Fig. 5: Applications of the rechargeable Na–Cl₂ battery based on ester-based electrolyte.

a Comparison of the retention capability of the rechargeable Na–Cl₂ batteries using ANM and SOCl₂ electrolytes. Voltage-time curves of the batteries were recorded in the fully charged states at 50 °C. The batteries were alternately cycled at 200 mAh g⁻¹ and 150 mA g⁻¹ to validate the electrochemical performance. b Photographs of the rechargeable Na–Cl₂ pouch cells after 3-day retention at 25 °C. c Variations of the temperature and voltage of the Na–Cl₂ pouch cell in the nail penetration test. The inset shows the temperature distribution of the cell right after the nail penetration test. d Cycling performance of rechargeable Na–Cl₂ pouch cell using the ANM electrolyte at a charge capacity of 100 mAh and a current density of 200 mA g⁻¹. e Cycling performance of the rechargeable Na–Cl₂ fiber battery based on the ANMC electrolyte at increasing temperatures, such as −20, 0, 25, 50, and 80 °C. The charge capacity and current density are 200 mAh g⁻¹ and 150 mA g⁻¹, respectively.