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The anode‐cathode interplay is an important but rarely considered factor that initiates the degradation of aqueous zinc ion batteries (AZIBs). Herein, to address the limited cyclability issue of V‐based AZIBs, Al2(SO4)3 is proposed as decent electrolyte additive to manipulate OH−‐mediated cross‐communication between Zn anode and NaV3O8 ⋅ 1.5H2O (NVO) cathode. The hydrolysis of Al3+ creates a pH≈0.9 strong acidic environment, which unexpectedly prolongs the anode lifespan from 200 to 1000 h. Such impressive improvement is assigned to the alleviation of interfacial OH− accumulation by Al3+ adsorption and solid electrolyte interphase formation. Accordingly, the strongly acidified electrolyte, associated with the sedated crossover of anodic OH− toward NVO, remarkably mitigate its undesired dissolution and phase transition. The interrupted OH−‐mediated communication between the two electrodes endows Zn||NVO batteries with superb cycling stability, at both low and high scan rates. [ABSTRACT FROM AUTHOR]

Aqueous Zn||vanadium oxide batteries (ZVBs) have recently received considerable attention owing to their high capacity, safety, environmental friendliness, and cost effectiveness. However, the limited cycling stability caused by the irreversible dissolution in traditional aqueous electrolytes still restricts their further application. Herein, a novel 3 m Zn(CF3SO3)2 electrolyte with a mixture solvent of propylene carbonate (PC) and H2O is adopted for aqueous vanadium‐based zinc‐ion batteries. With the manipulation of the electrolyte solvation structure, the optimized P20 (20% PC in volume ratio) electrolyte enables super‐stable cycling performance with high‐capacity retention of 99.5%/97% after 100/1000 cycles at 0.1/5 A g−1 at ambient environment in the Zn||NaV3O8·1.5H2O batteries. Systematical electrochemical testing and characterizations illustrate the addition of PC effectively reduces the active water molecule in Zn2+‐solvent cations and H+ in the electrolyte, thereby suppressing the cathode dissolution caused by the inserted H+ and co‐inserted H2O during the discharge/charge process. Impressively, the PC addition also enabled the Zn||NaV3O8·1.5H2O batteries present high specific capacity of 183/168 mAh g‐1 and high‐capacity retention of 100%/100% over 300/400 cycles at 0.1/0.2 A g‐1 at −40 °C, thus efficiently broadening the practical application for ZVB. This research may provide a promising strategy for designing high‐performance electrolytes for aqueous vanadium‐based batteries. [ABSTRACT FROM AUTHOR]

Aqueous zinc‐ion batteries (AZIBs) have received significant research attention and widely investigated because of their high intrinsic safety and cost effectiveness. Manganese dioxide has been regarded as a promising cathode material for AZIBs, attributed to its friendliness, abundant resources, high theoretical capacity, and high working voltage. Herein, a unique one-dimensional–three-dimensional (1D–3D) hybrid network with interconnected δ-MnO 2 nanowires was reported as a cathode material for AZIBs. A distinctive 3D nano network structure resulted in enhancement of electrolyte osmosis and significant increase in contact between electrode and electrolyte, and also provided more active sites and convenient rapid ion transport routes. Moreover, the fine nanowire structure and the optimum layer spacing resulted in easier insertion/deinsertion of ion in the active material. Taking advantage of this feature, the δ-MnO 2 cathode provides high reversible capacity, fast rate capability and good longevity for cycling. Further kinetic experiments revealed that Zn/δ‐MnO 2 system constitutes an electrochemical reaction regulated by the combination of ionic diffusion and pseudo-capacitance; and shows high energy efficiency during the charge/discharge states. This research may provide an advanced cathode material for AZIB development. [ABSTRACT FROM AUTHOR]