Suppressing Hydrogen Evolution via Anticatalytic Interfaces toward Highly Efficient Aqueous Zn-Ion Batteries.

Abstract

Aqueous Zn-ion batteries hold practical promise for large-scale energy storage because of the safety and affordability of aqueous-based electrolytes; in addition, the manufacturing process is significantly simplified by direct employment of Zn metal as an anode. However, hydrogen evolution due to near-surface water dissociation has hindered large-scale applications of them. Here, we report the suppression of the hydrogen evolution reaction via a CuN₃-coordinated graphitic carbonitride (CuN₃-C₃N₄) anticatalytic interface to achieve highly efficient aqueous Zn-ion batteries. Based on <i>in situ</i> gas chromatography and <i>in situ</i> synchrotron-based X-ray diffraction spectroscopy, we demonstrated that the hydrogen evolution reaction triggers the Zn₄SO₄(OH)₆·<i>x</i>H₂O formation. A combination of <i>in situ</i> infrared spectroscopy and density functional theory simulations has proved to stabilize near-surface H₃O⁺ species and regulate adsorption of H* intermediates by an anticatalytic interface for hydrogen evolution reaction suppression. Consequently, the anticatalytic interface greatly improves the Coulombic efficiency of Zn plating/stripping to ∼99.7% for 5500 cycles and the cycling reversibility to over 1300 h at 1 mA cm^-2 and 1 mAh cm^-2. With an anticatalytic interface, the full cell shows an excellent Coulombic efficiency of 98.3% over 400 cycles at 1C. These findings provide strategic insight for targeted designing of highly efficient aqueous Zn-ion batteries.