Hierarchical Electrode Constructed by carbon-coated Metal-Organic Framework Derivatives Supported on two-dimensional Ti3C2 nanosheets for Hybrid Li-ion Capacitors

Abstract

BackgroudMetal-organic frameworks (MOFs) (e.g., Co-MOF) had been a popular platform for synthesis electrode materials for lithium-ion capacitors (LICs) because of their high theoretical specific capacity and unique structural advantages. Recent researches have focused on the development of MOFs derivative-based composites with high specific surface area, high structural stability, and high electrical conductivity. Methods: Here a distinct Ti3C2/Co3O4@C heterostructure composite was prepared by a straightforward method via hydrogen bonding with carbon-coated Co-MOF derivative anchored on Mxene-Ti3C2 nanosheets. The carbon-coated hollow Co3O4 polyhedra could shorten Li+ diffusion paths, increase the specific surface area and mitigate structural changes during the Li+ storage process. Moreover, Ti3C2 sheets were acted as a conductive network, which could increase the Li+ transport rate and stability of the structure. SignificantServing as anode material, Ti3C2/Co3O4@C electrode showed a specific capacity of 1341 mAh/g at current density of 0.1 A/g, with 93% capacity maintenance at 2 A/g after 1000 cycles in the lithium-ion half cell. Furthermore, Ti3C2/Co3O4@C//AC LIC delivered a high energy of 106 Wh/kg at 7632 W/kg. The distinct heterostructure, straightforward, and excellent performance of the Ti3C2/Co3O4@C composite as anode could provide application prospects in LICs with high energy/power density.