Studies Of Additives Of Electrolyzing Copper Foil And Determination Of Each Component In The Electrolyte

With the rapid development of lithium ion battery industry, higher performance electrolytic copper foil which used in anode current collector is required. Developing excellent additive formula is one of the most important ways to the preparation of high performance electrolytic copper foil. The paper simulated the process parameters of factory for copper foil production and aimed at developing outstanding additives for brightness and high leveling copper foil prepared with high current density and studied electrodeposition of copper in presence of different additives. Futhermore, simple and reliable method was explored to detect the concentration of Cu2+、sulfuric acid and additive. The major contents were as follows:1.Six groups of two-component and three groups of three-component additive formulations were chosen to prepare electrolytic copper foil with high current density 7500 A·m-2. SEM showed that the microstructure of copper foil was smooth, dense and flawless. Gloss test showed that the surface brightness of copper foil was between 100 GS and 200 GS. Roughness test showed that copper foil surface conform to Ra<0.2μm, Rz<2.0μm. XRD analysis showed that the copper coating had an orientation along(111) crystal plane, which proved the high leveling of copper foil.2.The copper electrodepositions on copper electrode in the solutions containing 320 g/L Cu SO4?5H2O and 110 g/L H2SO4 with Cl-, BSP, RPE alone or in combination at 50℃ were studied by linear sweep voltammetry, cyclic voltammetry and chronoamperometry. Cl- and BSP have depolarization effect in the electrodeposition processes, but the polarization effect of RPE increase with the increase of RPE concentration. RPE can decrease the nuclear number and BSP can reduce the diffusion coefficient, but BSP can increase the nuclear number density. 30mg?L-1Cl-+5mg?L-1BSP+5mg?L-1RPE can increase the diffusion coefficient, apparent transfer coefficient and speed up the copper electrodeposition process. At beginning, the electrodeposition processes followed the instantaneous nucleation and then changed to the progressive nucleation gradually as time went on. But the processes would deviate from the theoretical model after longer nucleation time with Cl-, RPE, 30mg?L-1Cl-+5mg?L-1BSP+5mg?L-1RPE. It always followed the instantaneous nucleation in the presence of BSP.3.The equipment was designed for online monitoring the concentration of copper ion in the electrolyte. Copper ion concentration had a good linear relationship with the microampere meter reading. In addition, the influence of temperature on copper ion monitoring was calibrated.4.The concentration of sulfuric acid in the electrolyte was monitored by measuring the conductivity. Sulfuric acid concentration had a good linear relationship with the electrolyte conductivity. The influence of temperature on sulfuric acid monitoring was calibrated too.5.Copper sulphate was separated from the electrolyte,and the absorbance of supernatant was measured at wavelength of 270 nm. It showed that there was a good linear relationship between the absorbance and the concentration of DPS, and therefore the concentration of DPS can be inspected.