Microstructure and electrochemical performances of
LiF-coated spinel LiMn2O4
LiF-coated spinel LiMn2O4
(1. School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing 100081, China;
2. National Development Center for High Technology Green Materials, Beijing 100081, China)
2. National Development Center for High Technology Green Materials, Beijing 100081, China)
Abstract: LiF-coated LiMn2O4 samples were prepared via a chemical method. X-ray diffraction (XRD) patterns show that the bare LiMn2O4 and the LiF-coated LiMn2O4 samples are all spinel structure in space group. The apparent morphologies, the spectroscopic properties and the LiF distributions of the as-prepared samples were studied by scanning electronic microscopy (SEM), Fourier infrared spectroscopy (FTIR), transmission electronic microscopy (TEM), selected area electron diffractometry (SAED) respectively. The LiF-coated LiMn2O4 gets a more stable surface than bare LiMn2O4, and changes the interaction between the cathode material and the electrolyte. Therefore, it can endure overcharge in the secondary lithium batteries, and achieve better electrochemical performances even when charged to 4.7 V and 4.9 V.
Key words: spinel LiMn2O4; secondary lithium batteries; surface modification; LiF-coating