Conversion of Lignin Precursors to Carbon Fibers with Nanoscale Graphitic Domains

Abstract

Lignin is one of the most abundant and inexpensive natural biopolymers. It can be efficiently converted to low cost carbon fiber, monolithic structures, or powders that could be used directly in the production of anodes for lithium-ion batteries. In this work, we report thermomechanical processing methods relevant for the conversion of lignin precursors into carbon fiber-based anode materials, the impact of lignin precursor modification on melt processing, and the microstructure of the final carbon material. Modification of softwood lignin produced functionalities and rheological properties that more closely resemble hardwood lignin thereby enabling the melt processing of softwood lignin in oxidative atmospheres (air). The conversion process encompasses melt spinning of the lignin precursor, oxidative stabilization, and a low temperature carbonization step in a nitrogen/hydrogen atmosphere. We determined resistivities of individual carbon fiber samples and characterized the microstructure by scanning electron microscopy. Neutron diffraction reveals nanoscale graphitic domains embedded in an amorphous carbon matrix. These unique structural characteristics make biomass-derived carbon fibers a suitable material for energy storage applications with enhanced electrochemical performance.

Carbon Fibers Prepared from Melt Spun Peracylated Softwood Lignin: an Integrated Approach

“…This is why the use of carbon composites is still restricted to high‐end applications, whether in aerospace or in the automotive sector. In search of alternative sources, which are preferably biobased, renewable, and not associated with the volatile market prices for crude oil, both cellulose and lignin have (again) moved into the center of interest. Particularly lignin appears to bear high potential for the production of CFs for the following reasons: first, lignins are highly abundant, 100% biobased, and renewable.…”

Extrusion of Softwood Kraft Lignins as Precursors for Carbon Fibres

“…So far only fractionated softwood lignins, chemically modified softwood lignin, and those used with the addition of plasticisers have been successful (Baker and Rials 2013;Nordström et al 2013;Chatterjee et al 2014). Softwood kraft lignin is today the most available commercial lignin.…”

Electrically conductive kraft lignin-based carbon filler for polymers

“…Among the numerous potential materials applications of lignin, lignin-derived carbon fibres have received particular attention recently [10][11][12][13][14][15]. This is due to the increasing demand for low-cost alternatives to PAN-based carbon fibres that would find broad use in composites, such as for automotive production.…”