Rational design of a nested pore structure sulfur host for fast Li/S batteries with a long cycle life

Abstract

A nested pore structure carbon with spherical quad-modal pores was designed and used as a sulfur host material in Li/S batteries. The carbon pores were interconnected and there was an orderly distribution of 2.5, 15, 24 and 100 nm pores, giving a high pore volume of 4.15 cm³ g⁻¹. The delicate nested pore structure allowed a uniform distribution of sulfur and rapid access of the electrolyte across the carbon, leading to an excellent C-rate performance and cycle stability. Even at 3C, the C/S composite containing 78 wt% S still delivered a maximum discharge capacity of 1228 mA h g⁻¹ and maintained a reversible capacity of 914 mA h g⁻¹ after 200 cycles.