Structure and electrochemical performance of Li4Ti5O12-coated LiMn1.4Ni0.4Cr0.2O4 spinel as 5 V materials

LiMn1.4Cr0.2Ni0.4O4 and a series of Li4Ti5O12/LiMn1.4Cr0.2Ni0.4O4 composites were prepared by a solution method. XRD reveals that the LTO-coated LiMn1.4Cr0.2Ni0.4O4 samples have better crystallinity than that of pure LiMn1.4Cr0.2Ni0.4O4. SEM and EDX show that the surface of LiMn1.4Cr0.2Ni0.4O4 was successfully coated with Li4Ti5O12 particles after the surface modification treatment. Galvanostatic charge-discharge testing indicates 4 wt.% LTO-coated LiMn1.4Cr0.2Ni0.4O4 has the highest electrochemical performance among three samples, implying that surface modification is beneficial to the reversible intercalation and de-intercalation of Li+. (C) 2008 Elsevier B.V. All rights reserved.