Zinc ions pillared vanadate cathodes by chemical pre-intercalation towards long cycling life and low-temperature zinc ion batteries

Abstract

Recently, aqueous zinc ion batteries have emerged as attracting alternatives to conventional lithium ion batteries with the merits of low cost and operation safety. However, the Zn host material with fast Zn kinetic and could sustain reversible Zn2+ insertion and extraction is still a big challenge. Here, a nanowire morphology (NH4)2V6O16·1.5H2O nanostructures fabricated via a facile microwave-assisted hydrothermal reaction are presented as a prospective zinc ion battery cathode. The trapped Zn(H2O)62+ ions in the initial discharge process not only help make the vanadium oxide layer stable but also provide enough interlayer distance for fast ion kinetics during the preceding intercalation/deintercalation process. Owing to the large interplane distance pillared by cations, crystal water molecular and the high diffusion coefficient of (NH4)2V6O16·1.5H2O cathode, it presents an excellent low temperature performance (120 mAh g−1 at a current density of 0.1 A g−1) and highly reversible cycling performance (75% after 10000 cycles at 8 A g−1). The outstanding performance, the easy fabrication along with the low-cost feature make (NH4)2V6O16·1.5H2O cathode reliable in aqueous zinc ion battery application.