Improved solid interfacial kinetics and electrochemical performance for LiCoO2(1 1 0) textured thin-film lithium batteries

Abstract

The solid-solid interfaces have crucial, but still poorly understood, roles in the performance of thin-film lithium batteries (TFBs). The modulating of crystalline preferred growth orientation is an effective method to build rapid ionic diffusion channel with lower interfacial barrier. This work develops and reveals the interfacial electrochemical behaviors of textured cathode/solid electrolyte in TFBs by controlling preferred growth orientation of LiCoO2 (LCO) thin-film. The LCO(003) texture is transformed from the (440) plane of Co3O4 precursor with the lowest surface energy after annealing. Remarkably, oxygen reactive sputtering will promote the formation of LCO grains instead of Co3O4 species, resulting in the growth of LCO along (110) facet with the lowest volume strain-energy after annealing. TFBs (LCO/LiPON/Li) configuration with LCO(110) texture exhibit enhanced electrochemical performance with the capacity of about 101 mAh g−1 about twice than that of (003) texture on 10C-rates, owing to the lower interface and bulk resistance. These results indicate that the method of controlling the lattice orientation not only minimize the lithium-ion diffusion pathways in the film textures, but also is beneficial to the interface between LCO and LiPON electrolyte to establish high performance solid-state batteries.