foil, the welding carrier will press the battery cell, and then the welding head will weld the tab foil. When the welding head welds the tab foil, a pulling force is generated. Since the battery cell is restrained by the welding carrier, the tab foil is pressed by the welding pressure plate, resulting in the inability to release the stress at the junction of the ceramic layer and the black material, thereby creating the risk of the ceramic layer breaking. Therefore, it is necessary to design a welding special-shaped pressure plate and a lifting mechanism, so that during welding, the special-shaped baffle can allow the foil to have a margin, lift up the upper cover plate of the carrier, and after the pole piece is subjected to force, there is space for stress release, thereby avoiding the problem of easy fracture at the position where the ceramic layer and the material area are mutually dissolved. Utility Model Content

[0003] The utility model aims to provide a welding auxiliary tool for improving the fracture of the ceramic layer of the positive electrode sheet of a soft-pack battery, so as to solve the above-mentioned problems existing in the prior art.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A welding auxiliary tooling for improving the fracture of the ceramic layer of the positive electrode sheet of a soft-pack battery comprises a tab pressing plate, which is arranged above a welding seat between a welding head and a battery cell, and is used for pressing a tab foil material on the welding seat through the tab pressing plate, so that the tab foil material between the tab pressing plate and the battery cell is bent into a curved section capable of buffering pulling force.

[0006] As a preferred technical solution in the utility model, one end of the tab pressing plate pressing against the tab foil is an arc-shaped head structure.

[0007] As a preferred technical solution in the present invention, the end of the tab pressing plate pressing the tab foil is the pressing end, and the width of the pressing end gradually increases from the end in contact with the tab foil to the other end.

[0008] As a preferred technical solution in the utility model, a cylinder fixed in the vertical direction is arranged above the welding seat, and the piston rod of the cylinder is connected to the tab pressure plate.

[0009] As a preferred technical solution in the utility model, the welding auxiliary tooling also includes a lifting mechanism, which includes a fixed welding carrier lower plate and a welding carrier upper pressure plate that elastically slides above the welding carrier lower plate in the vertical direction, and the battery cell is pressed between the welding carrier upper pressure plate and the welding carrier lower plate.

[0010] As a preferred technical solution in the utility model, a welding jacking mechanism is arranged below the lower plate of the welding carrier, and a jacking rod of the welding jacking mechanism vertically penetrates the lower plate of the welding carrier and is connected to the upper pressure plate of the welding carrier.

[0011] As a preferred technical solution in the utility model, the lower end of the upper pressure plate of the welding carrier is connected to a limiting sleeve, and the upper end of the push rod is matched and inserted into the limiting sleeve.

[0012] As a preferred technical solution in the utility model, two limit members are fixedly arranged above the upper pressure plate of the welding carrier, and the middle part of the lower end of the two limit members is provided with a vertical limit rod slidably connected to the upper pressure plate of the welding carrier, and the upper pressure plate of the welding carrier is provided with an avoidance hole for facilitating its sliding along the two vertical limit rods; the outer sleeve of the vertical limit rod is connected with a spring that abuts between the limit member and the upper pressure plate of the welding carrier.

[0013] Beneficial effect: During welding, the utility model can press the tab foil material with the lower end of the tab pressure plate, so that the tab foil material between the tab pressure plate and the battery cell can be bent into a curved section that can buffer the pulling force, such as an S-shaped curved section. In this way, the tab foil material can have a certain deformation space, which reduces the pulling force of the welding head on the foil material, avoids the problem of the foil material and the pole piece being pulled during the welding process, and the ceramic layer and the black material miscible area being easily broken, thereby improving the safety performance of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the utility model;

[0015] Figure 2 It is a structural schematic diagram of the pole ear pressure plate in the utility model.

[0016] In the figure: 1-tab pressure plate; 2-welding head; 3-battery cell; 4-welding seat; 5-tab foil; 6-cylinder; 7-welding carrier lower plate; 8-welding carrier upper pressure plate; 9-elevator; 10-limiting member; 11-spring. DETAILED DESCRIPTION

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the utility model or the prior art, the utility model will be briefly introduced below in combination with the drawings and the description of the embodiments or the prior art. Obviously, the following description of the structure of the drawings is only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. It should be noted that the description of these embodiments is used to help understand the utility model, but does not constitute a limitation of the utility model.

