Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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Author: search.filters.author.Lee, Sun HwaInstitution Author: search.filters.institutionAuthor.Büyükçakır, Onur

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  • Article
    Citation - WoS: 41
    Citation - Scopus: 44
    Ultralong-Life Quinone-Based Porous Organic Polymer Cathode for High-Performance Aqueous Zinc-Ion Batteries
    (American Chemical Society, 2023) Büyükçakır, Onur; Büyükçakır, Onur; Yüksel, Recep; Begar, Ferit; Erdoğmuş, Mustafa; Arsakay, Madi; Lee, Sun Hwa; Kim, Sang Ouk; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
    We synthesized and studied a redox-active quinone-basedporousorganic polymer (rPOP) and found ultralong cycle life: it is a promisingorganic cathode for aqueous zinc-ion batteries (ZIBs). It has highphysicochemical stability and enhanced intrinsic conductivity fromits fused-aromatic conjugated skeleton. rPOP's high porosityallows for efficient Zn2+ infiltration through the poresduring charging-discharging cycles and contributes to the efficientutilization of redox-active quinone units. It delivers a specificcapacity of 120 mAh g(-1) at a current density of0.1 A g(-1) with a flat and long discharge plateau,which is critically important to provide a stable voltage output.It provides ultralong cycle life at a current density of 1.0 A g(-1) for 1000 and at 2.0 A g(-1) for 30 000cycles, with initial capacity retention of 95 and 66%, respectively.The co-insertion (Zn2+ and H+) charge storagemechanism was investigated using various electrochemical measurementsand ex/in situ structural characterization techniques, and is explainedherein. These findings contribute to a better understanding of thestructure-property relationship for rPOP and open a new avenuefor new organic cathode materials for high-performance next-generationaqueous batteries.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 5
    Structural Analysis of Hyperbranched Polyhydrocarbon Synthesized by Electrochemical Polymerization
    (Royal Society of Chemistry, 2022) Jiang, Yi; Büyükçakır, Onur; Nam, Hyunju; Kwak, Sang Kyu; Ruoff, Rodney S.; Lee, Sun Hwa; Seo, Jae Hong; Shin, Eunhye; Joo, Se Hun; Büyükçakır, Onur; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
    We describe a structural analysis method for a hyperbranched polyhydrocarbon (PHC) produced by electrochemical polymerization. Nuclear magnetic resonance (NMR) techniques including 1H-NMR, quantitative 13C-NMR, DEPT 13C-NMR, and 1H-13C HSQC 2D NMR along with elemental analysis and FTIR were used to experimentally assess the likely structure of this complex polymer with random branching. The polymer structure was modeled based on the NMR results. Room temperature density, refractive index, melting temperature, and IR spectrum were good matches to the values, and spectrum, calculated using the simulated structure. Calculated Hildebrand solubility parameters for the simulated structure rationalize the room temperature solubility measured in a range of solvents. The experimental and modeling methods are likely to be applicable to any type of highly branched random branching polymer. To the best of our knowledge, this is the first comprehensive elucidation of the structure of an unknown and randomly hyperbranched polymer by combining experimental results and theoretical simulation, and the methods described should find broad use in the future.