Effects of Li2O2 on structure and electrochemical properties of LiNi0.88Co0.09Al0.03O2 cathode materials

Abstract

Lithium nickel cobalt aluminate single crystal can sustain the high voltage mode operation to achieve high energy density. In this work, we have firstly discussed the effects of LiOH and Li2O2 on preparing the polycrystals and single crystals of LiNi0.88Co0.09Al0.03O2 (NCA) cathode material in detail. Based on serials of characterization such as XRD, SEM and electrochemical tests, the results show that LiNi0.88Co0.09Al0.03O2 cathodes prepared by using the Li2O2 exhibit reduced electrochemical polarization and enhanced long-term stability. Notably, the electrochemical properties of single crystals for LiNi0.88Co0.09Al0.03O2 prepared by using Li2O2 display an initial discharge capacity of 213.6 mAh/g, an optimized cycle retention of 91.1% after 100 cycles in a voltage range of 3.0–4.4 V. The strategies employed in this work demonstrate that the usage of Li2O2 can greatly improve the electrochemical performances of NCA cathode material whether in polycrystal or single crystals forms, finally providing a new way to realize a mileage breakthrough.