3D Co-doped carbon nanosheets as high-performance electrodes for Li-S batteries

Abstract

3D petal-shaped Cobalt-doped carbon nanosheets (PCoCNS) were synthesized as excellent sulfur hosts for lithium-sulfur (Li-S) batteries. Co doping enhanced the affinity of the carbon surface for lithium polysulfides (LiPSs), inhibiting the shuttle effect. The electrocatalytic effect of the PCoCNS electrode exhibited enhanced polysulfide conversion kinetics, thereby promoting Li₂S formation. Owing to the above advantages, the PCoCNS cathode exhibited satisfactory reversibility of 841 mAh/g with a high capacity retention of 91 %. Additionally, it displayed high coulombic efficiency (CE) values exceeding 97 % over 100 cycles at a current rate of 0.5C. Furthermore, the electrode demonstrated low polarization and exhibited an excellent rate performance, delivering a capacity of 575 mAh/g at the high rate of 3C. This study synthesized a promising sulfur cathode for enhancing the electrochemical performance of Li-S batteries.