Operando XRD study of LiMn1.5Ni0.5O4 high-voltage cathode under high-rate charge-discharge reaction.

Autor: Konya, T., Shiramata, Y., Nakamura, T.
Zdroj: Powder Diffraction; Supplement2019, Vol. 34, pS8-S13, 6p
Abstrakt: Structural variation of LiMn1.5Ni0.5O4 spinel cathode during the Li+ extraction/insertion reaction was studied using operando X-ray diffraction. It was found that the reaction in the voltage range from 3.5 to 4.9 V consisted of two consecutive two-phase reactions, where three spinel phases of LiMn1.5Ni0.5O4, Li0.5Mn1.5Ni0.5O4 and Mn1.5Ni0.5O4 were identified and the lattice volume change in the whole reaction was evaluated as 6%. The reactions were symmetric and reversible under low-current conditions, but some asymmetries were detected during high current operation. Furthermore, a two-phase reaction between cubic and tetragonal phases was observed in the low-voltage reaction at 2.1–3.5 V, where the lattice volume change was approximately 4.9%. The rate-determining step was discussed based on these operando results. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index