Fabrication of high electrochemical performance ternary lithium battery using LiNi0.8Co0.1Mn0.1O2 with nano-TiO2 coating

Abstract

With the increase of nickel content and the reduction of cobalt content in the ternary materials, LiNi_0.8Co_0.1Mn_0.1O₂ (NCM 811) meets the challenges in poor cycle stability and reduced safety. To address these problems, the coating method is considered as a promising technology to improve the performance of the ternary material. In the current work, NCM811 cathode materials coated with nano-TiO₂ are synthesized by using oxalic acid co-precipitation and wet coating with anhydrous ethanol methods. Then, the properties of our prepared ternary cathode material with different coating amounts have been investigated. We found that the nano-TiO₂-coated method can weaken the agglomeration phenomenon and particle dispersion in the preparation process, resulting in an improved reversibility of the redox reaction, reduced impedance and stable cycle performance of the battery. When the amount of coated nano-TiO₂ is equal to 1.5%, the best battery performances (the redox peak difference of 0.083 V and the coulomb efficiency in the first cycle of 95.98%) are obtained among all coating strategies. After cycling, a large particle size of the cathode material will accelerate the agglomeration phenomenon, resulting in a reduction of cycling performance. This work is in favor of supporting the electrode design of lithium battery.