本文關(guān)鍵詞：納米結(jié)構(gòu)氧化物基超級(jí)電容器電極設(shè)計(jì)與器件構(gòu)造　出處：《北京科技大學(xué)》2017年博士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 超級(jí)電容器 金屬氧化物 納米復(fù)合電極 界面調(diào)控 非對(duì)稱超級(jí)電容器

【摘要】：超級(jí)電容器具有功率密度大、充放電速度快、使用壽命長等優(yōu)勢,是一種優(yōu)良的儲(chǔ)能器件,在電動(dòng)汽車、現(xiàn)代通訊、航空航天以及國防設(shè)備等諸多領(lǐng)域擁有巨大的應(yīng)用前景。但較低的能量密度一直制約其應(yīng)用與發(fā)展,如何在保證高功率和長壽命優(yōu)勢的前提下,提高其能量密度是當(dāng)今的研究熱點(diǎn)。根據(jù)能量密度公式E=1/2CV~2,能量密度主要由電極材料電容量和器件電壓窗口決定。本論文旨在研制具有高功率密度和能量密度的非對(duì)稱型超級(jí)電容器。首先著眼于電極材料的可控制備、結(jié)構(gòu)優(yōu)化、能帶設(shè)計(jì)以及儲(chǔ)荷機(jī)理研究,以改善氧化物電極材料電化學(xué)性能,提高其電容量。在此基礎(chǔ)上,設(shè)計(jì)構(gòu)建了水系非對(duì)稱超級(jí)電容器,實(shí)現(xiàn)器件工作電壓窗口的拓寬。具體研究內(nèi)容如F:1.通過摻雜改性優(yōu)化正極材料的電輸運(yùn)性能提高電容量。設(shè)計(jì)構(gòu)建了連續(xù)流動(dòng)注入摻雜裝置,通過連續(xù)恒定速率注入反應(yīng)源,精確控制化學(xué)反應(yīng)液的濃度,有效抑制了反應(yīng)過程中Al~(3+)水解導(dǎo)致的生長液酸化的現(xiàn)象,可控制備了高載流子濃度的A1摻雜ZnO納米線陣列,其載流子濃度可以達(dá)到1.14×10~(19)cm~(-3),與傳統(tǒng)的摻雜方法相比(4.2×10~(16)cm~(-3)),載流子濃度提升了三個(gè)數(shù)量級(jí)。將這種高載流子濃度的A1摻雜ZnO納米線作為活性物質(zhì)NiO的導(dǎo)電支架,構(gòu)筑自支撐電極材料,有效的提高了電極材料電容量。2.通過能帶設(shè)計(jì)進(jìn)一步優(yōu)化正極材料界面電輸運(yùn)性能提高電容量。采用低溫水熱法在三維碳布基底上生長了 ZnO/NiO核殼結(jié)構(gòu)納米線陣列作為柔性自支撐電極。通過紫外光還原法在ZnO/NiO界面處嵌入Au納米粒子,研究界面電輸運(yùn)性能對(duì)電極材料電容量的影響。當(dāng)電流密度為5 mAcm-2時(shí),ZnO/Au/NiO電極材料的電容量為4.1 Fcm~(-2),與ZnO/NiO電極材料(0.5 Fcm~(-2))相比提升了 720%。性能的提升主要?dú)w功于金納米粒子可促進(jìn)電極/電解液界面處電荷的快速傳輸。除此之外,在充電過程中,Au納米粒子與NiO形成的界面肖特基勢壘可以在費(fèi)米能級(jí)處捕獲少量電子,這將導(dǎo)致放電過程中,額外電子的釋放。3.通過結(jié)構(gòu)設(shè)計(jì)增加負(fù)極材料反應(yīng)活性位點(diǎn)提高電容量。利用無模板水熱法制備了 Fe_20_3中空梭狀納米顆粒,中空孔隙結(jié)構(gòu)可以將電解液限制其中,在增加活性物質(zhì)反應(yīng)位點(diǎn)的同時(shí),縮短了活性物質(zhì)與電解液的之間的傳輸距離保證了離子的快速傳輸。當(dāng)電流密度為0.5 Ag~(-1)時(shí),電極材料比電容為249 Fg~(-1)。同時(shí),引入阿倫尼烏斯公式分析了大電流密度下電容量下降的原因。在此基礎(chǔ)上,考察了電極材料的溫度服役行為。在20℃-60℃的溫度范圍內(nèi),隨溫度升高,電極材料電容量沒有明顯變化,表明該電極可以在20℃-60℃溫度范圍內(nèi)穩(wěn)定工作。4.構(gòu)建非對(duì)稱超級(jí)電容器拓寬電壓窗口。通過設(shè)計(jì)利于界面電子傳輸?shù)哪軒ЫY(jié)構(gòu),在ZnO/Ni(OH)_2界面處引入TiO2嵌入層形成臺(tái)階狀能帶結(jié)構(gòu),制備了 ZnO/TiO_2/Ni(OH)_2核殼結(jié)構(gòu)納米線陣列作為正極材料。根據(jù)能帶理論,臺(tái)階狀能帶結(jié)構(gòu)可以減少充電過程中電子界面?zhèn)鬏攧輭?降低還原反應(yīng)發(fā)生的激活能,電容量因此被提高。進(jìn)一步通過水熱法制備了ZnO/Fe_2O_3復(fù)合納米材料作為超級(jí)電容器的負(fù)極,根據(jù)注入電荷平衡原則,正負(fù)電極材料質(zhì)量配比為1.00:3.53,成功組裝了非對(duì)稱超級(jí)電容器。器件的電壓窗口擴(kuò)展到1.6V,電流密度1 Ag~(-1)時(shí),非對(duì)稱超級(jí)電容器可以獲得146.8Fg~(-1)的比電容。功率密度為1350 Wkg~(-1)時(shí),能量密度為52.22 Whkg~(-1)。
[Abstract]:Super capacitor with high power density, fast charging and discharging, long service life and other advantages, is an excellent energy storage device in electric vehicles, modern communication, has great application prospect in aerospace and defense equipment and other fields. But the low energy density restricted its application and development, how to in the premise of ensuring high power and long life advantages, improve the energy density is the hotspot of the research. According to the energy density formula of E=1/2CV~2, the energy density is mainly determined by the electrode capacitance and voltage window. This paper aims at the asymmetric super capacitor was developed with high power density and energy density of the controlled preparation of. First, optimize the structure of focusing on electrode materials, energy band design and storage mechanism, in order to improve the electrochemical performance of electrode materials, raise its capacity. On this basis, the design of construction The river asymmetricsupercapacitor, broaden the device operating voltage window. The specific contents such as F:1. by doping modification of cathode materials to improve the electrical transport properties. The capacitance is designed and constructed a continuous flow injection mixing device, injected into the reaction source through continuous constant speed, precise control of chemical reaction liquid concentration, effective suppression in the course of the reaction of Al~ (3+) in the growth solution hydrolysis acidification phenomenon, controlled