Dual carbon Li-ion capacitor with high energy density and ultralong cycling life at a wide voltage window

Using the same materials for the cathode and anode in energy storage devices could greatly simplify the technological process and reduce the device cost significantly. In this paper, we assemble a dual carbon-based Li-ion capacitor with the active materials derived entirely from a single precursor, petroleum coke. For the anode, petroleum coke-derived carbon (PCC) is prepared by simple ball milling and carbonization, having a massive tap density (1.80 g cm(-3)) and high electrical conductivity (11.5 S cm(-1)). For the cathode, the raw petroleum coke is activated by KOH (petroleum coke-activated carbon (PC-AC) sample) to achieve a well-developed pore structure to meet a rapid capacitive behavior. As a result, in addition to the robust structural stability of both the anode and cathode, the assembled dual carbon Li-ion capacitor shows a high energy density (231 W h kg(-1)/206 W h L-1) and ultralong cycling life (up to 3000/10,000 cycles) at a wide voltage window. The excellent electrochemical response and simple production process make the PCC materials have great potential for practical application.

Automated summary

This paper explores the potential of using the same materials for the cathode and anode in energy storage devices, and successfully assembles a dual carbon-based Li-ion capacitor using petroleum coke-derived materials. The capacitor exhibits high energy density and long cycling life, making it highly promising for practical applications.