Ni_0.33Co_0.66(OH)F hollow hexagons woven by MWCNTs for high-performance lithium-ion batteries

A template-free two-step strategy is successfully developed for the low-cost one pot production of Ni_0.33Co_0.66(OH)F hollow hexagons woven by multi-walled carbon nanotubes (MWCNTs). The MWCNTs in situ thread the hollow Ni_0.33Co_0.66(OH)F hexagons and form an interconnected three-dimensional network. Owing to the integration of MWCNTs and the formation of a fluoride derivative as well as the unique hollow structure of the Ni_0.33Co_0.66(OH)F hexagon, the composite presents excellent electrochemical properties including high reversible capacity and stable cycle performance. As materials for lithium ion batteries, the Ni_0.33Co_0.66(OH)F hollow hexagons woven by MWCNTs deliver a high reversible capacity of 1014 mA h g^-1 after 100 charge-discharge cycles (current density of 100 mA g^-1). At a current density of 1000 mA g^-1, a high capacity of 585 mA h g^-1 also could be achieved, indicating the potential application of these materials in high-performance electrochemical energy storage.