Zn3V3O8 nanorods with outstanding electrochemical kinetics as novel anode for aqueous ammonium-ion batteries

Abstract

Aqueous ammonium-ion batteries (AAIBs) showed great potential in large-scale energy storage systems due to their low-cost, ultrafast kinetics, plentiful resources, inherent security and environmental friendliness. Herein, the well-dispersed Zn₃V₃O₈ nanorods and agglomerated MnV₂O₄ nanoparticles were prepared and firstly used as anodes for AAIBs. The ultrafast reaction kinetics and NH₄⁺ diffusion kinetics of Zn₃V₃O₈ were confirmed by systematically contrasting with MnV₂O₄. Specifically, Zn₃V₃O₈ delivered perfect cyclic performances with 82.6% capacity retention after 500 cycles. When coupled with the β-MnO₂ cathode, the β-MnO₂//Zn₃V₃O₈ full batteries submitted a maximum energy density of 86 Wh·kg⁻¹ and a maximum power density of 677 W·kg⁻¹. The phase transformation from Zn₃V₃O₈ to Zn₃(OH)₂V₂O₇·2H₂O during the first charge process and the reversible building/breaking behaviors of hydrogen bonds during the NH₄⁺ insertion/extraction processes were discussed by ex situ technology analyses. Thus, the fresh perceptions on the phase transformation laws and the hydrogen bonds evolution mechanisms could enrich the fundamental understanding of the NH₄⁺ storage mechanism, and promote the development of the practical applications for Zn₃V₃O₈ in aqueous ammonium-ion batteries.

Graphical abstract