Acta Phys. -Chim. Sin. ›› 2007, Vol. 23 ›› Issue (Supp): 40-45.doi: 10.3866/PKU.WHXB2007Supp10

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Synthesis and Properties of Layered LiNi0.8Co0.2-xMgxO2 Cathode Material

HOU Xian-Quan; JIANG Wei-Jun; QI Lu; HAN Li-Juan   

  1. CITIC Guoan Mengguli New Engery Technology Co. Ltd., Beijing 102200, P. R. China; New Energy Material and Technology Laboratory, Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
  • Received:1900-01-01 Revised:1900-01-01 Published:2008-01-04
  • Contact: QI Lu E-mail:qilu@pku.edu.cn

Abstract: LiNi0.8Co0.2-xMgxO2 (x=0.02, 0.03, 0.04) cathode materials were synthesized by co-precipitation method. The materials were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetry (TG), and differential scanning calorimetry (DSC). The results showed that the spherical products, without impurities, had a typical α-NaFeO2 layered structure. In the range of 3.0-4.3 V, at 0.5 mA·cm-2 of the current density, the first specific capacity was 184.8 mAh·g-1. After 50 cycles, the capacity retention was 94.2%. The DSC result showed that after the doping with Mg2+, the phase transition of LiNi0.8Co0.2-xMgxO2 was inhibited without distinct capacity fall. At the same time, the stability and cycling character was improved obviously.

Key words: Lithiumion secondary battery, Cathode material, High capacity, Doping