Composite copper foil and production process therefor

Abstract

A composite copper foil and a production process therefor, relating to the technical field of copper foil manufacturing. The composite copper foil comprises a substrate (70) and copper plated layers (80) provided on two sides of the substrate. The production process comprises: first, placing a substrate (70) into an acid tank (11), such that the surface of the substrate (70) is slightly corroded and thus coarsened; then using a moving mechanism (20) to take out the substrate (70) and using a rinsing assembly (30) to rinse same; then the moving mechanism (20) feeding the substrate (70) into an alkaline tank (12) for oil removal and, by means of a negative-pressure fan, air-drying the substrate (70) that has undergone the oil removal; then attaching a reducing agent to the substrate (70) and, in a chemical plating mode, soaking the substrate (70) in a reaction tank (90) filled with an electrolyte, such that elemental copper in the electrolyte is attached to the substrate to form copper plated layers; then increasing the thickness of the copper plated layers in a horizontal plating mode; and finally, attaching a negative electrode material to the copper plated layers, so as to complete the manufacturing of the composite copper foil. The copper plated layers have uniform thickness, and the copper foil exhibit good corrosion resistance and thermal conductivity.

Description

Composite copper foil and production process thereof Technical Field

[0001] The present application relates to the field of copper foil manufacturing, and in particular to a composite copper foil and a production process thereof. Background Art

[0002] With the development of new energy technologies, the popularity of electric vehicles is increasing. As the core of electric vehicles, power battery technology has also experienced rapid development. Traditional power batteries typically use pure copper foil. In power batteries, copper foil serves as a carrier for the battery's negative electrode active material, as well as a collector and conductor of negative electrode electrons, channeling the current generated by the battery's active material to generate a higher current. Copper foil is typically produced using electroplating, which, due to the applied current, allows for faster plating and therefore higher production efficiency.

[0003] Traditional copper foil is expensive to use and has a low energy density. When electroplated, the coating is thicker near the anode and thinner farther away. This results in poor copper plating uniformity, resulting in poor corrosion resistance and thermal conductivity, which needs to be improved.

[0004] Summary of the Invention

[0005] In order to improve the problem of poor copper plating uniformity, which leads to poor corrosion resistance and thermal conductivity of copper foil, the present application provides a composite copper foil and a production process thereof.

[0006] In a first aspect, the present application provides a production process for a composite copper foil, which adopts the following technical solution:

[0007] S1. First, the substrate is subjected to acid treatment, rinsing, degreasing and drying in sequence;

[0008] S2. Then, a reducing agent is attached to the dried substrate, and a copper plating layer with a thickness of 100 nm is deposited on the surface of the substrate by chemical plating. Then, the substrate is horizontally plated to increase the thickness of the copper plating layer on the surface of the substrate to 1000 nm, thereby obtaining a composite copper foil.

[0009] By adopting the above technical solution, when making composite copper foil, the substrate is pre-cut into several sections. Then, one section is treated with acid to slightly corrode the surface and make it rough. The substrate is then rinsed to remove any residual acid solution on the surface to prevent further corrosion. The substrate is then treated with alkaline solution to remove oil from the surface.

[0010] After degreasing, the solution on the substrate is adsorbed until the substrate is completely dry. A reducing agent is then attached to the dried substrate, and copper is attached to the surface of the substrate using chemical plating. Because the acidic solution makes the substrate surface relatively rough, it facilitates the attachment of copper. At this point, a 100nm thick copper coating is deposited on the surface of the substrate. The coating formed by the chemical copper plating is uniform and continuous, making the copper foil excellent in thermal conductivity and strong in corrosion resistance. The substrate is then horizontally plated again, increasing the thickness of the copper coating on the substrate surface to 1000nm, to obtain a composite copper foil.

[0011] Optionally, in step S1, the acid treatment is performed by placing the substrate in an acidic tank, and the alkaline treatment is performed by placing the substrate in an alkaline tank. The acidic tank and the alkaline tank are connected by a connecting frame, and the connecting frame is provided with a moving mechanism for driving the substrate to move. The moving mechanism includes:

[0012] A movable screw is provided on the connecting frame, the movable screw is arranged along the connecting line of the acidic tank and the alkaline tank, and the end of the movable screw is rotatably connected to the connecting frame;

[0013] A moving motor is provided on the connecting frame, wherein the output end of the moving motor is coaxially fixed with the moving screw, and the moving motor is used to drive the moving screw to rotate around the central axis of the moving screw;

[0014] A movable seat is sleeved on the movable screw and is threadedly connected to the movable screw. The side wall of the movable seat abuts against the connecting frame. The movable screw rotates to drive the movable seat to move along the length direction of the movable screw.

[0015] A clamping assembly is provided on the movable seat, wherein an air cylinder is provided, wherein the output shaft of the air cylinder faces downward and is connected to the clamping assembly, and the air cylinder is used to drive the clamping assembly to move up and down, and the clamping assembly is used to clamp the substrate.

[0016] By adopting the above technical solution, the moving motor is activated to drive the moving screw to rotate, which drives the moving seat to move along the length of the moving screw, thereby allowing the cylinder to drive the clamping assembly to move. When it is necessary to clamp a substrate in the acidic or alkaline tank below the connecting frame, the cylinder is activated to drive the clamping assembly downward until the clamping assembly moves to the substrate and clamps the substrate. The cylinder is then activated to drive the clamping assembly upward to move the substrate out of the acidic or alkaline tank.

[0017] Optionally, the clamping assembly includes:

[0018] Two limiting plates are fixed on the connecting frame, and the acidic tank and the alkaline tank each correspond to one limiting plate;

[0019] Two mounting plates, the top ends of the two mounting plates being hinged, the limit plate being insertable between the two mounting plates, a rotating rod being provided at the hinge point of the two mounting plates, the rotating rod being provided on the output shaft of the cylinder, and the mounting plates being rotatable around the central axis of the rotating rod;

[0020] A torsion spring is sleeved on the rotating rod, and both ends of the torsion spring are fixed to corresponding mounting plates respectively. A clamping plate is fixed to the bottom end of the mounting plate. The torsion spring is used to drive the two clamping plates to approach each other, and the two clamping plates are used to clamp the substrate.

