Anionic corrosion inhibitors facilitate preferential Zn (002) deposition in aqueous zinc-ion batteries

The formation of by-products significantly hinders ion transport in aqueous zinc-ion batteries (AZIBs), adversely affecting the stability of Zn metal anodes. Inspired by the scale-inhibition effect in oilfield chemistry, we introduced a hydrolysis-resistant 2-acrylamide-2-methylpropanesulfonic acid (AMPS) monomer additive with strong anionic groups into the electrolyte to form a high-quality solid electrolyte interphase. This interphase ensures the inhibition of hydrogen evolution reaction (HER), resulting in stabilizing the local pH through reduced H⁺ consumption and minimizing the formation of by-products. Leveraging the strong polarity of the –SO₃H in AMPS, the solvation structure of Zn²⁺ and the surface energy of the zinc substrate during deposition are effectively modulated. This behavior mitigates uneven nucleation at grain boundaries and defects, which facilitates the ordered deposition of Zn along the (002) plane, contributing to improved Zn electrode stability. Therefore, the Zn//Zn cell demonstrates cycling stability for over 4500 h at 1 mA·cm⁻²/1 mAh·cm⁻², while the Zn//MnO₂ full cell retains 84% of its capacity after 4500 cycles. We believe our design concept offers a new pathway for developing by-product-free high-stability AZIBs.