Surface modification of Li-rich layered Li[Li0.17Ni0.17Co0.10Mn0.56]O-2 oxide with LiV3O8 as a cathode material for Li-ion batteries

摘要

A Li-rich layered oxide Li[Li0.17Ni0.17Co0.10Mn0.56]O-2 is synthesized by a chemical deposition method. The surface modification with the LiV3O8 is introduced onto Li-rich layered Li[Li0.17Ni0.17Co0.10Mn0.56]O-2 oxide for the first time. The pristine and LiV3O8-coated Li[Li0.17Ni0.17Co0.10Mn0.56]O-2 cathode materials are investigated by X-ray diffraction (XRD), Special surface area analysis (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM), electrochemical measurement and charge-discharge testing techniques. After coating of LiV3O8, the bulk crystallographic structure, morphology and grain size of the layered Li[Li0.17Ni0.17Co0.10Mn0.56]O-2 are not essentially changed. Compared to the pristine sample, electrochemical performance of LiV3O8-coated samples has been obviously enhanced. Especially, the capacity retention of 3 wt% LiV3O8-coated sample reaches 943% after 100 charge/discharge cycles. Moreover, the rate capability is obviously increased for LiV3O8-coated samples with suitable thickness of coating. The discharge capacity of 3 wt% LiV3O8-coated sample at 2C rate is more than 157.9 mAh g(-1) Therefore, the surface modification with the LiV3O8 is an effective way to improve the electrochemical performance of Li-rich layered oxides. (C) 2016 Elsevier B.V. All rights reserved.