Electrodeposition of Al foil for the collector of lithium-ion batteries by electrorefining in [Emim]Cl-AlCl3 ionic liquid with O2− ion at room temperature: Electrochemical dissolution behavior of Al anode

Abstract

The continuous electrochemical dissolution of anode is significant to electrorefining in ionic liquid at room temperature. The electrochemically dissolved behavior of an aluminum anode was investigated in [Emim]Cl-AlCl3 ionic liquid with O2− ion by cyclic voltammetric method, constant potential dissolution, and SEM, EDS. It found that the dissolved process of the aluminum anode and electrodeposition of insulated darkness Al–O–Cl species exist together at a relatively low potential. Moreover, the Al–O–Cl species prevent the continuous dissolution of the aluminum anode. However, it can be electrochemically dissolved at a high potential that is beyond the anodic passivation potential, assuring continuous dissolution of the aluminum anode. Moreover, holding a constant anodic potential of 3.0 V for 30 min, we electrodeposited the dense and thin aluminum foil of 2.5 µm with a rough surface. The positive electrode of lithium-ion batteries using it as the collector shows superior properties.