Electrostatic Interaction‐directed Construction of Hierarchical Nanostructured Carbon Composite with Dual Electrical Conductive Networks for Zinc‐ion Hybrid Capacitors with Ultrastability

Abstract

Metal–organic framework (MOF)‐derived carbon composites have been considered as the promising materials for energy storage. However, the construction of MOF‐based composites with highly controllable mode via the liquid–liquid synthesis method has a great challenge because of the simultaneous heterogeneous nucleation on substrates and the self‐nucleation of individual MOF nanocrystals in the liquid phase. Herein, we report a bidirectional electrostatic generated self‐assembly strategy to achieve the precisely controlled coatings of single‐layer nanoscale MOFs on a range of substrates, including carbon nanotubes (CNTs), graphene oxide (GO), MXene, layered double hydroxides (LDHs), MOFs, and SiO2. The obtained MOF‐based nanostructured carbon composite exhibits the hierarchical porosity (Vmeso/Vmicro: 2.4), ultrahigh N content of 12.4 at.% and “dual electrical conductive networks.” The assembled aqueous zinc‐ion hybrid capacitor (ZIC) with the prepared nanocarbon composite as a cathode shows a high specific capacitance of 236 F g−1 at 0.5 A g−1, great rate performance of 98 F g−1 at 100 A g−1, and especially, an ultralong cycling stability up to 230 000 cycles with the capacitance retention of 90.1%. This work develops a repeatable and general method for the controlled construction of MOF coatings on various functional substrates and further fabricates carbon composites for ZICs with ultrastability.