▎ 摘　　要

Exploring scalable and cost-effective material preparation route is critical for achieving the commercialization of lithium-sulfur batteries. Herein, nitrogen and sulfur codoped carbon dots/reduced graphene oxide (N,S-CDs/ rGO) composites are facilely fabricated via hydrothermal and annealing treatment of a mixture of graphene oxide and egg-white without additional reactants. The egg-white, not only act as heteroatoms source, but also produce carbon dots. The as-prepared material possesses a porous architecture with N,S-codoping into both graphene and carbon dots. Benefiting from combined advantages of each constituent, such as superior electrical conductivity, abundant edges and doping sites, N,S-CDs/rGO cathodes (with 65 wt% and 76 wt% sulfur content) exhibits enhanced performances characterize by a higher rate capability and high sulfur utilization. For instance, N,S-CDs/rGO@S65 cathode exhibits a capacity of 1550 mAh g-1 at 0.5 C and still kept high capacities of 1038, 861.1 and 783.6 mAh g(-1) at 1, 3, and 5 C respectively. Even at an ultra high rate of 7 C, a capacity of 740.8 mAh g(-1) is sustained. Moreover the cathode retains 427.9 mAh g(-1) reversible capacity after 600 cycles at 5 C. This work provides a new route toward the simple design of cathode for advanced Li-S cells.