Abstract
LiNi0.6Mn0.2Co0.2O2 is one of the most promising positive electrode material for Li-ion batteries. Platelet-shaped particles of 17 nm and 86 nm thickness were obtained, with the required composition and a structure close to the ideal 2D layered structure (less than 5.2% Ni2+ ions in Li+ sites). The electrochemical performances and surface reactivity of the materials were characterized in Li-ion batteries and compared to that of 280 nm particles with a more conventional morphology. Post-cycling analyses revealed a particular reactivity at high potential for the platelets compared to the conventional particles. X-Ray photoelectron spectroscopy and ex situ XRD analyses were performed to characterize the composition of the positive electrode/electrolyte interface and the structural changes undergone by the three materials upon cycling respectively. This study showed that, as well as the particles’ composition, their morphology plays a significant role regarding the reactivity and the structural changes occurring during cycling at high potential.