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Cycle Stability of Silicon Nanoparticles Coated with Nitrogen-Doped Carbon Layer for Lithium Ion Battery Anode

Thursday, 23 June 2016
Riverside Center (Hyatt Regency)
C. R. Cho (Pusan National Universiry), H. S. Choi (Pusan National University), D. Pham-Cong (Pusan national University), and J. H. Cho (Pusan National University)
Silicon is one of the promising candidate materials for lithium ion anode. This anode has a theoretical specific capacity of 4200 mAh/g which is about 10 times higher than the commercial graphite anode. However, Si anode has a short cycle life during the lithiation-delithiation process because of its volume expansion of up to 400%. In this study, to improve the cycle stability of Si anode through the control of volume expansion, we fabricated the single crystal Si nanoparticles (dia. ~50 nm) by using laser photo-pyrolysis technique and then the nitrogen-doped carbon layer was coated on them by using FeCl3 source. The electrochemical performance of samples according to the amount of FeCl3(0.3-2g) was investigated. The capacity retention of the Si nanoparticle with N-doped carbon layer (Si@NC) sample was approximately 74.9% at 1C after 300 cycles. Surface chemical states for elements of the anode materials according to the thickness of nitrogen-dpoed carbon layer are mentioned in detail. The effect of the coating layer is very strong to prevent Si volume change, so our experimental result for cycling test could be expected.