Synthesis and Li-ion diffusion kinetic of Zn2(OH)3VO3 nanosheets with ultra-high electrochemical activity

Abstract It has been reported that 2-dimension Zn2(OH)3VO3 possesses the higher electrochemical activity. However, its morphology evolution, formation mechanism and electrochemical kinetics remain elusive. In this study, Zn2(OH)3VO3 nanosheets with a thickness of 20 ~ 50 nm were synthesized by a facile one-pot hydrothermal route without any post heat treatment. We reveal the morphology evolution through the reaction time manipulation and formation mechanism in terms of nucleation, crystallization and growth. Lithium storage performances of the obtained nanosheets were investigated, featuring a discharge capacity retention of 863 mAh g−1 after 100 cycles at 0.1 A g−1 and Coulombic efficiency of 99%. The reversible specific capacity reached 477 mAh g−1 even at 10 A g−1, indicating an analyzed diffusion-controlled mechanism. Furthermore, for the first time, the electrochemical kinetics of Zn2(OH)3VO3 nanosheets electrode during the first cycle were studied in detail by in situ Electrochemical impedance technology, which certified that the solid electrolyte interface (SEI) layer experienced the formation, dissolution and reformation process upon cycling. The present work might greatly promote the application of Zn2(OH)3VO3 in Li-ion batteries and other fields.