Anthraquinone-Enriched Conjugated Microporous Polymers as Organic Cathode Materials for High-Performance Lithium-Ion Batteries

• Published in: ACS applied energy materials Vol. 4; no. 12; pp. 14628 - 14639
• Main Authors: Mohamed, Mohamed Gamal, Sharma, Santosh U, Yang, Cheng-Han, Samy, Maha Mohamed, Mohammed, Ahmed A. K, Chaganti, Swetha V, Lee, Jyh-Tsung, Wei-Kuo, Shiao
• Format: Journal Article
• Language: English
• Published: American Chemical Society 27-12-2021
• Subjects: conjugated microporous polymers; Sonogashira−Hagihara couplings; anthraquinone; thermal stability; lithium-ion batteries
• ISSN: 2574-0962; 2574-0962
• DOI: 10.1021/acsaem.1c03270

Extended π-conjugated microporous polymers (CMPs) are useful as organic anode or cathode materials in lithium-ion batteries (LIBs), overcoming the issue of small organic molecules becoming soluble in the electrolytes during charge–discharge cycles. In this study, we constructed two CMPs (Py-A-CMP, TPE-A-CMP) containing anthraquinone (A) moieties (as redox-active units and sources of CO groups) and applied them as organic cathodes in LIBs. We synthesized the Py-A-CMP and TPE-A-CMP through Sonogashira–Hagihara couplings of 2,6-dibromoanthraquinone (A-Br2) with tetraethynylpyrene (Py-T) and tetraethynyltetraphenylethene (TPE-T), respectively. The TPE-A-CMP displayed high thermal decomposition temperatures (up to 539 °C) and char yields (up to 53 wt %). Electrochemical tests revealed that Py-A-CMP and TPE-A-CMP delivered discharge capacities (196.6 and 164.7 mAh g–1 at a C-rate of 0.1C, respectively) higher than those of other CMP materials. The capacity retention of TPE-A-CMP was 163 mAh g–1 (99.3%) over 400 cycles. The corresponding cells incorporating Py-T-CMP and TPE-T-CMP also exhibited excellent rate capability performance, maintaining discharge capacities of approximately 79 and 49 mAh g–1, respectively, at a high charge/discharge rate of 5C. Scanning electron microscopy confirmed the superior stability of both CMPs, revealing that these electrode materials remained intact, without any surface crack formation, during long-term cycling.