synthesis of A1 doped ZnO nanowires with high carrier concentration of the array, the carrier concentration can reach 1.14 * 10~ (19) cm~ (-3), compared with the traditional method of doping (4.2 * 10~ (16) cm~ (-3)), the carrier concentration increased by three orders of magnitude. The A1 doped ZnO nanowires with high carrier concentration as the conductive support active material NiO, build a free-standing electrode material, effectively improve the capacitance of.2. electrode materials by band. Plan to further optimize the cathode material interface electrical transport properties to improve the capacitance. By low temperature hydrothermal method in three-dimensional carbon cloth substrate grown ZnO/NiO nanowires with core-shell structure array as a flexible self-supporting electrode. By UV reduction method in the interface of ZnO/NiO embedded Au nanoparticles, interface study of electrical transport properties of capacitance electrode materials. When the current density is 5 mAcm-2, the capacitance of the electrode materials of ZnO/Au/NiO 4.1 Fcm~ (-2), and ZnO/NiO electrode materials (0.5 Fcm~ (-2)) compared to enhance the 720%. performance mainly due to the gold nanoparticles can promote the rapid transmission of the electrode / electrolyte interface charge. In addition, in charge in the process, the interface of Schottky barrier Au nanoparticles and the formation of NiO can be captured at the Fermi level small electron, which will result in the discharge process, the release of.3. by additional electronic structure design increase Anode materials of reactive sites to improve capacity. Using the template free hydrothermal method, Fe_20_3 hollow spindle shaped nanoparticles prepared hollow pore structure can be increased in the limit of electrolyte, active substance reaction sites at the same time, shorten the transmission distance between the active material and the electrolyte to ensure fast ion transport. When the current density is 0.5 Ag~ (-1), electrode specific capacitance of 249 Fg~ (-1). At the same time, the introduction of Arrhenius formula, analyzed the reason of electric capacity decreased under high current density. On this basis, the temperature of the service behavior of electrode materials were investigated. The temperature range of 20 DEG -60 DEG C, with the increase of temperature, electrode the material capacity did not change significantly, show that the electrode can construct asymmetric supercapacitor voltage window to broaden the stable operation of the.4. at 20 DEG -60 DEG temperature range. The interface design for the electronic transmission The band structure in ZnO/Ni (OH) _2 interface into TiO2 embedded layer forming step band structure, to prepare ZnO/TiO_2/Ni (OH) _2 core-shell nanowire arrays as cathode materials. According to the band theory, stepped to the charging process can reduce the electronic interface transmission barrier band structure, reduction the reaction activation energy, the capacitance is thus improved. Further prepared by hydrothermal method ZnO/Fe_2O_3 nano composite material as cathode of supercapacitor, charge injection according to the principle of balance, positive and negative electrode material mass ratio is 1.00:3.53, successfully assembled asymmetricsupercapacitor devices. The voltage window is extended to 1.6V, current density of 1 Ag~ (-1), asymmetric super capacitor can be 146.8Fg~ (-1) capacitance. The power density is 1350 Wkg~ (-1), the energy density of 52.22 Whkg~ (-1).

【學(xué)位授予單位】：北京科技大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類號(hào)】：TB383.1;TM53

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 王曉峰;阮殿波;尤政;;Application of spherical Ni(OH)_2/CNTs composite electrode in asymmetric supercapacitor[J];Transactions of Nonferrous Metals Society of China;2006年05期

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本文編號(hào)：1390189