The production of LiCoO2 cathode thick films for an all-solid-state microbattery

초록

Crack-free LiCoO2 films with a thickness more than 10 mu m have been prepared by a sol-gel derived screen-printing process, using two different-sized LiCoO2 powders (mean particle sizes: 6 mu m and 0.8 mu m). The slurry as a coating medium consists of LiCoO2 powders and a LiCoO2 SOl-gel precursor solution, which gives a well-dispersed slurry with high powder content. The slurry is screen-printed onto a Pt-coated alumina and annealed at relatively low temperatures as in a conventional sol-gel process. The feasibility of applying the fabricated films as cathodes for lithium rechargeable batteries is demonstrated. No obvious cracking after cycling was observed. Excellent cyclability was obtained. The films prepared using fine grain powders are less porous than those made from large grain powders, which lead to a better Coulombic efficiency for electrodes using the former. It is suggested that the novel process is promising for fabricating LiCoO2 thick films for potential applications in all-solid-state rechargeable lithium batteries.

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