Caffeine-Derived Noble Carbons as Ball Milling-Resistant Cathode Materials for Lithium-Ion Capacitors.

Energy consumption is a growing phenomenon in our society causing many negative effects such as global warming. There is a need for the development of new sustainable materials for energy storage. Carbons are materials derivable from biowaste that can rather easily store energy due to their high conductivity and surface area. However, their large-scale processing is challenging as derived materials can be rather heterogeneous and homogenization requires ball milling, a process that can damage carbons in the process of oxidation. Herein, we have prepared caffeine-derived noble nitrogen-doped carbon that withstands the ball milling process without significant oxidation. Additionally, it performs extraordinarily as a cathode material for lithium-ion capacitors, making it an attractive biowaste-derived alternative to commercial heavy metal cathodes.