Lightweight Freestanding CeF₃Nanorod/Carbon Nanotube Composite Interlayer for Lithium-Sulfur Batteries

Although the lithium-sulfur battery has been developed for many years, how to restrain the intrinsic polysulfide shuttle is still a hot topic. Recently, it has been found that adding a multifunctional interlayer between cathode and separator can effectively inhibit the shuttle of polysulfides, while the lightweight factor of the interlayer commonly is ignored. In this work, a kind of lightly freestanding interlayer (0.16-0.4 mg cm-3) consisting of CeF3 nanorod (prepared by in situ fluorination of CeO2 nanorod in carbonization at 700 °C) and carbon nanotubes film (CF) is prepared. In this network structure, the CF network displays high electronic conduction and enhances the reaction kinetics for sulfur; CeF3 can effectively adsorb polysulfides and enhance the cycle performance. Especially, the battery exhibits an initial specific capacity of 1505 mAh g-1 at 0.05 C, and the capacity decay after 100 cycles is only 0.063% per cycle. In addition, it retains a discharge capacity of 951 mAh g-1 over 100 cycles at 0.2 C and 542 mAh g-1 over 500 cycles at 1 C. Lightly freestanding CeF3/CNTs interlayer show a high application potential in the lithium-sulfur batteries.