Reduction of irreversible capacities of amorphous carbon materials for lithium ion battery anodes by Li2CO3 addition

Amorphous carbon materials for lithium ion battery anodes which contain a small amount of LiCO3 were prepared by three methods. The obtained materials were characterized using X-ray diffraction (XRD) analysis, Raman spectroscopy and CO2 adsorption experiments. Although the XRD profiles and Raman spectra of these materials were similar to those of carbon materials synthesized with no addition, the amount of CO2 adsorbed was largely decreased by Li2CO3 addition. These results suggest that the micropores in these materials were plugged and/or filled with Li2CO3. Galvanostatic lithium charging and discharging experiments showed that the irreversible capacity of the material can be significantly decreased by Li2CO3 addition, which is thought to be due to the plugging of the pore inlets by Li2CO3. Moreover, it was also found that the reversible capacities of the materials can be increased by adjusting both the amount of Li2CO3 addition and carbonization temperature. (C) 2004 Elsevier Ltd. All rights reserved.