High‐Voltage Supercapacitive Swing Adsorption of Carbon Dioxide

Supercapacitive swing adsorption (SSA) with garlic roots‐derived activated carbon achieves a record adsorption capacity of 312 mmol kg −1 at a low energy consumption of 72 kJ mol −1 and high mass loadings (>30 mg cm −2 ) at 1.0 V for 85%N 2 /15%CO 2 mixtures. The activated carbons are inexpensively prepared in a one‐step process using potassium carbonate, and air as activators. The adsorption capacity further increases with increasing voltage. At a voltage of 1.4 V, a sorption capacity of 524 mmol kg −1 at an energy consumption of 130 kJ mol −1 can be achieved. The volumetric sorption capacity is also enhanced and reaches values of 85.7 mol m −3 at 1.0 V, and 126 mol m −3 at 1.4 V. Cycle stability for at least 130 h is demonstrated.