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Summary: Aqueous zinc batteries (AZBs) hold great promise for advancing applications in next‐generation energy storage devices because of their high safety, high energy density, and low cost. However, zinc metal anodes have greatly impeded the application in AZBs due to their poor cycle performance. Short lifespan, which is caused by dendritic growth, deformation, corrosion, and competing hydrogen evolution, is very tricky. Herein, a stable Sn@Cu foam, prepared by plating tin on copper foam, is reported as the substrate of Zn anodes. We evaluate the quality of plating tin layers, which are prepared by using different tin salt solutions, and Na2SnO3 solution is eventually selected. Electrochemical tests show that Sn@Cu foam can not only inherit the merits of Cu foam but also suppress hydrogen evolution reaction and lower the initial heterogeneous nucleation barrier of deposited Zn. Moreover, in situ observation by optical microscope demonstrates that Zn dendrite growth on Sn layer is suppressed during the plating‐stripping process. As a result, a compact Zn layer on Sn@Cu foam is obtained (Zn/Sn@Cu foam), symmetrical cells display superior cycling life of 1800 h at 1 mA cm−2 for 1 mAh cm−2, and full cells with VO2 cathode deliver remarkably better cycling stability and longer lifespan. [ABSTRACT FROM AUTHOR]

Al is one of the principal alloying elements for Mg anodes. In this study, a series of Mg–Al alloys has been evaluated as anode materials for optimizing the Al addition amount in Mg anodes with the intention of improving the discharge performance in aqueous batteries. The effect of Al content on the discharge potential and corrosion resistance of the Mg anode has been investigated through microstructure characterization, electrochemical measurements in a half‐cell, discharge morphology analysis, and Mg–water battery tests. The results show that the Mg–1Al alloy possesses a larger corrosion resistance during discharge, with significant increase of the anode utilization efficiency at 1 and 5 mA/cm2 compared with pure Mg. However, a further increase of Al content does not continuously improve the discharge performance of the Mg anode with the decline of utilization efficiency due to the influence of the precipitated phase. This study contributes to a better understanding about the effect of Al on anodic dissolution and corrosion kinetics of the Mg anode. [ABSTRACT FROM AUTHOR]

Zn−Ni secondary battery is a promising candidate as next generation of energy storage battery. However, suffering from the poor cycle performance, its commercialization remains rather challenging. The severe dendrite growth of Zn anode and the rapid capacity decay caused by its uncontrollable dissolution and poor electronic conductivity of ZnO are the main factors. Herein, we report a novel Indium (In) doped ZnO/rGO anode material to inhibit ZnO dissolution through the generated C−O−Zn bond between ZnO and graphene. Meanwhile, the capacity decay decline due to the enhanced electronic conductivity of ZnO by the In doping and combination of graphene. As a result, In doped ZnO/rGO anode material delivers a high specific capacity of 643.4 mAh g−1 (coulombic efficiency 97.63 %) and remains 531.3 mAh g−1 after 125 cycles at 0.5 C, which are significantly higher than bare ZnO. [ABSTRACT FROM AUTHOR]

The constructed novel RMABs applying 1 M NaOH (aqueous)/"All in one" Mg anode electrolyte system with high reversibility and excellent cycle stability. [Display omitted] • "All in one" Mg anode is designed for RMABs. • 1 M NaOH (aqueous)/"All in one" Mg anode electrolyte system for RMABs is constructed. • High energy efficiency 69.7% and long lifespan of 506 h at 1 mA cm−2 are achieved. Rechargeable Magnesium-Air batteries (RMABs) are attracting significant attention for energy storage due to their uniqueness of high theoretical energy density, inherent safety and low cost. However, the exhibited poor energy efficiency as well as their short lifespan seriously hinder their further development. The main reason is that lacking a suitable electrolyte to balance the different needs of the cathode and anode, which can not only maintain the high reactivity of cathode but also achieving reversible stripping/plating of Mg anode and suppress its side reactions. To this end, we explored a novel "All in one" Mg anode and constructed a 1 M NaOH (aqueous)/"All in one" Mg anode electrolyte system for RMABs with high reversibility and excellent cycle stability. In particular, the unique design of "All in one" Mg anode which integrates Mg alloy layer, solid anolyte layer and ion exchange membrane layer, realizing the efficient reversible charge and discharge cycle of Mg anode in 1 M NaOH solution (catholyte). Thence, the availability of alkaline aqueous catholyte also preserve its high ORR/OER reactivity of air cathode, enabling the designed RMABs owns high energy efficiency 69.7% and long lifespan of 506 h at 1 mA cm−2. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mg anode in NaAc electrolyte exhibits uniform dissolution behavior. • Sufficiently inhibit the anodic hydrogen evolution corrosion of Mg anode. • Enhance the utilization efficiency of Mg anode up to 84% at 10 mA cm−2. • NaAc electrolyte is applied in a commercial Mg air battery. • Verify the anodic corrosion of Mg is related to its localized passive film rupture. Aqueous magnesium air batteries are promising energy conversion devices because of high theoretical energy density, inherent safety and low cost. However, their practical energy density is significantly limited due to the dramatic hydrogen evolution corrosion of Mg anode in conventional sodium chloride (NaCl) electrolyte. Herein, we suppress the hydrogen evolution reaction on the surface of Mg anode using sodium acetate (NaAc) electrolyte, in which Mg anode exhibits uniform anodic dissolution behavior without the notorious localized corrosion. It is demonstrated that acetate ion (Ac-) averts the localized passive film breakdown of Mg anode in virtue of its large diffusion energy barrier within the film. Therefore, the anodic hydrogen evolution phenomenon amid discharge is evidently repressed. This enables Mg anode to achieve a high utilization efficiency of 84 % at 10 mA cm−2 compared with 59 % in NaCl electrolyte. Mg air battery tests manifest that its specific energy based on the anode weight is boosted from 1370 to 1770 Wh kg−1. Finally, the practicality of NaAc electrolyte is confirmed in a commercial Mg air battery. This work provides a simple and scalable solution for high performance Mg air battery. [ABSTRACT FROM AUTHOR]