Efficient Na‐Ion Storage in 2D TiS 2 Formed by a Vapor Phase Anion‐Exchange Process

Hierarchical nanocomposites that couple downsized 2D materials with carbonaceous functional supports are promising electrode materials for metal ion batteries. Herein, a honeycomb‐like Na‐ion battery (NIB) anode material, which comprises 2D downsized TiS 2 nanocrystals uniformly dispersed in a 3D porous carbon honeycomb, is developed by a vapor phase anion‐exchange reaction of CS 2 with a dual‐template of TiO 2 sealing in hydrogen‐substituted graphdiyne (HsGDY). On the one hand, the 2D downsized TiS 2 nanolayers offer much more accessible active sites for both Na + storage and polysulfide trapping; on the other hand, the 3D porous hollow carbon nanoscale honeycomb not only provides numerous space‐confined nanorooms to reduce the stacking of the tiny 2D TiS 2 nanolayers and suppress the dissolution of polysulfide, but also works as built‐in 3D conductive networks to support the electron/ion transfer and buffer the volume expansion during cycling. In light of this, such a hybrid 3D TiS 2 @carbon honeycomb achieves a high reversible capacity with high‐rate and long‐life performance for NIBs.