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The slow reaction kinetics and structural instability of organic electrode materials limit the further performance improvement of aqueous zinc‐organic batteries. Herein, we have synthesized a Z‐folded hydroxyl polymer polytetrafluorohydroquinone (PTFHQ) with inert hydroxyl groups that could be partially oxidized to the active carbonyl groups through the in situ activation process and then undertake the storage/release of Zn2+. In the activated PTFHQ, the hydroxyl groups and S atoms enlarge the electronegativity region near the electrochemically active carbonyl groups, enhancing their electrochemical activity. Simultaneously, the residual hydroxyl groups could act as hydrophilic groups to enhance the electrolyte wettability while ensuring the stability of the polymer chain in the electrolyte. Also, the Z‐folded structure of PTFHQ plays an important role in reversible binding with Zn2+ and fast ion diffusion. All these benefits make the activated PTFHQ exhibit a high specific capacity of 215 mAh g−1 at 0.1 A g−1, over 3400 stable cycles with a capacity retention of 92 %, and an outstanding rate capability of 196 mAh g−1 at 20 A g−1. [ABSTRACT FROM AUTHOR]

Recently, aqueous zinc‐based batteries (AZBs) have become a promising candidate for energy storage devices due to the high safety of aqueous electrolytes and the appealing features of Zn anodes, for example, low cost and high theoretical capacity. However, the excessive growth of Zn electrodeposits as well as the uneven stacking of large hexagonal Zn crystal units always render loose and irregular electrodeposition or even dendritic growth, which seriously deteriorates the actual performance of AZBs. Herein, to refine the grain size of Zn electrodeposits, a trace of Pb2+ ions as a novel electrolyte additive is performed to inhibit the growth of Zn grain during the Zn electrodeposition. Owing to the higher adsorption energy of Pb2+ ions on Zn crystal when compared with Zn2+ ions, the strongly positively‐charged Pb2+ ions are tightly absorbed on the typical crystal planes of initially‐formed Zn nuclei, which block the way for the subsequent absorption and electroreduction of Zn2+ ions. As a result, the Pb2+ ions‐containing electrolyte refines the grain size of Zn electrodeposits from 7.43–7.87 μm to 0.88–2.26 μm, and affords a high reversibility of Zn plating/stripping behavior with a high Coulombic efficiency of 99.9 % over 1000 cycles. [ABSTRACT FROM AUTHOR]

Aqueous Zn-based batteries deliver thousands of cycles at high rates but poor recyclability at low rates. Herein, we reveal that this illogical phenomenon is attributed to the reconstructed electrode/electrolyte interface at high rates, wherein the condensed electrical double layer (EDL) and the tightly absorbed Zn2+ ions on the Zn electrode surface afford compact and corrosion-resistant Zn deposits. [ABSTRACT FROM AUTHOR]

Prussian blue analogs (PBAs) as insertion-type cathodes have attracted significant attention in various aqueous batteries to accommodate metal or non-metal ions while suffering from serious dissolution and consequent inferior lifespan. Herein, we reveal that the dissolution of PBAs primarily originates from the locally elevated pH of electrolytes that are caused by proton co-insertion during discharge. To address this issue, a water-locking electrolyte (WLE) has been strategically implemented, which interrupts the generation and Grotthuss diffusion of protons by breaking the well-connected hydrogen bonding network in aqueous electrolytes. As a result, the WLE enables the iron hexacyanoferrate to endure over 1000 cycles at a 1C rate and supports a high-voltage decoupled cell with an average voltage of 1.95 V. These findings provide insights for mitigating dissolution problems in electrode materials, thereby enhancing the viability and performance of aqueous batteries., (© 2024 Wiley‐VCH GmbH.)

The slow reaction kinetics and structural instability of organic electrode materials limit the further performance improvement of aqueous zinc-organic batteries. Herein, we have synthesized a Z-folded hydroxyl polymer polytetrafluorohydroquinone (PTFHQ) with inert hydroxyl groups that could be partially oxidized to the active carbonyl groups through the in situ activation process and then undertake the storage/release of Zn 2+ . In the activated PTFHQ, the hydroxyl groups and S atoms enlarge the electronegativity region near the electrochemically active carbonyl groups, enhancing their electrochemical activity. Simultaneously, the residual hydroxyl groups could act as hydrophilic groups to enhance the electrolyte wettability while ensuring the stability of the polymer chain in the electrolyte. Also, the Z-folded structure of PTFHQ plays an important role in reversible binding with Zn 2+ and fast ion diffusion. All these benefits make the activated PTFHQ exhibit a high specific capacity of 215 mAh g -1 at 0.1 A g -1 , over 3400 stable cycles with a capacity retention of 92 %, and an outstanding rate capability of 196 mAh g -1 at 20 A g -1 ., (© 2023 Wiley-VCH GmbH.)

Alkaline Zn-MnO 2 batteries feature high security, low cost, and environmental friendliness while suffering from severe electrochemical irreversibility for both the Zn anode and MnO 2 cathode. Although neutral electrolytes are supposed to improve the reversibility of the Zn anode, the MnO 2 cathode indeed experiences a capacity degradation caused by the Jahn-Teller effect of the Mn 3+ ion, thus shortening the lifespan of the neutral Zn-MnO 2 batteries. Theoretically, the MnO 2 cathode undergoes a highly reversible two-electron redox reaction of the MnO 2 /Mn 2+ couple in strongly acidic electrolytes. However, acidic electrolytes would inevitably accelerate the corrosion of the Zn anode, making long-lived acidic Zn-MnO 2 batteries impossible. Herein, to overcome the challenges faced by Zn-MnO 2 batteries, we propose a hybrid Zn-MnO 2 battery (HZMB) by coupling the neutral Zn anode with the acidic MnO 2 cathode, wherein the neutral anode and acidic cathode are separated by a proton-shuttle-shielding and hydrophobic-ion-conducting membrane. Benefiting from the optimized reaction conditions for both the MnO 2 cathode and Zn anode as well as the well-designed membrane, the HZMB exhibits a high working voltage of 2.05 V and a long lifespan of 2275 h (2000 cycles), breaking through the limitations of Zn-MnO 2 batteries in terms of voltage and cycle life.