safety, and low cost. [1][2][3][4][5] However, the strong electrostatic interaction with host materials originating from divalent chemistry leads to low output voltage, poor reversibility, and especially sluggish kinetics. Various cathode materials have been developed to navigate these challenges. Currently, the most studied cathode active materials are manganesebased [6][7][8][9] and vanadium-based [10][11][12][13] composites. Nonetheless, relative low operating voltage and poor rate performance remains as issues. To reach the operating voltage of electronic devices, multiple batteries must be connected in series. This practice increases the volume of battery and causes energy loss. Furthermore, poor rate capability limits application of Zn-ion batteries in high-power appliances.The Prussian blue analogues (PBAs) possessing a 3D open framework with large interstitial sites, [4][5][6][7][8][9][10][11][12][13][14][15][16] are considered as a promising host material for reversible Zn-ion intercalation/deintercalation with fast charge/discharge properties and high operational voltage, which is ascribed to its ideal crystal structure and desirable electrochemical properties. [17] Recently, hexacyanometallates with a typical formula of A x M′[M″(CN) 6 ] y ⋅nH 2 O (simply denoted as M′/M″ PBA) are investigated as cathode active materials for aqueous batteries including Li-, Na-, Mg-, Ca-, and Zn-ion batteries, where the A Herein, a two-species redox reaction of Co(II)/Co(III) and Fe(II)/Fe(III) incorporated in cobalt hexacyanoferrate (CoFe(CN) 6 ) is proposed as a breakthrough to achieve jointly high-capacity and high-voltage aqueous Zn-ion battery. The Zn/CoFe(CN) 6 battery provides a highly operational voltage plateau of 1.75 V (vs metallic Zn) and a high capacity of 173.4 mAh g −1 at current density of 0.3 A g −1 , taking advantage of the two-species redox reaction of Co(II)/Co(III) and Fe(II)/Fe(III) couples.Even under extremely fast charge/discharge rate of 6 A g −1 , the battery delivers a sufficiently high discharge capacity of 109.5 mAh g −1 with its 3D opened structure framework. This is the highest capacity delivered among all the batteries using Prussian blue analogs (PBAs) cathode up to now. Furthermore, Zn/CoFe(CN) 6 battery achieves an excellent cycling performance of 2200 cycles without any capacity decay at coulombic efficiency of nearly 100%. One further step, a sol-gel transition strategy for hydrogel electrolyte is developed to construct high-performance flexible cable-type battery. With the strategy, the active materials can adequately contact with electrolyte, resulting in improved electrochemical performance (≈18.73% capacity increase) and mechanical robustness of the solid-state device. It is believed that this study optimizes electrodes by incorporating multi redox reaction species for high-voltage and high-capacity batteries.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.

2 is maintained during the charging-discharging for up to 10 000 cycles. For wearable applications, the flexible solid-state batteries can be used as reliable and portable sources to power different wearable electronics such as a commercial smart watch, electroluminescent panel, and color electroluminescence line, which shows their large potentials for use in next-generation flexible and wearable battery technologies.

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.

(Photo)Electrochemical nitrogen reduction for ammonia (NH3) production is an appealing alternative to the traditional high-energy Haber-Bosch reaction. However, the future of this approach is bleak because of the ultralow N2...

concerning active source leakage and shuttle effect should be addressed, as they result in a lack of carrier and backward loading processes. The insulating nature of elemental I 2 causes it to rely on conductive supporters (mostly porous carbon) to transport electrons and redox. However, the carbon materials currently confine I 2 solely by physical means including adsorption and impregnation, resulting in uneven loading and sluggish interactions, especially considering its electrical neutrality and large radius. [12,13] Another noticeable issue concerns the generation of polyiodides and the associated shuttle effect, which can lead to undesirable selfdischarge problems. [4] MXenes are represented with a general formula of M n+1 X n T x , where M represents the transition metal (Ti, Nb, Zr, Cr, etc.), X stands for C or N, and T x is the surficial termination. They are meant to be a more ideal new carrier for I 2 , due to their exceptional electrical conductivity, abundant surface terminations (O, F, OH, etc.), periodic layered microstructure, and arrayed interlayer gap. [14-21] Furthermore, the efficient electron transport of the MXene skeleton is believed to rescue the insulating active materials to achieve ultrafast reaction kinetics. Meanwhile, the nanoscale interlayer galleries potentially confine the reaction products to suppress the common shuttle behavior. [22-29] Besides, the ceramic nature of MXenes is capable of buffering the inevitable volume change, hence escorting the composite Weak binding and affinity between the conductive support and iodine species leads to inadequate electron transfer and the shuttle effect. Herein, redox kinetics and duration are significantly boosted by introducing a Nb 2 CT X host that is classified as a layered 2D Nb-based MXene. With a facile electrodeposition strategy, initial I − ions are electrically driven to insert in the nanosized interlayers and are electro-oxidized in situ. Linear I 2 is firmly confined inside and benefits from the rapid charge supply from the MXene. Consequently, an aqueous Zn battery based on a Zn metal anode and ZnSO 4 electrolyte delivers an ultraflat plateau at 1.3 V, which contributes to 84.5% of the capacity and 89.1% of the energy density. Record rate capability (143 mAh g −1 at 18 A g −1) and lifespan (23 000) cycles are achieved, which are far superior to those of all reported aqueous MXenes and I 2-metal batteries. Moreover, the low voltage decay rate of 5.6 mV h −1 indicates its superior anti-self-discharge properties. Physicochemical analyses and density functional theory calculations elucidate that the localized electron transfer and trapping effect of the Nb 2 CT X MXene host are responsible for enhanced kinetics and suppressed shuttle behavior. This work can be extended to the fabrication of other I 2-metal batteries with long-lifetime expectations. Aqueous halide iodine batteries, which transport electrons through the direct conversion reaction between an I 2 element and I − ions, are increasingly getting noticed for their cost-ef...

