Cobalt nanoparticles encapsulated by nitrogen-doped carbon framework as anode materials for high performance lithium-ion capacitors

Abstract

In this work, we propose to prepare a nitrogen-doped nanocomposite ([email protected]) by one-step carbonization of the zeolite imidazole ester framework structure material (ZIF-67). Among them, the composite material uses porous carbon dodecahedron as the supporting framework, and the metal Co nanoparticles (12–15 nm) are encapsulated inside the carbon framework. The prepared nanocomposite demonstrates excellent electrochemical performance, and the electrode kinetic analysis shows extremely high pseudo-capacitance contribution and good cycle stability, almost no fluctuations during the cycle. Moreover, our assembled hybrid lithium-ion capacitor (LIC) has superb energy–density (125.28 Wh kg−1) and power-density (10 kW kg−1), and excellent cycle life (91.74% was retained after 1000 cycles), which is ascribed to the combined effect between the ideal component and multilayer structure of the prepared nanohybrid. This research work provides an effective solution for energy storage systems that take into account both high power and high energy density.