Effects of Zirconium Substitution on Electrochemical Performance of Li(Ni0.9C0.05Al0.05)O-2 for Lithium-Ion Batteries

Spherical precursor Ni0.9Co0.05Al0.03Zr0.02(OH)(2) was obtained by controlled crystallization method. A uniform mixture of Ni0.9Co0.05Al0.03Zr0.02(OH)(2) and LiOH center dot H2O was sintered under 750 degrees C in O-2 atmosphere to synthesize layered Li(Ni0.9Co0.05Al0.03Zr0.02)O-2 cathode material. SEM images show that the precursor and cathode material have well morphology. XRD patterns show that the product possesse a well-layered alpha-NaFeO2 structure. EDXS images show the Zr element in the material is distributed evenly. The cells with the material as cathode display excellent electrochemical performance: an initial discharge capacity of 221.5 mAh.g(-1) at 0.2C between 2.8 and 4.3 V with an initial coulombic efficiency of 90.3%, a discharge capacity of 192.7 mAh.g(-1) at 2C and a capacity retention rate of 92.2% after 100 cycles at 25 degrees C. As the temperature raised to 55 degrees C, the discharge capacity was 236.2 mAh.g(-1) at 0.2C in 2.8 similar to 4.3 V, and retained a capacity retention rate of 85.1% after 100 cycles at 2C.