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.