Rechargeable aqueous zinc ion batteries (AZIBs), as a rising star in aqueous ion batteries, are restricted by the narrow voltage window and the unsatisfactory reversibility, which are dominated by the high activity of H2O molecules, side reaction, Zn dendrites, and structural degeneration of the cathode. Electrolyte manipulation has seen a great deal of research recently, particularly various kinds of organic molecules have been shown to achieve outstanding effects on stabilizing the Zn anode, yet the exploration of the mechanism behind the high performance has not been thorough. In an attempt to find such underlying principles, the basic reactions and the corresponding progress on the anode side of AZIBs are first assessed. Then, the roles of organic molecules in recent studies are researched, followed by a deep insight into the role of organic molecules. Finally, several designed strategies are proposed for the further exploration of high performance aqueous rechargeable ZIBs through incorporating appropriate organic molecules in the electrolytes.

The renaissance of aqueous Zn ion batteries has drawn intense attention to Zn metal anode issues, including dendrites growth, dead Zn, low efficiency, and other parasitic reactions. However, against the widely used 2D Zn foil, in fact, the Zn powder anode is a more practical choice for Zn-based batteries in industrial applications, but the related solutions are rarely investigated. Herein, we focus on the Zn powder anode and disclose its unknown failure mechanism different from Zn foils. By utilization of 2D flexible conductive Ti 3 C 2 Tx MXene flakes with hexagonal close-packed lattice as electrons and ions redistributor, a stable and highly reversible Zn powder anode without dendrite growth and low polarization is constructed. Low lattice mismatch (∼10%) enables a coherent heterogeneous interface between the (0002) plane of deposited Zn and (0002) plane of the Ti 3 C 2 Tx MXene. Thus, the Zn 2+ ions are induced to undergo rapid uniform nucleation and sustained reversible stripping/plating with low energy barriers via the internally bridged shuttle channels. Paired with cyano group iron hexacyanoferrate (FeHCF) cathode, the FeHCF//MXene@ Zn full battery delivers superior cycle durability and rate capability, whose service life with a CE of near 100% touches 850% of bare Zn powder counterparts. The proposed Ti 3 C 2 Tx MXene redistributor strategy concerning high-speed electrons/ions channel, low-barrier heterogeneous interface, is expected to be widely applied to other alkali metal anodes.

Zn foil is widely used for studying the stability and dendrite formation behavior of Zn anodes. The reported long cycling life of rechargeable Zn batteries (RZBs) is obtained by testing a battery immediately after its fabrication neglecting the aging effects. The cycling performance demonstrated cannot, however, have practical applications. Using Zn foil as both the working electrode and current collector will cause many problems when the battery is scaled up. A Zn powder (Zn‐P)/current collector configuration is more practical. In this work, the corrosion of the Zn‐P@Cu anode‐induced cell swelling is first quantitatively studied. During the aging process of the Zn‐P@Cu electrode, hydrogen forms on the surface of Cu and the Zn‐P dissolves resulting in morphological changes. These phenomena can be attributed to galvanic corrosion between Cu and Zn. To address this issue, tin with a higher overpotential for hydrogen generation is plated on Cu surface. The results indicate that hydrogen evolution is ameliorated. With a low NP ratio (mass) of 10:7, considerably better storage and cycling performance are achieved for Zn‐P@Cu//MnO2. These results highlight the need to focus on the calendar life of RZBs and corrosion of the Zn anode.