![]() However, it still suffers from a fragile structure and possesses fewer active sites during cycling, which may result in poor ion transfer dynamics and inferior cycling stability. Meanwhile, B-phase vanadium dioxide (VO 2) with unique layer-type structure is expected to achieve highly reversible intercalation reaction. nH 2O constructed by bilayer structure has been proved to facilitate Zn reaction kinetics owing to the expanded interlayer spacing and weakened electrostatic repulsive force through beneficial “charge shield” effect.As one of the representative members, hydrated V 2O 5 ![]() In some cases, H 2O molecules serve as reactant that participate in the regulated materials, and the electrochemical behavior will be tuned after the electrochemical activation process. Recently, in situ self-transformation has been investigated as an effective strategy to reach capacity maximum value by utilizing phase transition activation in preprepared cathodes. In this regard, the continuous exploitation of vanadium oxides with specific charge-storage mechanisms that ensure extended life, and high capacity is still vital to explore. Although it can improve rate performance, at the expense of decreased theoretical energy density due to reduced Zn ion intercalation sites and higher molecular weight of the host material. Carbon heterojunction engineering is also developed to restrict the aggregation of the structure and promote electronic conductivity. Nevertheless, the boosted cycling stability using guest species as pillars is at the expense of capacity loss because of the unstable structure change and reduced valance of the parent cations. Preintercalation of cation ions as an efficient method is employed to enlarge interlayer spacing and ensure sufficient intercalation pathway. In addition, the severe collapse of crystal structure and dissolution of vanadium will occur during the zinc-ion insertion process, which causes production of extensive non-conductive interfaces and intrinsically sluggish reaction kinetics of irreversible Zn 2+ storage, thus leading to perceptible capacity decay. However, the strong electrostatic interaction between bulk lattice structures of cathode and divalent Zn ions inhibits zinc-ion diffusion. Benefiting from the different coordination environments, various crystal structures, and multiple valence states, vanadium-based oxides as the cathode materials have made attempts to emerge among many candidates by depending on the zinc-ion storage capability of outputting decent cyclability as well as high specific capacities. ![]() Exploring cathode materials with a good balance between rate performance, discharge capacity, and cycling stability is imperative for the development of aqueous ZIBs. However, the reported supplied cathode materials still encounter several challenges, such as low electrical conductivity and poor structural stability to provide fast, reversible Zn intercalation. Endowed with several favorable characteristics, including high theoretical capacity, low redox potential, and environmentally friendly features in water-based electrolytes, they can bridge the gap between traditional aqueous rechargeable batteries and lithium-ion batteries in terms of capacity attenuation and safety concerns. Aqueous zinc-ion batteries (ZIBs) utilizing multivalent zinc anodes have become a burgeoning means of energy storage device. This work not only paves a new route to design in situ self-transformation in energy storage devices, but also broadens the horizons of aqueous zinc-supplied cathodesĪdvanced electrochemical energy storage systems demand not only outstanding comprehensive performance but also operation safety to match the rise of electric vehicles and portable electronics. Importantly, such zinc-ion batteries with phase self-transition can also perform well at high-loading, sub-zero temperature, or pouch cell conditions for practical application. Using AVO cathode, an outstanding discharge capacity of 446 mAh g −1 at 0.1 A g −1, high rate capability of 323 mAh g −1 at 10 A g −1 and excellent cycling stability for 4000 cycles at 20 A g −1 with high capacity retention are demonstrated.
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