Graphite comes in two forms: natural graphite from mines and synthetic graphite from petroleum coke. Both types are used for Li-ion anode material with 55 percent gravitating towards synthetic and the balance to natural graphite.
Manufacturers preferred synthetic graphite because of its superior consistency and purity to natural graphite. This is changing and with modern chemical purification processes and thermal treatment, natural graphite achieves a purity of 99.9 percent compared to 99.0 percent for the synthetic equivalent.
Purified natural flake graphite has a higher crystalline structure and offers better electrical and thermal conductivity than synthetic material. Switching to natural graphite will lower production cost with same or better Li-ion performance. Synthetic graphite for Li-ion sells for around US $10,000 per ton whereas spherical graphite made from natural flake sells for US $7,000 (2015 prices). Unprocessed natural graphite is much cheaper, and besides cost, natural graphite is more environmentally friendly than synthetic graphite; it also forms the base for graphene, a scientist’s dream
