Print: | ISSN 0256-1115 |
Online: | ISSN 1975-7220 |
Korean Journal of Chemical Engineering,
Vol.23, No.2, 230-236, 2006 A study on carbon coating to silicon and electrochemical characteristics of Si-C|Li cells
The aim of this paper is to study the electrochemical behavior of Si-C material synthesized by heating amixture of silicon and polyvinylidene fluoride (PVDF) in the ratios of 5, 20, and 50wt%. The particle size of the syn-thesized material was found to be increased with increase in the PVDF ratio. The coexistence of silicon with carbonwas confirmed from the XRD analysis. A field emission scanning electron microscope (FESEM) study performed withthe material proved the improvement in coating efficiency with increase in the PVDF ratio. Coin cells of the type 2025were made by using the synthesized material, and the electrochemical properties were studied. An electrode was pre-pared by using the developed Si-C material. Si-C|Li cells were made with this electrode. A charge|discharge test wasperformed for 20 cycles at 0.1C hour rate. Initial charge and discharge capacities of Si-C material derived from 20wt%of PVDF was found to be 1,830 and 526mAh|g, respectively. Initial charge/discharge characteristics of the electrodewere analyzed. The level of reversible specific capacity was about 216mAh/g at Si-C material derivedfrom 20wt% of PVDF, initial intercalation efficiency (IIE), intercalation efficiency at initial charge/discharge, was68%. Surface irreversible specific capacity was 31mAh/g, and average specific resistance was 2.6ohm*g.
[References]
|