Aqueous Zn-based batteries deliver thousands of cycles at high rates but poor recyclability at low rates. Herein, we reveal that such illogical phenomenon is attributed to the reconstructed electrode/electrolyte interface...

Alkaline Zn–MnO2 batteries feature high security, low cost, and environmental friendliness while suffering from severe electrochemical irreversibility for both the Zn anode and MnO2 cathode. Although neutral electrolytes are supposed to improve the reversibility of the Zn anode, the MnO2 cathode indeed experiences a capacity degradation caused by the Jahn–Teller effect of the Mn3+ ion, thus shortening the lifespan of the neutral Zn–MnO2 batteries. Theoretically, the MnO2 cathode undergoes a highly reversible two-electron redox reaction of the MnO2/Mn2+ couple in strongly acidic electrolytes. However, acidic electrolytes would inevitably accelerate the corrosion of the Zn anode, making long-lived acidic Zn–MnO2 batteries impossible. Herein, to overcome the challenges faced by Zn–MnO2 batteries, we propose a hybrid Zn–MnO2 battery (HZMB) by coupling the neutral Zn anode with the acidic MnO2 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 MnO2 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–MnO2 batteries in terms of voltage and cycle life.

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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.

Using thermal evaporation technology, Ni-CNT are grown in-situ on nickel plates as the cathode of Li-O2 batteries. This integrated electrode structure eliminates the negative impact of binders on the electrochemical performance and greatly reduces the process for preparing the lithium oxygen battery cathode. Ni-CNT exhibit excellent catalytic activity, and provide an ultrahigh discharge specific capacity of approximately 4.3 mAh cm−2 at 0.1 mA cm−2, the discharge voltage plateau is stable above 2.79 V. In addition, it exhibits a low polarization potential of only 3.34 V during charging, which is much lower than that of the commercial Ru-CNT cathode, and the cycle life of 151 cycles is much higher than that of the commercial Ru-CNT cathode even under a high specific capacity (0.3 mAh cm−2). This self-supporting structure provides abundant space for oxygen transmission and discharge products, and shows great application prospects.