Cobalt sulfide nanoparticles anchored in three-dimensional carbon nanosheet networks for lithium and sodium ion batteries with enhanced electrochemical performance.

In order to improve the conductivity and electrochemical activity, CoS nanoparticles anchored in three-dimensional carbon nanosheet networks (3D CoS@CNNs) are fabricated by a simple strategy with the assistance of NaCl. Combining the advantages of nanoscale and porous structure, 3D CoS@CNNs can retard the aggregation of CoS nanoparticles, provide abundant electrochemical active sites, as well as accommodate the mechanical stress during the cycling of lithium ion batteries (LIBs) or sodium ion batteries (SIBs). Thus, when evaluated as an anode for LIBs, the as-prepared 3D CoS@CNNs electrode exhibits outstanding electrochemical performance with a high reversible capacity of 935mAhg after 200 cycles at 0.25Ag. As for SIBs, it also delivers superior cycling stability with a capacity of 249mAhg after 50 cycles at 0.1Ag. These results demonstrate that 3D CoS@CNNs composite has potential to be utilized as an anode material for LIBs/SIBs with enhanced electrochemical performance.