Molten Salt Synthesis of Multi-Faceted Pure-Phase Spinel LiNi0.5Mn1.5O4 Platelets

The spinel LiNi0.5Mn1.5O4 is largely studied as a positive electrode material for lithium-ion batteries, but further optimization of its properties are required to enable its commercialization. The superior electrochemical performance of the disordered polymorph of LiNi0.5Mn1.5O4 is limited by its traditional method of synthesis. This solid-state route generates impurities that reduce specific capacity and results in the formation of octahedral particles with exposed {111} facets, thus limiting explo-ration of the effects of surface orientation. In this work, we report for the first time the preparation of a disordered impurity-free LiNi0.5Mn1.5O4 with platelet-like morphology via molten salt synthesis. We discovered that these platelets exhibit multi-ple surface orientations, including {111}, {112} and six other high-indexed facets, and deliver equivalent energy storage performance to their octahedral counterpart. Such ability to tune primary particle morphology and orientation will open the gate to investigate mechanisms at the individual particle level using spectroscopy and microscopy techniques.