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, Al2 (SO4 )3 is proposed as decent electrolyte additive to manipulate OH- -mediated cross-communication between Zn anode and NaV3 O8 ⋅ 1.5H2 O (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.