Fig. 4: Electrochemical properties of the rechargeable Na–Cl₂ battery using the ester-based electrolyte.

a Galvanostatic charge-discharge curves of the rechargeable Na–Cl₂ batteries using the AM and ANM electrolytes at 150 mA g⁻¹. The charge capacity is 1200 mAh g⁻¹, corresponding to an areal capacity of 1.4 mAh cm⁻². b Cycling performance of the rechargeable Na–Cl₂ batteries using the AM and ANM electrolytes at 1000 mA g⁻¹. The specific charge capacity is 200 mAh g⁻¹. c Nyquist plots of the Na–Cl₂ batteries using the AM and ANM electrolytes. d Cycling performance of the rechargeable Na–Cl₂ battery using the ANM electrolyte at 80 °C. The charge capacity and current density are 800 mAh g⁻¹ (0.9 mAh cm⁻²) and 200 mA g⁻¹, respectively. The inset shows the representative galvanostatic charge-discharge curves of the resultant battery at the 12th cycle. e Galvanostatic charge-discharge curves of the rechargeable Na–Cl₂ battery using the ANMC electrolyte at increasing temperatures from −40 °C to 80 °C. The charge capacity and current density are 200 mAh g⁻¹ and 150 mA g⁻¹, respectively. f Cycling performance of the rechargeable Na–Cl₂ battery using the ANMC electrolyte at −40 °C. The charge capacity and current density are 200 mAh g⁻¹ and 150 mA g⁻¹, respectively.