Natural graphite cycling behavior

The material was developed by the Research Institute of Electrocarbon Products (RIECP, Russian Federation) on the basis of natural graphite specially for application in Lithium-Ion cells. The samples were given with symbolic numbers, without certificates. The anodes, made of RIECP powder, had the capacity about 300 mA-h/g. The typical dicharge characteristic is submitted on Fig. 6. Irreversible capacity is about 16%. Concerning the cycle behavior, this material is not as stable as other ones tested (Fig. 10). 

In less highly graphitized natural graphite, there are some impurities and defects, and as a result, the electrochemical performance is poorer. The reversible capacity drops below 300 mAh/g, the initial coulombic efficiency is less than 80%, and cycling behavior needs improvement. 

Cycling behavior of natural graphite (A) before and after mild oxidation by different oxidant solutions at 60°C. (Adapted from Wu, Y.P. et al., J. Power Sources 111 329-334, 2002.)... 

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