Composite current collector roll welding device

Abstract

The utility model discloses a composite current collector roll welding device, which relates to the technical processing field of energy storage devices and comprises a composite current collector unwinding mechanism, an upper foil unwinding mechanism, a lower foil unwinding mechanism, a roll welding mechanism and a guide wheel. Wherein the roll welding mechanism comprises an upper welding wheel for transmitting a heat source or ultrasonic waves and a lower welding wheel for transmitting the heat source or the ultrasonic waves, the upper welding wheel and the lower welding wheel are oppositely arranged, foil materials on the two sides of the current collector are efficiently and simultaneously welded, the device is simple, and the production efficiency is greatly improved; furthermore, the composite current collector roll welding device further comprises a step counting wheel and a control device, the linear speed of the roll welding mechanism is adjusted and controlled to be matched with the linear speed of the step counting wheel, and the high linear speed of the roll welding mechanism promotes the welding area to move towards the composite current collector unwinding mechanism as soon as possible; the problem that the metal expansion of the welding area causes the belt moving deviation of the composite current collector / foil welding body is well solved, and finally the welding yield of the composite current collector and the foil is improved.

Description

Technical Field

[0001] This utility model relates to the field of energy storage device technology processing, and in particular to a composite current collector roller welding device. Background Technology

[0002] In current power batteries, copper foil is mostly used for the negative electrode current collector, while aluminum foil is mostly used for the positive electrode current collector. However, traditional current collectors...

[0003] Batteries manufactured using single-cell technology may suffer thermal runaway due to damage caused by dendrite growth, external forces, or other factors, posing a safety risk of combustion and explosion. Therefore, composite current collector technology has emerged. The main function of a composite current collector is to gather the current generated by the battery's active materials to form a larger output current. Compared to traditional single-cell current collectors, the base film material in the composite current collector acts like a fuse; when encountering a short circuit failure mode, it can quickly break or melt, thus preventing further current conduction and ultimately stopping the cell from burning, ensuring battery safety.

[0004] However, composite current collectors have a sandwich structure of metal-base film-metal, meaning the metals on both sides cannot conduct electricity. Therefore, conductors (tabs) need to be welded to both sides to enable the electronic path. This requires using the tabs of traditional current collectors and composite current collectors to transfer the current from the cell. The most common method is to use ultrasonic roll welding to weld the composite current collector to foil to prepare a shaped electrode roll, and then weld multiple layers of foil to the metal tabs to achieve the conduction of all electrode circuits.

[0005] During the welding process of composite current collector 2 and foil 3 to form formed electrode roll 1, the area where the composite current collector 2 and foil 3 undergo thermal deformation during welding is called the welding zone 4, and the area outside the welding zone is called the material zone 5. The structure is as follows: Figure 1 and Figure 2 .

[0006] Utility model patent application CN208539000U discloses a welding device and processing equipment for a secondary battery current collector. This application uses a welding device to weld foil material input to the welding station onto a portion of a composite current collector, allowing the foil material to be used as a tab of the composite current collector. Through the transfer of the foil material, the current in the battery cell can be transmitted. The processing equipment includes a foil and composite current collector winding and unwinding device, a welding device, a tension adjustment device, and a web guiding device, etc.

[0007] However, the composite current collector in this application uses single-sided welding during the roll welding process, which is less efficient for current collectors that are processed with double-sided welded foil.

[0008] The welding requires a large amount of energy, and the metals have good ductility. Therefore, during the welding process, the area being welded will extend. The mismatch between the linear speed of the material area and the welding area will cause the electrode roll to shift, affecting the stability of this process and further affecting the production yield. Utility Model Content

[0009] To address the lack of an efficient device for welding foil materials on both sides of a current collector, this application provides a composite current collector roll welding device.

[0010] Firstly, this application provides a composite current collector roller welding mechanism:

[0011] A composite current collector roller welding device is used to weld foil to both sides of a composite current collector, including...

[0012] Composite current collector unwinding mechanism

[0013] The upper foil unwinding mechanism is located on the upper side of the composite current collector unwinding mechanism.

[0014] The lower foil unwinding mechanism is located below the composite current collector unwinding mechanism.

[0015] Roll welding mechanism including drive components,

[0016] Guide wheels that abut against the surface of foil or composite current collectors.

[0017] The roller welding mechanism also includes an electric heating device or an ultrasonic generator;

[0018] The roller welding mechanism includes an upper welding wheel for transmitting heat or ultrasonic waves and a lower welding wheel for transmitting heat or ultrasonic waves, and the upper welding wheel and the lower welding wheel are arranged opposite to each other.

