Triphenylamine-Based Metal–Organic Frameworks as Cathode Materials in Lithium-Ion Batteries with Coexistence of Redox Active Sites, High Working Voltage, and High Rate Stability

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• 作者：Zhe Peng ; Xiaohui Yi ; Zixuan Liu ; Jie Shang ; Deyu Wang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：June 15, 2016
• 年：2016
• 卷：8
• 期：23
• 页码：14578-14585
• 全文大小：506K
• 年卷期：0
• ISSN：1944-8252

文摘

Through rational organization of two redox active building block, a triphenylamine-based metal–organic framework (MOF) material, Cu-TCA (H₃TCA = tricarboxytriphenyl amine), was synthesized and applied as a cathode active material for the first time in lithium batteries. Cu-TCA exhibited redox activity both in the metal clusters (Cu⁺/Cu²⁺) and organic ligand radicals (N/N⁺) with separated voltage plateaus and a high working potential vs Li/Li⁺ up to 4.3 V, comparing with the current commercial LiCoO₂ cathode materials. The electrochemical behaviors of this MOF electrode material at different states of charge were carefully studied by cyclic voltammetry, X-ray photoelectron spectroscopy, and photoluminescence techniques. Long cycling stability of this MOF was achieved with an average Coulombic efficiency of 96.5% for 200 cycles at a 2 C rate. Discussing the electrochemical performances on the basis of capacity contributions from the metal clusters (Cu⁺/Cu²⁺) and organic ligands (N/N⁺) proposes an alternative mechanism of capacity loss for the MOF materials used in lithium batteries. This improved understanding will shed light on the designing principle of MOF-based cathode materials for their practical application in battery sciences.