The electrochemical performance of pitch coke anodes containing hollow carbon nanostructures and nickel nanoparticles for high-power lithium ion batteries

Pitch cokes with abundant hollow carbon nanostructures (HCNs) and nickel nanoparticles were prepared from pitch containing nickel nanoparticles by simple heat-treatment process. The effects of nickel content and heat-treatment temperatures on the electrochemical properties were analyzed systematically. Two kinds of pitch cokes were studied in detail and both of them revealed excellent electrochemical performances, such as high reversible capacity, excellent rate capability and good cycling properties that the capacity becoming bigger with cycling. The microstructure of the samples was characterized by X-ray diffraction and transmission electron microscopy. Combined with the electrochemical performances, it was assumed that the HCNs should play an important role in the enhancing electrochemical properties as the reservoir for the lithium storage and transfer. A sample composed mainly of HCNs was fabricated to verify the hypothesis.