[0021] By adopting this technical solution, when clamping a substrate in an acidic or alkaline tank, the movable motor first drives the movable screw, causing the movable seat to move the clamping assembly directly above the substrate. The pneumatic cylinder is then activated, driving the rotating rod to move the two mounting plates downward. Initially, the two mounting plates are close to each other under the action of the torsion spring, that is, the two clamping plates are in abutment. When the clamping plates reach the corresponding limit plates, the movable screw is driven to rotate, causing the mounting plates to move closer to the limit plates until the limit plates are inserted between the two mounting plates and below the rotating rod.

[0022] At this time, the cylinder continues to drive the clamping plate downward, while the limit plate remains stationary, causing the limit plate to slide relative to the mounting plate in the direction of the rotating rod. This pushes the two mounting plates away from each other, overcoming the elastic force of the torsion spring, thereby gradually widening the distance between the two mounting plates and causing the clamping plates to open until the gap between the two clamping plates is sufficient to allow the substrate to be inserted. The movable lead screw is then reversed, causing the mounting plate to move away from the limit plate until the limit plate is relatively withdrawn from between the two mounting plates. At this point, the mounting plate loses its thrust, and the torsion spring recovers its deformation, causing the two clamping plates to approach and abut against the substrate. At this point, the two clamping plates relatively squeeze and secure the substrate. When the cylinder drives the mounting plate upward, the clamping plates clamp the substrate and withdraw it from the acid or alkaline tank.

[0023] Optionally, in step S1, the substrate is rinsed using a rinsing assembly, the rinsing assembly comprising:

[0024] A water tank is fixed on the connecting frame and is located between the acidic pool and the alkaline pool, and a water box is provided on the top of the water tank;

[0025] A water pipe is fixed to the connecting frame, one end of the water pipe is connected to the water tank, a water pump is provided on the water pipe, and the water pump is used to pump water from the water tank into the water pipe, and a plurality of water outlets are opened on the bottom wall of the water pipe above the water box;

[0026] The rotating motor is arranged on the movable seat, and the output end of the rotating motor is connected to the cylinder to drive the cylinder to rotate the output shaft of the cylinder.

[0027] By adopting this technical solution, when the clamping plate, holding the substrate, moves to the top of the water box, the water pump is activated, pumping water from the water tank into the water pipe. The water is then sprayed out of the water outlet onto the substrate below, where it flows downward along the surface of the substrate, rinsing it. The water flowing through the substrate ultimately falls into the water box, preventing it from flowing around and affecting the working environment. The water box also collects the water, allowing it to be recycled and reducing water waste.

[0028] During the process of water discharge from the water outlet, the rotating motor can also be started to drive the cylinder to drive the substrate to rotate around the output shaft of the cylinder, so that different positions of the substrate are alternately moved to the bottom of the water outlet, realizing the all-round flushing of the substrate by the water outlet, increasing the comprehensiveness of cleaning and improving the cleanliness of the substrate.

[0029] Optionally, in step S2, the substrate is placed in a reaction tank for chemical plating, the reaction tank is fixed to the connecting frame, and the reaction tank is provided with two drive assemblies for driving the substrate to swing around the middle of the substrate, the two drive assemblies are symmetrical about the vertical center axis of the reaction tank, and the drive assemblies include:

[0030] an air inlet pipe, disposed at the bottom of the reaction tank and connected to the reaction tank;

[0031] a water baffle provided in the air inlet pipe, one end of the water baffle being hinged to the inner wall of the air inlet pipe, and the other end being inclined toward the direction close to the reaction pool; a side of the water baffle close to the reaction pool being connected to the inner wall of the air inlet pipe via a propulsion spring, the propulsion spring being used to propel the water baffle toward a direction away from the reaction pool, and the water baffle being used to block the air inlet pipe;

[0032] An air intake check valve is provided on the side wall of the air intake pipe. The air intake hole is located on the side of the water baffle away from the reaction tank. The air intake check valve is provided in the air intake hole to limit the gas in the air intake pipe from being discharged from the air intake hole.

[0033] The piston is arranged in the intake pipe, the circumferential side wall of the piston is in contact with the inner wall of the intake pipe, the piston is located on the side of the intake one-way valve away from the water baffle, and the piston can move in the intake pipe.

[0034] By adopting the above technical solution, initially, the propulsion spring causes the water baffle to abut against the inner wall of the air inlet pipe, thereby blocking the air inlet pipe. When the substrate is placed horizontally in the reaction tank, the substrate gradually settles to the bottom of the reaction tank under the action of gravity. At this time, the piston is first moved away from the air inlet check valve, so that negative pressure is formed in the air inlet pipe, and the gas outside the air inlet pipe enters the air inlet hole and enters the air inlet pipe through the air inlet check valve. The water baffle is sucked by the air inlet pipe, so that the side of the water baffle away from the connection between the water baffle and the air inlet pipe is more tightly abutted against the inner wall of the water inlet pipe, thereby improving the sealing performance of the water baffle in blocking the air inlet pipe, thereby limiting the electrolyte solution in the reaction tank from entering the air inlet pipe on the side of the water baffle away from the reaction tank.

[0035] The piston is then driven to move toward the intake check valve. The intake check valve, affected by the thrust of the gas in the intake pipe, blocks the intake hole, preventing the gas in the intake pipe from exiting the intake pipe through the intake hole. The gas in the intake pipe, however, pushes the water baffle toward the reaction pool, overcoming the elastic force of the propulsion spring, causing the water baffle to rotate around the connection between the water baffle and the inner wall of the intake pipe. This causes the side of the water baffle near the reaction pool to gradually separate from the inner wall of the intake pipe and move toward the reaction pool, creating a gap between the water baffle and the side wall of the intake pipe, allowing the gas in the intake pipe to enter the reaction pool through the gap.

[0036] The gas moves upward from the bottom of the reaction tank, thereby exerting an upward thrust on the bottom wall of the substrate, causing the substrate to move in the electrolyte solution, thereby allowing the substrate to come into contact with the electrolyte solution at different positions in the reaction tank. The entry of the gas into the electrolyte solution and the movement of the substrate can both cause the electrolyte solution to flow, allowing the surface of the substrate to fully contact the copper ions in the electrolyte solution, thereby making the copper element attached to the surface of the substrate more uniform, achieving a more complete and uniform copper plating on the surface of the substrate, and improving the quality of the copper plating.

