Kraft lignin-derived carbon sheets produced by molten salt-assisted thermal treatment - Graphitization behavior of the sheet structures

: Meščeriakovė Sara-Maaria, Sermyagina Ekaterina, Mäkilä Ermei, Meščeriakovas Arūnas, Karhunen Tommi, Nissinen Ville, Suvanto Sari, Lähde Anna

Publisher: ELSEVIER SCIENCE SA

: 2022

: Diamond and Related Materials

: DIAMOND AND RELATED MATERIALS

: DIAM RELAT MATER

: 109146

: 127

: 7

: 0925-9635

: 1879-0062

DOI: https://doi.org/10.1016/j.diamond.2022.109146

: https://www.sciencedirect.com/science/article/pii/S0925963522003284

The synthesis of high-value carbon materials from lignin-based feedstocks to variable applications has been under intensive research. Production of well ordered crystalline carbon as 2H-graphite has been challenging due to the generally poor graphitizability of lignins. Herein, we produced kraft-lignin-derived carbon materials and studied their graphitization behavior. We show that the use of a LiCI-KCI molten salt mixture promoted the formation of sheet-like carbon structures. Furthermore, these structures indicated improved crystallinity after annealing at 700 degrees C. This was not observed in the case of kraft-lignin annealed without the presence of a salt mixture. These structures were further thermally post-treated at 1900 degrees C and 2400 degrees C in an argon atmosphere by induction annealing to study their graphitization tendency. The high-temperature treatment further emphasized the crystalline structure difference between the LiCI-KCI salt-treated and non-LiCI-KCI-treated kraft lignin samples.