FRACTIONATION AND UPGRADE OF ENDOCARP LIGNIN TO CARBON- SILICON NANOCOMPOSITES AS AN ANODE MATERIAL IN LITHIUM-ION BATTERIES

A holistic use of lignocellulosic biomass by converting lignin to high-value products and cellulose and hemicelluloses to biofuel will greatly enhance the economic viability of a biorefinery. In this study, a three-dimensional, interconnected carbon/silicon composite was synthesized from silicon nanoparticles (Si NPs) with either deep eutectic solvent (DES) or alkaline pretreatment-extracted lignin from endocarp biomass. The endocarp lignin derived composite electrodes exhibited superior electrochemical performance in a half-coin cell lithium-ion battery setup. DES lignin derived C/Si NPs composite reached a discharging capacity of 1563 mAh g(-1); while alkaline lignin derived C/Si NPs composite reaching a discharging capacity of 1605 mAh g(-1) at a current density of 0.72 A g(-1). Despite the comparable electrochemical performance, DES pretreatment led to a higher overall sugar yield from the liquid streams after pretreatment and enzymatic hydrolysis. This study demonstrates the utilization of endocarp lignin in electrochemical energy storage applications.