Bimetal-organic frameworks derived ternary metal sulphide nanoparticles embedded in porous carbon spheres/carbon nanotubes as high-performance lithium storage materials

摘要: Abstract Designing advanced structures to ameliorate the deficiencies of conversion anodes in terms poor conductivity and sever volume change over cycling is still attracting area for fundamental research but challenging, toward which more efforts are needed. Here, we demonstrate synthesis a hierarchical composite CoNi2S4 from sulfurizing elaborately designed Co/Ni bimetal-organic frameworks (MOF-74) precursors with well-defined sphere morphology. In this composite, nanoparticles evenly embedded carbon nanosheets situ carbonized organic ligand self-assembled into porous spheres short nanotubes (CNTs) deeply rooted surface (CoNi2S4@PCS/CNTs). The structure provides favourable paths electrolyte penetration spaces changing upon cycling, while outwardly grew CNTs skeleton guarantee fast electron transfer. Beneficial robust plus synergetic effect two different metal elements, obtained CoNi2S4@PCS/CNTs demonstrates excellent lithium storage performance reversible capacity (1250 mAh g−1 at 500 mA g−1), cycle stability (843 mAh g−1 1 A g−1 after 600 cycles) rate capability (608 mAh g−1 4 g−1). kinetic analysis reveals that benefit capacitive contribution under faradaic pseudocapacitive mechanism, especially high current densities. This work an effective strategy combines metals insertion advantages design enhance materials.