Evaluation of low-purity natural graphite as a cost-effective anode active material for lithium ion batteries

Low-purity natural graphite as an anode active material for lithium ion batteries was studied in order to reduce the cost of lithium ion batteries. The electrochemical performance of low-purity natural graphite was compared to that of high-purity commercial grade graphite. No significant differences of the morphology or crystal structure were observed in the SEM, XRD, and Raman measurements. Based on the EDX and ICP-AES results, relatively larger amounts of Al and Fe than other impurities were found in the low-purity natural graphite powders. Although the LP18-99 sample contained various impurities, it showed good performance in comparison with the NG-R sample.