Rechargeable aqueous Zn ion batteries have been regarded as one of the most promising candidates for next-generation energy storage devices due to their low cost, non-toxicity and high safety. However, the dendrite growth of Zn anode and severe undesired side-reactions largely limited their practical application. Here, we developed a bismuth (Bi)-PVDF layer with unique 3D cross-linked and branch-liked structures as a protective layer on the Zn surface (Zn@Bi-PVDF) to suppress the formation of Zn dendrites and side-reactions, leading to the uniform plating and stripping of Zn during the cycles. Consequently, the symmetric cell with Zn@Bi-PVDF electrodes exhibits long cycling life over 2400 h at a current density of 1 mA cm−2 with a fixed capacity of 1 mAh cm−2. When the Zn@Bi-PVDF anode is paired with a NaV3O8·1.5H2O (NVO) cathode, the fabricated Zn@Bi-PVDF//NVO cell maintains a high reversible capacity of 175.5 mAh g−1 at 1 A g−1 after 500 cycles with an initial capacity reten
Abstract
Rechargeable aqueous Zn-ion batteries promise high capacity, low cost, high safety, and sustainability for large-scale energy storage. The Zn metal anode, however, suffers from the dendrite growth and side reactions that are mainly due to the absence of an appropriate solid electrolyte interphase (SEI) layer. Herein, the in situ formation of a dense, stable, and highly Zn -conductive SEI layer (hopeite) in aqueous Zn chemistry is demonstrated, by introducing Zn(H PO ) salt into the electrolyte. The hopeite SEI (≈140 nm thickness) enables uniform and rapid Zn-ion transport kinetics for dendrite-free Zn deposition, and restrains the side reactions via isolating active Zn from the bulk electrolyte. Under practical testing conditions with an ultrathin Zn anode (10 µm), a low negative/positive capacity ratio (≈2.3), and a lean electrolyte (9 µL mAh ), the Zn/V O full cell retains 94.4% of its original capacity after 500 cycles. This work provides a simple yet practical s
Abstract
Zinc-ion batteries (ZIBs) are regarded as a promising candidate for next-generation energy storage systems due to their high safety, resource availability, and environmental friendliness. Nevertheless, the instability of the Zn metal anode has impeded ZIBs from being reliably deployed in their proposed applications. Specifically, dendrite formation and the hydrogen evolution reaction (HER) on the Zn surface significantly compromise the Coulombic efficiency and cycling stability of ZIBs. In recent years, increasing efforts have been devoted to overcoming these obstacles by electrode structure design, interface modification, and electrolyte/separator optimization. To achieve an insightful and comprehensive understanding of these strategies, it is worth analyzing and categorizing them according to their intrinsic mechanisms. Considering this, an overview of the anodic stabilization strategies is provided. First, the fundamentals of the Zn metal anode are introduced, and the as
Abstract
Vanadium-based materials are fascinating potential cathodes for high energy density Zn-ion batteries (ZIBs), due to their high capacity arising from multi-electron redox chemistry. Most vanadium-based materials suffer from poor rate capability, however, owing to their low conductivity and large dimension. Here, we propose the application of V C MXene (V CT ), a conductive 2D nanomaterial, for achieving high energy density ZIBs with superior rate capability. Through an initial charging activation, the valence of surface vanadium in V CT cathode is raised significantly from V /V to V /V , forming a nanoscale vanadium oxide (VO ) coating that effectively undergoes multi-electron reactions, whereas the inner V-C-V 2D multi-layers of V CT are intentionally preserved, providing abundant nanochannels with intrinsic high conductivity. Owing to the synergistic effects between the outer high-valence VO and inner conductive V-C-V, the activated V CT presents an ultrahigh rate per