Lattice Mn3+ Behaviors in Li4Ti5O12/LiNi0.5Mn1.5O4 Full Cells

High voltage spinels LiNi0.5Mn1.5O4 (LNMO) with different contents of residual lattice Mn3+ have been evaluated in full cells using Li4Ti5O12 (LTO) as anode. Greatly improved cycling stability has been observed for all spinels in LTO-limited full cell, compared with those in LNMO-limited ones, while the underlying mechanisms are quite different. Shallow cycling of LNMO in LTO-limited cells does not require complete transition to the third cubic phase, reducing the phase boundaries that Li+ has to overcome and thus improving the cell performances. However, in LNMO-limited cells, influences of lattice Mn3+ are more easily exemplified in the Li+ deficient environment and superior electrochemical performance are observed for spinel with higher content of lattice Mn3+. (C) 2013 The Electrochemical Society.