[0019] The guide wheel includes a first guide wheel disposed between the upper welding wheel and the upper foil unwinding mechanism and abutting against the surface of the foil; the guide wheel includes a second guide wheel disposed between the lower welding wheel and the lower foil unwinding mechanism and abutting against the surface of the foil.

[0020] In this application, the linear velocity of the welding zone is the surface length of the composite current collector / foil welded body that passes through per unit time; the linear velocity of the material zone is the surface length of the foil that passes through per unit time.

[0021] The drive unit drives the upper and lower welding wheels to roll, and the energy from the heat source or ultrasonic source enables the composite current collector to be welded to the foil material as one unit.

[0022] The first and second guide wheels are set to tightly attach the foils on both sides of the composite current collector to the surface of the composite current collector. Then, the composite current collector is passed through the upper and lower welding wheels and welded into a shaped electrode roll.

[0023] The composite current collector conveyed by the composite current collector unwinding mechanism, the upper foil conveyed by the upper foil unwinding mechanism, and the lower foil conveyed by the lower foil unwinding mechanism are combined together by guide wheels. Then, they pass through the upper welding wheel and the lower welding wheel, which are arranged opposite to each other, and simultaneously weld the upper foil and the lower foil to the composite current collector to form a shaped electrode roll, thereby improving production efficiency.

[0024] Furthermore, the distance between the upper welding wheel and the lower welding wheel is 20-300μm.

[0025] Furthermore, the distance between the upper welding wheel and the lower welding wheel is 20-40 μm.

[0026] Furthermore, the width of the roller welding mechanism is smaller than the width of the welding zone.

[0027] Furthermore, the composite current collector roller welding device also includes

[0028] A step counting wheel, and a control device that receives the linear velocity feedback from the step counting wheel, judges and adjusts the linear velocity of the roller welding mechanism, wherein the step counting wheel includes a first step counting wheel that abuts against the surface of the foil in the welding area; the control device is electrically connected to the first step counting wheel in the welding area and the roller welding mechanism respectively.

[0029] Furthermore, the distance between the first step counting wheel and the upper or lower welding wheel is less than 1m.

[0030] Furthermore, the control device is a PLC device.

[0031] Furthermore, the step counting wheel includes a second step counting wheel, which abuts against the surface of the foil material in the material area, and the second step counting wheel is electrically connected to the control device.

[0032] Furthermore, the roll welding mechanism includes a motor encoder that can accept linear speed feedback from the control device and adjust the linear speed of the roll welding mechanism.

[0033] Furthermore, the composite current collector roller welding device also includes a winding mechanism for collecting the formed electrode rolls.

[0034] The welding process of the composite current collector roller welding mechanism includes the following steps:

[0035] ① The composite current collector conveyed by the composite current collector unwinding mechanism, the upper foil conveyed by the upper foil unwinding mechanism and the lower foil conveyed by the lower foil unwinding mechanism are combined together by guide wheels, and then pass through the upper welding wheel and the lower welding wheel arranged opposite to each other, simultaneously welding the upper foil and the lower foil together with the composite current collector to form a welding zone.

[0036] ② The first step counting wheel collects the surface length of the composite current collector / foil welded body passing through the welding zone per unit time, i.e., the linear velocity, and feeds it back to the PLC device;

[0037] ③ The PLC device calculates the difference between the linear velocity fed back by the first step counting wheel and the preset linear velocity or the measured linear velocity;

[0038] ④ If the difference is greater than 1cm / min, the PLC device will transmit the linear velocity fed back by the first step counting wheel to the motor encoder of the roller welding mechanism.

[0039] ⑤ The motor encoder of the roller welding mechanism adjusts the linear speed of the upper and lower welding wheels to the linear speed fed back from the first step counting wheel received from the PLC device.

[0040] In step ③, the preset linear velocity is the unwinding speed of the composite current collector unwinding mechanism; the measured linear velocity is the linear velocity of the material zone fed back by the second step counting wheel.

[0041] Composite current collectors require significant welding energy during roll welding, and the metals themselves possess excellent ductility. During welding, the welded area expands, and the mismatch between the linear speeds of the material zone and the welding zone leads to tape deviation. This application comprehensively considers the tape deviation problem caused by the speed difference between the material zone and the welding zone during composite current collector welding. It achieves speed variation of the roll welding mechanism based on feedback from the step counter wheel. By adjusting the linear speed of the roll welding mechanism to match the linear speed of the step counter wheel, the higher linear speed of the roll welding mechanism prompts the welding zone to move towards the composite current collector unwinding mechanism side as quickly as possible. This effectively solves the problem of tape deviation in the composite current collector / foil welded body caused by metal expansion in the welding zone, ultimately improving the yield rate of composite current collector and foil welding.

