The effect of carboxymethyl cellulose swelling on the stability of natural graphite particulates in an aqueous medium for lithium ion battery anodes

The effect of carboxymethyl cellulose (CMC) swelling on the stability and chemical properties of a natural graphite suspension in an aqueous medium was investigated. Suspensions prepared at different pH were characterized according to swelling behavior, rheology, green microstructural observation, and measurement of the pore size. A correlation was found between dispersion stability and electrochemical performance. It was found that the swelling of CMC was a critical factor influencing the stability of graphite suspensions. This was evidenced by observations of the green microstructures and changes noted in sedimentation behaviors. Electrochemical experiments using a Li/organic electrolyte/natural graphite anode half-cell and 750 mAh-class lithium ion cells exhibited an initial discharge capacity above 340 mAh g(-1) and an improved charge-discharge efficiency.