[0037] Optionally, a water-blocking film is provided in the intake pipe, the circumferential side wall of the water-blocking film is fixed to the inner wall of the intake pipe, and the water-blocking film is located on the side of the baffle close to the reaction pool, and is used to limit the electrolyte in the reaction pool from entering the intake pipe.

[0038] By adopting this technical solution, when the intake pipe is delivering gas to the reaction pool, one side of the water baffle separates from the inner wall of the intake pipe, allowing gas to pass through the water-blocking membrane and enter the reaction pool. When the intake pipe stops delivering gas to the reaction pool, the water baffle, driven by the propulsion spring, presses against the inner wall of the intake pipe, blocking the intake pipe. Simultaneously, the water-blocking membrane also restricts the electrolyte solution in the reaction pool from entering the intake pipe, preventing it from passing through the water baffle as the propulsion spring rotates the water baffle. This further reduces the possibility of electrolyte in the reaction pool entering the intake pipe and improves the sealing performance of the intake pipe with respect to the electrolyte solution in the reaction pool.

[0039] Optionally, the air intake valve includes an air intake membrane, the circumferential side wall of the air intake membrane is fixed in contact with the inner wall of the air intake hole, an air vent is opened through the air intake membrane, the air vent is connected to the air intake hole, and a sealing plate is fixed on the inner wall of the air intake hole. When the air intake membrane is in contact with the sealing plate, the sealing plate is used to seal the air vent.

[0040] By adopting the above technical solution, when the piston moves in the direction away from the air inlet hole, the negative pressure in the air inlet pipe draws the gas outside the air inlet pipe into the air inlet pipe, so that the gas outside the air inlet pipe enters the air inlet hole and applies a thrust toward the piston to the air inlet membrane, causing the air inlet membrane to deform, that is, the middle part of the air inlet membrane bulges toward the piston, so that there is a gap between the sealing plate and the air inlet membrane, so that the gas can enter between the sealing plate and the inner wall of the air inlet hole from the gap between the sealing plate and the air inlet membrane, and then enter the air inlet pipe through the air vents on the air inlet membrane.

[0041] When the piston moves toward the air inlet hole, the gas in the air inlet pipe pushes the air inlet membrane away from the piston, causing the air inlet membrane to deform until it contacts the sealing plate. At this time, the edge of the air vent is completely in contact with the sealing plate, causing the sealing plate to block the air vent. As a result, the air inlet membrane and the sealing plate cooperate to block the air inlet hole, thereby restricting the gas in the air inlet pipe and preventing it from moving out of the air inlet pipe through the air inlet hole.

[0042] Optionally, a sliding assembly for driving the piston to move is provided at the bottom of the reaction tank, and the sliding assembly includes:

[0043] A sliding frame is slidably connected to the bottom of the reaction tank, and the sliding frame can move horizontally. The sliding frame is located between the two pistons and is connected to the pistons through a sliding rod;

[0044] Two sliding racks are relatively fixed on the inner wall of the sliding frame, and the sliding assembly is arranged in the horizontal direction;

[0045] An incomplete gear is rotatably connected to the reaction pool. The incomplete gear is located in the sliding frame and between the two sliding racks. The incomplete gear can be meshed with the sliding racks.

[0046] By adopting this technical solution, the incomplete gear is driven to rotate. When the incomplete gear meshes with one of the sliding racks, it drives the entire sliding frame and the sliding rod to move. This causes the two pistons to move in the same direction. One intake pipe pushes gas into the reaction cell, while the other intake pipe absorbs and stores gas. This causes one side of the substrate to move upward in the electrolyte solution, achieving an inclined suspension of the substrate in the reaction cell.

[0047] When the incomplete gear rotates until it separates from the sliding rack, the sliding frame drives the piston to stop moving. The teeth on the incomplete gear then rotate to the other side and mesh with the other sliding rack, thereby driving the other sliding rack to move. Because the two sliding racks are located on either side of the incomplete gear, they move in opposite directions when driven by the incomplete gear, driving the other sliding rack to move the sliding frame in the opposite direction, achieving the reset of the two pistons. The air intake pipe that originally sucked in gas now delivers gas into the reaction cell, pushing the other side of the substrate upward, causing the substrate to swing around the center of the substrate as the axis, achieving full contact between the substrate and the electrolyte solution.

[0048] In a second aspect, the present application also provides a composite copper foil using the following technical solution:

[0049] A composite copper foil is produced by adopting the above-mentioned production process of the composite copper foil.

[0050] By adopting this technical solution, the uniform and continuous coating formed by electroless copper plating ensures excellent thermal conductivity, reducing temperature differences within the battery cell. The copper foil also exhibits strong corrosion resistance, with no detachment of the copper coating after 168 hours of electrolyte immersion. The composite copper foil also has a low sheet resistance and can support charge and discharge rates of 4C and above. The composite copper foil also exhibits excellent weldability, with no delamination of the copper coating during ultrasonic or laser welding.

[0051] Optionally, the substrate is PET, TPU, PP, PI or TPI.

[0052] By adopting the above technical solution and using the above materials for the substrate, the combustion safety of the battery can be greatly improved, while the weight of the substrate is reduced, thereby increasing the energy density of the battery. At the same time, the substrate can also reduce the shedding of active materials caused by metal shrinkage, which can improve the cycle life of the battery.

[0053] In summary, this application has at least one of the following beneficial effects:

[0054] 1. The uniform and continuous coating formed by chemical copper plating makes the copper foil have excellent thermal conductivity, reducing the temperature difference within the battery cell. It has strong corrosion resistance. Specifically, after immersion in electrolyte for 168 hours, the copper plating layer does not fall off. The composite copper foil also has low square resistance and can support charge and discharge rates of 4C and above. The composite copper foil has excellent weldability, and the copper plating layer does not peel off during ultrasonic welding or laser welding.

[0055] 2. The material of the substrate can greatly improve the combustion safety of the battery, while reducing the weight of the substrate, thereby increasing the energy density of the battery. At the same time, the substrate can also reduce the shedding of active materials caused by metal shrinkage, which can improve the cycle life of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] FIG1 is a schematic structural diagram of a moving mechanism in a production process of a composite copper foil in an embodiment of the present application;

[0057] Figure 2 is an enlarged view of point A in Figure 1;

[0058] FIG3 is a cross-sectional view of the structure of the flushing assembly;

[0059] FIG4 is a structural diagram of a reaction tank;

[0060] FIG5 is a cross-sectional view of the structure of the reaction tank;

[0061] FIG6 is a cross-sectional view of the structure of the air intake pipe;

[0062] FIG7 is an enlarged view of point B in FIG5 .

