Circuit board-like CoS/MXene composite with superior performance for sodium storage

Electrochemical performance of Ti3C2 MXene sheet is restricted by the modest specific capacity and self-re-stacking. To conquer the defects, we designed cobalt sulfide and Ti3C2 MXene flake composite (CoS/MXene) with heterolayered architecture, in which ultrafine CoS nanoparticles (similar to 6 nm) were anchored on MXene flakes. In this structure, the role of MXene is similar to printed circuit board, which providing conducive network. As anode for sodium ion batteries, CoS/MXene electrode delivers a high reversible capacity of 267 mA h g(-1 )after 1700 cycles at 2 A g(-1) with an extreme low capacity decay rate of only similar to 0.0072% per cycle, and an outstanding rate performance with 272 mA h g(-1) at 5 A g(-1).