本文選題：過渡金屬氧化物 + 納米陣列�。� 參考：《華中師范大學》2017年博士論文

【摘要】：隨著現(xiàn)代社會對能源需求的增加,人們對大容量高功率儲能設(shè)備的要求也越來越高。納米材料由于其具有的小尺寸效應(yīng),量子尺寸效應(yīng),表面效應(yīng)和宏觀量子隧道效應(yīng)而受到人們的廣泛研究,并在現(xiàn)代社會的各個領(lǐng)域得到大量的應(yīng)用,同時也被視為下一代儲能器件的關(guān)鍵性技術(shù)。在各種納米材料中,納米陣列材料,由于其相比于其它納米結(jié)構(gòu)有著更為優(yōu)異的性能而受到研究工作人員的廣泛關(guān)注,并被視為未來能源技術(shù)領(lǐng)域的重要研究方向。納米陣列材料所具有的特性有:(1)能提供直接的電子傳輸通道,提高電極材料的導電性;(2)減少離子在活性物質(zhì)中的擴散距離,增強材料的倍率性能;(3)極大的比表面積,增加電極材料與電解液的接觸面,減少充放電時間;(4)更穩(wěn)固的結(jié)構(gòu),能承受更大的體積膨脹和機械降解;(5)直接生長在集流體上,能省去導電添加劑和粘結(jié)劑的使用;(6)其較為松散的結(jié)構(gòu)和形貌較易于構(gòu)建更多種類的復合材料,并在不同材料之間產(chǎn)生協(xié)同效應(yīng);(7)相比于粉體材料,納米陣列材料有著更穩(wěn)固的結(jié)構(gòu),因而會對環(huán)境產(chǎn)生的影響更小,而且更加安全。同時納米陣列材料還存在許多的缺陷,嚴重的制約了其在儲能器件方面的大規(guī)模應(yīng)用。相比于其它納米材料,納米陣列材料的制備過程相對更加復雜,制備成本更加高昂,不利于大規(guī)模生產(chǎn);而且陣列材料在一維尺度上受到限制,使得陣列材料只能作為薄膜材料使用。在本論文中,我們通過探索不同陣列材料的生長過程,著力于克服其在制備與一維尺度上的困難與限制,以及通過特殊的方法將那些不能生長出納米線陣列的材料制備成納米線陣列的形貌。此外我們同時還進一步的研究如何提高電極材料的性能,是得其能夠進一步的被大規(guī)模實際應(yīng)用。本文的主要研究工作有以下幾個方面:1、利用水熱法,我們首先在碳布基底上得到了生長均勻的MnO2納米片薄膜。同時針對MnO2材料性能的不足與缺陷,設(shè)計了新型的MnO2/PPy復合納米薄膜材料。通過對其導電性的改善而提高了其電化學穩(wěn)定性與倍率性能,通過對MnO2納米材料在不同條件的電解質(zhì)下所裝配的電容器進行阻抗分析,我們得到了實驗性能最好的H3PO4/PVA凝膠電解質(zhì)。該電解質(zhì)不僅對氧化錳的性能有一定的幫助,同時還使得MnO2/PPy復合材料的實際應(yīng)用更有優(yōu)勢。得益于電極材料的優(yōu)越性能與電解質(zhì)的穩(wěn)定,該準固態(tài)超級電容器的最高能量密度可以達到2.04 μWh cm-2,同時其最高功率密度可以達到0.432mWcm-2,表現(xiàn)出了優(yōu)異的電容性能。該電容器同時在0.8 V高電壓的條件下穩(wěn)定循環(huán)1000次之后,仍能保持93.2%的初始容量,進一步證明了MnO2/PPy復合納米薄膜材料有著極其穩(wěn)定的電化學性能。2、我們通過對ZnO生長機理的研究,利用晶體成核與生長的特性,成功的掌握了 ZnO納米線陣列可控生長的方法,并能得到幾十微米長的超長ZnO納米線陣列。然后通過進一步實驗,我們成功的在ZnO納米線陣列的表面裝載了大量的MnO2活性物質(zhì)。通過研究MnO2生長的條件以及隨后樣品的電化學性能,我們成功的篩選并得到了有著超高面積比容量的ZnO/MnO2復合納米線陣列材料,極大的提高了 MnO2材料在超級電容器方面的實用性。通過進一步的電化學測試,我們證實了該材料優(yōu)異的電化學性能。該電極材料有著最大112mF cm-2的超高容量,并有著較為優(yōu)異的電化學穩(wěn)定性,在1000次循環(huán)后仍然能保持81mF cm-2容量。遠高于一般薄膜電極的超高容量,使其更具有商業(yè)應(yīng)用的價值。3、通過巧妙的設(shè)計,我們利用簡單的水熱法及電沉積法制備合成了 Ti02-Mo03核殼納米線陣列電極材料。TiO2-MoO3核殼納米線陣列由于其獨特的形貌,其各個材料之間的協(xié)同效應(yīng)有:(1)Ti02材料在鋰電池充放電過程中(即使是在高倍率電流密度下)表現(xiàn)出優(yōu)異的結(jié)構(gòu)穩(wěn)定性,其體積膨脹在反應(yīng)過程中幾乎沒有,因而作為支柱材料可以極大的提升MoO3材料整體的循環(huán)穩(wěn)定性和倍率性能;(2)MoO3納米殼層材料,能提供相對較大的容量和較高的電導性;(3)陣列結(jié)構(gòu)設(shè)計能簡化電極材料的制備過程,以及提供活性材料與集流體之間直接的電子傳輸渠道;(4)三維電極結(jié)構(gòu)的設(shè)計極大的提高電極材料在單位面積上負載的活性物質(zhì)質(zhì)量。當Ti02與MoO3的質(zhì)量比為1:1時,TiO2-MoO3核殼納米線陣列的質(zhì)量比容量能達到670 mA g-1,循環(huán)穩(wěn)定性能達到200次以上,以及其面積比容量能達到3.986 mAh cm-2,其性能能比的上一般的商用鋰離子電池。同時我們還利用TiO2-Mo03核殼納米線陣列負極材料與LiCoO2薄膜正極材料相搭配組裝了全電池設(shè)備,該電池的最大能量密度可以達到285 Whkg1,同時其最大的功率密度可以達到1086W kg-1,其優(yōu)異的性能具有較大的實用性,同時其復合模式也能應(yīng)用在其它的納米材料上。
[Abstract]:With the increasing demand for energy in modern society, the demand for large capacity and high power energy storage equipment is becoming higher and higher. Nanomaterials have been widely studied by people because of their small size effect, quantum size effect, surface effect and macroscopic quantum tunneling effect, and have been widely used in various fields of modern society. At the same time, it is considered as a key technology for the next generation of energy storage devices. In all kinds of nanomaterials, nanoarray materials have been widely concerned by researchers because of their superior performance compared to other