Nanophase ZnV2O4 as stable and high capacity Li insertion electrode for Li-ion battery

Spinel ZnV2O4 nanoparticles are synthesized by a hydrothermal method and its properties are characterized using XRD, SEM, TEM, and electrochemical test. The structural and morphological characterizations show that ZnV2O4 sample has high purity and well crystallization with crystal size less than 20 nm. The as prepared electrode shows stable capacity over 660 mAh g(-1) in the voltage range of 0.01-3.0 V at 50 mA g(-1). The reaction mechanism with lithium ion is also investigated through ex-XRD and -TEM. It shows that the pristine ZnV2O4 is transformed to isostructural spinel LixV2O4 (x close to 7.6) and metal Zn phase during the first lithiation process. Then the spinel LixV(2)O(4) seems to perform a topotactic intercalation reaction mechanism and that the in-situ formed LixV(2)O(4) can still keep its spinel matrix while allowing more than 5.7 lithium reversibly into/out over 50 cycles. (C) 2015 Elsevier B.V. All rights reserved.