(674b) Electrochemical Studies on Graphitized Biocarbon Derived from Hydrothermally Liquefied Low Ash Content Corn Stover

Biomass-derived biocarbon has gained considerable attention due to its abundance, low-cost, and chemical structures conducive for energy storage applications, particularly supercapacitors. Lignocellulosic components embedded within the cell wall of biomass substrates can provide a fine template for enhanced ion storage, transport, and rate capabilities, desirable for electrochemical storage. Due to its abundant availability of agricultural residues such as Corn Stover, in this research we have utilized the homogenized low ash content corn stover milled and sieved to desired specifications. As obtained corn stover is converted to hydrochar via catalytic hydrothermal liquefaction in the presence of Ni(NO₃)₂ catalyst at 275^oC and its morphological properties such as surface area, pore volume and diameter were enhanced in the presence of ZnCl_2, followed by thermal activation at 450^oC. Later as derived hydrochar is pH neutralized and acid washed with dilute HCl to extract metal contaminants. Biochar underwent thermal carbonization at 850 °C for 3 h to enhance pore structures and graphitization, conducive for electrochemical applications. Electrochemical results demonstrated specific capacitances in excess of 300 F g^-1, comparable to literature values for corn stover-derived biocarbons. Physical and electrochemical characterizations, such as BET, ATR-FTIR, Raman, XRD, cyclic voltammetry and chronopotentiometry, will be discussed to give fundamental insights into biocarbon enhancement. The results obtained during the electrochemical characterization and studies will be presented.