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

Abstract

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, Fe 3 O 4 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 Fe 3 O 4 @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. Loading Fe 3 O 4 nanoparticles on paper-derived carbon scaffold is demonstrated to greatly improve reversible capacity and cycle stability when used as the interlayer in lithium–sulfur batteries, because of the effective ionic sieve, which can selectively sieve Li + ions while efficiently inhibiting undesired polysulfides from moving to the anode side.