Fig. 2.

Electrochemical performance of cells with different sulfur mass loading. a, b Charge–discharge profiles of lithium–sulfur (Li–S) cells with sulfur loading of 2.5 mg cm⁻² and 5 mg cm⁻² under different porosity. c Cycle performance of cells with the sulfur loading of 5 mg cm⁻² under porosity of 70, 60, 50, and 40%. d Electrochemical impedance spectrum of sulfur electrode with porosity of 70, 60, and 50% (sulfur loading of 2.5 mg cm⁻²). e, f Li–S battery with electrolyte composed of dimethoxyethane (DME) and dioxolane (DOL) as solvent with 0.4 M lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)−0.6 M LiNO₃ and 3 M LiTFSI–0.2 M LiNO₃ (sulfur loading of 2.5 mg cm⁻²)