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Flexible zinc‐air batteries have received widespread attention due to their high specific energy and eco‐friendly environment. However, the water in the hydrogel is easily lost to the external environment because of the semi‐open structure zinc‐air batteries, leading to performance degradation of the batteries. Here a saline gel of NaCl‐KOH‐PAA (sodium chloride‐potassium hydroxide‐polyacrylic acid) without soaking in the alkaline solution before use is designed, refining the grid structure of the hydrogel and reducing water loss through NaCl doping. Meanwhile, the gel exhibits no significant decrease in ion conductivity before and after NaCl doping and can maintain stability of around 170 and 150 mS cm−1 at room temperature and −20 °C, respectively. The results demonstrate that the lifetime of flexible zinc‐air batteries with NaCl‐doped hydrogel can be extended by nearly 50%. The NaCl doping gel also displays superior flexibility under extreme physical deformation conditions. Moreover, the phenomenon of hydrogel delamination with NaCl doping is observed and the mechanism of gel water retention is uncovered. These findings will pave the way for developing flexible zinc‐air battery. [ABSTRACT FROM AUTHOR]

Flexible Al–air batteries have attracted widespread attention in the field of wearable power due to the high theoretical energy density of Al metal. However, the efficiency degradation and anodizing retardation caused by Al parasitic corrosion severely limit the performance breakthrough of the batteries. Herein, a Prussian‐blue bifunctional interface membrane is proposed to improving the discharge performance of hydrogel‐based Al–air battery. When a rational 12 mg·cm−2 membrane is loaded, the effect of anticorrosion and activation is optimal thanks to the formation of a stable and breathable interface. The results demonstrate that a flexible Al–air battery using the membrane can output a high power density of 65.76 mW·cm−2. Besides, the battery can achieve a high capacity of 2377.43 mAh·g−1, anode efficiency of 79.78%, and energy density of 3176.39 Wh·kg−1 at 10 mA·cm−2. Density functional theory calculations uncover the anticorrosion‐activation mechanism that Fe3+ with a large number of empty orbitals can accelerate electrons transfer, and nucleophilic reactant [FeII(CN)6]4− promotes the Al3+ diffusion. These findings are beneficial to the inhibition of interfacial parasitic corrosion and weakening of discharge hysteresis for flexible Al–air batteries. [ABSTRACT FROM AUTHOR]

Flexible Zn–air batteries (FZABs) have attracted more attention due to their high specific energy, excellent stability, and unique rechargeability. However, these batteries are limited by the low conductivity of the gel electrolytes used. Here a quasi‐liquid gel with ionic conductivity comparable to liquid electrolytes is presented. The gel pore structure is guided and modified in situ with large‐size silica to achieve clear and unbroken pores. The reduced skeleton structure leads to a significant increase in ionic conductivity to 562.6 mS cm−1, enabling a peak power density of 154 mW cm−2 and a cycle life of over 40 h with a low charge–discharge gap. The FZABs also exhibit a high lifetime and potential advantages in 10 mA cm−2 charge/discharge testing, and demonstrate excellent performance in practical applications. This study offers new possibilities for developing high‐performance quasi‐liquid gels and innovative concepts for FZABs. [ABSTRACT FROM AUTHOR]

Metal–air batteries have become one of the new potential sources of electrochemical energy due to the excellent electrochemical characteristics, environmental friendliness and cheap cost. Whereas, the commercialization of the metal–air batteries is still subject to the sluggish kinetics on air electrode and hydrogen evolution corrosion as well as dendrite growth of metal anode. Recently, the applied magnetic field, as a technology for transferring energy across physical space, receives more attention, can improve the performance of metal–air batteries by promoting mass transfer, accelerating charge transfer and enhancing electrocatalytic ability based on magnetohydrodynamic effect, Kelvin force effect, Hall effect, Spin selectivity effect, Maxwell stress effect and Magnetothermal effect. This review provides the recent progress in the research on the relative mechanism and characteristic of the magnetic field in the metal–air batteries. [ABSTRACT FROM AUTHOR]

Adv. Funct. Mater. 2023, 33, 2303719DOI: 10.1002/adfm.202303719The authors regret a mistake at the first sentence of "Preparation of Pore‐Enlarged PAA Electrolyte" part (page 7) in the "Experimental Section". The amount of MBA added should be 0.0833g instead of 0.833g.By Nuo Shang; Keliang Wang; Manhui Wei; Yayu Zuo; Pengfei Zhang; Hengwei Wang; Zhuo Chen; Daiyuan Zhong and Pucheng PeiReported by Author; Author; Author; Author; Author; Author; Author; Author; Author [Extracted from the article]

• A double cross-linked gel polymer is self-designed and constructed. • The obtained gel electrolyte shows excellent physical and chemical properties. • The assembled flexible zinc-air battery exhibits extreme conditions adaptability. Flexible zinc-air batteries have attracted more and more attention as an efficient and promising energy storage system. However, traditional gel electrolytes and flexible batteries have disadvantages such as poor mechanical properties and weak adaptability to extreme conditions. Here, we report a self-designed double cross-linked high-performance gel electrolyte (PAAK-M) for flexible zinc-air batteries, which is synthesized by polymerization of acrylamide (AM) monomer with the neutralized product of acrylic acid (AA) and potassium hydroxide (KOH) under heating conditions. Benefiting from the unique mechanical structure and excellent performance of PAAK-M gel, the assembled flexible zinc-air battery exhibits a high power density of 126 mW cm−2 and a long cycle life of over 55 h at room temperature. More importantly, the battery not only shows remarkable electrochemical performance over a wide temperature range (−20 °C to 100 °C), but also has good stability and practicality under various extreme conditions. Two zinc-air batteries integrated in series can reliably provide energy for LEDs and electronic clock. This study opens up a new idea for the development of high-performance gel electrolytes and provides a new strategy for the research of flexible batteries with the ability to adapt to extreme conditions. [ABSTRACT FROM AUTHOR]

Flexible Al-air batteries are seen as the next generation of power devices for portable electronics due to the high capacity, low cost and environmental friendliness. However, the anodic parasitic reactions hinder their commercialization. Here, we develop a Zn2+@Agar hydrogel membrane for flexible Al-air battery, whose formed Zn-dominated interphase can inhibit hydrogen evolution and passivation of the Al anode, improving the discharge performance of the battery. The results show that the hydrogen evolution rate of Al anode is as low as 1.65 × 10−2 mg cm−2s−1 when 0.5 M Zn2+ are contained in the membrane, and the passivation layer of Al 2 O 3 is also broken by Zn-dominated interphase. Al-air battery with this membrane has a high capacity of 2592 mAh g−1, specific energy of 2847 mWh g−1 and anode utilization ratio of 86.98% at 10 mA cm−2 at 25 °C, and the battery has a high capacity of 2286 mAh g−1, specific energy of 2084 mWh g−1 and anode utilization ratio of 76.71% at 0 °C. Furthermore, the mechanism of interaction between single chain agar molecule and anode surface is revealed, which greatly promotes the commercial application for flexible Al-air batteries using Zn2+@Agar hydrogel membrane. [Display omitted] • A Zn2+@Agar hydrogel membrane is developed for flexible Al-air battery. • Zn-dominated interphase inhibits the parasitic reactions of Al anode. • The anode utilization ratio of Al-air battery can reach 86.98% at 10 mA cm−2 at 25 °C. • The capacity of Al-air battery is up to 2592 mAh g−1 at 10 mA cm−2 at 25 °C. • Al-air battery with Zn2+@Agar hydrogel membrane has good low-temperature adaptability. [ABSTRACT FROM AUTHOR]