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Rechargeable aqueous Zn‐VOx batteries are attracting attention in large scale energy storage applications. Yet, the sluggish Zn2+ diffusion kinetics and ambiguous structure–property relationship are always challenging to fulfil the great potential of the batteries. Here we electrodeposit vanadium oxide nanobelts (VO‐E) with highly disordered structure. The electrode achieves high capacities (e.g. ≈5 mAh cm−2, 516 mAh g−1), good rate and cycling performances. Detailed structure analysis indicates VO‐E is composed of integrated amorphous‐crystalline nanoscale domains, forming an efficient heterointerface network in the bulk electrode, which accounts for the good electrochemical properties. Theoretical calculations indicate that the amorphous‐crystalline heterostructure exhibits the favorable cation adsorption and lower ion diffusion energy barriers compared to the amorphous and crystalline counterparts, thus accelerating charge carrier mobility and electrochemical activity of the electrode. [ABSTRACT FROM AUTHOR]

Rechargeable aqueous Zn‐VOx batteries are attracting attention in large scale energy storage applications. Yet, the sluggish Zn2+ diffusion kinetics and ambiguous structure–property relationship are always challenging to fulfil the great potential of the batteries. Here we electrodeposit vanadium oxide nanobelts (VO‐E) with highly disordered structure. The electrode achieves high capacities (e.g. ≈5 mAh cm−2, 516 mAh g−1), good rate and cycling performances. Detailed structure analysis indicates VO‐E is composed of integrated amorphous‐crystalline nanoscale domains, forming an efficient heterointerface network in the bulk electrode, which accounts for the good electrochemical properties. Theoretical calculations indicate that the amorphous‐crystalline heterostructure exhibits the favorable cation adsorption and lower ion diffusion energy barriers compared to the amorphous and crystalline counterparts, thus accelerating charge carrier mobility and electrochemical activity of the electrode. [ABSTRACT FROM AUTHOR]

[Display omitted] • NH 4 + storage properties of VO x @PPy are studied for the first time. • Synergistic interaction between VO x and PPy enhances the performance of the composite electrode. • The NH 4 +/H+ co-insertion mechanism is proposed. • VO x @PPy exhibits a high capacity of 195 mAh/g. Aqueous ammonium-ion batteries (AAIBs) are attracting attention, mainly due to the unique interaction between NH 4 + and the host materials. Yet, few studies focus on the development of high-performance anode materials for NH 4 + storage, hindering the applications of AAIBs. Herein, we study the electrochemical NH 4 + storage properties of an electrodeposited vanadium oxide/polypyrrole (VO x @PPy) electrode with a core–shell structure. The strong interaction between PPy and VO x enhances the electrochemical performance of the composite electrode. The electrons in N atoms from PPy are attracted by V cations from VO x , resulting in the enhanced protonation level of PPy and the reduction of V in the composite material. Therefore, VO x @PPy exhibits a high specific capacity of 195.36 mAh/g at 0.2 A/g in ammonium acetate electrolyte, outperforming other reported anode materials for NH 4 + storage. In addition, the conformal PPy coating can efficiently suppress VO x dissolution, leading to good cycling stability for VO x @PPy. We assembled an aqueous ammonium-ion battery using VO x @PPy as the anode. The device exhibits a good energy density of 74.1 Wh kg−1 at the power density of 75.6 W kg−1. This work highlights the advantages of the hybrid organic/inorganic materials for NH 4 + storage and could push the development of aqueous ammonium-ion batteries. [ABSTRACT FROM AUTHOR]