An ultrathin lithium battery copper foil and a production process of an ultrathin lithium battery copper foil with tear-proof edges

Abstract

The present application relates to a kind of production process of ultra-thin lithium battery copper foil tear-proof edge, which is completed by electrolytic equipment, and the electrolytic equipment includes electrolytic cell, cathode roller, anode plate and auxiliary cathode, and the production process includes that copper is dissolved to be solution, electrolytic equipment is pretreated, wherein pretreatment includes that the cathode roller is polished, the polished cathode roller is installed in electrolytic cell by O-ring and the thickness of the edge of anode plate is increased;Copper sulfate electrolyte is made into original foil by electrodeposition under the action of direct current in the electrolytic equipment after pretreatment, and the voltage of auxiliary cathode is higher than that of electrolytic cell.The ultra-thin lithium battery copper foil and the production process of ultra-thin lithium battery copper foil tear-proof edge can obtain the ultra-thin lithium battery copper foil with good performance and appearance, so as to overcome the defects of tear edge, broken foil and other problems in the prior art production process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium copper foil production, in particular to an ultra-thin lithium copper foil and a production process for preventing the edge of the ultra-thin lithium copper foil from being torn. BACKGROUND

[0002] Lithium copper foil is widely used in the lithium ion battery industry. As a support body and current collector of the negative electrode material, lithium copper foil is an important component material of lithium ions. It has the advantages of low price, good electrical conductivity, small size, light weight, etc.

[0003] The production of lithium copper foil mainly includes three processes: copper dissolution, foil production, and product slitting. Specifically, copper is first dissolved to form a solution, then copper sulfate electrolyte is electrolyzed in a dedicated electrolysis device under the action of direct current to form a raw foil through electrodeposition, and then the raw foil is subjected to anti-oxidation treatment in an anti-oxidation tank on the foil production machine. Lithium copper foil is different from standard foil. Lithium copper foil has a bright color on both sides, and the surface crystalline form is approximately the same. The side close to the cathode roller is smooth, which is called a smooth surface. The other side is also bright due to the effect of additives, which is called a rough surface. With the increasing requirement for lithium battery energy storage, the thickness of lithium copper foil also changes. That is, lithium copper foil is becoming thinner and thinner. The existing production equipment mainly produces 4.5-8 micron lithium copper foil and the production method. In the production process, problems such as tearing and breaking of the foil often occur, which seriously affects mass production.

[0004] Therefore, in view of the technical problems existing in the prior art, the present application provides a production process for preventing the edge of an ultra-thin lithium copper foil from being torn to solve the defects of the prior art production process that is prone to tearing and breaking of the foil. SUMMARY

[0005] Therefore, the present application solves the technical problems existing in the prior art and provides a production process for preventing the edge of an ultra-thin lithium copper foil from being torn, which can obtain an ultra-thin lithium copper foil with good performance and appearance, thereby overcoming the defects of the prior art production process that is prone to tearing and breaking of the foil.

[0006] To solve the above technical problems, the present application provides a production process for preventing the edge of an ultra-thin lithium copper foil from being torn, which is completed by an electrolysis device. The electrolysis device includes an electrolysis tank, a cathode roller, an anode plate, and an auxiliary cathode. The production process includes the following steps:

[0007] S1: Dissolve copper to form a solution and pretreat the electrolysis device, wherein the pretreatment includes grinding the cathode roller, installing the ground cathode roller in the electrolysis tank through an O-ring, and increasing the thickness of the edge of the anode plate;

[0008] S2: in the pretreated electrolytic device, the copper sulfate electrolyte is prepared into a primary foil by electrodeposition under the action of direct current, wherein the auxiliary cathode voltage is higher than the electrolytic cell voltage.

[0009] In one embodiment of the present application, in S1, the polishing of the cathode roller includes polishing the edge of the cathode roller and grinding the whole cathode roller.

