Optimized cyclic and electrochemical performance by organic ion N(CH3)4+ pre-inserted into N(CH3)4V8O20 cathode and hierarchy distributive Zn anode in aqueous zinc ion batteries.

• The desired N(CH3)4V8O20 material, N(CH3)4+ of which exclusively acts as structural pillar, was firstly synthesized by facile one-step hydrothermal method and applied in AZIBs. • The N(CH3)4+ as structural pillar not only amplifies the interlayer spacing of 11.5 Å but also enhances structure stability, which actually optimizes the electrochemical performance overall. • The hierarchy distributive Zn anode grown on carbon paper with 3D braid architecture has proved effective. • It delivers a high capacity of 360 mAh g − 1 at 0.5 A g − 1 and capacity retention 97% after 5000 cycles at 50 A g − 1 with capacity of 105 mAh g − 1. Vanadate based cathode materials have been enormously investigated into aqueous zinc-ion batteries (AZIBs) in current research due to high specific capacity and large layer spacing that can accommodate sufficient ions. However, bulk vanadate based cathode materials suffer from a rapid capacity decaying as a result of low electronic conductivity, inferior ion diffusion kinetics and unstable structure during the zinc ion de/intercalation. Meanwhile, the inescapable zinc dendrite formation and reactive irreversibility during long cyclic testing also lead to growing polarization and poor cyclic performance. Herein, we put forward a strategy of structural design by synergistically introducing quaternary ammonium cation within vanadium bronze structure. The desired N(CH 3) 4 V 8 O 20 material, pure monomorph phase, was firstly synthesized by facile one-step hydrothermal method, which owns lattice spacing of 11.5 Å and stable crystalline structure for faster kinetics, higher capacity and better cyclic stability. Combined with the optimized 3D braid architecture of Zn@carbon paper anode, the as-obtained AZIBs exhibit a high capacity of 360 mAh g −1 at 0.5 A g −1. While the current density raises to 100 folds from 0.5 A g −1 to 50 A g −1, appreciable capacity of 105 mAh g −1 and outstanding stability of ultra-long lifespan with capacity retention 97% after 5000 cycles are achieved. Combining the sound investigations of experimental practices and computational research, mechanism of rapid and stable Zn2+ storage was systemically demonstrated. The optimized electrochemical performance could be attributed to highly reversible ion de/intercalation, superior ion diffusion kinetics and no side reactions. This work leads to a new strategy of the design for cathodes in AZIBs and unfolds a new path for the actualization of high-up vanadate based materials. [Display omitted] [ABSTRACT FROM AUTHOR]