Two-dimensional mesoporous B, N co-doped carbon nanosheets decorated with TiN nanostructures for enhanced performance lithium–sulfur batteries

Two-dimensional (2D) mesoporous B, N co-doped carbon/TiN (BNC-TN) composites were synthesized for the first time via hydrogel method followed by an ionothermal route using polyvinyl alcohol, guanidine carbonate, and boric acid as the carbon, nitrogen, and boron sources, NH2-MIL-125 (Ti) as the TiN precursor. The as-synthesized BNC-TN not only possesses mesoporous 2D sheet-like structure, adjustable B, N co-doping and TiN content, but also effectively alleviates the lithium polysulfides (LiPSs) shuttle effect because of the porous framework, as well as polar TiN and doping heteroatoms as chemical anchors of LiPSs. S@BNC-TN cathode exhibited a high initial overall discharge capacity of 1130.9 mA h g−1 and a discharge capacity of 951.5 mA h g−1 after 50 cycles. This material offers a promising pathway to alleviate challenges facing lithium–sulfur batteries.