Fig. 5

Electrochemical performance of cathodes. a Initial discharge–charge profiles at 0.1 C between 1.7 and 2.8 V vs. Li⁺/Li, b cyclic capacities and Coulombic efficiencies at 0.1 C for 200 cycles, c discharge–charge voltage profiles of the porous carbon nanofiber/sulfur/black phosphorus quantum dot (PCNF/S/BPQD) cathode at different rates, d cyclic capacities at different rates, e high plateau and low plateau discharge capacities derived from rate performance, f cyclic performance of the PCNF/S/BPQD at 0.1 C for 200 cycles with increasing sulfur loadings of 4, 6, and 8 mg cm⁻²