Process optimization for producing hierarchical porous bamboo-derived carbon materials with ultrahigh specific surface area for lithium-sulfur batteries

Bamboo derived porous carbon materials, as inexpensive and environmentally friendly, microporous material sources, have been attracting enthusiastic attention for energy storage applications. In this work three different processes were employed to prepare three types of bamboo derived porous carbon materials. Among them, the sample prepared via a one-step activation method delivered the largest total pore volume (1.146 cm3 g−1) and the largest specific surface area (1824.4 m2 g−1) owning to a hierarchical porous structure. After the sample was used to encapsulate sulfur (S) to prepare carbon/S composite as cathodes for Li-S batteries. The composite loaded with 58.5 wt% S exhibited a high initial capacity of 1453 mAh g−1 at a rate of 0.1 C (1 C = 1675 mA g−1). A reversible capacity of 255 mAh g−1 was maintained after 500 cycles at 1 C with a capacity decay rate of only 0.0016% per cycle. This suggests that the bamboo derived porous carbon could be a promising conductive carbon matrix for carbon/S composite cathodes in Li-S batteries.