Single-atom Zn for boosting supercapacitor performance

Single-atom metal-incorporated carbon nanomaterials (CMs) have shown great potential towards broad catalytic applications. In this work, we show that N-doped porous CMs embedded with redox-able Zn atoms exhibit superior capacitive performance. High Zn (similar to 2.72 at.%)/N (similar to 12.51 at.%) doping were realized by incorporating Zn2+ and benzamide into the condensation and carbonization of formamide and subsequent annealing at 900 degrees C. The Zn and N species are mutually benefited during the formation of ZnN4 motif. The as-obtained Zn1NC material affords a very large capacitance of 621 F.g(-1) (at 0.1 A.g(-1)), superior rate capability (similar to 65% retention at 100 A.g(-1)), and excellent cycling stability (0.00044% per cycle at 10 A.g(-1)). These merits are attributed to the high Zn/N loading, atomic Zn-boosted pseudocapacitive behavior, large specific surface area (similar to 1,085 m(2).g(-1)), and rich pore hierarchy, thus ensuring both large pseudo-capacitance (e.g., similar to 37.9% at 10 mV.s(-1)) and double-layer capacitance. Besides of establishing a new type of high Zn/N-loading carbon materials, our work uncovers the capacitive roles of atomically dispersed metals in CMs.

Automated summary

This study demonstrates the potential of N-doped porous CMs with redox-able Zn atoms to achieve high Zn/N loading, pseudocapacitive behavior, and cycling stability, laying the foundation for a new type of high Zn/N-loading carbon materials.