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.