nanostructures, and are regarded as an important research direction in the field of energy technology in the future. There are: (1) can provide direct electronic transmission channels to improve the conductivity of electrode materials; (2) reduce the diffusion distance of ions in the active material, enhance the ratio of the material; (3) maximum specific surface area, increase the contact surface of the electrode material and electrolyte, reduce charge and discharge time; (4) a more stable structure, can withstand a larger volume expansion. And mechanical degradation; (5) direct growth on the collection of fluids can save the use of conductive additives and adhesives; (6) its looser structure and morphology are easier to build more kinds of composite materials and produce synergistic effects between different materials; (7) the nano array material has a more stable structure than the powder material, and therefore the ring will be on the ring. The impact of the environment is smaller and safer. At the same time, there are many defects in nanoscale array materials, which seriously restrict its large-scale application in energy storage devices. Compared to other nanomaterials, the preparation process of nanomaterials is more complex, the cost of preparation is higher, and it is not conducive to mass production; and the array material is not good. The material is limited on one dimensional scale so that the array material can only be used as a film material. In this paper, by exploring the growth process of different array materials, we focus on overcoming the difficulties and limitations on the preparation and one dimension, and the preparation of materials that can not be produced by a rice wire array through a special method. In addition, we have further studied how to improve the performance of electrode materials, and it is necessary to further be applied in large scale. The main research work of this paper is as follows: 1, using the hydrothermal method, we first obtained the uniform MnO2 nanoscale film on the carbon substrate. In view of the defects and defects of the properties of MnO2 materials, a new type of MnO2/PPy composite nano thin film material was designed. By improving its conductivity, the electrochemical stability and multiplex performance were improved. Through the impedance analysis of the capacitor assembled under different conditions of the electrolyte of MnO2 nanomaterials, we got the best experimental performance. H3PO4/PVA gel electrolyte. This electrolyte not only helps the performance of manganese oxide, but also makes the application of the MnO2/PPy composite more advantageous. Thanks to the superior performance of the electrode material and the stability of the electrolyte, the maximum energy density of the quasi solid supercapacitor can reach 2.04 mu Wh cm-2, and the highest energy density of the supercapacitor can be reached at the same time. The power density can reach 0.432mWcm-2, showing excellent capacitive performance. The capacitor can still maintain the initial capacity of 93.2% after a stable cycle of 1000 times under the condition of 0.8 V high voltage. It