A covalent organic framework as a dual-active-center cathode for a high-performance aqueous zinc-ion battery

Hongbao Li; Mengge Cao; Zhenli Fu; Quanwei Ma; Longhai Zhang; Rui Wang; Fei Liang; Tengfei Zhou; Chaofeng Zhang

doi:10.1039/d3sc07013a

A covalent organic framework as a dual-active-center cathode for a high-performance aqueous zinc-ion battery

Chem Sci. 2024 Jan 27;15(12):4341-4348. doi: 10.1039/d3sc07013a. eCollection 2024 Mar 20.

Authors

Hongbao Li¹, Mengge Cao¹, Zhenli Fu¹, Quanwei Ma¹, Longhai Zhang¹, Rui Wang¹, Fei Liang¹, Tengfei Zhou¹, Chaofeng Zhang¹

Affiliation

¹ Institutes of Physical Science and Information Technology, Leibniz International Joint Research Center of Materials Sciences of Anhui Province, Anhui Province Key Laboratory of Environment-Friendly Polymer Materials, Key Laboratory of Structure and Functional Regulation of Hybrid Material (Ministry of Education), Anhui University Hefei 230601 China cfz@ahu.edu.cn.

Abstract

Organic electrode materials have shown significant potential for aqueous Zn ion batteries (AZIBs) due to their flexible structure designability and cost advantage. However, sluggish ionic diffusion, high solubility, and low capacities limit their practical application. Here, we designed a covalent organic framework (TA-PTO-COF) generated by covalently bonding tris(4-formylbiphenyl)amine (TA) and 2,7-diaminopyrene-4,5,9,10-tetraone (PTO-NH₂). The highly conjugated skeleton inside enhances its electron delocalization and intermolecular interaction, leading to high electronic conductivity and limited solubility. The open channel within the TA-PTO-COF provides ionic diffusion pathways for fast reaction kinetics. In addition, the abundant active sites (C[double bond, length as m-dash]N and C[double bond, length as m-dash]O) endow the TA-PTO-COF with a large reversible capacity. As a result, the well-designed TA-PTO-COF cathode delivers exceptional capacity (255 mA h g^-1 at 0.1 A g^-1), excellent cycling stability, and a superior rate capacity of 186 mA h g^-1 at 10 A g^-1. Additionally, the co-insertion mechanism of Zn²⁺/H⁺ within the TA-PTO-COF cathode is revealed in depth by ex situ spectroscopy. This study presents an effective strategy for developing high-performance organic cathodes for advanced AZIBs.