High-frequency supercapacitors with phosphorus-doped Ketjen black

Compact supercapacitors (SCs) have attracted attention for their great potential to replace bulky aluminum electrolytic capacitors (AECs) in alternating current (AC) line filtering applications. Herein, the fabrication of a high-frequency SC is reported using Ketjen black (KB) nanoparticles doped with phosphorus (P) to achieve a high areal capacitance of up to 2.26 mF cm-2 along with a high-rate capability, with a phase angle of -80.2 degrees at 120 Hz. The high performance of the phosphorus-doped KB (designated PKB) SC with a 6 M KOH aqueous electrolyte is associated with its increased surface wettability and additional capacitive sites provided by the P-doping. Density functional theory (DFT) calculations further indicate that the P-doping enhances the interactions between the electrolyte ions and the carbon surface, thus leading to an improved electrochemical performance. These results suggest that the P-doped carbonbased SC could be highly favored in replacing conventional AECs in various high-frequency electronic devices. (c) 2023 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

A high-frequency supercapacitor using phosphorus-doped Ketjen black nanoparticles is fabricated, achieving a high areal capacitance of up to 2.26 mF cm-2 and a high-rate capability with a phase angle of -80.2 degrees at 120 Hz. The excellent electrochemical performance of the phosphorus-doped KB supercapacitor is attributed to increased surface wettability and additional capacitive sites provided by the phosphorus doping. These results suggest the potential of phosphorus-doped carbon-based supercapacitors as a replacement for conventional aluminum electrolytic capacitors in high-frequency electronic devices.