The relationship between voltage window, resistance, and energy consumption is shown in Figure . The resistance values vary between 10 Ω.cm 2 to 16 Ω.cm 2 within the standard deviation from -1 V to -1.6 V, suggesting that thicker GR-AC electrodes (1 mm) with high mass-loadings (38 mg/cm 2 ) can still show good charge transport behavior. These resistance values are lesser than all the previously reported biomass-derived electrodes used for SSA. This signifies that the modified synthesis and electrode preparation procedure for garlic-roots derived activated carbon electrodes is critical to achieve better electronic conductivity. A record low energy consumption of ∼70 kJ.mol -1 is observed at -1 V voltage window (Figure ). The energy consumption increases to 97 kJ.mol -1 at -1.2 V, 166 kJ.mol -1 at -1.4 V, and 311 kJ.mol -1 at -1.6 V, respectively. Since energy consumption is the ratio of energy loss to the moles of CO2 adsorbed, the increased energy loss at high voltage windows results in increased energy consumption values. Minimizing the voltage holding times and increasing the SSA adsorption rates can improve the energy consumption values. To verify this statement, we performed additional experiments at higher gas flow rate of 5 sccm compared to 1 sccm used in the previous experiments. The results showed that the SSA energy consumption can be reduced to 130 kJ kJmol -1 at -1.4 V and 191 kJmol -1 at -1.6 V, respectively (Table ). The experiments further showed that the full CO2 adsorption capacity of GR-AC electrodes is 524 mmol.kg -1 at -1.4 V and 578 mmol.kg -1 at -1.6 V. The adsorption kinetics also increases at higher flow rates, but the gas purity decreases (Figure ). Additional SSA experiments at voltage window of -2.0 V (Figure ) showed large deviation from the capacitive type of behavior, poor coulombic/energy efficiency, and very large energy consumption, arguing that the working voltage window of SSA must be within the recommended operating voltage window of carbon-based aqueous supercapacitors (< 1.6 V). A comparison of SSA adsorption and desorption capacities after ageing the electrodes for six days showed significantly higher CO2 desorption capacity (807 mmol.kg -1 ) at -2 V compared to the adsorption capacity (641 mmol.kg -1 ), while the adsorption and desorption capacity at -1.6 V are almost the same (∼570 mmol.kg -1 ) (Figure ). This indicates that at very high voltage the carbon in the electrodes is partially oxidized to form CO2, further confirming the detrimental effects of electrodes charging above the 1.6 V limit. The charge efficiency (CE) of GR-AC electrodes is around 0.3 up to -1.2 V which is higher than all the previously reported values. The CE slightly reduces to 0.26 at -1.4 V, and further reduces to 0.21 at -1.6 V (Figure ). The improved charge efficiencies may be due to improved pore accessibility to H + /HCO3 -/CO3 2-, leading to a more effective removal of these ions from the chemical equilibrium. Nevertheless, further improvement in CE without narrowing down the voltage window or using expensive ion-selective membranes is desirable, which may be achieved through further pore size engineering of activated carbons. Time energy efficiency (TEE) signifies the amount of CO2 adsorbed per unit time per unit energy and is maximum at -1 V (Figure ). TEE decreases almost linearly from 2.0 μmol.KJ -1 .s -1 at -1 V to 0.4 μmol.KJ -1 .s -1 at -1.6 V. Further minimization of cycle times and energy consumption at high voltage windows are needed to increase the TEE values.