Reversible metal and ligand redox chemistry in two-dimensional iron-organic framework for sustainable lithium-ion batteries

• Main Authors: Geng, Jiarun, Ni, Youxuan, Zhu, Zhuo, Wu, Quan, Gao, Suning, Hua, Weibo, Indris, Sylvio, Chen, Jun, Li, Fujun
• Other Authors: School of Chemical and Biomedical Engineering
• Format: Article
• Language: English
• Published: 2023
• Subjects: Engineering::Chemical engineering; Metalorganic Frameworks; Redox Chemistry
• Online Access: https://hdl.handle.net/10356/170107
• Institution: Nanyang Technological University

Metal-organic frameworks (MOFs) are emerging as attractive electrode materials for lithium-ion batteries, owing to their fascinating features of sustainable resources, tunable chemical components, flexible molecular skeletons, and renewability. However, they are faced with a limited number of redox-active sites and unstable molecular frameworks during electrochemical processes. Herein, we design a novel two-dimensional (2D) iron(III)-tetraamino-benzoquinone (Fe-TABQ) with dual redox centers of Fe cations and TABQ ligands for high-capacity and stable lithium storage. It is constructed of square-planar Fe-N2O2 linkages and phenylenediamine building blocks, between which the Fe-TABQ chains are connected by multiple hydrogen bonds, and then featured as an extended π-d-conjugated 2D structure. The redox chemistry of both Fe3+ cations and TABQ anions is revealed to render its remarkable specific capacity of 251.1 mAh g-1. Benefiting from the intrinsic robust Fe-N(O) bonds and reinforced Li-N(O) bonds during cycling, Fe-TABQ delivers high capacity retentions over 95% after 200 cycles at various current densities. This work will enlighten more investigations for the molecular designs of advanced MOF-based electrode materials.