K. Shell, V. Amar, B. Maddipudi, A. Thakkar, R. Shende, S. Kumar, R.B. Gupta
Virginia Commonwealth University,
United States
Keywords: unhydrolyzed solids, biochar, biocarbon, thermal activation, supercapacitors, corn-stover
Summary:
Use of biomass is an emerging and promising alternative to produce carbon electrodes for supercapacitors. Lignin rich unhydrolyzed solids (UHS) obtained from alkaline pretreatment of corn stover were hydrothermally liquefied (HTL) and the solid residue obtained from after the HTL reaction was acid washed to pH neutral and the biochar thus obtained was converted to biocarbon using a facile one-step thermal activation process. Activation was carried out in a Carbolite tubular furnace at 850 °C for 3 hours at a heating rate of 5 °C min-1 under light Ar flow. Biocarbon was converted into electrode ink by generating a slurry of 80% biocarbon, 10% high conducting carbon black (Super P), and 10% polytetrafluoroethylene (PTFE, 60 wt % in H2O). Slurry was applied to Ni foam cathode material, dried, pressed, then templated and insulated with chemical resistant epoxy. Electrochemical measurements were conducted using a CH Instruments potentiostat (CHI 660E). Specific capacitances determined via cyclic voltammetry (CV) and charge-discharge (CD) were found to be greater than 200 Fg-1. Surface area characterizations were conducted using a BET analyzer. Detailed discussions on electrochemical performance, surface characterizations, and percent yield will be reported.