THE LINIO2 SOLID-SOLUTION AS A CATHODE MATERIAL FOR RECHARGEABLE LITHIUM BATTERIES

Samples of LixNi2-xO2 (0.91 < x < 0.99), synthesized by the solid-state reaction between LINO(3) and Ni(OH)(2) were characterized by X-ray diffraction, chemical analyses and electrochemical tests. A good correlation is found between x and the Bragg intensity ratios R((102)) = {I-(102) + I-(106)}/I-(101) and R((003)) = I-(003)/I-(104). The electrochemical activity of the sample as exhibited by the discharge capacity in the first cycle is a function of x with a maximum at x = 0.97-0.98. The discharge capacity of the optimized sample at a 7 h rate is strongly dependent on the end charge voltage in the range from 4.1 to 4.3 V and reaches a 220 mAh/g at U-(max.) = 4.45 V. The cycling stability after the first five to eight cycles is 99.88%, i.e., a capacity loss of only 0.12% per cycle.