Carbon-coated silicon nanoparticle-embedded carbon sphere assembly electrodes with enhanced performance for lithium-ion batteries. Issue 44 (18th April 2016)

• Record Type: Journal Article
• Authors: Gueon, Donghee; Lee, Jaehyun; Lee, Joong Kee; Moon, Jun Hyuk
• Is Part Of: RSC advances. Volume 6:Issue 44(2016)
• Page Start: 38012
• Page End: 38017
• Publication Date: 2016-04-18
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra00238b
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : We demonstrate carbon-coated silicon nanoparticles embedded in monodisperse carbon spheres for lithium-ion batteries with high capacity retention. Abstract : The uniform dispersion of Si materials in a carbon matrix while maintaining the nanomorphology of Si is required to achieve higher performance lithium-ion batteries (LIBs). Carbon-coated silicon nanoparticles embedded in monodisperse carbon spheres (C-SNP/CSs) were assembled by a simple mixing approach. We obtained high silicon contents up to 56 wt% for the composite electrodes. The C-SNP/CS anodes delivered a reversible specific capacity of 1230 mA h g −1 for 56 wt% Si and 953 mA h g −1 for 44 wt% Si at 800 mA g −1 after 150 charge/discharge cycles. The capacity retention after 150 cycles was 73% for the 56 wt% Si and 86% for 44 wt% Si C-SNP/CS electrodes, while the bare C-SNPs without CSs displayed only 32% retention. The high cycle performance indicates that the CSs effectively alleviated the mechanical stress induced by the large volume changes of Si during the charge/discharge cycles. Moreover, the high capacity retention reveals the high electrical conductivity of the electrodes, provided by the assembled morphology the CSs and the carbon-shell on the silicon nanoparticles(SNPs). The use of CSs with C-SNPs is a facile method to obtain a uniformly-dispersed mixture and can be readily scaled for practical applications.