Chi 760 electrochemical workstation

CR2032 coin cells were assembled in an argon-filled glove box (O₂ and H₂O levels < 0.1 ppm) for the electrochemical measurements, where the as-prepared sulfur electrode, Celgard 2500 membrane, and Li foil were used as the cathode, separator, and anode, respectively. The electrolyte was 1.0 mol L⁻¹ lithium bis (trifluoromethanesulfonyl) imide (LiTFSI) and 1.0% lithium nitrate (LiNO₃) dissolved in the cosolvents of 1,3-dioxolane (DOL) and 1,2-dimethoxyethane (DME) (v/v = 1:1) with N-CD additives of 0, 0.3, 0.5, 1.0, and 5.0 wt%. The ratio of added electrolyte volume/active sulfur weight was set at 20 μL mg⁻¹. Galvanostatic charge–discharge tests were carried out within the cut-off voltages of 1.7−2.8 V using a LAND CT2001A cell test instrument. The current density and the specific capacity were calculated according to the mass of elemental sulfur (1C = 1675 mA g⁻¹). For shuttle current measurement, cells with a sulfur loading of ~2 mg cm⁻² were assembled without adding LiNO₃. In the cycling process at 0.2 C, the shuttle current of cells was detected via potentiostatic hold on charge at 2.38 V. Cyclic voltammetry measurements were conducted on a Chenhua CHI-760 electrochemical workstation with a scan rate of 0.1 mV s⁻¹ in the potential range of 1.7–2.8 V.