Biomass waste-derived carbon is an attractive alternative with environmental benignity to obtain carbon material. In this
study, we prepare carbon from coffee grounds as a biomass precursor using a simple, inexpensive, and environmentally
friendly method through physical activation using only steam. The coffee-derived carbon, having a micropore-rich structure
and a low extent of graphitization of disordered carbon, is developed and directly applied to lithium-ion battery anode material.
Compared with the introduction of the Ketjenblack (KB) conducting agent (i.e., coffee-derived carbon with KB), the
coffee-derived carbon itself achieves a reversible capacity of ~200 mAh/g (0.54 lithium per 6 carbons) at a current density
of 100 mA/g after 100 cycles, along with excellent cycle stability. The origin of highly reversible lithium storage is
attributed to the consistent diffusion-controlled intercalation/de-intercalation reaction in cycle life, which suggests that the
bulk diffusion of lithium is favorable in the coffee-derived carbon itself, in the absence of a conducting agent. This study
presents the preparation of carbon material through physical activation without the use of chemical activation agents and
demonstrates an application of coffee-derived carbon in energy storage devices.

Author

Ji Hyun Um1†, Yunok Kim2†, Chi-Yeong Ahn3,4, Jinsoo Kim5, Yung-Eun Sung3,4, Yong-Hun Cho6*,
Seung-Soo Kim7*, and Won-Sub Yoon2*
1Integrated Energy Center for Fostering Global Creative Researcher, Sungkyunkwan University, Suwon 16419, South Korea
2Department of Energy Science, Sungkyunkwan University, Suwon 16419, South Korea
3School of Chemical and Biological Engineering, Seoul National University, Seoul 08826, South Korea
4Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, South Korea
5Department of Chemical Engineering, Kyung Hee University, Yongin 17104, South Korea
6Division of Energy Engineering, Kangwon National University, Samcheok 25913, South Korea
7Department of Chemical Engineering, Kangwon National University, Samcheok 25913, South Korea