Effect of Dopants on the Functional Properties of Lithium-Rich Cathode Materials for Lithium-Ion Batteries
L. S. Pechen, Е. В. Махонина, A. А. Medvedeva, А. М. Rumyantsev, Yury Koshtyal, Yu. А. Politov, Alexander S. Goloveshkin, И.Л. Еременко
Abstract
A comparative study was made of the effect of the dopant nature on the electrochemical performance of lithium-rich oxides of the general composition 0.5Li2MnO3⋅0.5LiMn0.33Ni0.33Co0.31M0.02O2 (M = Mg, Cr, Zr). The obtained materials were tested as cathodes in CR2032 coin-type cells versus lithium metal. The results of the study attested to the fact that the main role in the degradation of the material is played by the migration of transition metals, which depends on the dopant-oxygen binding energy. The doping with magnesium suppresses the phase transition, thus stabilizing the oxide structure. By the 110th cycle in the voltage range of 2.5–4.8 V at a current of 100 mA/g, the sample doped with magnesium retains 10% more specific energy than the initial oxide.