LiCoO 2 thin film cathode fabricated by pulsed laser deposition

LiCoO 2 polycrystalline thin film cathode was prepared by pulsed laser deposition (PLD). The higher power density of the excimer laser beam leads to the film consisting of highly crystallized cylindrical nanoparticles. Furthermore, the film thickness plays an important role on the film orientation as well as the diameter of the oxide cylinders. The film orientation was not fixed with (003) plane parallel to the substrate while the thickness was up to 300 nm. Meanwhile, the diameter of part of the cylindrical particles was increased due to a preferred growth induced by a driving force changing from surface energy to volume strain energy. The electrochemical tests indicate that flat charge/discharge plateaus corresponding to the first‐order phase transition appear at around 3.85 V vs. Li/Li + , resulting in high utilization of the active material and good capability retention.