Interfacial water masking agent: Dynamic synergistic regulation of anode and cathode for ultra-long-life aqueous zinc metal batteries

The aqueous zinc-metal batteries (AZMBs) are still facing challenges due to the harmful reactions including dendrites formation, corrosion and dissolution. Herein, a novel electrolyte is presented which can simultaneously constructs a doubled-electrode interface masking agent (DEIMA) both on the anode and cathode surfaces. Specifically, the introduced theophylline (TPL) is preferably adsorbed on the electrode/electrolyte interface (EEI), forming a mask layer that dynamically regulates the EEI structure during charge and discharge to reduce the influence of H₂O on the electrode. Moreover, the TPL molecules effectively diminishing the desolvation energy barrier and weakening the reactivity of H₂O, and reduces the dissolution of vanadium in the cathode material. Consequently, the Zn||Zn symmetric cell achieves a long-life of exceeding 2400 h at 5 mA cm⁻², and the Zn//VO₂ full cell retains a capacity of 191.6 mAh g⁻¹ after 1300 cycles. This strategy provides a straightforward approach to address the challenges by AZMBs.