Fractionation and Upgrade of Endocarp Lignin to Carbon- Silicon Nanocomposites as an Anode Material In Lithium-Ion Batteries

Abstract

HighlightsDeep eutectic solvent (DES) pretreatment of endocarp biomass led to higher overall glucose yield and lignin extraction.High performance anode materials were synthesized using Si nanoparticles and DES or alkaline extracted lignin.The core-shell structure formed during pyrolysis contributes to the enhanced electrochemical performance.Abstract.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. Keywords: Anode, Lignin, Lithium-ion battery, Silicon nanoparticles.