CoSe/Co nanoparticles wrapped by in situ grown N-doped graphitic carbon nanosheets as anode material for advanced lithium ion batteries

Transition metal chalcogenides are potentially promising anode materials for fabricating good-performance lithium-ion batteries (LIBs). Here in this work, CoSe nanoparticles are synthesized via a facile heating process using cobalt-based metal organic framework (ZIF-67) and selenium powder as precursor, and, simultaneously, the in situ formation of N-doped graphitic carbon (NC) nanosheets is also achieved by adding certain amount of dicyandiamide, finally forming a unique structure, in which CoSe/Co nanoparticles are wrapped in layered carbon nitride nanosheets (CoSe/Co@NC). The incorporation of NC coating helps maintain the structural integrity of the composite, ensuring its stability in long term cycling. As a result, the CoSe/Co@NC composite presents a specific capacity of about 630 mAh g−1 at 0.2 A g−1 after 100 cycles and 640 mAh g−1 at 1 A g−1 after 500 cycles.