[0063] In the figure: 10, connecting frame; 11, acid tank; 12, alkaline tank; 20, moving mechanism; 21, moving screw; 22, moving motor; 23, moving seat; 24, cylinder; 25, clamping assembly; 251, limit plate; 252, mounting plate; 2521, clamping plate; 253, rotating rod; 254, torsion spring; 30, flushing assembly; 31, water tank; 311, water box; 32, water pipe; 321, water outlet; 33, water pump; 34. Rotating motor; 40. Driving assembly; 41. Inlet pipe; 411. Inlet hole; 42. Water baffle; 43. Propulsion spring; 44. Inlet check valve; 441. Inlet membrane; 4411. Air vent; 442. Sealing plate; 45. Piston; 50. Water-blocking membrane; 60. Sliding assembly; 61. Sliding frame; 611. Sliding rod; 62. Sliding rack; 63. Incomplete gear; 70. Base material; 80. Copper plating; 90. Reaction tank. DETAILED DESCRIPTION

[0064] The present application is further described in detail below with reference to Figures 1-7.

[0065] The present invention discloses a process for producing composite copper foil. Referring to FIG1 , the process includes an acidic tank 11 and an alkaline tank 12. A substrate 70 can be placed vertically in the acidic tank 11 and subjected to an acidic treatment to roughen the surface of the substrate 70. Similarly, the substrate 70 can be placed vertically in the alkaline tank 12 to degrease the surface of the substrate 70. The acidic and alkaline tanks 11 and 12 are connected by a connecting frame 10. The connecting frame 10 is located above the acidic and alkaline tanks 11 and 12.

[0066] 1 and 2 , a moving mechanism 20 is provided on the connecting frame 10 to facilitate transporting the substrate 70. The moving mechanism 20 includes a moving screw 21, a moving motor 22, a moving seat 23, and a clamping assembly 25. The moving screw 21 is horizontally placed above the acidic tank 11 and the alkaline tank 12. The end of the moving screw 21 is rotatably connected to the connecting frame 10. The moving motor 22 is mounted on the connecting frame 10 via bolts. The output end of the moving motor 22 is coaxially fixed to the end of the moving screw 21 and is used to drive the moving screw 21 to rotate around the central axis of the moving screw 21 on the connecting frame 10. That is, when the moving motor 22 is started, it drives the moving screw 21 to rotate, driving the moving seat 23 to move along the length of the moving screw 21, thereby causing the cylinder 24 to drive the clamping assembly 25 to move.

[0067] 1 and 2 , the movable seat 23 is sleeved on the movable screw 21 and is threadedly connected to the movable screw 21. The circumferential side walls of the movable seat 23 are in contact with the connecting frame 10, so that the movable seat 23 cannot rotate around the central axis of the movable screw 21. A cylinder 24 is provided on the movable seat 23, and the output shaft of the cylinder 24 is vertically downward. The clamping assembly 25 is connected to the output shaft of the cylinder 24, and the cylinder 24 can drive the clamping assembly 25 to move up and down. When the cylinder 24 drives the clamping assembly 25 to move down to the substrate 70 in the acidic tank 11 and the alkaline tank 12, the clamping assembly 25 can automatically start to clamp the substrate 70. When the cylinder 24 drives the clamping assembly 25 to move upward, the substrate 70 can be pulled out of the acidic tank 11 or the alkaline tank 12.

[0068] 1 and 2 , the clamping assembly 25 includes two limiting plates 251 and two mounting plates 252 . The two limiting plates 251 are on the same horizontal line and are both fixed to the connecting frame 10 . One limiting plate 251 is located at the opening of the acidic tank 11 , and the other limiting plate 251 is located at the opening of the alkaline tank 12 .

[0069] Referring to Figures 1 and 2, the top ends of the two mounting plates 252 are hinged together. A rotating rod 253 is inserted at the hinge point of the two mounting plates 252, allowing the mounting plates 252 to rotate about the central axis of the rotating rod 253. A mounting bracket is fixed to the end of the output shaft of the cylinder 24, and the rotating rod 253 is horizontally inserted through the mounting bracket and fixed to the mounting bracket. A torsion spring 254 is sleeved on the rotating rod 253, one end of the torsion spring 254 being fixed to one of the mounting plates 252 and the other end being fixed to the other mounting plate 252. A clamping plate 2521 is fixed to the bottom end of the mounting plates 252. The torsion spring 254 drives the two mounting plates 252 toward each other, so that in the initial state, the two clamping plates 2521 are in a state of mutual contact.

[0070] When it is necessary to clamp the substrate 70 in the acidic tank 11 or the alkaline tank 12, the movable motor 22 is first used to drive the movable screw 21 to move, so that the movable seat 23 drives the clamping assembly 25 to move directly above the substrate 70. Then, the cylinder 24 is activated to drive the rotating rod 253 to move the two mounting plates 252 downward. Initially, the two mounting plates 252 are close to each other under the action of the torsion spring 254, that is, the two clamping plates 2521 are in abutment. When the clamping plates 2521 reach the corresponding limit plates 251, the movable screw 21 is driven to rotate, so that the mounting plates 252 approach the limit plates 251 until the limit plates 251 are inserted between the two mounting plates 252 and are located below the rotating rod 253.

[0071] 1 and 2 , the cylinder 24 continues to drive the clamping plate 2521 downward, while the limiting plate 251 remains stationary, causing the limiting plate 251 to slide relative to the mounting plate 252 in the direction of the rotating rod 253. This pushes the two mounting plates 252 away from each other, overcoming the elastic force of the torsion spring 254, thereby gradually widening the distance between the two mounting plates 252 and causing the clamping plates 2521 to open until the gap between the two clamping plates 2521 is sufficient for inserting the substrate 70. The movable lead screw 21 is then reversed, causing the mounting plates 252 to move away from the limiting plate 251 until the limiting plate 251 is relatively withdrawn from between the two mounting plates 252. At this point, the mounting plates 252 lose their thrust, and the torsion spring 254 recovers its deformation, causing the two clamping plates 2521 to approach and abut against the substrate 70. At this point, the two clamping plates 2521 compress and secure the substrate 70. When the cylinder 24 drives the mounting plate 252 to move upward, the clamping plate 2521 clamps the substrate 70 and pulls it out of the acidic tank 11 or the alkaline tank 12 .

