Journal Article

Benzotrithiophene‐sulfonate covalent‐organic frameworks: Supramolecular proton pumps for high‐rate aqueous zinc‐ion energy storage systems

Peng, Haijun, Bielejewski, Michał, Zhuang, Xiaodong, Ciesielski, Artur, Xu, Shunqi, Pakulski, Dawid, Samorì, Paolo, Montes‐García, Verónica, Jiang, Kaiyue, Richard, Fanny

2024

Overview

Proton chemistry is becoming a focal point in the development of zinc‐ion energy storage devices due to its swift H+ insertion/extraction kinetics. This characteristic feature confers to electrodes a remarkable power density, rate capability, and prolonged cycling durability. However, the storage mechanism of H+ in electrodes based on covalent‐organic frameworks (COFs) has not been thoroughly investigated. In this work, we introduce an unprecedented concept involving a supramolecular approach based on the design of a benzotrithiophene‐sulfonate COF (COF‐BTT‐SO3H) with remarkable storage capacity for simultaneous insertion and extraction of H+ and Zn2+. The ad hoc positioning of the ‐SO3H groups within the COF‐BTT‐SO3H structure facilitates the formation of a robust H‐bonded network. Through density functional theory calculations and employing in situ and ex situ analyses, we demonstrate that this network functions as a spontaneous proton ion pump leading to enhanced ion‐diffusion kinetics and exceptional rate performance in zinc‐ion energy storage devices. COF‐BTT‐SO3H reveals a high capacity of 294.7 mA h/g (0.1 A/g), a remarkable maximum energy density of 182.5 W h/kg, and power density of 14.8 kW/kg, which are superior to most of the reported COF‐based electrodes or other organic and inorganic electrode materials in Zn2+ energy storage devices. A novel supramolecular approach is introduced using a benzotrithiophene sulfonate imine‐linked covalent‐organic framework (COF‐BTT‐SO3H), enabling remarkable co‐storage of H+ and Zn2+ via three different active sites. COF‐BTT‐SO3H exhibits high capacity of 294.7 mAh/g, outstanding maximum energy density (182.5 Wh/kg), and superior power density (14.8 kW/kg), surpassing most COF‐based electrodes and other materials in Zn2+ energy storage.

• Publisher: John Wiley & Sons, Inc,Wiley
• Subject: Acids / charge storage mechanism / Chemical bonds / Chemical Sciences / Covalent organic frameworks / Density functional theory / Design / Diffusion pumps / Diffusion rate / Electrode materials / Electrodes / Electrolytes / Energy storage / Fourier transforms / functional porous materials / Functionals / Hydrogen / Insertion / Kinetics / Material chemistry / NMR / Nuclear magnetic resonance / Polymers / proton pump / Protons / Spectrum analysis / Storage capacity / Zinc / zinc‐ion energy storage devices