The influence of mechanical activation on the synthesis, structure and electrochemical performance of LiNiO2 and LiNi1-xCoxO2

The influence of mechanical activation (MA) and initial reagents on the synthesis, structure and electrochemical performance of LiNiO₂, LiNi_1-xAl_xO₂, LiNi_1-yСо_yO₂ and LiNi_1-y-xCo_yAl_xO₂ (y = 0.2; 0.3; x = 0.05) was studied. NiO, α- and β-modification of hydroxides Ni(OH)₂ и Ni_1-y, as well as LiOH и Li₂CO₃ were used. It was established that the multistep interaction in nonactivated mixture of hydroxides occurs, including the dehydration of Ni(OH)2 to form NiO and the melting of LiOH, while in the activated mixture the final product is formed at lower temperatures in solid phase. Comparison of the influence of different reagents on the phase homogeneity and stoichiometry of LiNiO₂ showed that the best results are obtained when using lithium and nickel hydroxides, especially α-Ni(OH)₂. Precursor effect is not so strong for LiNi_1-yCo_yO₂. Cycling studies show the positive influence of MA on the properties of the cathode materials.