Cobalt based selenides nanocrystals modified with multifunctional carbon nanotubes for high performance lithium ion batteries.

Design and fabrication of transition metal chalcogenides hybrids for improved electrochemical performance are hotspot in materials research field. In this work, Co 0.85 Se and CuCo 2 Se 4 nanocrystals anchored on the carbon nanotubes are designed and synthesized using multifunctional carbon nanotubes as template (Co 0.85 Se/CNTs and CuCo 2 Se 4 /CNTs). The cooperation of the Co 0.85 Se and CuCo 2 Se 4 nanocrystals and the multifunctional carbon nanotubes effectively alleviate the volume variation, enhance the active reaction site and accelerate the charge transfer of Li+. Therefore, the Co 0.85 Se/CNTs and CuCo 2 Se 4 /CNTs hybrids deliver excellent electrochemical performance including superior cycle stability and high rate capacities. At high rate of 2000 mA g−1, the reversible capacities up to 566 and 479 mAh g−1 are achieved after 500 cycles. [Display omitted] • Co 0.85 Se and CuCo 2 Se 4 nanocrystals anchored on multifunctional CNTs were fabricated. • The coorperation of nanocrystals and CNTs improve the electrochemical performance. • Co 0.85 Se/CNTs and CuCo 2 Se 4 /CNTs display excellent performance at high current rate. [ABSTRACT FROM AUTHOR]