Nickel Oxide Nanoparticles/Ordered Mesoporous Carbon Nanocomposites as Anode Materials for Lithium-Ion Battery with Improved Electrochemical Performance

A controllable synthetic route was developed to synthesize nanocrystalline NiO nanoparticles incoporated in ordered mesoporous carbon (OMC), with an adjustable size, content and distribution of NiO nanoparticles, as anode materials for lithium ion batteries (LIBs) with improved electrochemical lithium storage performance. The effects of size, distribution and content of NiO nanoparticles on the electrochemical performances of the mesoporous NiO/OMC nanocomposites as anode materials for LIBs were investigated using galvanostatical charge-discharge and cyclic voltammetry techniques. An optimal 20% NiO content of the one-step route synthesized of 20NiO/OMC nanocomposite with NiO nanoparticles homogeneously embedded within OMC matrices, and with a smaller size of 10 nm of NiO nanoparticles, displays a highly improved rate capability and reversible capacity for LIBs, exhbiting a high specific capacity up to 762 mAh g(-1), and a high coulombic efficiency of up to 98.4% after 60 cycles at a current density of 100 mA g(-1). Even at a high current of 1600 mA g(-1), it still delivers a capacity of 272 mAh g(-1), about 5 times the capacity of pure OMC sample. Such significant improvement of electrochemical performance is ascribed to the unique structures of the NiO/OMC nanocomposites with a variety of favorable properties. The OMC matrix with a thin wall provides short solid-state diffusion length of Li, building electron passway between the dielectric NiO nanoparticles, hinder the agglomeration of NiO nanoparticles and buffer the volume change of NiO during discharge/charge processes. The addition of appropriate amount of NiO nanoparticles provides a proper surface area to appropriately reduce the number of active sites of OMC and increase the capacity retention. The synergetic effect between the conducting OMC matrix and NiO nanoparticles makes it a promising anode material for LIBs with high specific capacity, high rate capability, high coulombic efficiency.