With continuous price drop of the renewable electricity, electrochemical CO₂ capture approaches are gaining increasing attention owing to their advantages of low temperature operation, high energy efficiency and flexible plug-and-play operation mode. However, the existing electrochemical approaches are either energy-intensive or inefficient with impractically low current densities. Herein, we report an electrowinning-coupled CO₂ capture (ECC) system which integrates commercially-applied hydrometallurgical technique of electrowinning with solvent-based CO₂ absorption for an energy-efficient CO₂ capture. Using copper as the electrochemical medium and ammonia as the CO₂ capture sorbent, the ECC system receives comprehensive investigations including thermodynamic modelling, linear sweep voltammetry measurement, microkinetic modelling, CO₂ desorption performance measurement and full ECC cell operation. We experimentally achieve a low energy requirement of 52 kJ_e/mol CO₂ at anodic and cathodic current densities of 470 A/m² and 2500 A/m², respectively. This energy performance is very competitive with the state-of-the-art electrochemical CO₂ capture systems that usually require electrical energy of > 100 kJ_e/mol CO₂ at current density of > 50 A/m². The experimentally-obtained results indicate that the ECC system using inexpensive copper electrodes and ammonia-based electrolytes can offer a practical approach for energy-efficient CO₂ capture.