Electrochemical and Structural Properties of xLi2M‘O3·(1−x)LiMn0.5Ni0.5O2 Electrodes for Lithium Batteries (M‘ = Ti, Mn, Zr; 0 ≤ x ⩽ 0.3)

Authors: Jeom-Soo Kim, Christopher S. Johnson, John T. Vaughey, Michael M. Thackeray, Stephen A. Hackney, Won‐Sub Yoon, Clare P. Grey - Chemistry of Materials 2004 cited by 505

Electrochemical and structural properties of x Li 2 M‘O 3 ·(1− x )LiMn 0.5 Ni 0.5 O 2 electrodes (M‘ = Ti, Mn, Zr; 0 ≤ x ≤ 0.3) for lithium batteries are reported. Powder X-ray diffraction, lattice imaging by transmission electron microscopy, and nuclear magnetic resonance spectroscopy provide evidence that, for M‘ = Ti and Mn, the Li 2 M‘O 3 component is structurally integrated into the LiMn 0.5 Ni 0.5 O 2 component to yield “composite” structures with domains having short-range order, rather than true solid solutions in which the cations are uniformly distributed within discrete layers. Li 2 TiO 3 and Li 2 ZrO 3 components are electrochemically inactive, whereas electrochemical activity can be induced into the Li 2 MnO 3 component above 4.3 V vs Li 0 . When cycled in lithium cells, x Li 2 MnO 3 ·(1− x )LiMn 0.5 Ni 0.5 O 2 electrodes with x = 0.3 provide capacities in excess of 300 mA·h/g over the range 4.6−1.45 V.