[0010] In one embodiment of the present application, in S1, the method for polishing the edge of the cathode roller includes: first polishing for 1-2 hours using a 120-grit oilstone, then polishing for 1-2 hours using a 150-grit oilstone, then polishing for 0.5-1 hour using a 180-grit, 240-grit and 320-grit oilstone respectively, and finally polishing the edge of the cathode roller to the same color as the roller surface using a 600-grit oilstone.

[0011] In one embodiment of the present application, in S1, the method for grinding the whole cathode roller includes: first grinding the whole cathode roller at least two rounds using a 180-grit grinding wheel, then grinding at least two rounds using a 320-grit grinding wheel, and finally grinding at least one round using a 600-grit grinding wheel.

[0012] In one embodiment of the present application, the time for one round of grinding using a 320-grit grinding wheel is 1-2 hours, and the time for one round of grinding using a 600-grit grinding wheel is 1.5-2.5 hours.

[0013] In one embodiment of the present application, all the grinding wheels are used to stay for a set time when starting to polish the edge of the cathode roller, and also stay for a set time when ending to polish the edge of the cathode roller.

[0014] In one embodiment of the present application, in S2, the cathode roller is preheated before the electrolytic cell is filled with liquid, and the preheating time is 20-30 min.

[0015] In one embodiment of the present application, the cathode roller rotates at a speed of 2 m / minute during preheating.

[0016] In one embodiment of the present application, in S2, the auxiliary cathode voltage is 1-1.2 V higher than the electrolytic cell voltage.

[0017] In addition, the present application also provides an ultra-thin lithium battery copper foil prepared by the production process of the ultra-thin lithium battery copper foil without tearing edge.

[0018] The above technical solutions of the present application have the following advantages compared with the prior art:

[0019] The production process of the super-thin lithium battery copper foil and the super-thin lithium battery copper foil anti-tearing edge can obtain the super-thin lithium battery copper foil with good performance and appearance, thereby overcoming the defects of the prior art production process, such as easy tearing edge and broken foil. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to make the content of the present application more easily understood, the present application will be further described in detail below according to specific embodiments of the present application and in conjunction with the accompanying drawings.

[0021] Figure 1 A flowchart of the production process of the super-thin lithium battery copper foil and the super-thin lithium battery copper foil anti-tearing edge according to the embodiments of the present application is shown. DETAILED DESCRIPTION

[0022] The present application will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present application and implement it, but the embodiments are not limiting to the present application.

[0023] Please refer to Figure 1 The embodiments of the present application provide a production process of a super-thin lithium battery copper foil anti-tearing edge, which is completed by an electrolysis device, the electrolysis device includes an electrolysis tank, a cathode roller, an anode plate and an auxiliary cathode, and the production process includes the following steps:

[0024] S1: Dissolve copper into a solution and pretreat the electrolysis device, wherein the pretreatment includes polishing the cathode roller, installing the polished cathode roller in the electrolysis tank through an O-ring and increasing the thickness of the edge of the anode plate.

[0025] S2: Electrolyze copper sulfate electrolyte in the pretreated electrolysis device to form a raw foil through electrodeposition under the action of direct current, wherein the voltage of the auxiliary cathode is higher than the voltage of the electrolysis tank.

[0026] In the production process of the super-thin lithium battery copper foil anti-tearing edge disclosed in the embodiments of the present application, in S1, the polishing of the cathode roller includes polishing the edge of the cathode roller and grinding the whole cathode roller. The method for polishing the edge of the cathode roller includes: first polishing for 1-2 hours using a No. 120 oil stone, then polishing for 1-2 hours using a No. 150 oil stone, then polishing for 0.5 hours using a No. 180, No. 240 and No. 320 oil stone respectively, and finally polishing the edge of the cathode roller to the same color as the roller surface using a No. 600 oil stone.

