Catechol‐Coordinated Framework Film‐based Micro‐Supercapacitors with AC Line Filtering Performance

Coordination polymer frameworks (CPFs) have broad applications due to their excellent features, including stable structure, intrinsic porosity, and others. However, preparation of thin‐film CPFs for energy storage and conversion remains a challenge because of poor compatibility between conductive substrates and CPFs and crucial conditions for thin‐film preparation. In this work, a CPF film was prepared by the coordination of the anisotropic four‐armed ligand and CuII at the liquid–liquid interface. Such film‐based micro‐supercapacitors (MSCs) are fabricated through high‐energy scribing and electrolytes soaking. As‐fabricated MSCs displayed high volumetric specific capacitance of 121.45 F cm−3. Besides, the volumetric energy density of MSCs reached 52.6 mWh cm−3, which exceeds the electrochemical performance of most reported CPF‐based MSCs. Especially, the device exhibited alternating current (AC) line filtering performance (−84.2° at 120 Hz) and a short resistance capacitance (RC) constant of 0.08 ms. This work not only provides a new CPF for MSCs with AC line filtering performance but also paves the way for thin‐film CPFs preparation with versatile applications. AC/RC: A new coordination polymer framework film is prepared by liquid–liquid interfacial method based on an anisotropic catechol ligand. As‐fabricated in‐plane micro‐supercapacitors (MSCs) exhibit high volumetric specific capacitance of 121 F cm−3, typical alternating current (AC) line filtering performance, and short resistance capacitance (RC) time constant of 0.08 ms. This work provides a new material and processing method towards MSCs with AC line filtering performance.