[0072] 1 and 3 , a flushing assembly 30 is provided on the connecting frame 10 to flush the acid-treated substrate 70 and prevent excessive corrosion of the substrate 70. The flushing assembly 30 includes a water tank 31, a water pipe 32, and a rotating motor 34. The water tank 31 is fixed to the connecting frame 10 and located between the acidic tank 11 and the alkaline tank 12. An open-topped water container 311 is fixed to the top of the water tank 31. The water pipe 32 is located above the acidic tank 11 and the alkaline tank 12 and is fixed to the connecting frame 10. The water pipe 32 extends along the length of the movable screw 21. One end of the water pipe 32 is connected to the water tank 31, and the other end is a closed structure. A water pump 33 is installed at the connection between the water pipe 32 and the water tank 31 to pump water from the water tank 31 into the water pipe 32.

[0073] 1 and 3 , a plurality of water outlets 321 are defined on the bottom wall of the water pipe 32. These outlets 321 are spaced apart along the length of the water pipe 32 and are all located within the water storage box 311. A rotary motor 34 is bolted to the movable base 23. The output end of the rotary motor 34 is secured to the housing of the cylinder 24. The rotary motor 34 is capable of driving the cylinder 24 to rotate about its output shaft.

[0074] After the clamping plate 2521, holding the substrate 70, moves to the position directly above the water container 311, the water pump 33 is activated, pumping water from the water tank 31 into the water pipe 32. The water is then sprayed out of the water outlet 321 onto the substrate 70 below. The water then flows downward along the surface of the substrate 70, rinsing the substrate 70. The water flowing through the substrate 70 ultimately falls into the water container 311, preventing it from flowing around and affecting the working environment. The water container 311 also collects the water for recycling, reducing water waste.

[0075] 1 and 3 , while water is flowing out of the water outlet 321 , the rotating motor 34 can also be started to drive the cylinder 24 to drive the substrate 70 to rotate around the output shaft of the cylinder 24 , so that different positions of the substrate 70 are alternately moved to the bottom of the water outlet 321 , thereby achieving all-round flushing of the substrate 70 by the water outlet 321 , thereby increasing the comprehensiveness of the cleaning and achieving a better cleaning effect on the substrate 70 .

[0076] 1 and 4 , a reaction tank 90 is also fixed to the connecting frame 10. The reaction tank 90 stores an electrolyte solution containing copper ions. The reaction tank 90 is located on the side of the alkaline tank 12 away from the acidic tank 11. Referring to FIG4 and FIG5 , the substrate 70 can lie flat in the reaction tank 90 in a horizontal state and easily deposit at the bottom of the reaction tank 90 under the action of gravity. In order to allow the substrate 70 to fully contact the electrolyte solution, two drive assemblies 40 are provided at the bottom of the reaction tank 90. ​​The two drive assemblies 40 are symmetrically arranged about the central axis of the reaction tank 90. ​​The drive assemblies 40 apply an upward thrust to the substrate 70 from the bottom of the reaction tank 90. ​​The two drive assemblies 40 are activated alternately, causing the substrate 70 to swing left and right with the middle of the substrate 70 as the axis.

[0077] 5 and 6 , the drive assembly 40 includes an air intake pipe 41, a water baffle 42, an air intake one-way valve 44, and a piston 45. The air intake pipe 41 is an L-shaped pipe. The end of the vertical section of the air intake pipe 41 passes through the bottom of the reaction tank 90 and is connected to the reaction tank 90. ​​The water baffle 42 is located on the vertical section of the air intake pipe 41. Specifically, one side of the water baffle 42 is hinged to the inner wall of the air intake pipe 41 through a rotating shaft, and the other side is inclined toward the direction close to the reaction tank 90. ​​When the side of the water baffle 42 away from the rotating shaft abuts the inner wall of the air intake pipe 41, the circumferential side walls of the water baffle 42 abut against the inner wall of the air intake pipe 41, thereby blocking the air intake pipe 41.

[0078] Referring to Figures 5 and 6, in order to enable the side of the water baffle 42 away from the rotating shaft to abut against the inner wall of the air inlet pipe 41, a thrust spring 43 is fixed on the side of the water baffle 42 close to the reaction pool 90, and one end of the thrust spring 43 away from the water baffle 42 is fixed to the inner wall of the air inlet pipe 41, and the thrust spring 43 is used to push the water baffle 42 in a direction away from the reaction pool 90.

[0079] 5 and 7 , an air inlet hole 411 is provided through the end of the horizontal section of the air inlet pipe 41, and an air inlet one-way valve 44 is located in the air inlet hole 411. The air inlet one-way valve 44 includes an air inlet membrane 441. The air inlet membrane 441 is made of flexible rubber material and can be deformed. The circumferential side wall of the air inlet membrane 441 is fixed in contact with the inner wall of the air inlet hole 411. An air vent 4411 is provided through the air inlet membrane 441. The air vent 4411 is connected to the air inlet hole 411. A sealing plate 442 is fixed on the inner wall of the air inlet hole 411. The sealing plate 442 only blocks part of the air inlet hole 411. When the air inlet membrane 441 is in contact with the sealing plate 442, the sealing plate 442 is used to seal the air vent 4411.

[0080] The piston 45 is located in the horizontal section of the intake pipe 41 , and the circumferential side wall of the piston 45 abuts against the inner wall of the intake pipe 41 . The piston 45 can move horizontally in the intake pipe 41 toward or away from the intake hole 411 .

[0081] 6 and 7 , initially, the propulsion spring 43 causes the water baffle 42 to abut against the inner wall of the air inlet pipe 41, thereby blocking the air inlet pipe 41. When the substrate 70 is horizontally placed in the reaction tank 90, the substrate 70 gradually settles to the bottom of the reaction tank 90 under the action of gravity. At this time, the piston 45 is first moved away from the intake one-way valve 44, so that a negative pressure is formed in the intake pipe 41, and the gas outside the intake pipe 41 enters the intake hole 411. At this time, the gas applies a thrust to the intake membrane 441 to move toward the piston 45, causing the intake membrane 441 to deform, that is, the middle part of the intake membrane 441 bulges toward the direction close to the piston 45, so that a gap exists between the sealing plate 442 and the intake membrane 441, so that the gas can enter between the sealing plate 442 and the intake membrane 441 from the gap between the sealing plate 442 and the inner wall of the intake hole 411, and then enter the intake pipe 41 through the air vent 4411 on the intake membrane 441.

