Graphite is a naturally occurring form of crystalline carbon also called plumbago. It consists of carbon and is a native element found in igneous and metamorphic rocks and is a mineral of extremes being soft and pliable yet very stable within ordinary atmospheric conditions. In its natural form graphite has a layered structure with rings of six carbon atoms arranged in widely spaced horizontal sheets. Synthetic graphite is man-made created through a production process.
Thanks to its unique makeup graphite has a wide range of uses in metallurgy and manufacturing making it one of the most popular materials in the modern world. From simple purposes of replacing the ‘lead’ in pencils it is used in lubricants and in lithium ion batteries and solar panels to name a few of its uses. Natural vs synthetic is a relevant discussion because graphite has two forms, natural graphite which is mined and synthetic graphite which is produced from petroleum coke or coal tar.
Natural graphite as the name indicates is created naturally and is available in three forms:
Crystalline vein graphite
All three forms have unique properties that make them suitable for certain applications which is why natural graphite can be found in an astounding number of modern manufacturing from electronics, aerospace, hot metal processing, friction, lubricants to name a few.
Synthetic graphite is made by graphitising or high-temperature treatment of non-graphitic carbon or amorphous carbon materials. It is used in many manufacturing industries such as for conductive fillers, rubber and plastic compounds, drilling applications, coatings, fuel cell bi-polar places, corrosion products and electrolytic processes to name a few examples.
Colour difference – Natural graphite has a more opaque quality to its dark grey to black colouring while synthetic graphite is flatter in its colouring though of a similar hue.
Graphite density – Graphite natural flake is rougher than that of the synthetic because it has more impurities. Synthetic graphite has a higher density than natural graphite with a thermal conductivity of about 700-1500w while natural graphite is about 300-700w.
Price difference – Synthetic graphite is significantly more expensive than natural graphite owing to the manufacturing process which is quite energy intensive. The cost difference can be double or even triple that of the standard price of natural graphite.
The key difference between the two types of graphite is the manufacturing process. There is a demand currently in the battery industry for synthetic graphite because it has a fast charge turnaround and longevity. Today synthetic graphite accounts for over 50% of the anode market. The industry is as a whole making a shift towards natural graphite because it has the advantage of cost and having a smaller impact on the environment. The only emissions from natural graphite are those created during mining whereas synthetic graphite produces more than 3x Co2 and other harmful emissions owing to the production process, which is energy intensive and costly. On the other hand synthetic graphite is less affected by problems that affect mining or mining areas which can disrupt output.
The key properties that make graphite essential element for as clean technology:
High thermal conductivity
High electrical conductivity
High energy density
High temperature resistance
Long life cycle
Relatively low cost – natural graphite
Natural and synthetic graphite are used together as a mix wherever possible with both forms of graphite having their secured place in the industrial marketplace. Batteries can use both types of graphite materials and as a result graphite is projected to see a large increase in demand, with the demand varying for each type as the industries develop.
Both synthetic graphite and natural graphite will continue to be an important mineral or raw material as the world moves towards decarbonisation, electric vehicles and clean energy technology. While currently there is a huge demand for synthetic graphite for a green economy there is a clear leaning towards natural graphite as more industries look towards transitioning towards clean energy.