Sulfur embedded in one-dimensional French fries-like hierarchical porous carbon derived from a metal–organic framework for high performance lithium–sulfur batteries

Abstract

Lithium–sulfur (Li–S) batteries suffer from poor cycling stability mainly caused by one of their own drawbacks, namely, the shuttle effect, which makes them far from conquering the marketplace. To tackle this problem, a novel French fries-like hierarchical porous carbon (FLHPC) with a one-dimensional (1D) structure was constructed by carbonizing an aluminum metal–organic framework (Al-MOF). In FLHPC, sulfur was infiltrated mainly into the micro- and mesopores, while macro-pores were used to facilitate the transportation of Li ions (Li⁺). On the basis of this concept, even without LiNO₃ as additive, Li–S batteries not only delivered a high initial discharge capacity of nearly 1200 mA h g⁻¹ at 0.1 C (1 C = 1672 mA h g⁻¹) but also showed good cycling stability with a capacity retention of 68% at 0.5 C after 200 cycles. In addition, when the capacity rate (C-rate) was increased to 2 C, a high discharge capacity of 763 mA h g⁻¹ was obtained after 20 cycles, proving their excellent C-rate performance.