K. Huynh, B. Maddipudi, Z. Fickbohm, G. Bauer, R. Shende
South Dakota School of Mines,
United States
Keywords: cardboard, hydrothermal, carbon, ASC
Summary:
Cardboard is commonly used as a packing material such as shipping boxes, cereal boxes, milk or juice cartons, and more. About 850 million tons of cardboard are disposed annually in the United States, which is the one of the largest fractions of municipal solid waste. Disposed cardboard along with other waste material is usually land up in landfills, which contributes to the greenhouse gases emission. Given limited availability of landfills, the cardboard waste can be valorized, which will also curb the greenhouse emission. As the cellulose content in a cardboard is approximately 50%, it can serve as a potential candidate for high-value carbon products. Typically, cellulose-based feedstocks such as lignocellulosic biomass can be subjected to hydrothermal carbonization (HTC) that generates hydrochar, which can be used as a soil amendment material, or it can be further activated to produce porous carbon (POC) as an electrode material for energy storage devices. Recently, our group has reported the use of corn-stover derived POC for asymmetric supercapacitors (ASCs) and reported a maximum specific capacitance of 315 F/g. It is our understanding the overlapped and intercalated pore structures can enhance the electrochemical performance of energy storage devices. In this investigation, a cardboard was subjected to HTC to derive hydrochar, which was activated using KOH to obtain POC. Both hydrochar and POC materials were characterized by Brunauer-Emmett-Teller (BET) surface area analyzer, and Fourier transform infrared (FTIR) spectroscopy. Asymmetric supercapacitor is fabricated with POC as anode with a metal oxide cathode material and gel electrolyte and tested. The porous carbon derived from cardboard was found to be suitable for supercapacitors. The purpose of using a gel electrolyte is to avoid drying issue during multiple cycling. Electrochemical performance of as-fabricated ASCs will be presented.