[0018] Example:

[0019] like Figure 1 and Figure 2 As shown, this embodiment provides a welding auxiliary tooling for improving the fracture of the ceramic layer of the positive electrode sheet of a soft-pack battery, including a tab pressing plate 1, which is arranged above a welding seat 4 between a welding head 2 and a battery cell 3, and is used to press the tab foil 5 located on the welding seat 4 through the tab pressing plate 1, so that during welding, the tab foil 5 located between the tab pressing plate 1 and the battery cell 3 can be bent into a bent section that can buffer the pulling force.

[0020] During welding, the utility model presses the tab foil 5 with the lower end of the tab pressing plate 1, so that the tab foil 5 between the tab pressing plate 1 and the battery cell 3 can be bent into a curved section that can buffer the pulling force, such as an S-shaped curved section. In this way, the tab foil 5 can have a certain deformation space, which reduces the pulling force of the welding head on the foil, avoids the problem that the foil and the pole piece are pulled during the welding process, and the ceramic layer and the black material are easily broken in the mutually dissolved area, thereby improving the safety performance of the battery.

[0021] In practice, the tab pressing plate 1 is installed at the front end of the welding head and is spaced a certain distance from the welding head. The tab pressing plate 1 first descends to a certain height and then descends together with the welding head to press the tab foil before welding.

[0022] As a preferred implementation scheme in this embodiment, it needs to be further explained that the end of the tab pressing plate 1 pressing the tab foil 5 is an arc-shaped head structure, so that when the tab pressing plate 1 presses the tab foil 5, the contact position is not a contact surface, which is more conducive to causing the tab foil 5 to bend and deform, thereby forming a curved section that can buffer the pulling force.

[0023] As a preferred implementation scheme in this embodiment, it needs to be further explained that the end of the tab pressing plate 1 pressing against the tab foil 5 is the pressing end of the pressing plate, and the width of the pressing end of the pressing plate gradually increases from the end in contact with the tab foil 5 to the other end, that is, the pressing end of the pressing plate can be a trapezoidal structure that is wide at the top and narrow at the bottom, or a notch can be cut on the side of the pressing end of the pressing plate close to the battery cell 3, so that the tab foil 5 can be actively bent and deformed, thereby forming a curved section that can buffer the pulling force.

[0024] As a preferred implementation scheme in this embodiment, it needs to be further explained that a cylinder 6 fixed in the vertical direction is arranged above the welding seat 4, and the piston rod of the cylinder 6 is connected to the tab pressure plate 1. The control is simple and stable, the force can be accurately controlled, and both hands can be freed.

[0025] As a preferred implementation scheme in this embodiment, it needs to be further explained that the welding auxiliary tooling also includes a lifting mechanism, which includes a fixed welding carrier lower plate 7 and a welding carrier upper pressure plate 8 that elastically slides above the welding carrier lower plate 7 in the vertical direction. The battery cell 3 is pressed between the welding carrier upper pressure plate 8 and the welding carrier lower plate 7 to ensure the stability of the battery cell 3 during welding.

[0026] As a preferred implementation scheme in this embodiment, it needs to be further explained that a welding jacking mechanism is provided below the lower plate 7 of the welding carrier, and a jacking rod 9 of the welding jacking mechanism vertically penetrates the lower plate 7 of the welding carrier and is connected to the upper pressing plate 8 of the welding carrier. During welding, the upper pressing plate 8 of the carrier rises through the welding jacking mechanism, so that the battery cell 3 can be fixed by the carrier during welding, and when the electrode foil is pulled during welding, a buffer space is reserved so that the pulling force can be released.

[0027] It should be noted that, preferably, the welding lifting mechanism can adopt an existing structure, or can be several electric telescopic rods or telescopic cylinders, and the push rod 9 is a telescopic rod of the electric telescopic rod or a piston rod of the telescopic cylinder, which can be adjusted according to actual conditions, and this embodiment does not make specific restrictions. Alternatively, the lifting and lowering of the push rod 9 is directly controlled by the telescopic cylinder.

[0028] As a preferred implementation scheme in this embodiment, it needs to be further explained that the lower end of the upper pressure plate 8 of the welding carrier is connected to a limiting sleeve, and the upper end of the push rod 9 is matched and inserted into the limiting sleeve to ensure that the welding lifting mechanism can stably drive the upper pressure plate 8 of the carrier to rise and fall.

