ABSTRACT
LiNi0.6Co0.2Mn0.2O2 cathode materials were surface-modified by coating with a dual conductive poly(3,4-ethylenedioxythiophene)-co-poly(ethylene glycol) (PEDOT-co-PEG) copolymer, and their resulting electrochemical properties were investigated. The surface-modified LiNi0.6Co0.2Mn0.2O2 cathode material exhibited a high discharge capacity and good high rate performance due to enhanced transport of Li(+) ions as well as electrons. The presence of a protective conducting polymer layer formed on the cathode also suppressed the growth of a resistive layer and inhibited the dissolution of transition metals from the active cathode materials, which resulted in more stable cycling characteristics than the pristine LiNi0.6Co0.2Mn0.2O2 cathode material at 55 (o)C.
ABSTRACT
Spinel LiMn1.5Ni0.5O4 materials with different morphologies were prepared by solid-state reaction method using nano-sized Mn-Ni-O precursor powders. The effect of annealing temperature on the physical properties and electrochemical performance of the LiMn1.5Ni0.5O4 cathode materials was investigated. As the annealing temperature was increased from 700 to 1000 degrees C, the particle size distinctly increased. The nano-sized LiMn1.5Ni0.5O4 powder obtained at 800 degrees C exhibited a high initial discharge capacity of 130 mA h g(-1) and good rate capability. The LiMn1.5Ni0.5O4 material annealed at higher temperature (1000 degrees C) exhibited good cycling stability.
