Bio-Inspired Zymogen-Activation Strategy for On-Demand and Bilateral Interphase Formation in Aqueous Zinc-Ion Batteries

Aqueous zinc-ion batteries (AZIBs) possess distinct benefits in cost and safety, but bilateral interfacial failures on Zn anodes and MnO₂ cathodes constrain their practical applications. Inspired by zymogen-to-enzyme activation, this work proposes a biomimetic, intelligent electrolyte additive strategy that enables on-demand protection on both electrodes. This strategy employs an inert additive, 1,4-butane sultone (BS), which preferentially adsorbs on the electrode surfaces. Upon water attack and localized pH increase, BS can be activated, generating open-ring derivatives (OBS) to facilitate the in situ construction of bilateral protective interphases with organic–inorganic composite components. Concurrently, it optimizes Zn²⁺ solvation structures to lower the desolvation energy barrier. Residual BS further traps SO₄²⁻ and H₂O and sustains the OBS formation for preventing interfacial alkalization. Consequently, the BS-modified Zn//Zn cell delivers a lifespan exceeding 4000 h, and the Zn//Cu cell attains an ultrahigh initial Coulombic efficiency of 97.62%. Zn//MnO₂ full cells maintain capacity retention of 92.7% and 80.5% after 100 cycles at 0.2 A g⁻¹ and 8000 cycles at 6 A g⁻¹, respectively. Such a strategy not only delivers a high-performance electrolyte additive for AZIBs but also offers biomimetic inspiration for the development of electrolytes in other metal-based battery systems.