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

•Spinel ZnV2O4 nanoparticles are synthesized by a hydrothermal method.•ZnV2O4 remains stable capacity over 660 mAh g−1 after 50 cycles.•The reaction mechanism with lithium ion is also investigated through ex-XRD and -TEM.

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 LixV2O4 seems to perform a topotactic intercalation reaction mechanism and that the in-situ formed LixV2O4 can still keep its spinel matrix while allowing more than 5.7 lithium reversibly into/out over 50 cycles.

Graphical abstractSpinel ZnV2O4 nanoparticles was synthesized by a hydrothermal method, which deliver still stable capacity of 660 mAh g−1 after 50 cycles between 0.01 and 3.0 V, suggesting excellent cycling stability. Additionally, the reaction mechanism with lithium ion is also investigated through ex-XRD and -TEM.Figure optionsDownload full-size imageDownload as PowerPoint slide