Integrated Covalent Organic Framework/Carbon Nanotube Composite as Li-Ion Positive Electrode with Ultra-High Rate Performance



Gao, Hui, Zhu, Qiang, Neale, Alex R ORCID: 0000-0001-7675-5432, Bahri, Mounib ORCID: 0000-0002-8336-9158, Wang, Xue, Yang, Haofan, Liu, Lunjie, Clowes, Rob, Browning, Nigel D ORCID: 0000-0003-0491-251X, Sprick, Reiner Sebastian
et al (show 3 more authors) (2021) Integrated Covalent Organic Framework/Carbon Nanotube Composite as Li-Ion Positive Electrode with Ultra-High Rate Performance. ADVANCED ENERGY MATERIALS, 11 (39). p. 2101880.

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Abstract

Covalent organic frameworks (COFs) are promising electrode materials for Li-ion batteries. However, the utilization of redox-active sites embedded within COFs is often limited by the low intrinsic conductivities of bulk-grown material, resulting in poor electrochemical performance. Here, a general strategy is developed to improve the energy storage capability of COF-based electrodes by integrating COFs with carbon nanotubes (CNT). These COF composites feature an abundance of redox-active 2,7-diamino-9,10-phenanthrenequinone (DAPQ) based motifs, robust β‑ketoenamine linkages, and well-defined mesopores. The composite materials (DAPQ-COFX—where X = wt% of CNT) are prepared by in situ polycondensation and have tube-type core-shell structures with intimately grown COF layers on the CNT surface. This synergistic structural design enables superior electrochemical performance: DAPQ-COF50 shows 95% utilization of redox-active sites, long cycling stability (76% retention after 3000 cycles at 2000 mA g−1), and ultra-high rate capability, with 58% capacity retention at 50 A g−1. This rate translates to charging times of ≈11 s (320 C), implying that DAPQ-COF50 holds excellent promise for high-power cells. Furthermore, the rate capability outperformed all previous reports for carbonyl-containing organic electrodes by an order of magnitude; indeed, this power density and the rapid (dis)charge time are competitive with electrochemical capacitors.

Item Type: Article
Uncontrolled Keywords: covalent organic frameworks, Li-ion cells, positive electrode, ultra-high rate performance
Divisions: Faculty of Science and Engineering > School of Engineering
Faculty of Science and Engineering > School of Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 07 Sep 2021 08:24
Last Modified: 24 Jan 2023 17:21
DOI: 10.1002/aenm.202101880
Open Access URL: https://doi.org/10.1002/aenm.202101880
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3136114