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收集所有交通大學研究人員與學生個人或團體所發表之各項學術著作，涵蓋期刊論文、教師專書、學位論文等項。;;Collections of Publications of NCTU Researchers and Students Like Journal Papers and Thesis.

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🏛️國立陽明交通大學機構典藏

Author: search.filters.author.Chang, Jeng-KueiSubject: search.filters.subject.energy storage

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    Nanocatalyst-Assisted Fine Tailoring of Pore Structure in Holey-Graphene for Enhanced Performance in Energy Storage
    (2019-10-09)
    Dutta, Dipak
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    Jiang, Jian-Yong
    ;
    Jamaluddin, Anif
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    He, Shih-Ming
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    Hung, Yu-Han
    Nanoporous holey-graphene (HG) shows potential versatility in several technological fields, especially in biomedical, water filtration, and energy storage applications. Particularly, for ultrahigh electrochemical energy storage applications, HG has shown promise in addressing the issue of low gravimetric and volumetric energy densities by boosting of the ion-transport efficiency in a high-mass-loaded graphene electrode. However, there are no studies showing complete control over the entire pore architecture and density of HG and their effect on high-rate energy storage. Here, we report a unique and cost-effective method for obtaining well-controlled HG, where a copper nanocatalyst assists the predefined porosity tailoring of the HG and leads to an extraordinary high pore density that exceeds 1 x 10(3) mu m(-2). The pore architectures of the hierarchical and homogenous pores of HG were realized through a rationally designed nanocatalyst and the annealing procedure in this method. The HG electrode with a high mass loading results in improved supercapacitor performance that is at least 1 order of magnitude higher than conventional graphene flakes (reduced electrochemically exfoliated graphene (rECG)) in areal capacitance (similar to 100% retention of capacitance until 15 000 cycles), energy density, and power density. The diffusion coefficient of the HG electrode is 1.5-fold higher than that of rECG at a mass loading of 15 mg cm(-2), indicating excellent ion-transport efficiency. The excellent ion-transport efficiency of HG is further proved by nearly 4-fold magnitude lowering of its R-ion (the ionic resistance in the electrolyte-filled pores) value as compared with rECG when estimated for equivalent high-mass loaded electrodes. Furthermore, the HG exhibits a packing density that is 2 orders of magnitude higher than rECG, revealing the utility of the maximum electrode mass and possessing higher volumetric capacitance. The perfect tailoring of HG with optimized porosity allows the achievement of high areal capacitance and excellent cycling stability due to the facile ion-and charge-transport at high-mass-loaded electrodes, which could open a new avenue for addressing the long-existing issue of practical application of graphene-based energy storage devices.
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    A Water-Soluble NaCMC/NaPAA Binder for Exceptional Improvement of Sodium-Ion Batteries with an SnO2-Ordered Mesoporous Carbon Anode
    (2018-11-23)
    Patra, Jagabandhu
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    Rath, Purna Chandra
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    Li, Chi
    ;
    Kao, Hsien-Ming
    ;
    Wang, Fu-Ming
    SnO2@CMK-8 composite, a highly promising anode for Na-ion batteries (NIBs), was incorporated with polyvinylidene difluoride (PVDF), sodium carboxymethylcellulose (NaCMC), sodium polyacrylate (NaPAA), and NaCMC/NaPAA mixed binders to optimize the electrode sodiation/desodiation properties. Synergistic effects between NaCMC and NaPAA led to the formation of an effective protective film on the electrode. This coating layer not only increased the charge-discharge Coulombic efficiency, suppressing the accumulation of solid-electrolyte interphases, but also kept the SnO2 nanoparticles in the CMK-8 matrix, preventing the agglomeration and removal of oxide upon cycling. The adhesion strength and stability towards the electrolyte of the binders were evaluated. In addition, the charge-transfer resistance and apparent Na+ diffusion of the SnO2@CMK-8 electrodes with various binders were examined and post-mortem analyses were conducted. With NaCMC/NaPAA binder, exceptional electrode capacities of 850 and 425 mAh g(-1) were obtained at charge-discharge rates of 20 and 2000 mA g(-1), respectively. After 300 cycles, 90 % capacity retention was achieved. The thermal reactivity of the sodiated electrodes was studied by using differential scanning calorimetry. The binder effects on NIB safety, in terms of thermal runaway, are discussed.