Amorphous Soft Carbon Coated Graphite As Anode Material for Lithium Ion Battery
In this study, we report the characteristics of anode which is made from the amorphous soft carbon coated natural graphite and charge-discharge behavior of half cells. The electrodes were prepared by pasting an aqueous slurry with styrene butadiene rubber (SBR), and carboxymethyl cellulose (CMC).
The charge–discharge tests were performed in CR2032 coin cell. Half cells consisted of the working electrode to be studied, Li metal as the counter electrode, and Celgard 2400 separator. 1 M LiPF6in ethylene carbonate and dimethyl carbonate (1:1 by volume) was used to electrolyte. Anode half-cells were tested between 1.5 V and 5 mV at a C-rate of 0.1 C. Microstructure of the amorphous soft carbon coating layer on graphite particle was observed using TEM to examine the cycle stability. Fig. 1 shows structural stability of carbon layer after charge-discharge cycles and thickness of carbon layer was about 50nm. Fig. 2 shows the charge(Li insertion)-discharge(Li extraction) curves of the amorphous soft carbon coating sample versus non-coating sample for the first cycle, charged in CC-CV mode and discharged in CC mode. The discharge capacity obtained at carbon coated sample is about 330 mAh/g and the columbic efficiency is about 90 %.
This research was financially supported by the Ministry of Trade, Industry and Energy(MOTIE) and Korea Institute for Advancement of Technology(KIAT) through the Promoting Regional specialized Industry
 Y. Chen, G.X. Wang, J.P. Tian, K. Konstantinov, H.K. Liu, Electrochim. Acta 50 (2004) 435–441.