Microwave-assisted hydrothermal synthesis of a high-voltage microcube LiMn1.5Ni0.5O4-8 spinel cathode material

Abstract

Electric vehicles (EVs) require high operating voltages as well as high-capacity batteries. One candidate material that has received a great deal of attention is the nickel-substituted "high-voltage" spinel LiMn1.5Ni0.5O4, which offers the advantages of both higher capacity and higher operating voltage than spinel LiMn2O4. These features, along with the relatively benign constituent elements, have made this material a top choice for the next generation of high-power batteries. In this study, LiMn1.5Ni0.5O4-8 materials were synthesized by a microwave-assisted hydrothermal method. Analyses show that microwave irradiation enables the tuning of the Mn3+ concentration, which is related to the degree of disorder and enhances the electrochemical performance. However, with increasing synthesis time, the material limit of the elastic strain was exceeded, and the structure became morphologically unstable, which deteriorated the electrochemical performance. Thus, further efforts are necessary to improve its intrinsic stability. The LiMn1.5Ni0.5O4-8 cathode active material may be suitable for the rapid charging of electric vehicle batteries.