Morphological evolution and surface orientation effects of nickel manganese oxide in the preparation of LNMO cathode material

Abstract

The study investigated the evolution of LNMO (LiNi0.5Mn1.5O4) morphology and surface orientation as a function of increasing temperature. The results show that at an initial calcination temperature of 750 °C, LNMO exhibits spherical polyhedral with (111), (110), and (100) facets and relatively small particle sizes. In response to increasing temperatures, the particle size increases, the number of crystal facets decreases, and the material ultimately transitions to a typical spinel structure. Notably, the LNMO material calcined at 750 °C demonstrates a high lithium-ion migration rate, retaining 81.24% of its capacity after 500 cycles at a 2 C rate. This exceptional performance is attributed to the exposure of multiple crystal facets, suitable particle size, and the presence of Mn³⁺, which collectively stabilize the crystal structure and provide suitable pathways for Li⁺ transport.