[0042] The composite current collector can be a composite current collector in the molded electrode roll of conventional batteries such as ternary cathode material, lithium iron phosphate cathode material, sodium battery cathode, graphite anode, silicon-carbon anode, and silicon-oxygen anode.

[0043] Beneficial effects:

[0044] 1. This application provides a device that can efficiently weld foil materials on both sides of a current collector simultaneously. The device is simple and greatly improves production efficiency.

[0045] 2. Furthermore, the composite current collector roll welding device also includes a step counter wheel and a control device; this application comprehensively considers the problem of tape shift caused by the speed difference between the material zone and the non-material zone during composite current collector welding, and realizes that the speed of the roll welding mechanism can be varied according to the feedback of the step counter wheel. By adjusting the linear speed of the roll welding mechanism to match the linear speed of the step counter wheel, the higher linear speed of the roll welding mechanism prompts the welding zone to move towards the composite current collector unwinding mechanism side as soon as possible, which effectively solves the problem of tape shift of the composite current collector / foil welded body caused by the metal expansion in the welding zone, and ultimately improves the yield of composite current collector and foil welding. Attached Figure Description

[0046] Figure 1This is a schematic diagram of the structure of the formed electrode roll in this utility model;

[0047] Figure 2 This is a schematic diagram of the welding structure between the formed electrode roll and the foil in this utility model;

[0048] Figure 3 This is a schematic diagram of the composite current collector roller welding mechanism in this utility model.

[0049] Figure label:

[0050] 1. Forming coil; 2. Composite current collector; 3. Foil; 4. Welding area; 5. Material area; 6. Composite current collector unwinding mechanism; 7. Upper foil unwinding mechanism; 8. Lower foil unwinding mechanism; 9. Roll welding mechanism; 10. Upper welding wheel; 11. Lower welding wheel; 12. Step counting wheel; 13. Rewinding mechanism; 14. Guide wheel; 121. First step counting wheel; 141. First guide wheel; 142. Second guide wheel. Detailed Implementation

[0051] To make the present technical solution clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] Example 1

[0053] The composite current collector roller welding device has the following structure: Figure 3 It includes a composite current collector unwinding mechanism 6, an upper foil unwinding mechanism 7 disposed on the upper side of the composite current collector unwinding mechanism 6, a lower foil unwinding mechanism 8 disposed on the lower side of the composite current collector unwinding mechanism 6, a roller welding mechanism 9 including a drive unit (servo motor) and an ultrasonic source, a guide wheel 14, a step counting wheel 12, and a control device (PLC device) that receives the linear speed feedback from the step counting wheel 12, judges and adjusts the linear speed of the roller welding mechanism 9.

[0054] The step counting wheel 12 includes a first step counting wheel 121 disposed in the welding area 4.

[0055] The roller welding mechanism 9 includes an upper welding wheel 10 for transmitting ultrasonic waves, a lower welding wheel 11 for transmitting ultrasonic waves, and a motor encoder. The upper welding wheel 10 and the lower welding wheel 11 are arranged opposite to each other, and the distance between the upper welding wheel 10 and the lower welding wheel 11 is 30μm.

[0056] The control device is electrically connected to the first step counting wheel 121 and the roller welding mechanism 9, respectively.

[0057] The composite current collector 2, upper foil 3, and lower foil 3 are sequentially conveyed by the composite current collector unwinding mechanism 6, upper foil unwinding mechanism 7, and lower foil unwinding mechanism 8, overlapping and forming a welding area; the upper welding wheel 10 and lower welding wheel 11 are set on both sides of the welding area, forming a welding area 4 after welding.

[0058] The guide wheel 14 abuts against the composite current collector 2 or the foil 3 for guidance.

[0059] The guide wheel 14 includes a first guide wheel 141 disposed between the upper welding wheel 10 and the upper foil unwinding mechanism 7 and abutting against the surface of the foil 3; the guide wheel 14 includes a second guide wheel 142 disposed between the lower welding wheel 11 and the lower foil unwinding mechanism 8 and abutting against the surface of the foil 3.

[0060] The first step counting wheel 121 is positioned in the welding zone 4 and contacts the foil 3. It is used to measure the surface length of the composite current collector / foil welded body passing through the welding zone 4 per unit time, i.e., the linear velocity, and feeds it back to the PLC device.

[0061] The PLC device receives the linear velocity fed back by the first step counting wheel 121 and calculates the difference between the linear velocity fed back by the first step counting wheel 121 and the preset or measured linear velocity. If the difference is greater than 1 cm / min, the PLC device determines that the speed of the upper welding wheel 10 and the lower welding wheel 11 needs to be adjusted, and feeds back the linear velocity fed back by the first step counting wheel 121 to the motor encoder of the roller welding mechanism 9.

