METHOD OF MAKING FLEXIBLE GRAPHITE FOIL AND FOIL Russian patent published in 2009 - IPC C01B31/04 C04B35/536 

FIELD: chemistry.

SUBSTANCE: invention can be used in chemical, metallurgical, automobile and other engineering fields. Initial graphite particles for oxidation are electrochemically treated with a solution of nitric acid with concentration of 20-60% with electric quantity of 450-700 mA·h/g. Oxidised graphite particles are washed, dried and thermally processed in a non-oxidising atmosphere for foaming. Vermicular graphite particles are obtained, expanded in the direction of the crystallographic axis C, and then rolled into a foil. The flexible graphite foil is characterised by specific surface area of said expanded graphite vermicular particles of 95-152 m²/g and average ratio L/D≥40, where L - is the length of the vermicular particle, D - diametre of the cross-section of the particle.

EFFECT: density of foil - 1,0-1,4 g/l, strength - 8-17 MPa, elasticity - 13-26%.

7 cl, 1 tbl, 1 ex