[0082] The water baffle 42 is affected by the suction force of the air inlet pipe 41, so that the side of the water baffle 42 away from the rotating shaft is more tightly pressed against the inner wall of the water inlet pipe 32, thereby making the sealing performance of the water baffle 42 in blocking the air inlet pipe 41 better, thereby limiting the electrolyte solution in the reaction tank 90 from entering the air inlet pipe 41 on the side of the water baffle 42 away from the reaction tank 90.

[0083] 6 and 7 , the piston 45 is then driven to move toward the air intake one-way valve 44, and the gas in the air intake pipe 41 applies a thrust on the air intake membrane 441 in the direction away from the piston 45, causing the air intake membrane 441 to deform until the air intake membrane 441 abuts against the sealing plate 442. At this time, the edge of the air vent 4411 is completely abutted against the sealing plate 442, so that the sealing plate 442 blocks the air vent 4411, so that the air intake membrane 441 and the sealing plate 442 cooperate to block the air intake hole 411, thereby limiting the gas in the air intake pipe 41 from moving out of the air intake pipe 41 through the air intake hole 411.

[0084] The gas in the intake pipe 41 applies a thrust to the water baffle 42 in the direction close to the reaction pool 90, overcoming the elastic force of the propulsion spring 43, so that the water baffle 42 rotates around the rotating shaft, so that the side of the water baffle 42 close to the reaction pool 90 gradually separates from the inner wall of the intake pipe 41 and moves toward the reaction pool 90, so that a gap exists between the water baffle 42 and the side wall of the intake pipe 41, so that the gas in the intake pipe 41 can enter the reaction pool 90 through the gap.

[0085] 6 and 7 , gas moves upward from the bottom of the reaction cell 90, thereby exerting an upward thrust on the bottom wall of the substrate 70, causing the substrate 70 to move in the electrolyte solution. The two air inlet pipes 41 alternately pump air into the two ends of the substrate 70, causing the substrate 70 to swing left and right, thereby allowing the substrate 70 to contact the electrolyte solution at different locations in the reaction cell 90. The entry of gas into the electrolyte solution and the movement of the substrate 70 both cause the electrolyte solution to flow, allowing the surface of the substrate 70 to fully contact the copper ions in the electrolyte solution. This results in a more uniform copper deposit on the surface of the substrate 70, resulting in a more complete and uniform copper plating 80 on the surface of the substrate 70, thereby improving the quality of the copper plating 80.

[0086] 4 and 5 , in order to drive the two pistons 45 to move alternately, a sliding assembly 60 is provided at the bottom of the reaction pool 90. The sliding assembly 60 includes a sliding frame 61 and an incomplete gear 63. The sliding frame 61 is a rectangular frame. Sliding racks 62 are fixed on the upper and lower inner walls of the sliding frame 61. The incomplete gear 63 is rotatably connected to the reaction pool 90 and is driven to rotate by a motor. The incomplete gear 63 is located in the sliding frame 61 and between the two sliding racks 62. The incomplete gear 63 can engage with the sliding racks 62. Sliding rods 611 are fixed on both sides of the sliding frame 61 in the width direction. The end of the sliding rod 611 away from the sliding frame 61 is inserted into the intake pipe 41 and fixed to the piston 45.

[0087] 4 and 5 , the motor drives the incomplete gear 63 to rotate. When the incomplete gear 63 engages with one of the sliding racks 62, it drives the entire sliding frame 61, driving the sliding rod 611 to move. This causes the two pistons 45 to move in the same direction. That is, one air inlet pipe 41 pushes gas into the reaction cell 90, while the other air inlet pipe 41 absorbs and stores gas. This causes one side of the substrate 70 to move upward in the electrolyte solution, achieving an inclined suspension of the substrate 70 in the reaction cell 90.

[0088] When the incomplete gear 63 rotates to separate from the sliding rack 62, the sliding frame 61 drives the piston 45 to stop moving, and then the teeth on the incomplete gear 63 rotate to the other side and mesh with the other sliding rack 62, thereby driving the other sliding rack 62 to move. Because the two sliding racks 62 are located on both sides of the incomplete gear 63, the two sliding racks 62 move in opposite directions under the drive of the incomplete gear 63, thereby driving the other sliding rack 62 to drive the sliding frame 61 in the opposite direction, realizing the reset of the two pistons 45, so that the inlet pipe 41 that originally sucked gas sends gas into the reaction tank 90, pushing the other side of the substrate 70 upward, causing the substrate 70 to swing around the middle of the substrate 70, and achieving full contact between the substrate 70 and the electrolyte solution.

[0089] Referring to Figure 6 , a water-blocking membrane 50 is installed in the intake pipe 41. This membrane is made of ePTFE (expanded polytetrafluoroethylene) waterproof and breathable membrane. The circumferential sidewalls of the membrane 50 are bonded to the inner wall of the intake pipe 41. The membrane 50 is located on the side of the baffle plate closest to the reaction cell 90 and prevents the electrolyte in the reaction cell 90 from entering the intake pipe 41.

[0090] When the air inlet pipe 41 is delivering gas to the reaction cell 90, one side of the water baffle 42 separates from the inner wall of the air inlet pipe 41, allowing gas to pass through the water-blocking membrane 50 and enter the reaction cell 90. When the air inlet pipe 41 stops delivering gas to the reaction cell 90, the water baffle 42, under the action of the propulsion spring 43, presses against the inner wall of the air inlet pipe 41, blocking the air inlet pipe 41. At the same time, the water-blocking membrane 50 also restricts the electrolyte solution in the reaction cell 90 from entering the air inlet pipe 41, preventing the electrolyte solution from passing through the water baffle 42 during the process of the propulsion spring 43 pushing the water baffle 42 to rotate. This further reduces the possibility of electrolyte in the reaction cell 90 entering the air inlet pipe 41 and improves the sealing performance of the air inlet pipe 41 with respect to the electrolyte solution in the reaction cell 90.

