MoS2‐Nanosheet‐Decorated 2D Titanium Carbide (MXene) as High‐Performance Anodes for Sodium‐Ion Batteries

Sodium‐ion batteries (SIBs) are a promising alternative to lithium‐ion batteries for large‐scale energy storage applications. The intriguing 2D transition‐metal carbides/carbonitrides, also called MXenes, are increasingly being investigated as anodes as for SIB applications, owing to the merits of their metallic conductivity, low diffusion barrier for Na+, and good mechanical properties. However, the issue of low specific capacity has proven to be a difficult challenge to overcome. Herein, we synthesize a composite of MoS2/Ti3C2Tx to improve the ion accessibility of MXene layers by increasing the interlayer space and boost its specific capacity, where the MoS2 nanosheets are intercalated between Ti3C2Tx layers through a hydrothermal route. When tested as a SIB anode, the MoS2/Ti3C2Tx composite yielded a high specific capacity of 250.9 mAh g−1 over 100 cycles. More remarkably, the MoS2/Ti3C2Tx electrode displayed an exceeding rate performance with a capacity of 162.7 mAh g−1 at 1 A g−1. Remarkable rate performance: The hierarchical architecture of a MoS2/Ti3C2Tx composite is credited for an improved electrochemical performance, in which ultrasmall MoS2 nanosheets expand the interspacing of Ti3C2Tx layers, making the surface active sites more accessible for Na+.