[0027] As an example, the imported grinding stone can be used to grind the edge part, and the 120# oil stone is used to grind for 1 hour, the 150# oil stone is used to grind for 1 hour, then the 180# oil stone, the 240# oil stone and the 320# oil stone are used to grind for 0.5 hour respectively, and finally the 600# oil stone is used to grind the edge part to the color similar to the roller surface of the cathode roller, so that the edge part of the cathode roller after grinding can not be torn.

[0028] In S1, the method for grinding the whole cathode roller includes: first using the 180# grinding wheel to grind the whole cathode roller for at least two rounds, then using the 320# grinding wheel to grind for at least two rounds, and then using the 600# grinding wheel to grind for at least one round. The time for one round of the 320# grinding wheel is 1-2 hours, and the time for one round of the 600# grinding wheel is 1.5-2.5 hours. The grinding wheel is used to stay for a set time when starting to grind the edge part of the cathode roller, and also stays for a set time when ending the grinding of the edge part of the cathode roller.

[0029] As an example, the imported grinding wheel can be used during grinding, the 180# grinding wheel is used to grind back and forth for two rounds, the 320# grinding wheel is used to grind for two rounds at a speed of 90 minutes per round, and then the 600# grinding wheel is used to grind for one round at a speed of 120 minutes per round. When starting to grind the edge part of the cathode roller, stay for 20 seconds for about two rounds, and when ending the grinding of the edge part of the cathode roller, also stay for 20 seconds, so that the edge part can achieve good smoothness and maintain good peeling force during foil stripping, and the edge part is not torn.

[0030] In the production process of the ultra-thin lithium battery copper foil anti-tearing edge disclosed in the embodiment of the present application, the size of the pole distance directly affects the thickness of the copper foil under the condition of the same current. As the lithium battery foil becomes thinner and thinner, the tearing problem has been bothering copper foil manufacturers. The edge part is thickened, which can reduce the tearing phenomenon during copper foil peeling. Therefore, the present application increases the thickness of the anode to increase the thickness of the edge part of the copper foil.

[0031] In the production process of the ultra-thin lithium battery copper foil anti-tearing edge disclosed in the embodiment of the present application, the electrolytic cell is cleaned before starting, especially the two lip-shaped seals, and whether it can be sealed is checked. If there is a liquid leakage phenomenon, replace it in time. The liquid leakage on both sides will cause the thickness of the edge part to be uneven during electroplating, causing tearing.

[0032] In the production process of the ultra-thin lithium battery copper foil anti-tearing edge disclosed in the embodiment of the present application, a 10mm O-shaped ring with a steel wire is selected before the roller is installed. The O-shaped groove is confirmed to be 8.2mm wide. The O-shaped ring is used to install the ground cathode roller in the electrolytic cell.

[0033] The auxiliary cathode is also an important part in preventing tearing edge, the size of the delivered current, the shape of the auxiliary cathode and the size of the contact surface of the auxiliary cathode directly affect whether tearing edge can be prevented. Therefore, the shape of the auxiliary cathode is made into a U shape, the bottom of the auxiliary cathode is 100mm away from the groove bottom, the connection of the copper pole of the auxiliary cathode is designed into a concave shape to increase the contact area, the delivered voltage is generally larger than that of the standard foil, and is generally 1-1.2 volts higher than the tank voltage, the auxiliary cathode is checked frequently when the roll is changed after 24 hours, and the auxiliary cathode is replaced at any time when the effect cannot be achieved, so that the copper ions at the edge are few, and tearing edge is prevented.

[0034] In the production process of the ultra-thin lithium battery copper foil disclosed in the embodiment of the present application, the guide wheel of the cathode roller at the O-shaped ring into the groove is an adjustable guide wheel with flexible rotation and a gap of substantially zero, the O-shaped ring must be checked for wear at all times, and must be replaced if it is not round or the surface is rough, to ensure that it is fitted to the O-shaped groove, so as to reduce tearing edge.

[0035] In the production process of the ultra-thin lithium battery copper foil disclosed in the embodiment of the present application, in S2, the cathode roller is preheated before the electrolytic tank is filled, and the preheating time is 20-30 minutes. The cathode roller rotates at a speed of 2m / minute during preheating.

