SURFACE PURIFICATION OF NATURAL GRAPHITE AND USE OF PURIFIED GRAPHITE IN A CARBON-LITHIUM ANODE

摘要

The present invention relates to the specific physical or chemical purification of natural graphite ore. This purification is applied specifically to the surface of natural graphite to allow the formation of a passivation film during the first discharge or intercalation of lithium in graphite when the latter is used in a lithium-ion battery. Grinding to a small size before purification allows optimization of the particle distribution, resulting in a much more homogeneous electrode. This grinding takes place in the presence of the natural impurities of the graphite which play the role of micro-abrasive and gives hardness to the graphite which increases these mechanical properties.