Solid-state NMR studies of modified LiCoO2 as cathodes of lithium rechargeable battery

As a cathode material for commercial lithium rechargeable battery, layered lithium cobalt oxide, LiCoO2, is the most attractive cathode material due to its high specific capacity, high operating cell voltage, and excellent recycleability. To understand the local environment by modification of LiCoO2, diverse LiCoO2 materials, such as LixCoO2 (X = 1.0, 1.05, and 1.1), and Al-doped and Al2O3-coated LiCoO2, have been studied by solid-state NMR techniques. Herein, observed Li-7 and Al-27 magic angle spinning (MAS) NMR spectra are simulated to determine the quadrupole coupling constant (CQ) and the asymmetric parameter (eta) of each atomic sites. The structural states of lithium and aluminum in those samples were successfully identified by them.