Preparation And Electrochemical Property Research Of Carbon Based Composites For Lithium Batteries

A large amount of fossil fuel consumption brings up with rigorous environmental issues,the single energy structure will not meet the increasing needs in the future.The development of secondary clean energy has attracted soaring attention in recent years,especially the lithium-ion batteries(LIB).With the rapid technical progress and the popular of electrical vehicles,the energy density of traditional lithium-ion batteries cannot satisfy the urgent needs,vast research has been focused on seeking for the nextgeneration high energy density devices.Metal oxides has been widely used in energy storage devices as its low cost and high theoretical specific capacity,corresponded with inferior conductivity and integrated stability.It will promote the high energy density devices by rational design of the structure and preparation method.Firstly,the paper presents the fabrication of Fe3O4 nanoparticles encapsulated in the carbon nanosheets via simple template method,and used for anode material of LIB.The interlinked carbon nanosheets construct the 3D conductive network,the abundant pore structure shorten the diffusion path of lithium ion,enabling fast electrochemical kinetics.On the other hand,the 10 nm Fe3O4 nanoparticles distributed uniformly in the sheets.The pore structure will greatly buffer the volume change during the cycling process.The synergistic effect of the composites ensure the integrated stability and enhanced electrochemical performance.Secondly,the thesis proposed the separator modification with interwoven scaffold like MoO3@CNT interlayer for lithium-sulfur(Li-S)batteries.The CNTs enhanced the overall conductivity,resulting in better rate performance.On other side,the MoO3 nanorods enfolded by CNTs uniformly has powerful chemical interaction with polysulfides,which mitigate the shuttle effect significantly.Moreover,the interwoven structure can deliver abundant pores facilitates the diffusion of lithium ions,guarantee the outstanding performance in Li-S batteries.Finally,the paper stated the preparation of TiN-KB decorated hollow carbon fibers via coaxial electrospinning and combined with sulfur for high performance lithium-sulfur batteries.The SAN,TiO2 nanoparticles and ketjen black composites was used for the core solution,after the carbonization in 700? for 3 h,the SAN was completed removed and left with the hollow structure.Subsequently,the TiO2 nanoparticles was reduced to TiN nanoparticles with remarkable higher conductivity under 1000°C in Ar and H2.The prominent transformation was turned out by the enhanced electrochemical performance compared with TiO2-KB decorated hollow carbon nanofibers.