Microstructure and cycling behavior of LiAl0.1Mn1.9O4 cathode for lithium secondary batteries at 3 V

LiAl0.1Mn1.9O4 is synthesized using three different Mn-precursors through solid-state sintering. Although the powder structures of LiAl0.1Mn1.9O4 appear to be identical when examined by powder X-ray diffraction (XRD) analysis, the reversible capacity ranges from 50 to 120 mAh g−1, depending on the Mn-precursor, when cycled from 2.2 to 3.6 V. Transmission electron microscopy (TEM) structural analysis shows that there are subtle differences among the microstructures of the as-prepared powders. Although all three powders exhibit capacity fade, typical of the spinel material at 3 V, it is found that the particle size and morphology, as well as the structural difference, play an important role in improving or further degrading the cycling behavior of the spinel material.