[0091] The implementation principle of the production process of a composite copper foil in an embodiment of the present application is as follows: when making the composite copper foil, several sections of substrate 70 are cut in advance, and then a section of substrate 70 is placed vertically in the acid tank 11 so that the substrate 70 is completely immersed in the acid solution. The acid solution corrodes the surface of the substrate 70, making the surface of the substrate 70 rough. Then, the moving motor 22 is started to drive the moving screw 21 to rotate, so that the moving seat 23 drives the clamping plate 2521 to reach the top of the acid tank 11, and then the cylinder 24 is started to drive the clamping assembly 25 to move down and clamp the substrate 70.

[0092] Next, the cylinder 24 is activated to move the clamping assembly 25 upward, removing the substrate 70 from the acid tank 11. The movable screw 21 then rotates to drive the connecting base, causing the clamping plate 2521 to move the substrate 70 above the water storage box 311. The water pump 33 is activated, drawing water from the water tank 31 and spraying it out through the water outlet 321 to clean the substrate 70. The cleaned substrate 70 is then transported to the alkaline tank 12 by the movable screw 21 and the movable seat 23 for degreasing, and is lifted up by the cylinder 24 for drying. The connecting seat then drives the substrate 70 to the reaction tank 90, and the driving component 40 is used to deliver gas to the reaction tank 90, so that the two ends of the substrate 70 lying flat in the reaction tank 90 are alternately thrust, thereby swinging left and right, causing the electrolyte solution to flow. The surface of the substrate 70 can thus fully contact the copper ions in the electrolyte solution, so that the copper element attached to the surface of the substrate 70 is more uniform, and the copper plating 80 on the surface of the substrate 70 is relatively complete and uniform, thereby improving the quality of the copper plating 80.

[0093] The present invention discloses a production process of a composite copper foil, comprising the following steps:

[0094] S1. First, the substrate 70 is placed in the acidic tank 11. After the surface of the substrate 70 is slightly corroded and roughened, the substrate 70 is immediately removed from the acidic tank 11 using the moving mechanism 20. The substrate 70 is then rinsed using the rinsing assembly 30. The rinsed substrate 70 is then placed in the alkaline tank 12 for surface degreasing. After the degreasing is completed, the substrate 70 is again removed from the alkaline tank 12 using the moving mechanism 20. The solution on the substrate 70 is then adsorbed by a negative pressure blower until the substrate 70 is completely dry.

[0095] S2. Attach a reducing agent to the dried substrate 70. In the embodiment of the present application, the reducing agent can be formaldehyde. The substrate 70 is immersed in a reaction tank 90 filled with an electrolyte by chemical plating. The reducing agent converts the copper ions in the electrolyte into copper element and attaches to the substrate 70. At this time, a copper plating layer 80 with a thickness of 100 nm is deposited on the surface of the substrate 70. Then, the substrate 70 is placed in a copper sulfate solution, and the thickness of the copper plating layer 80 on the surface of the substrate 70 is increased to 1000 nm by horizontal plating, thereby completing the manufacture of the composite copper foil.

[0096] The copper coating 80 on the composite copper foil produced in the above steps is formed by chemical copper plating. Its uniformity and continuity ensure excellent thermal conductivity, reducing temperature differences within the battery cell. It also exhibits strong corrosion resistance, specifically, the copper coating 80 remained intact after 168 hours of electrolyte immersion. Furthermore, the composite copper foil has a low sheet resistance and can support charge and discharge rates of 4C and above. The composite copper foil also exhibits excellent weldability, with no peeling of the copper coating 80 during ultrasonic or laser welding.

[0097] Substrate 70 can be made of PET, TPU, PP, PI, or TPI. Using these materials significantly improves the battery's combustion safety while reducing the weight of substrate 70, thereby increasing the battery's energy density. Substrate 70 also reduces the loss of active material caused by metal shrinkage, thereby extending the battery's cycle life.

[0098] The product performance of the composite copper foil in the embodiment of this application is as follows:

[0099] The thickness of the copper plating is 1.0um, while the thickness of the substrate is 2.5um, 4.5um and 5um;

[0100] Width: 350-800mm;

[0101] Mass per unit area: 32-36g / m 2 ;

[0102] Tensile strength: ≥150Mpa at room temperature and 80℃;

[0103] Elongation at break: ≥3.0%;

[0104] Surface roughness: ≤0.8um;

[0105] Square resistance: ≤0.1Ω;

[0106] Peel force: ≥10N / cm;

[0107] Copper content: ≥99.8;

[0108] Pinholes and penetration points: ≤2;

[0109] Wettability: ≥42mN / m;

[0110] Thermal conductivity: 384 / 294 / 384W / K*m;

[0111] Corrosion resistance: electrolyte ratio 1:1:1, room temperature / 168h, copper layer does not peel off;

[0112] Weldability: ultrasonic welding and laser welding;

[0113] Resistivity: ≤2.5x10 -8 ;

[0114] Antioxidation performance: Under the condition of 140℃ / 15min, there is no obvious color change on both sides;

[0115] Surface energy: >38.

[0116] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A production process for composite copper foil, characterized in that: The following steps are involved: S1, firstly, subjecting the substrate (70) to acid treatment, washing, degreasing treatment, and drying in sequence; S2. A reducing agent is then attached to the dried substrate (70), and a copper plating layer (80) with a thickness of 100 nm is deposited on the surface of the substrate (70) by chemical plating. The substrate (70) is then horizontally plated to increase the thickness of the copper plating layer (80) on the surface of the substrate (70) to 1000 nm, thereby obtaining a composite copper foil.

