Spinel LiMn2-xNixO4 cathode materials for high energy density lithium ion rechargeable batteries

The practical limitations of fully lithium ion insertion and extraction into LiMn2O4 cathode structure without any structural instability make it unsuitable in commercial Li-ion rechargeable batteries. In this work, we showed that those partially substituted by Ni, i.e., LiMn2-xNixO4 (0 <= x <= 0.5), prepared by sol-gel technique, could be used as a potential candidate for high energy density and high voltage Li-ion battery applications with superior rate capabilities. The improved structural stability of the cathode was probed by x-ray diffraction and micro-Raman spectroscopy. The density-functional theoretical calculations were employed to identify the minimum energy needed for Li+ diffusion pathway and activation energy in the spinel framework with different Ni ion concentrations. Our results showed significant enhancement in the properties with 25 at. % of Ni solid-solution doping in LiMn2O4 host and the experimental results are in line with the theoretical computations. (C) 2009 American Institute of Phyics. [DOI: 10.1063/1.3103483]