Probing Al Distribution in LiCoAlO Materials Using Li, Al, and Co MAS NMR Combined with Synchrotron X-ray Diffraction.

We prepared Al-doped LCO (LCA) powders with low Al content (4%) with a controlled Li/(Co + Al) stoichiometry by a solid-state reaction using LiCO and two types of Co/Al precursors: simply mixed (CoO and AlO) or heat-treated (CoO and AlO). These samples were thereby used to propose a reliable protocol with the aim to discuss the homogeneity of the Al doping for LiCoAlO (LCA) prepared with low Al content by evidencing the distribution of Al within the powders, which clearly affects the electrochemical profiles of associated LCA//Li cells. For all samples we initially also characterized the Li/(Co + Al) stoichiometry by Li MAS NMR, to discard the possible effect of excess Li in the samples.

Influence of the Initial Li/Co Ratio in LiCoO on the High-Voltage Phase-Transitions Mechanisms.

The influence of the initial Li/Co stoichiometry in LiCoO (LCO) (1.00 ≤ Li/Co ≤ 1.05) on the phase-transition mechanisms occurring at high voltage during lithium deintercalation ( V > 4.