Mitsubishi achieves microwave graphite

Driven by the increasing demand for high-power compact batteries, Mitsubishi Heavy Industries has devised a method to produce high-quality graphite from carbon powder using microwaves. Graphite is used for the anodes in lithium-ion batteries, which are used in mobile phones and other electronic equipment.

Microwave production of graphite has previously been thought impossible, because the high conductivity of carbon, as well as its tendency to reflect radiation, made it very difficult to obtain the high temperatures needed to transform amorphous carbon into the ordered stucture of graphite. Traditionally, graphite is made in a graphitising furnace, a batch system which has several drawbacks: the working environment is hot and dusty and production takes several days per batch.

The MHI process uses microwaves to heat carbon powder to 3200 degrees C, a previously unattained temperature. This aligns the molecular structure of the carbon.

Now that MHI researchers have confirmed the microwave process's feasilibity on a laboratory scale, they hope to incorporate it into a continuous process.