[0029] As a preferred implementation scheme in this embodiment, it needs to be further explained that two limit members 10 are fixedly arranged above the upper pressure plate 8 of the welding carrier, and the middle part of the lower end of the two limit members 10 is provided with a vertical limit rod slidably connected to the upper pressure plate 8 of the welding carrier, and the upper pressure plate 8 of the welding carrier is provided with an avoidance hole for facilitating its sliding along the two vertical limit rods; the outer sleeve of the vertical limit rod is connected with a spring 11 abutting between the limit member 10 and the upper pressure plate 8 of the welding carrier. When the welding lifting mechanism presses the upper pressure plate 8 of the carrier up and down, the spring 11 can be compressed and the stability of the upper pressure plate 8 of the carrier is ensured at the same time. When the upper pressure plate 8 of the carrier needs to move downward, the push rod 7 descends, and the elastic force of the spring 11 and the gravity of the upper pressure plate 8 of the carrier itself can make the upper pressure plate 8 of the carrier descend, and the control is simple and convenient.

[0030] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. 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 welding auxiliary tool for improving the fracture of the ceramic layer of the positive electrode sheet of a soft-pack battery, characterized in that: The invention comprises a tab pressing plate (1), which is arranged above a welding seat (4) between a welding head (2) and a battery cell (3) and is used for pressing a tab foil (5) located on the welding seat (4) by the tab pressing plate (1), so that the tab foil (5) located between the tab pressing plate (1) and the battery cell (3) is bent into a bent section capable of buffering pulling force.

2. A welding auxiliary tool for improving the fracture of the ceramic layer of the positive electrode sheet of a soft-pack battery according to claim 1, characterized in that: One end of the tab pressing plate (1) pressing against the tab foil (5) is an arc-shaped head structure.

3. The welding auxiliary tooling for improving the fracture of the ceramic layer of the positive electrode sheet of a soft-pack battery according to claim 1, characterized in that: One end of the tab pressing plate (1) pressing against the tab foil (5) is the pressing end of the pressing plate, and the width of the pressing end of the pressing plate gradually increases from the end in contact with the tab foil (5) to the other end.

4. A welding auxiliary tool for improving the fracture of the ceramic layer of the positive electrode sheet of a soft-pack battery according to any one of claims 1 to 3, characterized in that: A cylinder (6) fixed in a vertical direction is arranged above the welding seat (4), and a piston rod of the cylinder (6) is connected to the tab pressure plate (1).

5. A welding auxiliary tool for improving the fracture of the ceramic layer of the positive electrode sheet of a soft-pack battery according to any one of claims 1 to 3, characterized in that: The welding auxiliary tooling also includes a lifting mechanism, which includes a fixedly arranged welding carrier lower plate (7) and a welding carrier upper pressure plate (8) elastically sliding above the welding carrier lower plate (7) in a vertical direction, and the battery cell (3) is pressed tightly between the welding carrier upper pressure plate (8) and the welding carrier lower plate (7).

6. A welding auxiliary tool for improving the fracture of the ceramic layer of the positive electrode sheet of a soft-pack battery according to claim 5, characterized in that: A welding jacking mechanism is provided below the lower plate (7) of the welding carrier, and a jacking rod (9) of the welding jacking mechanism vertically penetrates the lower plate (7) of the welding carrier and is connected to an upper pressing plate (8) of the welding carrier.

7. A welding auxiliary tool for improving the fracture of the ceramic layer of the positive electrode sheet of a soft-pack battery according to claim 6, characterized in that: The lower end of the upper pressure plate (8) of the welding carrier is connected to a limiting sleeve, and the upper end of the push rod (9) is matched and inserted into the limiting sleeve.

8. The welding auxiliary tooling for improving the fracture of the ceramic layer of the positive electrode sheet of a soft-pack battery according to claim 5, characterized in that: Two limiting members (10) are fixedly arranged above the upper pressure plate (8) of the welding carrier, and the middle parts of the lower ends of the two limiting members (10) are provided with vertical limiting rods slidably connected to the upper pressure plate (8) of the welding carrier, and the upper pressure plate (8) of the welding carrier is provided with avoidance holes for facilitating its sliding along the two vertical limiting rods; the outer shell of the vertical limiting rod is connected with a spring (11) abutting between the limiting member (10) and the upper pressure plate (8) of the welding carrier.

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