Anchoring SnS 2 on TiC/C Backbone to Promote Sodium Ion Storage by Phosphate Ion Doping.

Tin disulfide (SnS2) shows promising properties toward sodium ion storage with high capacity, but its cycle life and high rate capability are still undermined as a result of poor reaction kinetics and unstable structure. In this work, phosphate ion (PO43-)-doped SnS2(P-SnS2) nanoflake arrays on conductive TiC/C backbone are reported to form high-quality P-SnS2@TiC/C arrays via a hydrothermal-chemical vapor deposition method. By virtue of the synergistic effect between PO(4)(3-)doping and conductive network of TiC/C arrays, enhanced electronic conductivity and enlarged interlayer spacing are realized in the designed P-SnS2@TiC/C arrays. Moreover, the introduced PO(4)(3-)can result in favorable intercalation/deintercalation of Na(+)and accelerate electrochemical reaction kinetics. Notably, lower bandgap and enhanced electronic conductivity owing to the introduction of PO(4)(3-)are demonstrated by density function theory calculations and UV-visible absorption spectra. In view of these positive factors above, the P-SnS2@TiC/C electrode delivers a high capacity of 1293.5 mAh g(-1)at 0.1 A g(-1)and exhibits good rate capability (476.7 mAh g(-1)at 5 A g(-1)), much better than the SnS2@TiC/C counterpart. This work may trigger new enthusiasm on construction of advanced metal sulfide electrodes for application in rechargeable alkali ion batteries.