Lignin-based carbon foams and composites and related methods

A method of making a carbon foam, the method comprising:

• (a) subjecting a precursor composition comprising an amount of at least partially decomposed lignin to a first pressure for a first time, optionally, while heating the precursor composition to a first temperature, thereby providing a compressed precursor composition;
• (b) heating the compressed precursor composition to a second, higher temperature for a second period of time while subjecting the compressed precursor composition to a second pressure to further decompose the at least partially decomposed lignin and to generate pores within the compressed precursor composition, thereby providing a porous, decomposed precursor composition;
• and
• (c) heating the porous, decomposed precursor composition to a third temperature for a third time to carbonize, and optionally, to graphitize, the porous, decomposed precursor composition to provide the carbon foam, wherein the at least partially decomposed lignin has been formed by heating raw lignin to an elevated temperature and for a time to at least partially decompose the raw lignin.

A method of making a carbon foam, the method comprising:

• (a) subjecting a precursor composition comprising an amount of at least partially decomposed lignin to a first pressure for a first time, optionally, while heating the precursor composition to a first temperature, thereby providing a compressed precursor composition;
• (b) heating the compressed precursor composition to a second, higher temperature for a second period of time while subjecting the compressed precursor composition to a second pressure to further decompose the at least partially decomposed lignin and to generate pores within the compressed precursor composition, thereby providing a porous, decomposed precursor composition;
• and
• (c) heating the porous, decomposed precursor composition to a third temperature for a third time to carbonize, and optionally, to graphitize, the porous, decomposed precursor composition to provide the carbon foam, wherein the carbon foam is characterized by a compressive strength of at least about 20 MPa.