Petroleum Coke as an Efficient Single Carbon Source for High-Energy and High-Power Lithium-Ion Capacitors

Lithium-ion capacitors (LICs) with the capability of high energy and high power are considered to be attractive for advanced energy storage applications. However, the design and fabrication of suitable electrode materials with desirable properties by a facile approach using cost-effective precursors are still a great challenge. In this work, we have utilized petroleum coke, an unavoidable industrial waste with high carbon content, as a single carbon source to synthesize both a high surface area activated carbon cathode and a low surface area disordered carbon anode. A lithium-ion capacitor fabricated using all-petroleum coke-derived carbon materials exhibits a high energy density of 80 W h/kg and a high power density of 8.4 kW/kg as well as long life span (85% capacity retention after 10,000 charge–discharge cycles at 1 A/g). Systematic characterization analysis demonstrates that unique characteristics of carbon electrode materials including hierarchical pores, high surface area, and graphene-like structured activated carbon contribute synergistically to the outstanding performance of the petroleum coke-based LIC. More importantly, the facile approach adopted in the present study to synthesize both cathode and anode materials from a single source is an effective way for high value-added utilization of petroleum coke at the commercial level.