Unconventional Carbon: Alkaline Dehalogenation of Polymers Yields N‐Doped Carbon Electrode for High‐Performance Capacitive Energy Storage

Polymers are important precursors for the fabrication of carbon materials. Herein, halogenated polymers are explored as precursors for the synthesis of high‐quality carbon materials via alkaline dehalogenation. It is found that the halogen elements (F, Cl) connecting to vinylidene units are highly reactive so that dehalogenation can take place a few seconds at room temperature by simple hand grinding in the presence of strong inorganic alkaline. Furthermore, the halogen element‐leaving sites are shown to be susceptible to heteroatom doping (e.g., N doping) to become stable capacitive sites for charge storage (e.g., ions). By using a mixture of NaOEt and KOH as dehalogenation reagents, abundant hierarchical pores (macro/meso/micropores) in the resultant doped carbon matrix for fast mass transportation can be created. Very high capacitance (328 F g −1 at 0.5 A g −1 ) and rate capability (75.3% retention at 50 A g −1 and 62.5% retention at 100 A g −1 ) are observed for the newly developed halogenated polymer‐derived doped carbon materials.