Prussian blue analogue (PBA)-type metal hexacyanoferrates are considered as significant cathodes for zinc batteries (ZBs). However, these PBA-type cathodes, such as cyanogroup iron hexacyanoferrate (FeHCF), suffer from ephemeral lifespan (≤1000 cycles), and inferior rate capability (1 A g −1 ). This is because the redox active sites of multivalent iron (Fe(III/II)) can only be very limited activated and thus utilized. This is attributed to the spatial resistance caused by the compact cooperation interaction between Fe and the surrounded cyanogroup, and the inferior conductivity. Here, it is found that high-voltage scanning can effectively activate the C-coordinated Fe in FeHCF cathode in ZBs. Thanks to this activation, the Zn-FeHCF hybrid-ion battery achieves a record-breaking cycling performance of 5000 (82% capacity retention) and 10 000 cycles (73% capacity retention), respectively, together with a superior rate capability of maintaining 53.2% capacity at superhigh current density of 8 A g −1 (≈97 C). The reversible distortion and recovery of the crystalline structure caused by the (de)insertion of zinc and lithium ions is revealed. It is believed that this work represents a substantial advance on PBA electrode materials and may essentially promote application of PBA materials. Zinc BatteriesThe ORCID identification number(s) for the author(s) of this article can be found under https://doi.Zinc batteries (ZBs) established on the storage of divalent zinc ion in cathodic hosts are being intensively studied because of the high energy density of metallic zinc anode and the intrinsic safety performance. [1][2][3][4] The appropriate plating/stripping voltage (≈-0.76 V vs SHE) of zinc makes it electrochemically stable in water, which enables ZBs to avoid the employment of toxic organic electrolytes and complex assembly processes in glovebox compared with the lithium and sodium counterparts. [5][6][7] This advantage of zinc anode enables researchers to pay more attention to develop cathodic host materials. [8][9][10][11][12] Among these materials, MnO 2based cathodes possess high specific capacity based on the single electron transfer reaction of Mn(IV)/Mn(III), while the

In this work, a high‐voltage output and long‐lifespan zinc/vanadium oxide bronze battery using a Co0.247V2O5⋅0.944H2O nanobelt is developed. The high crystal architecture could enable fast and reversible Zn2+ intercalation/deintercalation at highly operational voltages. The developed battery exhibits a high voltage of 1.7 V and delivers a high capacity of 432 mAh g−1 at 0.1 A g−1. The capacity at voltages above 1.0 V reaches 227 mAh g−1, which is 52.54% of the total capacity and higher than the values of all previously reported Zn/vanadium oxide batteries. Further study reveals that, compared with the pristine vanadium oxide bronze, the absorption energy for Zn2+ increases from 1.85 to 2.24 eV by cobalt ion intercalation. Furthermore, it also shows a high rate capability (163 mAh g−1 even at 10 A g−1) and extraordinary lifespan over 7500 cycles, with a capacity retention of 90.26%. These performances far exceed those for all reported zinc/vanadium oxide bronze batteries. Subsequently, a nondrying and antifreezing tough flexible battery with a high energy density of 432 Wh kg−1 at 0.1 A g−1 is constructed, and it reveals excellent drying and freezing tolerance. This research represents a substantial advancement in vanadium materials for various battery applications, achieving both a high discharge voltage and high capacity.

Despite these attractive merits, the performance is largely limited by unstable Zn chemistry in aqueous electrolyte with mildly acidic environment. [4][5][6] The produced hydrated [Zn(H 2 O) x ] 2+ ion complex species and the free water outside the Zn 2+ -solvation sheath induce severe interfacial side reactions, including Zn corrosion and H 2 evolution, along with aggravation of nonuniform Zn deposition. [7][8][9] This inevitably results in low Coulombic efficiency (CE) and can ultimately compromise safety (e.g., battery swelling and explosion, shortcircuit failure). [10] To circumvent the problems, many attempts have been made, including Zn alloying, [11] surface modification, [12,13] structure optimization of Zn host, [14,15] adoption of Zn 2+ intercalation anode material, [16,17] and compositional design of electrolyte. [18][19][20] Among them, electrolyte design is the most expedient solution with the potential to scale up from lab to practical application, owing to its superior repeatability and diversity. Recently, super-concentrated electrolytes are explored to interrupt original solvated balance and improve Zn reversibility. [21][22][23][24] The most representative example was proposed by Wang et al., where the Zn 2+ is surrounded by bis(trifluoromethanesulfonyl) imide (TFSI -) instead of water molecules due to the formation of copious [Zn(TFSI)] + ionic pairs with close coordination. [25][26][27][28] However, a high concentration of reaction-unrelated salt or flammable organic species in the electrolyte may induce safety and reaction kinetic issues with occurring costs, going against the initial rationale behind using AZIBs. [29] As such, investigations now are focusing on developing electrolyte additives on Zn 2+ -solvation structure in dilute solutions, such as methanol, [30] polyhydric alcohols, [31,32] dimethyl sulfoxide, [33,34] and polyacrylamide. [35] Although the Zn deposition behavior is optimized, many organic additives are still plagued by limited alleviation of side reactions. [10] Meanwhile, most of them hugely increase the polarization voltage while improving the cycling stability, leading to inferior electrochemical performance under practical conditions with high current density and areal capacity. Currently, rationally developing a class of advanced multifunctional additives remains challenging and a general additive design principle is accordingly of great significance for aqueous Zn chemistry.Carbonyl-containing liquid organics, such as N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), and acetoneThe benefits of Zn, despite many of its performance advantages (e.g., high theoretical capacity and low redox potential), are compromised by severe side reactions and Zn dendrite growth in aqueous electrolytes, due to the coordinated H 2 O within the Zn 2+ -solvation sheath and reactive free water in the bulk electrolyte. Unlike most efforts focused on costly super-concentrated electrolytes and single additive species, a universal strategy is proposed to boost Zn reversibility in dil...

Zinc metal is an ideal candidate for aqueous rechargeable batteries due to its high theoretical capacity and natural abundance. However, its commercialization is inevitably challenged by several critical factors such as dendrite growth and parasitic side‐reactions, leading to low coulombic efficiency and a limited lifespan. Herein, a modified Zn foil with a zincophilic ZnSe layer deposited by a simple selenization process is proposed. An order of magnitude stronger adsorption capability toward Zn2+ ions and uniform ion diffusion tunnels of ZnSe enables lower nucleation energy barrier and faster ion‐diffusion kinetics. Meanwhile, detrimental Zn corrosion in aqueous system is also effectively mitigated. As a result, ZnSe@Zn anode shows reversible Zn plating/stripping (1700 h at 1 mA cm−2) with ultra‐low voltage hysteresis (41 mV), contributing to exceptional cycling stability over 500 cycles with negligible capacity fading for the ZnSe@Zn/MnO2 full cell.

Aqueous zinc ion batteries (AZIBs) have recently sparked an enormous surge of research attentions, due to their eco-friendliness, low-production cost, and exceptional electrochemical performance. Nonetheless, initial exploration mainly focused on...