Copper foil production conjoint machine and high-bonding strength copper foil technology for lithium ion battery

[0049] Example 1:

[0050] Conjoined processors for copper foil production, see Figure 4 and Figure 5 , including a raw foil machine 5 and a post-processing machine 6, the raw foil machine includes a cathode roll 5-1, an arc-shaped anode tank 5-2, the cathode roll is rotated in the anode tank, and the post-processing machines are sequentially connected to include copper foil. Pretreatment tank 6-1, first washing tank 6-2, passivation tank 6-3, second washing tank 6-4 and winding device 6-5; wherein, the post-processing machine is connected after the raw foil machine , the straight-line distance between the copper foil input roller 7 in the pretreatment tank of the post-processing machine and the copper foil peeling roller 8 of the green foil machine is not more than 3 meters. There is a roughening-treated anode plate 10, and at the same time, a curing-treated anode plate 11 is respectively provided on the two surfaces of the copper foil along the outgoing direction in the pretreatment tank.

[0051] In order to improve the control of the roughness of the rough surface of the copper foil, a further optimization scheme of this embodiment is that the upper ports 5-2-1 of the anode tank on both sides of the cathode roll are set as the copper sulfate solution inlet, and the bottom of the anode tank is set as the copper sulfate solution inlet. The end is provided with the copper sulfate solution outlet 5-2-2, the upper port is connected with the copper sulfate solution upper tank 12 through the pipeline, the copper sulfate solution 13 flows in from the upper port of the anode tank, and flows out from the copper sulfate solution outlet at the bottom end of the anode tank, This structure can very conveniently control the flow rate of the copper sulfate solution in the anode tank, and realize the control of the roughness of the copper foil matte surface.

[0052] In order to achieve the effect of copper foil pretreatment, a further optimization scheme of this embodiment is that the cured anode plate and the copper foil surface are arranged in parallel, and the distance between the cured anode plate and the copper foil surface is between 35mm and 60mm, and the optimized distance is 50mm; the roughened anode plate and the copper foil surface are arranged at an included angle 14 of 0.5 to 5 degrees along the traveling direction of the copper foil, and the optimum angle of the included angle is 2 degrees. The distance between the roughened anode plate and the nearest end of the copper foil surface is between 35mm and 60mm, and the optimal distance is 40mm.

[0053] Example 2:

[0054] The process of high bonding strength copper foil for lithium ion batteries, this process is based on the post-processing process of high bonding strength copper foil for lithium ion batteries of the copper foil production conjoined machine in Example 1. The content of the post-processing machine in Example 1 should be As the content of the post-processing machine in this embodiment, the post-processing process includes conveying the copper foil with double-sided roughness Rz less than 1.7 microns and Ra less than 0.25 microns from the peeling roller of the green foil machine and feeding it through the copper foil introduction roller. The post-processing machine performs double-sided roughening treatment, double-sided curing treatment, water washing, double-sided passivation treatment and water washing, wherein the double-sided roughening treatment and double-sided curing treatment are both in the pretreatment tank of the post-processing machine. In the pretreatment tank, two sides of the copper foil in the direction of entering the tank are respectively provided with roughened anode plates, and at the same time in the pretreatment tank, two sides of the copper foil in the direction of exiting the tank are respectively provided with anode plates for curing treatment , as the copper foil first passes through the two roughening anode plates in the pretreatment tank, and then passes between the two curing anode plates, the roughening and curing processes of the copper foil are: roughening treatment Between the anode plate and the copper foil at a current density of 5 – 10 A/dm 2 Power on, roughen the copper foil, cure the anode plate and the copper foil at a current density of 3 – 7 A/dm 2 After electrification, the copper foil is cured, and the solution for roughening and curing is deionized water as the basic solvent, wherein:

[0055] Copper sulfate 40-120 g/l

[0056] Sulfuric acid 60-100 g/l

[0057] Temperature 20-40℃.

[0058] A further optimized solution of this embodiment is that the roughening treatment and the curing treatment are completed with the same solution in one tank.

[0059] The passivation treatment in the embodiment may be the usual anti-oxidation passivation treatment in the current post-treatment.

[0060] The cured anode plate and the copper foil surface are arranged in parallel, the distance between the cured anode plate and the copper foil surface is between 35mm and 60mm, and the optimal distance is 50mm; in the roughened treatment anode plate and the copper foil surface along the copper foil The direction of travel is set at an angle of 0.5 to 5 degrees, and the optimal angle is 2 degrees. The distance between the roughened anode plate and the nearest end of the copper foil surface is between 35mm and 60mm, and the optimal distance is 40mm.

[0061] Example 3:

[0062] Since the usual anti-oxidation passivation treatment is the anti-oxidation passivation treatment containing chromium, because chromium is a carcinogen, no matter it is an acidic or alkaline chromic acid solution, it cannot meet the requirements of environmental protection. Chromium-containing products are prohibited from being imported in the European Union (RoHS) and the United States. It has also been included in the zero-discharge wastewater standard in China. Therefore, this embodiment is a further optimized scheme on the basis of Embodiment 2, and the solution of the passivation treatment is deionized water as the basic solvent, and its process parameters are:

[0063] Sodium stannate 6-20 g/l

[0064] Sodium hydroxide 8 g/l

[0065] Temperature 30-60℃

[0066] Current density 0.5 – 1.5 A/dm 2 ,

[0067] Electrodeposition thickness is less than 0.5 microns.

[0068] Among them, sodium stannate is a standard chemical product in the market.