[0036] The ultra-thin lithium battery copper foil and the production process of the ultra-thin lithium battery copper foil disclosed in the embodiment of the present application can obtain an ultra-thin lithium battery copper foil with good performance and appearance, thereby overcoming the defects of the prior art production process, such as easy tearing edge and broken foil.

[0037] Corresponding to the above-mentioned method, the embodiment of the present application also provides an ultra-thin lithium battery copper foil prepared by using the production process of the ultra-thin lithium battery copper foil disclosed in the embodiment of the present application, which can obtain an ultra-thin lithium battery copper foil with good performance and appearance, thereby overcoming the defects of the prior art production process, such as easy tearing edge and broken foil.

[0038] Obviously, the above-mentioned embodiments are only examples for the purpose of clarity, and are not limiting. For those skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, it is not necessary and impossible to exhaust all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A production process of an ultra-thin lithium electro-copper foil with tear-proof edge, which is completed by an electrolysis device, the electrolysis device comprising an electrolysis tank, a cathode roller, an anode plate and an auxiliary cathode, characterized in that, The production process comprises the following steps: S1: Dissolve copper into a solution and pretreat the electrolytic equipment, wherein the pretreatment comprises polishing the cathode roller, installing the polished cathode roller in the electrolytic tank through an O-ring, and increasing the thickness of the edge of the anode plate; S2: Electrolyze the copper sulfate electrolyte in the pretreated electrolytic equipment through electrodeposition under the action of direct current to produce a raw foil, wherein the auxiliary cathode voltage is higher than the electrolytic tank voltage; in S2, the auxiliary cathode voltage is 1-1.2V higher than the electrolytic tank voltage.

2. The production process of an ultra-thin lithium battery copper foil with tear-proof edge according to claim 1, characterized in that: In S1, polishing the cathode roller comprises polishing the edge of the cathode roller and grinding the entire cathode roller.

3. The production process of an ultra-thin lithium battery copper foil with tear-proof edge according to claim 2, characterized in that: In S1, the method for polishing the edge of the cathode roller comprises: first polishing for 1-2 hours using a 120-grit oilstone, then polishing for 1-2 hours using a 150-grit oilstone, then polishing for 0.5-1 hour using a 180-grit, 240-grit and 320-grit oilstone respectively, and finally polishing the edge of the cathode roller to the same color as the roller surface using a 600-grit oilstone.

4. The production process of an ultra-thin lithium battery copper foil with tear-proof edge according to claim 2, characterized in that: In S1, the method for grinding the entire cathode roller comprises: first grinding the entire cathode roller at least two rounds using a 180-grit grinding wheel, then grinding at least two rounds using a 320-grit grinding wheel, and then grinding at least one round using a 600-grit grinding wheel.

5. The production process of an ultra-thin lithium battery copper foil with tear-proof edge according to claim 4, characterized in that: The time for one round of grinding using a 320-grit grinding wheel is 1-2 hours, and the time for one round of grinding using a 600-grit grinding wheel is 1.5-2.5 hours.

6. The production process of an ultra-thin lithium battery copper foil with tear-proof edge according to claim 4, characterized in that: All grinding wheels are used to stay for a set time when starting to polish the edge of the cathode roller, and also stay for a set time when ending to polish the edge of the cathode roller.

7. The production process of an ultra-thin lithium battery copper foil with tear-proof edge according to claim 1, characterized in that: In S2, the cathode roller is preheated before the electrolytic tank is filled with liquid, and the preheating time is 20-30 minutes.

8. The production process of an ultra-thin lithium battery copper foil with tear-proof edge according to claim 1, characterized in that: The cathode roller rotates at a speed of 2m / minute during preheating.

9. An ultra-thin lithium battery copper foil produced by the production process of an ultra-thin lithium battery copper foil without edge tearing according to any one of claims 1-8.

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