화학공학소재연구정보센터
Journal of Materials Science, Vol.53, No.3, 2149-2160, 2018
Three-dimensional Si/hard-carbon/graphene network as high-performance anode material for lithium ion batteries
The Si/hard-carbon/graphene (Si/HC/G) composite material used as lithium ion battery (LIB) anode was synthesized by emulsion polymerization of the mixture of resorcinol and formaldehyde in the suspension of silicon nanoparticles, followed by loading on the graphene sheets and annealing treatment of 800 A degrees C. The as-prepared three-dimensional Si/HC/G composite is composed of the Si/HC microspheres on the graphene network. In the portion about Si/HC, some of the Si nanoparticles are embedded into the hard carbon, which can provide the great strength alleviating the volume expansion and shrinkage of Si. The graphene portion can connect Si/HC microspheres preventing the electrode cracks and can provide the pathway to improve the transport of electrons and diffusion of lithium ions. Hence, the Si/HC/G composite could not only avoid the pulverization of the Si-based material but also enhance the electronic conductivity, displaying excellent electrochemical performances. Compared with the HC and Si/HC samples, the Si/HC/G composite possesses the specific charge capacity of 514.8 mA h g(-1) at the high current density of 2 A g(-1) and has the high charge capacity of 818 mA h g(-1) at the current density of 100 mA g(-1) after 100 charge and discharge cycles. Resultantly, the Si/HC/G composite shows great potential for the application of lithium ion battery anode material in the future.