Hard Carbon/SiOx Composite Active Material Prepared from Phenolic Resin and Rice Husk for Li-ion Battery Negative Electrode

The composite negative electrode active material of Li-ion batteries (LIBs) was fabricated using phenolic resin (PR) and agricultural waste of rice husk (RH). Because silicates were intrinsically composed in RH, the composite of hard carbon (HC) and SiO x (HC/SiO x composite) was readily prepared by carbonizing the mixture of PR and RH. Li-ion insertion and extraction capacity of the HC/SiO x composite was evaluated in a half-cell con fi guration using Li metal as the counter electrode, in comparison with those of the carbonized RH and the commercial HC. It was revealed the HC/SiO x composite exhibited 30% higher speci fi c capacity of Li-ion insertion/extraction than did the commercial HC. In addition to this, its capacity retention was found to be approximately equal to that of the commercial HC. The performance comparison of the HC/SiO x composite and the carbonized RH suggested that hybridization of HC and SiO x was useful to alleviate the capacity fading of the SiO x part with maintaining the increased speci fi c capacity attributed to the SiO x part. Cost-effective active material for the LIB negative electrode with acceptable performances could be realized by the simple carbonization of the mixture of PR and RH. The produced HC/SiO x composite was promising for vehicle applications requiring excellent cycle performance and high cost effectiveness.