CeO2-webbed carbon nanotubes as a highly efficient sulfur host for lithium-sulfur batteries

The lithium-sulfur batteries have obtained tremendous interest as the next-generation of rechargeable battery systems due to the high theoretical specific capacity of sulfur, 1675 mAh g(-1). However, the practical application of lithium-sulfur batteries is still hindered by fast capacity fading and poor cycling stability. In this work, CeO(2-)webbed carbon nanotubes (CeO2@ CNT) is designed and synthesized by solvothermal reaction and used as a conceptually new sulfur host for lithium-sulfur batteries. In this unique architecture, the carbon nanotubes form a three-dimension porous conductive network to provide fast electron paths. In addition, the nanosized CeO2 crystallites can chemically bind polysulfides to suppress the polysufides diffusion into electrolyte. As a result, the lithium-sulfur batteries based on this electrode material exhibit high specific capacity, superior cycling stability, and good rate capability. Reversible specific capacities of 1359 and 715 mAh g(-1) are achieved at rates of 0.1 and 1C, respectively, together with an excellent cycling stability of 0.07% capacity decay per cycle over 600 cycles at 0.5 C.