The surface modification with Li2O-2B2O3 glass is introduced into LiNi0.5Co0.2Mn0.3O2 cathode materials in a bid to improve the high voltage electrochemical and thermal properties for the first time. X-ray diffraction, scanning electron microscopy, transmission electron microscope and X-ray photoelectron spectroscopy results show that the Li2O-2B2O3 glass is successfully coated on the surface of LiNi0.5Co0.2Mn0.3O2. It has been found that the electrochemical performances and thermal stability of LiNi0.5Co0.2Mn0.3O2 are obviously improved after Li2O-2B2O3 glass modification. Notably, the 2 wt.% Li2O-2B2O3 coated sample provides a high capacity retention of 90.1% after 100 repeated cycles, compared with 72.3% for the bare one. The outstanding high voltage electrochemical performance and thermal stability of the coated materials are related to the fact that the multifunctional Li2O-2B2O3 coating layer, which can not only isolate the bulk LiNi0.5Co0.2Mn0.3O2 from direct contact with the electrolyte, but also facilitate the diffusion of lithium ions as well as diminish charge transfer impedance of the cell.