화학공학소재연구정보센터
Journal of Power Sources, Vol.112, No.2, 557-561, 2002
Anomalous step at x(center dot)=(center dot)0.7 in potential-composition profiles of LixCryMn2-yO4 spinels at low temperature
In order to investigate the relation between spinel type structure and anomaly in potential-composition profile of stoichiometric LiMn2O4 spinel at low temperature (T less than or equal to 278 K), several LiCryMn2-yO4 type spinels (y = 0.01-0.25) have been synthesized by conventional solid-state reaction and their potential-composition (phi-x; LixCryMn2-yO4) profiles at 273 K have been recorded. The phi-x profiles of the specimens (y = 0.01-0.03) show an anomalous stepwise feature as one that stoichiometric LiMn2O4 shows at low temperature. However, the step at x = 0.7 becomes weak with increase of the value y, and finally disappears. In the specimens, Mn and Cr are considered to occupy only 16d sites of spinel type structure. As compared with the phi-x profiles of lithium-excess type spinels Li1-deltaMn2-deltaO4 and lithium-deficient type spinels Li1-deltaMn2O4, the gradual result suggests that state of Mn lattice strongly affects the appearance of anomalous step at x = 0.7.