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Rational Material Architecture Design for Better Energy Storage.

機(jī)譯：合理的材料架構(gòu)設(shè)計(jì)，以實(shí)現(xiàn)更好的能量存儲(chǔ)。

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Human civilization relies on an abundant and sustainable supply of energy. Rapidly increasing energy consumption in past decades has resulted in a fossil-fuel shortage and ecological deterioration. Facing these challenges, humankind has been diligently seeking clean, safe and renewable energy sources, such as solar, wind, waves and tides, to offset the diminishing availability or to take place of fossil fuels. At the same time, the search for strategies to reduce fossil-fuel consumption and decrease CO2 emission, such as to replace tradition vehicles by electrical vehicles (EVs), is demanded. However, the energy harvested from renewable sources must be stored prior to its connection to electric grids or delivery to customers, and EVs need sufficient on-board power sources. These essential needs have made energy storage a critical component in the creation of sustainable society.;Among all energy storage technologies, electrochemical energy storage within batteries or electrochemical capacitors (ECs) is the most promising approach, since as-stored chemical energy can be effectively delivered as electrical energy with high energy density and power density, high efficiency, long service life and effective cost. However, the performance of current batteries and ECs are constrained by poor material properties, though great effort has been made to improve materials during the past few years. The objective of this dissertation is to address the limitation of current energy storage materials by rational architecture design according to the well-recognized principles and criteria. To achieve this goal, the research strategy is to design and fabricate multifunctional architectures by integrating distinct material structures and properties to address the limitation of traditional materials and create a new family of high-performance energy storage materials with desired properties.;Different types of energy storage architectures were investigated and compared with conventional structures to demonstrate such design concepts. First, hierarchically porous carbon particles with graphitized structures were designed and synthesized by an efficient aerosol-spray process. By comparison with commercially available activated carbon and CNTs, it was found that hierarchical pore architecture is important for providing high surface area and fast ion transport, which leads to high capacitance and high power EDLC materials. Secondly, MnO2/mesoporous carbon nanocomposites were designed. MnO2 layers with different thicknesses were deposited on mesoporous carbon scaffolds with hierarchical pore structure and the charge storage performance of the composites was correlated to MnO2 layer thickness. It was determined that a suitable thickness is critical to ensure good electronic conductivity, sufficient electrolyte diffusion and high capacitance. Thirdly, interpenetrating oxide nanowire/CNT network structures were designed and fabricated by an in situ hydrothermal reaction. The composition, CNT length, pore structure, V2O5 structure, electrode thickness and architecture are critical factors. Synergistic effects obtained between V2O 5 nanowires and CNTs resulted in an optimal composition with the highest storage performance. Long CNTs led to robust flexible electrodes, while a hierarchical V2O5 structure enabled storage of both lithium and sodium ions at high rates. Thus, electrode architectures can be engineered to achieve high-rate, thick electrodes for bulk energy storage. Last, various architectures obtained through integrating nanocrystals and CNTs were designed and fabricated using ultrafine TiO2 nanocrystals as a model system. Electrodes were fabricated by directly coating