2. The production process of the composite copper foil according to claim 1, characterized in that: In step S1, the substrate (70) is placed in an acidic tank (11) for acid treatment, and the substrate (70) is placed in an alkaline tank (12) for alkaline treatment. The acidic tank (11) and the alkaline tank (12) are connected via a connecting frame (10). The connecting frame (10) is provided with a moving mechanism (20) for driving the substrate (70) to move. The moving mechanism (20) includes: A movable lead screw (21) is provided on the connecting frame (10), the movable lead screw (21) being arranged along the connecting line of the acidic pool (11) and the alkaline pool (12), and the end of the movable lead screw (21) is rotatably connected to the connecting frame (10); A moving motor (22) is provided on the connecting frame (10), wherein the output end of the moving motor (22) is coaxially fixed with the moving screw (21), and the moving motor (22) is used to drive the moving screw (21) to rotate around the central axis of the moving screw (21); A movable seat (23) is sleeved on the movable lead screw (21) and is threadedly connected to the movable lead screw (21); a side wall of the movable seat (23) abuts against the connecting frame (10); the movable lead screw (21) rotates to drive the movable seat (23) to move along the length direction of the movable lead screw (21); A clamping assembly (25) is provided on the movable seat (23), and a cylinder (24) is provided on the movable seat (23). The output shaft of the cylinder (24) is downwardly directed and connected to the clamping assembly (25). The cylinder (24) is used to drive the clamping assembly (25) to move up and down, and the clamping assembly (25) is used to clamp the substrate (70).

3. The production process of the composite copper foil according to claim 2, characterized in that: The clamping assembly (25) comprises: Two limiting plates (251) are fixed on the connecting frame (10), and the acidic pool (11) and the alkaline pool (12) each correspond to one limiting plate (251); Two mounting plates (252), the top ends of the two mounting plates (252) are hinged, the limiting plate (251) can be inserted between the two mounting plates (252), a rotating rod (253) is passed through the hinge point of the two mounting plates (252), the rotating rod (253) is arranged on the output shaft of the cylinder (24), and the mounting plate (252) can rotate around the central axis of the rotating rod (253); The torsion spring (254) is sleeved on the rotating rod (253), and the two ends of the torsion spring (254) are respectively fixed to the corresponding mounting plates (252). The bottom end of the mounting plate (252) is fixed with a clamping plate (2521). The torsion spring (254) is used to drive the two The clamping plates (2521) are close to each other, and the two clamping plates (2521) are used to clamp the substrate (70).

4. The production process of the composite copper foil according to claim 2, characterized in that: In step S1, a flushing assembly (30) is used to flush the substrate (70), and the flushing assembly (30) includes: A water tank (31) is fixed on the connecting frame (10) and is located between the acidic pool (11) and the alkaline pool (12), and a water container (311) is provided on the top of the water tank (31); A water pipe (32) is fixed on the connecting frame (10), one end of the water pipe (32) is connected to the water tank (31), a water pump (33) is provided on the water pipe (32), and the water pump (33) is used to pump water in the water tank (31) into the water pipe (32), and a plurality of water outlets (321) are provided on the bottom wall of the water pipe (32) above the water box (311); A rotating motor (34) is provided on the movable seat (23), and an output end of the rotating motor (34) is connected to the cylinder (24) for driving the cylinder (24) to rotate about an output shaft of the cylinder (24).

5. The production process of the composite copper foil according to claim 2, characterized in that: In step S2, a substrate (70) is placed in a reaction tank (90) for chemical plating. The reaction tank (90) is fixed on the connecting frame (10). Two driving assemblies (40) are provided in the reaction tank (90) for driving the substrate (70) to swing around the middle of the substrate (70). The two driving assemblies (40) are symmetrical about the central axis of the reaction tank (90) in the vertical direction. The driving assemblies (40) include: an air inlet pipe (41), disposed at the bottom of the reaction tank (90) and communicating with the reaction tank (90); A water baffle (42) is provided in the air inlet pipe (41), one end of the water baffle (42) is hinged on the inner wall of the air inlet pipe (41), and the other end is inclined in a direction close to the reaction pool (90). The side of the water baffle (42) close to the reaction pool (90) is connected to the inner wall of the air inlet pipe (41) through a propulsion spring (43). The propulsion spring (43) is used to propel the water baffle (42) in a direction away from the reaction pool (90). The water baffle (42) is used to block the air inlet pipe (41); An air intake check valve (44), wherein an air intake hole (411) is provided on a side wall of the air intake pipe (41), the air intake hole (411) is located on a side of the water retaining plate (42) away from the reaction tank (90), and the air intake check valve (44) is provided in the air intake hole (411) and is used to limit the gas in the air intake pipe (41) from being discharged from the air intake hole (411); A piston (45) is provided in the intake pipe (41), wherein the circumferential side wall of the piston (45) abuts against the inner wall of the intake pipe (41), the piston (45) is located on a side of the intake one-way valve (44) away from the water baffle (42), and the piston (45) is movable in the intake pipe (41).

6. The production process of the composite copper foil according to claim 5, characterized in that: A water-blocking film (50) is provided in the air intake pipe (41), and the circumferential side wall of the water-blocking film (50) is fixedly attached to the inner wall of the air intake pipe (41). The water-blocking film (50) is located on a side of the baffle close to the reaction pool (90) and is used to limit the electrolyte in the reaction pool (90) from entering the air intake pipe (41).

7. The production process of the composite copper foil according to claim 5, characterized in that: The air intake valve includes an air intake membrane (441), the circumferential side wall of the air intake membrane (441) is fixedly abutted against the inner wall of the air intake hole (411), an air vent (4411) is provided through the air intake membrane (441), the air vent (4411) is communicated with the air intake hole (411), and a sealing plate (442) is fixed on the inner wall of the air intake hole (411), and when the air intake membrane (441) is abutted against the sealing plate (442), the sealing plate (442) is used to seal the air vent (4411).

8. The production process of the composite copper foil according to claim 5, characterized in that: A sliding assembly (60) for driving the piston (45) to move is provided at the bottom of the reaction tank (90), and the sliding assembly (60) includes: A sliding frame (61) is slidably connected to the bottom of the reaction tank (90), and the sliding frame (61) can move in a horizontal direction. The sliding frame (61) is located between the two pistons (45) and is connected to the pistons (45) through a sliding rod (611); Two sliding racks (62) are relatively fixed on the inner wall of the sliding frame (61), and the sliding assembly (60) is arranged in a horizontal direction; An incomplete gear (63) is rotatably connected to the reaction pool (90). The incomplete gear (63) is located in the sliding frame (61) and between the two sliding racks (62). The incomplete gear (63) can mesh with the sliding racks (62).

9. A composite copper foil, characterized in that A composite copper foil produced using the production process of the composite copper foil according to claim 1.

10. The composite copper foil according to claim 9, characterized in that The substrate (70) is PET, TPU, PP, PI or TPI.

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