title: 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.
abstract: 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(+)/Cu(2+)) 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(+)/Cu(2+)) 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.
authors.affiliation: Institute of New Energy Technology, ‡Key Laboratory of Magnetic Materials and Devices, and §Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences , Ningbo 315201, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Peng
authors.affiliation: Institute of New Energy Technology, ‡Key Laboratory of Magnetic Materials and Devices, and §Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences , Ningbo 315201, China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Yi
authors.affiliation: Institute of New Energy Technology, ‡Key Laboratory of Magnetic Materials and Devices, and §Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences , Ningbo 315201, China.
authors.forename: Zixuan
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Institute of New Energy Technology, ‡Key Laboratory of Magnetic Materials and Devices, and §Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences , Ningbo 315201, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Shang
authors.affiliation: Institute of New Energy Technology, ‡Key Laboratory of Magnetic Materials and Devices, and §Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences , Ningbo 315201, China.
authors.forename: Deyu
authors.initials: D
authors.lastname: Wang
keywords: Coulombic efficiency; capability rate; lithium-ion battery; metal−organic framework; redox activity