Electrochemical properties of LiCoO_2 thin film electrode prepared by ink-jet printing technique

摘要

LiCoO_2 thin film electrodes with a thickness of about 1.2 μm were fabricated by an improved ink-jet printing method. LiCoO_2 powder was synthesized via a modified sol-gel method. The LiCoO_2 ink could be easily prepared by an ultrasonic dispersion technique using a commercially available surfactant. The jet printing LiCoO_2 thin films were characterized by X-ray diffraction and Raman spectroscopy, scanning electron microscopy, cyclic voltammetry, charge/discharge cycling and electrochemical impedance spectroscopy. Experimental results showed that the LiCoO_2 thin film electrodes present excellent cycling performance at high discharge rate. At discharge current density of 180 μA/cm~2 (at this current density, the battery can be fully discharged in 12 min), the initial discharge capacity was 120 mAh/g, and after 100 charge-discharge cycles, the capacity loss was only 5%. It can be even charge-discharged at the current density as high as 384 μA/cm~2.