Efficient Supercapacitor Energy Storage Using Conjugated Microporous Polymer Networks Synthesized from Buchwald–Hartwig Coupling

Abstract

Supercapacitors have received increasing interest as energy storage devices due to their rapid charge–discharge rates, high power densities, and high durability. In this work, novel conjugated microporous polymer (CMP) networks are presented for supercapacitor energy storage, namely 3D polyaminoanthraquinone (PAQ) networks synthesized via Buchwald–Hartwig coupling between 2,6-diaminoanthraquinone and aryl bromides. PAQs exhibit surface areas up to 600 m² g⁻¹, good dispersibility in polar solvents, and can be processed to flexible electrodes. The PAQs exhibit a three-electrode specific capacitance of 576 F g⁻¹ in 0.5 m H₂SO₄ at a current of 1 A g⁻¹ retaining 80–85% capacitances and nearly 100% Coulombic efficiencies (95–98%) upon 6000 cycles at a current density of 2 A g⁻¹. Asymmetric two-electrode supercapacitors assembled by PAQs show a capacitance of 168 F g⁻¹ of total electrode materials, an energy density of 60 Wh kg⁻¹ at a power density of 1300 W kg⁻¹, and a wide working potential window (0–1.6 V). The asymmetric supercapacitors show Coulombic efficiencies up to 97% and can retain 95.5% of initial capacitance undergo 2000 cycles. This work thus presents novel promising CMP networks for charge energy storage.

Superior electrochemical energy storage electrodes are achieved through rational design of redox-active nitrogen-rich conjugated microporous polymers using a unique Buchwald–Hartwig coupling method. The energy storage mechanism of the polymers is illustrated, providing insights for the synthesis of electroactive materials toward efficient energy storage, batteries, and other electrochemical devices.

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