Carbon Foam Fibers with a Concentric Tube‐Core/Three‐Dimensional Nanosheet‐Sheath Structure for High‐Performance Lithium‐Sulfur Batteries

Owing to their superior electrical conductivity and large specific surface areas, carbon nanomaterials are widely applied as hosts for lithium‐sulfur (Li−S) batteries. However, it is challenging to design and prepare hierarchical porous carbon nanomaterials with unique structures that have excellent performances for Li−S batteries. Herein, hierarchical carbon foam fibers (HPCFs) with a concentric tube‐core/three‐dimensional nanosheet‐sheath structure have been rationally designed and fabricated through solution‐combustion and etching methods, and are suitable for Li−S batteries. The as‐prepared HPCFs, with a sulfur loading of 72 wt.%, possess a high initial discharge capacity of 1097.3 mAh g −1 and 68.7 % retention after 500 cycles at 0.2 C. The as‐designed structure can efficiently improve conductivity, suppress the dissolution of polysulfides, and provide quick electron‐/ion‐transfer channels, which are beneficial for designing advanced sulfur cathodes for high‐performance Li−S batteries.