T. Ohzuku et al., Comparative study of solid-state redox reactions of LiCo1/4Ni3/4O2 and LiAl1/4Ni3/4O2 for lithium-ion batteries, ELECTR ACT, 45(1-2), 1999, pp. 151-160
Comparative study of the solid-state redox reactions of LiCo1/4Ni3/4O2 and
LiAl1/4Ni3/4O2 was carried out by XRD and electrochemical methods. XRD exam
inations indicated that the reactions proceeded in single phase for both sa
mples. The change in interlayer distance between MeO2-sheets for LiCO1/4Ni3
/4O2 or LiAl1/4Ni3/4O2 was almost the same as that for LiNiO2 in the region
0 < x 1 3/4 in Li1-xMeO2 (Me=Ni, Co1/4Ni3/4, Or Al1/4Ni3/4) Reversible pot
entials as a function of x were measured and the solid-state redox reaction
s involving in the lithium insertion reactions were characterized by using
simple equations to describe the redox potentials. According to our results
, substitution of aluminum for nickel in LiNiO2 raised the levels of solid-
state redox potentials primarily derived from nickel species by about 0.1 V
, while the substitution of cobalt did not affect the solid-state redox pot
entials in that range. Differences and similarities between the solid-state
electrochemical reactions of LiCo1/4Ni3/4O2 and LiAl1/4Ni3/4O2 were discus
sed therefrom. (C) 1999 Elsevier Science Ltd. All rights reserved.