is further proved that the MnO2/PPy composite nanomaterials have extremely stable electrochemical performance.2. We pass on the mechanism of ZnO growth. The study, using the characteristics of crystal nucleation and growth, successfully grasped the method of controlled growth of ZnO nanowire arrays, and obtained a long ZnO nanowire array of dozens of microns. Then, through further experiments, we successfully loaded a large number of MnO2 active substances on the surface of the ZnO nanowire array. The conditions for the growth of MnO2 were studied. As well as the electrochemical performance of the subsequent samples, we successfully screened and obtained the ZnO/MnO2 composite nanowire array with super high area specific capacity, which greatly improved the practicability of the MnO2 material in supercapacitor. By further electrochemical testing, we confirmed the excellent electrochemical performance of the material. The material has the super high capacity of the maximum 112mF cm-2, and has excellent electrochemical stability. After 1000 cycles, it can still maintain the capacity of 81mF cm-2. It is far higher than the super high capacity of the ordinary film electrode, making it more valuable in commercial application. By ingenious design, we make use of simple hydrothermal method and electrodeposition method to prepare it. Ti02-Mo03 nuclear shell nanowire array electrode material.TiO2-MoO3 nuclear shell nanowire array, due to its unique morphology, the synergistic effect of various materials: (1) Ti02 material exhibits excellent structural stability during charge discharge process of lithium batteries (even at high rate current density), and its volume expansion is almost not in the reaction process. Therefore, as a pillar material, it can greatly improve the cyclic stability and multiplying performance of the MoO3 material as a whole; (2) the MoO3 nanoscale material can provide relatively large capacity and higher conductivity; (3) the array structure design can simplify the preparation of the electrode material and provide the direct electronic transmission channel between the active material and the fluid collector. (4) the design of the three-dimensional electrode structure greatly improves the quality of the active material loaded on the surface of the electrode material. When the mass ratio of Ti02 to MoO3 is 1:1, the mass specific capacity of the TiO2-MoO3 nuclear shell nanowire array can reach 670 mA g-1, the cyclic stability performance is up to 200 times, and the area specific capacity can reach 3.986 mAh cm-2, The performance can be compared with the ordinary commercial lithium ion batteries. At the same time, we also use the TiO2-Mo03 nuclear shell nanowire array negative electrode and the LiCoO2 film positive material to assemble the full battery equipment. The maximum energy density of the battery can reach 285 Whkg1, and the maximum power density can reach 1086W kg-1. It has great practicability and its compound mode can also be applied to other nano materials.
【學位授予單位】：華中師范大學
【學位級別】：博士
【學位授予年份】：2017
【分類號】：TB383.1

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