Loading Fe3O4 nanoparticles on paper-derived carbon scaffold toward advanced lithium–sulfur batteries

Lithium–sulfur batteries (LSBs) are regarded as a competitive next-generation energy storage device. However, their practical performance is seriously restricted due to the undesired polysulfides shuttling. Herein, a multifunctional interlayer composed of paper-derived carbon (PC) scaffold, Fe3O4 nanoparticles, graphene, and graphite sheets is designed for applications in LSBs. The porous PC skeleton formed by the interweaving long-fibers not only facilitates fast transfer of Li ions and electrons but also provides a physical barrier for the polysulfide shuttling. The secondary Fe3O4@graphene component can reduce the polarization, boost the attachment of polysulfides, and promote the charging-discharging kinetics. The outer graphitic sheets layers benefit the interfacial electrochemistry and the utilization of S-containing species. The efficient obstruction of polysulfides diffusion is further witnessed via in situ ultraviolet-visible characterization and first-principles simulations. When 73% sulfur/commercial acetylene black is used as the cathode, the cell exhibits excellent capacity retention with high capacities at 0.5 C for 1000 cycles and even up to 10 C for 500 cycles, an ultrahigh rate capability up to 10 C (478 mAh g−1), and a high areal-sulfur loading of 8.05 mg cm−2. The strategy paves the way for developing multifunctional composites for LSBs with superior performance.