[1Gp01-06] Thin Film (TF)

[1Gp04] Compositionally-graded epitaxial thin films of La-doped LiCoO₂ for lithium-ion secondary batteries

*Kenichi Kaminaga¹, Kanta Suzuki¹, Daigo Nanasawa², Shintaro Yasui², Shingo Maruyama¹, Yuji Matsumoto¹ (1. Department of Applied Chemistry, Tohoku University, 2. Laboratory for Materials and Structures, Tokyo Institute of Technology)

A lithium-ion cathode material, LiCoO₂ (LCO) has been demonstrated to enhance battery performance through partial substitution of Co³⁺ with heavy metal elements. Also, the attention in this research field has recently shifted towards possible further improvements in the battery performance through the doping concentration continuously varied, e.g., from the center to the surface of a cathode, known as “compositionally-graded materials”. However, both these previous attempts were made only with polycrystalline materials that inevitably included grain boundaries and polymorphism. In this study, we report on the respective effects of La doping and its compositionally-graded structure on the battery performance of LCO in the epitaxial thin film form.