Mn Cluster-Embedded N/F Co-Doped Carbon toward Mild Aqueous Supercapacitors

Aqueous supercapacitors have occupied a significant position among various types of stationary energy storage equipment, while their widespread application is hindered by the relatively low energy density. Herein, N/F co-doped carbon materials activated by manganese clusters (NCM) are constructed by the straightforward experimental routine. Benefiting from the elevated conductivity structure at the microscopic level, the optimized NCM-0.5 electrodes exhibited a remarkable specific capacitance of 653 F g^-1 at 0.4 A g^-1 and exceptional cycling stability (97.39% capacity retention even after 40,000 cycles at the scanning rate of 100 mV s^-1) in a neutral 5 M LiCl electrolyte. Moreover, we assembled an asymmetric device pairing with a VO_x anode (NCM-0.5//VO_x), which delivered a durable life span of 95% capacity retention over 30,000 cycles and an impressive energy density of 77.9 Wh kg^-1. This study provides inspiration for transition metal element doping engineering in high-energy storage equipment.