Laser-Printed and Processed LiCoO2 CathodeThick Films for Li-Ion Microbatteries

Thick-film electrodes (LiCoO2 cathode and carbon anode) are laser-printed onto metallic current collectors for fabricating Li-ion microbatteries. Microbatteries fabricated with these laser-printed thick-film electrodes demonstrate a significantly higher discharge capacity and power density than those made by sputter-deposited thin-film techniques. This increased performance is attributed to the porous structure of the laser-printed electrodes that allows improved ionic and electronic transport through the thick electrodes (up to ~100 µm) without a significant increase in internal resistance. Laser structuring process is applied to increase active surface area of the laser-printed LiCoO2 cathode films for improving cycle stability of microbatteries at high charging/discharging currents. Laser structuring parameters, including laser pulse number and laser fluence, are optimized for improving surface morphology of the films.