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 Li_xCoO₂ (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 ⁷Li and ²⁷Al magic angle spinning (MAS) NMR spectra are simulated to determine the quadrupole coupling constant (C_Q) and the asymmetric parameter (η) of each atomic sites. The structural states of lithium and aluminum in those samples were successfully identified by them.