Enhanced performances of Li/polysulfide batteries with 3D reduced graphene oxide/carbon nanotube hybrid aerogel as the polysulfide host

Highlights: • Li/polysulfide batteries are proposed to improve the kinetics of sulfur batteries. • Reduced graphene oxide (rGO)-based aerogels are optimized as polysulfide host. • Nitrogen-doped rGO/CNT hybrid aerogel achieves high performances and long stability. Li-S batteries, though promising for long-distance electrical vehicles, are still not practically viable mainly due to the short cycling life arising from the polysulfide shuttle. Herein, we demonstrate a Li/polysulfide battery with 3D nitrogen-doped reduced graphene oxide (rGO)/carbon nanotube (CNT) hybrid aerogel as the binder-free and self-standing host for liquid polysulfide-containing catholyte. Hetero-dopants of nitrogen and CNT additives are found to significantly improve the electrochemical performances due to the abundant active catholyte/electrolyte interfaces, high rate charge-transfer paths, and spatially uniform depositing/stripping of reactants. The final hybrid aerogel achieves long cycling stability (0.11% capacity fading rate for 400 cycles) and high rate capability (767 mAh/g_sulfur at 2 C rate) at a high areal sulfur loading weight of ~6 mg/cm².