Nanosized octahedral LiNi0.5Mn1.5O4 with predominant (111) facet as high performance cathode for Lithium-ion batteries

Abstract Nanosized octahedral LiNi0.5Mn1.5O4 with predominant (111) facet has been successfully fabricated using Mn3O4 nanoparticles precursors via a two-step synthesis, which involves a hydrothermal treatment and the subsequent calcination. The physical properties of the Mn3O4 precursor and the resultant LiNi0.5Mn1.5O4 were characterized by XRD (X-ray diffraction), TEM (transmission electron microscopy) and SEM (scanning electron microscopy). The charge-discharge tests show that the resultant LiNi0.5Mn1.5O4 exhibits excellent cyclability and rate capability, which delivers a discharge capacity of about 117 mAh g− 1 after 300 cycles, and maintains 94% of its initial discharge capacity (124.7 mAh g− 1) at 1C, even at a rate of 40C, a specific capacity of 99.2 mAh g− 1 could be still obtained for the O-LNMO. The superior electrochemical performance of the LNMO is mainly attributed to the synergistic effect of the nanosized octahedral structure and exposed (111) facets of the prepared LiNi0.5Mn1.5O4. We found that the nanosized octahedral structure can not only accommodate the lattice stress caused by John-Teller distortion but also provide short paths for Li+ ion transportation in the material. Additionally, the obtained predominant (111) facet is helpful to the formation of protective SEI film on the spinel LiNi0.5Mn1.5O4 electrode.