Manipulating OH⁻‐Mediated Anode‐Cathode Cross‐Communication Toward Long‐Life Aqueous Zinc‐Vanadium Batteries

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, Al 2 (SO 4 ) 3 is proposed as decent electrolyte additive to manipulate OH − ‐mediated cross‐communication between Zn anode and NaV 3 O 8 ⋅ 1.5H 2 O (NVO) cathode. The hydrolysis of Al 3+ 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 Al 3+ 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.