Solid State Ionics, Vol.130, No.3-4, 221-228, 2000
Phase segregation of LixMn2O4 (0.6 < x < 1) in non-equilibrium reduction processes
Chemical synthesis routes to LixMn2O4 (0.15 less than or equal to x less than or equal to 1) in non-equilibrium reduction processes were developed to carry out detailed structural analysis. Non-equilibrium LixMn2O4 (0.15 less than or equal to x less than or equal to 1) samples were prepared by chemical lithiation of lambda-MnO2 with LiI for 24 h; longer than 1 week was needed to reach true equilibrium at room temperature. The samples were characterized by X-ray diffraction analysis. The phase diagram was different from that in the equilibrium state; three cubic phases (phases A, B and C) were observed for LixMn2O4 (0.15 less than or equal to x less than or equal to 1). There were two regions of two-phase coexistence: the region of 0.25 < x < 0.55 (phase B + phase C) and 0.6 < x < 1.0 (phase A + phase B). In the compositional range of 0.6