[0062] The unwinding speed of the composite current collector unwinding mechanism 6 is 0-50m / min; the diameter of the step counting wheel 12 is 1-20cm; the diameter of the roller welding mechanism 9 is 1-20cm; the width of the material zone 5 is 20-100cm; the thickness of the welding zone 4 is 4-20μm; and the thickness of the material zone 5 is 20-300μm.

[0063] The process of double-sided welding of current collector / foil materials using a composite current collector roller welding device includes the following steps:

[0064] ① The composite current collector 2 conveyed by the composite current collector unwinding mechanism 6, the upper foil 3 conveyed by the upper foil unwinding mechanism 7, and the lower foil 3 conveyed by the lower foil unwinding mechanism 8 are combined together by the guide wheel 14. Then, they pass through the upper welding wheel 10 and the lower welding wheel 11, which are arranged opposite to each other. The heat from the upper welding wheel 10 and the lower welding wheel 11 simultaneously welds the upper foil 3 and the lower foil 3 to the composite current collector 2 to form the welding area 4.

[0065] ② The first step counting wheel 121 collects the surface length of the composite current collector / foil welded body passing through the welding zone 4 per unit time, i.e., the linear velocity, and feeds it back to the PLC device;

[0066] ③ The PLC device calculates the difference between the linear velocity fed back by the first step counting wheel 121 and the preset linear velocity (the unwinding speed of the composite current collector unwinding mechanism 6);

[0067] ④ If the difference is greater than 1 cm / min, the PLC device will transmit the linear velocity fed back by the first step counting wheel 121 to the motor encoder of the roller welding mechanism 9.

[0068] ⑤ The motor encoder of the roller welding mechanism 9 adjusts the linear speed of the upper welding wheel 10 and the lower welding wheel 11 to the linear speed fed back from the first step counting wheel 121 received from the PLC device.

[0069] The above embodiments only illustrate several implementation methods of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A composite current collector roller welding device for welding foil to both sides of a composite current collector, characterized in that, include Composite current collector unwinding mechanism The upper foil unwinding mechanism is located on the upper side of the composite current collector unwinding mechanism. The lower foil unwinding mechanism is located below the composite current collector unwinding mechanism. Roll welding mechanism including drive components, Guide wheels that abut against the surface of foil or composite current collectors. The roller welding mechanism also includes an electric heating device or an ultrasonic generator; The roller welding mechanism includes an upper welding wheel for transmitting heat or ultrasonic waves and a lower welding wheel for transmitting heat or ultrasonic waves, and the upper welding wheel and the lower welding wheel are arranged opposite to each other. The guide wheel includes a first guide wheel disposed between the upper welding wheel and the upper foil unwinding mechanism and abutting against the surface of the foil; the guide wheel includes a second guide wheel disposed between the lower welding wheel and the lower foil unwinding mechanism and abutting against the surface of the foil. The composite current collector roller welding device also includes Pedometer wheel A control device that receives the linear velocity feedback from the step counter wheel, judges it, and adjusts the linear velocity of the roller welding mechanism. The step counting wheel includes a first step counting wheel that abuts against the surface of the foil in the welding area; the control device is electrically connected to the first step counting wheel and the roller welding mechanism respectively.

2. The composite current collector roller welding device according to claim 1, characterized in that, The distance between the upper and lower welding wheels is 20-300 μm.

3. The composite current collector roller welding device according to claim 2, characterized in that, The distance between the upper and lower welding wheels is 20-40 μm.

4. The composite current collector roller welding device according to claim 1, characterized in that, The width of the roller welding mechanism is smaller than the width of the welding zone.

5. The composite current collector roller welding device according to claim 1, characterized in that, The distance between the first step counting wheel and the upper or lower welding wheel is less than 1m.

6. The composite current collector roller welding device according to claim 1, characterized in that, The control device is a PLC device.

7. The composite current collector roller welding device according to claim 1, characterized in that, The step counting wheel includes a second step counting wheel, which abuts against the surface of the foil in the material area, and the second step counting wheel is electrically connected to the control device.

8. The composite current collector roller welding device according to claim 1, characterized in that, The roller welding mechanism includes a motor encoder that can accept linear speed feedback from a control device and adjust the linear speed of the upper and / or lower welding rollers.

9. A composite current collector roller welding device according to claim 1, characterized in that, The composite current collector roller welding device also includes a winding mechanism for collecting the formed electrode rolls.

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