Graphite Investors Beware - Prices Are About To Collapse, page-8

"The issue of course is lack of Supply (not lack of Demand). Cheap high quality consistency spherical graphite is rare in the market"

Which is the main reason most battery manufacturers prefer to stick to synthetic - a consistent product.

A lot of graphite companies have spruiked they can achieve battery grade spherical graphite ( sample material), but are yet to produce a consistent product from a commercial plant.