SYNTHESIS AND PROPERTIES OF LINIO2 AS CATHODE MATERIAL FOR SECONDARY BATTERIES

The optimum preparation condition and electrochemical properties of Li NiO2, as the cathode material for lithium secondary batteries were inv estigated. LiNiO2 samples were prepared from Li(OH)(2) . H2O and Ni(OH )(2) in the range from 500 to 900 degrees C. The compound prepared in an oxygen atmosphere at 700 degrees C exhibited the highest discharge capacity of 200 mAh/g in the voltage range from 3.0 to 4.3 V. The stru cture and charge-transfer resistance of the Li1-xNiO2 compound were ex amined at each state-of-charge by X-ray diffractometry and a.c. impeda nce spectroscopy. The charge-transfer resistances were low in the rang e of 0.15 <x<0.75, which was related to the expansion of the interlaye r distance between NiO2 layers.