Enhanced cycling stability of La modified LiNi0.8-xCo0.1Mn0.1LaxO2 for Li-ion battery
(School of Metallurgy and Environment, Central South University, Changsha 410083, China)
Abstract: A series of layered LiNi0.8-xCo0.1Mn0.1LaxO2 (x=0, 0.01, 0.03) cathode materials were synthesized by combining co-precipitation and high temperature solid state reaction to investigate the effect of La-doping on LiNi0.8Co0.1Mn0.1O2. A new phase La2Li0.5Co0.5O4 was observed by XRD, and the content of the new phase could be determined by Retiveld refinement and calculation. The cycle stability of the material is obviously increased from 74.3% to 95.2% after La-doping, while the initial capacity exhibits a decline trend from 202 mA·h/g to 192 mA·h/g. The enhanced cycle stability comes from both of the decrease of impurity and the protection of newly formed La2Li0.5Co0.5O4, which prevents the electrolytic corrosion to the active material. The CV measurement confirms that La-doped material exhibits better reversibility compared with the pristine material.
Key words: nickel-rich cathode material; La-doping; electrochemical property; cycle stability; Li-ion diffusion coefficient