Superior Lithium-Ion Storage at Room and Elevated Temperature in an Industrial Woodchip Derived Porous Carbon

Abstract

An industrial pyrolysis process converted loblolly pine tree woodchips into porous carbonaceous particles that are tested as a promising lithium ion battery anode. SureCarbon, a Tennessee company, demonstrated scalability for the KOH activation and pyrolysis process by producing hundreds of kilograms of carbon from the sustainable wood precursor. Material characterization reveals amorphous carbon structure, with 1580 m 2 /g BET surface area and 0.883 cc/g pore volume. Galvanostatic cycling was performed at a C/10 rate in a half cell (carbon vs Li + /Li), achieving a stable capacity of 700 mAh/g and 1000 mAh/g at 22 and 50 °C, respectively. Cycling at 50 °C increases lithium ion diffusion rates into the electroactive carbon but lowers the Coulombic efficiency and long-term cell cyclability due to electrolyte degradation. Electrochemical impedance spectroscopy studies reveal the decreased charge transfer and diffusional resistance in a porous carbon electrode compared to conventional graphite, making it an attractive anode material for lithium ion batteries.