Electrochemical Behavior of a Graphite Electrode Prepared by Anodic Electrophoretic Deposition

Abstract

We have used anodic electrophoretic deposition (EPD) to prepare a graphite electrode of the lithium-ion battery. The technique initially gave a copper-oxide layer on the graphite electrode, but the oxide gradually transformed to metallic copper in the charge/discharge process. The technique improved performance of the graphite electrode significantly. The deposited copper-oxide/metallic-copper layer changed the reaction of the anode with the carbonate-based organic electrolyte. At 55°C, the EPD graphite electrode (EGE) lost 1% capacity in 25 cycles with a charge/discharge current of 0.2 C, but the capacity of a conventional graphite electrode (CGE) decreased 33%. Formation of metallic copper lowered drastically the charge-transfer resistance of the EGE, which favors a good C-rate discharge for the electrode. At a charge/discharge current of 0.5 C, the capacity of the EGE was 220 mAh/g, which is twice as large as the 100 mAh/g of the CGE. The anodic EPD is a good technique to prepare a graphite electrode.