Lotus Root-like Structured Carbon Fibers as Encapsulated Sulfur Host for Lithium Sulfur Batteries

Novel lotus root-like carbon fibers with hierarchical pores are synthesized using alginate fibers as precursor. The as-prepared carbon fibers are of high specific surface area (similar to 1354 m(2) g(-1)) and large pore volume (similar to 1.27 m(2) g(-1)). The unique structure could,effectively anchor sulfur, confine polysulfides and provide sufficient space to buff sulfur volumetric expansion, which plays an important role during the electrochemical reaction of lithium sulfur batteries. Thus the lotus root-like carbon fibers/sulfur composite demonstrates a high initial capacity of 1477 mAh g(-1) at 0.1 C, excellent cycling stability (a reversible capacity of 1040.7 mAh g(-1) after 100 cycles), and good rate performance. (C) 2015 The Electrochemical Society. All rights reserved.