Lattice Mn³⁺Behaviors in Li₄Ti₅O₁₂/LiNi_0.5Mn_1.5O₄Full Cells

High voltage spinels LiNi 0.5 Mn 1.5 O 4 (LNMO) with different contents of residual lattice Mn 3+ have been evaluated in full cells using Li 4 Ti 5 O 12 (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 Mn 3+ are more easily exemplified in the Li + deficient environment and superior electrochemical performance are observed for spinel with higher content of lattice Mn 3+ .