Rational Design of a MnO Nanoparticle-Embedded Carbon Nanofiber Interlayer for Advanced Lithium–Sulfur Batteries

Lithium–sulfur (Li–S) batteries with superb theoretical capacity possess great potential to achieve high-energy density storage systems; however, many inherent and fatal obstacles, especially for polysulfide shuttling, greatly hinder the wide-range application of this technique. Herein, a rationally designed multichannel carbon nanofiber interlayer embedded with MnO nanoparticles (MnO/mCNF) is presented as a multifunctional interlayer to cope with the shuttling problem in Li–S batteries. MnO/mCNF can provide multifunctionalities including physical blocking, chemical/physical adsorption, and rapid polysulfide conversion synchronously, enabling more active sulfur to participate in energy-storage reactions. The multichannel architecture provides sufficient active surfaces and active sites to anchor polysulfides. Consequently, the Li–S batteries packed with a MnO/mCNF interlayer presented a high reversible capacity (730 mA h g–1 at 1 C; 92% capacity retention after 400 cycles). Density functional theory calculation results infer that the MnO particles have strong adsorption ability with all kinds of polysulfides, which take responsibility for the suppression of polysulfides. This work paves a scalable method for the practical application of Li–S batteries.