Improved Na Storage Performance with the Involvement of Nitrogen-Doped Conductive Carbon into WS2 Nanosheets

Tungsten disulfide (WS2) material is regarded as one of the most promising anode candidates for sodium ion batteries (SIBs). However, the exploration of this material still remains a great challenge to improve its cycling capacity. In this paper, nitrogen-doped conductive carbon/WS2 nanocomposites (WS2-NC) were fabricated based on the synthesis of the pure WS2 and conductive carbon/WS2 (WS2-C) nanocomposites. The reversible capacity of the as-prepared WS2-NC is stabilized at ∼360 mA h g(-1) at the density of 100 mA g(-1), even ∼200 mA h g(-1) at 1 A g(-1), presenting much better cycling performance than pure WS2 and conductive carbon/WS2 (WS2-C) samples. This excellent performance is further attributed to obviously promoted interfacial reaction in WS2 nanosheets at a low voltage platform (0.3-0.0 V), which is considered to closely relate to the incorporation of nitrogen-doped conductive carbon into WS2 nanosheets. Generally, this work presents an obviously enhanced Na storage performance by the incorporation of N-doped carbon into WS2 nanosheets to promote their interfacial reaction at low voltage platform. It could provide guidelines to create other high-capacity anode sulfide materials for SIBs.