In Situ Formed Core-Shell LiZn x Mn 2- x O 4 @ZnMn 2 O 4 as Cathode for Li-Ion Batteries.

Elemental doping and surface modification are commonly used strategies for improving the electrochemical performance of LiMnO, such as the rated capacity and cycling stability. In this study, in situ formed core-shell LiZnMnO@ZnMnO cathodes are prepared by tuning the Zn-doping content. Through comprehensive microstructural analyses by the spherical aberration-corrected scanning transmission microscopy (Cs-STEM) technique, we shed light on the correlation between the microstructural configuration and the electrochemical performance of Zn-doped LiMnO. We demonstrate that part of Zn ions dope into the spinel to form LiZnMnO in bulk and other Zn ions occupy the 8a sites of the spinel to form the ZnMnO shell on the outermost surface. This in situ formed core-shell LiZnMnO@ZnMnO contributes to better structural stabilization, presenting a superior capacity retention ratio of 95.8% after 700 cycles at 5 C at 25 °C for the optimized sample (LiZnMnO), with an initial value of 80 mAh g. Our investigations not only provide an effective way toward high-performance LIBs but also shed light on the fundamental interplay between the microstructural configuration and the electrochemical performance of Zn-doped spinel LiMnO.