Effect of Side-Plane Width on Lithium-Ion Transportation in Additive-Free LiCoO2 Crystal Layer-Based Cathodes for Rechargeable Lithium-Ion Batteries

Abstract

Rechargeable lithium-ion batteries (LIBs) with improved performance, including higher power, higher energy density, and superior cycling performance, are in demand for highly specialized applications. The design and synthesis of cathode materials with effective shapes surrounded by suitable faces for Li-ion transportation are essential for high-performance LIBs. In the present work, we address the effects of side-plane width on the Li-ion diffusion coefficient and charge transfer resistance of additive-free LiCoO2 electrodes composed of highly controlled crystals with exposed {101}, {012}, and {104} faces. The changes in the shape and order of orientation in the LiCoO2 crystals were evaluated using electron microscopic observations and X-ray diffraction measurements. The discharge capacity drastically increased from 87.9 to 131.5 mA·h·g–1 on increasing the width of the side plane in the LiCoO2 crystal from ca. 11 to ca. 59 nm. Further, electrochemical impedance spectroscopy revealed that the Li-ion diffus...