Decoupling ionic transfer kinetics via undercoordinated constraints for energy-efficient and high-quality zinc electrowinning

Zinc electrowinning (ZE), a carbon-intensive process, suffers from high energy consumption due to the parasitic hydrogen evolution reaction (HER) and poor deposit quality. Conventional adsorption-based additives fail to simultaneously deliver high current efficiency (CE) and low cell voltage, sustaining energy inefficiency. To address this limitation, we propose an electrolyte engineering through undercoordinated topology constraint (UTC) to regulate Zn ²⁺ and proton transfer kinetics. Using weakly-coordinating additives, UTC weakens SO ₄ ²⁻ -Zn ²⁺ interactions while preserving locally continuous but long-range disordered hydrogen bond (HB) networks, thereby increasing the translational freedom ( f _trans ) of Zn ²⁺ and restricting proton transport. The resulting kinetics decoupling facilitates zinc deposition and suppresses HER at high current densities, thereby elevating CE and saving energy. Implemented with acetonitrile (ACN) as a model molecule, the decoupled ion transport homogenizes the interfacial ion and field distribution and directs the growth of corrosion-resistant (101)-faceted deposits. And the ACN-induced UTC enables ZE to achieve 94.3% CE with an energy demand of 2531.4 kWh t ^− 1 at 500 A m ^− 2 (40 ℃), a factor of only 1.55 above the theoretical minimum. It also demonstrates robust performance under extreme F ⁻ contamination (1 g L ^− 1 ), simultaneously boosting CE by 11.96% and slashing energy consumption by 12.87% at 700 A m ^− 2 . This work establishes electrolyte topology engineering as a powerful pathway to sustainable and energy-efficient metal electrowinning.