Production Technology Of8μm Ultra-thin Electrolytic Copper Foils With Double Shining Used In Lithium Battery

Ultra-thin electrolytic copper foil is the necessary basic raw material in lithiumbattery manufacture, in which the8μm double shining electrolytic copper foil is themost representative. It’s urgent to develop a stable and efficient ultra-thin electrolyticcopper foil production process that suitable to industrial production due to theproblems such as unstable process.The influence of different process parameters on the morphology andmechanical properties of electrolytic copper foil and the effect of bis-(3-sulfopropyl)(SP), polyethylene glycol(PEG), hydroxyethylcellulose(HEC), gelatin(SOUL-G) areinvestigated by SEM(scanning electron microscope), microcomputer controlelectronic universal testing machine and drawing machine in this article. The resultsshow that the concentration requirements of Cu2+、H2SO4are lower than that ofstandard foil while the flow requirements are higher and the best production processparameters are Cu2+70g/L，H2SO4100g/L，Cl-30g/L and current density0.6-0.7A/cm2. The additive experiment reveals that PEG can increase the depositonover-potential and promote the growth of grain-oriented; SP can improve themechanical properties, but cause copper foil warp; HEC will cause copper foil warppartly while has certain effect of reducing the roughness; gelatin(SOUL-G) can makethe ultra-thin copper foil have certain surface roughness, but has no obvious effect onmechanical properties. The appropriate level for various factors in additiveexperiment is: PEG1.5mg/L，HEC0.3mg/L，SP0.6mg/L，gelatin0.4mg/L.The flow rate of the electrolyte、the choice of the anode material and the processfor surface anti-oxidation are improved according to the actual condition ofelectrolytic copper foil industrialization production. The results show that up intakeway and high velocity are more suitable for the production of ultra-thin electrolyticcopper foils for reducing gas bubble and roughness; insoluble anode(DSA)isrecommended in ultra-thin electrolytic copper foils production because that theinsoluble nonconductive particles adhering to the surface of lead anode is one of thereasons that form pinholes, the purity of electrolyte should be ensured meanwhile; the system of glucose solution added chromium anhydride formation is suitable forcopper foil surface anti-oxidation and also is suitable for lithium battery anode bakingand welding.