Impact of the biomass precursor composition in the hard carbon properties and performance for application in a Na-ion battery
Résumé
Biomass-derived hard carbon is gaining more and more attention to be used as a negative electrode for Na-ion batteries. However, the biomass precursors properties are often ignored when analyzing the final properties and performance of the derived hard carbons. Herein, we present, for the first time, an interdisciplinary and systematic study comprising 25 different biomass precursors, to elucidate the role of the biomass precursor composition in the final hard carbon properties. The elemental and macromolecular composition of the 25 biomass precursors were completely characterized. Moreover, the resulting 25 hard carbon samples were synthesized, characterized, and tested under the same conditions. The results showed a correlation between the ash content of the biomass precursor and the final reversible capacity, plateau capacity and average oxidation voltage of the hard carbon materials. Grass derived hard carbons would seem to present the strongest correlations because of their high ash content, rich in Si and Ca. Some woody and shells derived hard carbons delivered the best reversible capacities and initial coulombic efficiencies. The latter results seemed correlated to the high carbon content and the low ash content in these types of precursors. Finally, the macromolecular composition of the biomass precursor was not observeddid not seem to affect the final hard carbon properties, except for lignin-rich biomass precursors that delivered higher hard carbon yields.