Interfacial Engineering on Cathode and Anode with Iminated Polyaniline@rGO-CNTs for Robust and High-Rate Full Lithium–Sulfur Batteries

Abstract

Lithium–sulfur batteries (LSBs) currently suffer from severe polysulfide shuttling, slow redox kinetics at the sulfur cathode, and irreversible dendrite growth at the lithium anode. To address these issues, a dual interfacial engineering strategy on both the cathode and anode is proposed. For the cathode, iminated polyaniline (iPANI) is used to achieve energetic engineering to induce mid-energy level to the adsorption of polysulfides, and catalyze the redox conversion of sulfur species, and realize morphological engineering via self-assembly of iPANI onto a scaffold integrated by reduced graphene oxide (rGO) and carbon nanotubes (CNTs), namely iPANI@rGO-CNTs. For the anode, the highly conductive and lithiophilic nature and porous nanostructure of the iPANI@rGO-CNTs composite facilitates the uniform deposition of lithium-ions, significantly preventing the growth of lithium dendrites. Density functional theory calculations suggest that the iminated functional group at the excited state in iPANI can significantly suppress the shuttling effect, catalyze the conversion of sulfur species, and enhance the conversion of the sulfur species on the sulfur cathode. With the synergic effects of the iPANI@rGO-CNTs nanoreactors, the as-prepared LSBs deliver an excellent rate capability and outstanding cycling life. This large-scale production and application of the iPANI@rGO-CNTs nanocomposite may lead to the eventual commercialization of LSBs.