Fig. 1

Schematic for the preparation process of O-NiCo2S4/CNT composite"

Fig. 2

(a) XRD patterns; (b) Raman patterns; (c) TGA patterns of NiCo2S4/CNT and O-NiCo2S4/CNT composites"

Fig. 3

(a) SEM image; (b) TEM image; and (c) SAED image of NiCo2S4/CNT; (d) SEM image; (e) TEM image; (f) SAED image and (g) HRTEM of O-NiCo2S4/CNT; (h) HAADF-STEM of O-NiCo2S4/CNT and the corresponding EDS-Mapping"

Fig. 4

High-resolution spectra of (a) Co 2p; (b) Ni 2p; (c) S 2p; (d) O 1s and (e) C 1s of NiCo2S4/CNT and O-NiCo2S4/CNT composites; (f) UV-vis image of Li2S6, CNT, O-CNT, NiCo2S4/CNT, and O-NiCo2S4/CNT at 3 mmol/L (inset shows the visualized adsorption image)"

Fig. 5

(a) CV plots of PP, CNT, NiCo2S4/CNT and O-NiCo2S4/CNT functionalized separators at a sweep rate of 0.1 mV/s; (b) Tafel curve fits corresponding to the oxidation and (c) reduction reactions"

Fig. 6

(a)—(c) CV plots of Li-S cells by using PP, NiCo2S4/CNT, and O-NiCo2S4/CNT functionalized separators at scan rates of 0.1—0.5 mV/s; (d)—(f) corresponding to their peak current versus scan rate square root fits"

Fig. 7

(a) CV profiles of Li2S6 symmetric cells comprising different functionalized separators; (b)—(d) nucleation behavior of different functionalized separators in Li2S8 electrolyte; deposited Li2S morphology for (e) CNT, (f) NiCo2S4/CNT, and (g) O-NiCo2S4/CNT"

Fig. 8

Cycling performance of NiCo2S4/CNT at different E/S ratios with 0.2 C current density"

Fig. 9

(a) EIS diagrams of different functionalized separators; (b) charge/discharge curves of O-NiCo2S4/CNT at different multipliers; (c) multiplier performance diagrams of different functionalized separators; (d) charge/discharge curves of O-NiCo2S4/CNT at 0.2 C current density; (e) cycle performance of different functionalized separators at 0.2 C current density"