thin film TiO2 on conductive Indium-Tin-Oxide (ITO) glass, by conformably coating nanocrystals on pre-formed CNT papers, or by solvation-induced assembly between nanocrystals and CNTs. It was demonstrated that thick electrodes with high charge capacity, high rate performance and cycling stability rely on functional architecture that simultaneously provides high electronic conductivity, easy ion diffusion, abundant surface actives sites and robust structure and interfaces. The general conclusion derived from these studies is that the energy storage performance of electrode materials can be significantly improved by constructing rational architectures that provide effective ion diffusion, good electronic conductivity, fast electrode reaction, robust structure and a stable interface, which normally cannot be obtained with conventional materials. This strategy also can be extended to other devices, such as batteries and fuel cells, providing a general design platform for high performance energy materials. Further exploration in this research direction will ultimately lead to high energy, high power, and long life energy storage devices for many applications, including portable electronics, EVs and grid-scale energy storage.
機(jī)譯：人類文明依靠豐富而可持續(xù)的能源供應(yīng)。在過(guò)去的幾十年中，能源消耗的迅速增加導(dǎo)致化石燃料短缺和生態(tài)惡化。面對(duì)這些挑戰(zhàn)，人類一直在努力尋找清潔，安全和可再生的能源，例如太陽(yáng)能，風(fēng)能，海浪和潮汐，以抵消日益減少的可利用量或替代化石燃料。同時(shí)，需要尋找減少化石燃料消耗和減少CO2排放的策略，例如用電動(dòng)汽車（EV）代替?zhèn)鹘y(tǒng)汽車。但是，從可再生能源收集的能源必須先存儲(chǔ)起來(lái)，然后再與電網(wǎng)連接或交付給客戶，而且電動(dòng)汽車需要足夠的車載電源。這些基本需求已使能量存儲(chǔ)成為創(chuàng)建可持續(xù)發(fā)展社會(huì)的關(guān)鍵組成部分。在所有能量存儲(chǔ)技術(shù)中，電池或電化學(xué)電容器（EC）中的電化學(xué)能量存儲(chǔ)是最有前途的方法，因?yàn)榭梢杂行У卮鎯?chǔ)化學(xué)能以高能量密度和功率密度，高效率，長(zhǎng)使用壽命和有效成本的電能形式輸送。然而，盡管在過(guò)去的幾年中已經(jīng)在改善材料方面做出了巨大的努力，但是目前的電池和EC的性能受到不良的材料性能的限制。本文的目的是根據(jù)公認(rèn)的原理和準(zhǔn)則，通過(guò)合理的架構(gòu)設(shè)計(jì)來(lái)解決當(dāng)前儲(chǔ)能材料的局限性。為了實(shí)現(xiàn)這一目標(biāo)，研究策略是通過(guò)集成不同的材料結(jié)構(gòu)和特性來(lái)設(shè)計(jì)和制造多功能架構(gòu)，以解決傳統(tǒng)材料的局限性，并創(chuàng)建具有所需特性的高性能儲(chǔ)能材料新系列。對(duì)存儲(chǔ)體系結(jié)構(gòu)進(jìn)行了研究，并將其與常規(guī)結(jié)構(gòu)進(jìn)行比較以證明這種設(shè)計(jì)概念。首先，通過(guò)有效的氣溶膠噴涂工藝設(shè)計(jì)并合成了具有石墨化結(jié)構(gòu)的分層多孔碳顆粒。通過(guò)與市售活性炭和CNT進(jìn)行比較，發(fā)現(xiàn)分層孔結(jié)構(gòu)對(duì)于提供高表面積和快速離子傳輸非常重要，這導(dǎo)致了高電容和高功率的EDLC材料。其次，設(shè)計(jì)了MnO2 /介孔碳納米復(fù)合材料。不同厚度的MnO2層沉積在具有分級(jí)孔結(jié)構(gòu)的介孔碳支架上，復(fù)合材料的電荷存儲(chǔ)性能與MnO2層的厚度相關(guān)。已確定合適的厚度對(duì)于確保良好的電子導(dǎo)電性，足夠的電解質(zhì)擴(kuò)散和高電容至關(guān)重要。第三，通過(guò)原位水熱反應(yīng)設(shè)計(jì)并制備了互穿氧化物納米線/ CNT網(wǎng)絡(luò)結(jié)構(gòu)。組成，CNT長(zhǎng)度，孔結(jié)構(gòu)，V2O5結(jié)構(gòu)，電極厚度和結(jié)構(gòu)是關(guān)鍵因素。在V2O 5納米線和CNT之間獲得的協(xié)同效應(yīng)導(dǎo)致了具有最高存儲(chǔ)性能的最佳成分。長(zhǎng)的CNT導(dǎo)致了堅(jiān)固耐用的柔性電極，而分層的V2O5結(jié)構(gòu)則使鋰離子和鈉離子能夠以高速率存儲(chǔ)。因此，可以對(duì)電極體系結(jié)構(gòu)進(jìn)行設(shè)計(jì)以實(shí)現(xiàn)高速率，厚電極，以存儲(chǔ)大量能量。最后，使用超細(xì)TiO2納米晶體作為模型系統(tǒng)，設(shè)計(jì)和制造了通過(guò)整合納米晶體和CNT獲得的各種結(jié)構(gòu)。通過(guò)直接在導(dǎo)電銦錫氧化物（ITO）玻璃上涂覆薄膜TiO2，在預(yù)先形成的CNT紙上均勻涂覆納米晶體，或者通過(guò)溶劑誘導(dǎo)的納米晶體與CNT之間的組裝來(lái)制造電極。結(jié)果表明，具有高充電容量，高倍率性能和循環(huán)穩(wěn)定性的厚電極依賴于功能架構(gòu)，該功能架構(gòu)可同時(shí)提供高電子電導(dǎo)率，易于離子擴(kuò)散，豐富的表面活性位點(diǎn)以及堅(jiān)固的結(jié)構(gòu)和界面。從這些研究中得出的一般結(jié)論是，通過(guò)構(gòu)建合理的體系結(jié)構(gòu)可以顯著改善電極材料的儲(chǔ)能性能，這些體系結(jié)構(gòu)具有有效的離子擴(kuò)散，良好的電子導(dǎo)電性，快速的電極反應(yīng)，堅(jiān)固的結(jié)構(gòu)和穩(wěn)定的界面，而通常這是無(wú)法獲得的。用常規(guī)材料。該策略還可以擴(kuò)展到其他設(shè)備，例如電池和燃料電池，從而為高性能能源材料提供通用設(shè)計(jì)平臺(tái)。在此研究方向上的進(jìn)一步探索最終將導(dǎo)致高能，高功率和長(zhǎng)壽命的儲(chǔ)能設(shè)備，可用于許多應(yīng)用，包括便攜式電子設(shè)備，電動(dòng)汽車和電網(wǎng)規(guī)模的儲(chǔ)能。

著錄項(xiàng)

  • 作者

    Chen, Zheng.;

  • 作者單位

    University of California, Los Angeles.;

  • 授予單位 University of California, Los Angeles.;
  • 學(xué)科 Engineering Chemical.;Engineering Materials Science.
  • 學(xué)位 Ph.D.
  • 年度 2012
  • 頁(yè)碼 330 p.
  • 總頁(yè)數(shù) 330
  • 原文格式 PDF
  • 正文語(yǔ)種 eng
  • 中圖分類
  • 關(guān)鍵詞

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