本文選題：π共軛材料　切入點(diǎn)：鋰離子電池　出處：《哈爾濱工業(yè)大學(xué)》2015年博士論文　論文類型：學(xué)位論文

【摘要】：傳統(tǒng)化石能源的廣泛使用帶來了環(huán)境的污染和資源的枯竭,以太陽能和風(fēng)能為代表的可再生能源的利用日益受到廣泛的關(guān)注,同時(shí)發(fā)展與之配套的儲(chǔ)能系統(tǒng)是解決上述可再生能源間歇性和分散性缺點(diǎn)的關(guān)鍵。作為儲(chǔ)能系統(tǒng)的核心,開發(fā)一種具有高儲(chǔ)能密度、長(zhǎng)循環(huán)壽命和快速充放電能力的儲(chǔ)能電極材料就顯得尤為重要和急迫。在本論文工作中,基于π共軛體系材料在儲(chǔ)能方面的優(yōu)勢(shì),以π共軛材料的結(jié)構(gòu)優(yōu)化設(shè)計(jì)為導(dǎo)向,制備一系列基于π共軛體系復(fù)合儲(chǔ)能材料,旨在提升儲(chǔ)能材料的電化學(xué)綜合特性,具體包括如下幾個(gè)方面內(nèi)容:(1)基于石墨烯(GNs)與亞甲基藍(lán)(MB)染料分子間的π-π相互作用,使染料分子吸附在石墨烯表面,同時(shí)限制石墨烯片層重新堆垛。這種處理方法,在去除染料污染物的同時(shí),將其廢棄物資源化利用,得到了一種新型的超級(jí)電容材料。該材料在1 A/g充放電倍率下,經(jīng)過800次循環(huán),比電容依然可以保持在187 F/g,電容保持率大于98%。(2)發(fā)展了一種溶劑熱自組裝方法制備了納米簇的Fe_3O_4/GAs復(fù)合材料,Fe_3O_4納米簇均勻地分散在石墨烯氣凝膠三維導(dǎo)電網(wǎng)絡(luò)中,其中Fe_3O_4納米簇減少了鋰離子傳輸?shù)穆窂?有利于充放電過程中鋰離子的快速輸運(yùn),多孔的石墨烯氣凝膠保證了活性物質(zhì)與電解液充分的接觸并有效地緩沖了電極的體積膨脹,使得Fe_3O_4/GAs復(fù)合電極的倍率及循環(huán)性能都得到了極大的改善。該材料在0.5 C、12 C和35 C的倍率下放電,放電容量分別為1221、392和118 mAh/g。在6C的放電倍率下,經(jīng)300次充放電循環(huán),Fe_3O_4/GAs復(fù)合電極材料依然保持著577 mAh/g的放電容量。(3)在發(fā)展的溶劑熱自組裝方法的基礎(chǔ)上,針對(duì)SnO_2材料的特點(diǎn),進(jìn)一步發(fā)展了一種穩(wěn)定電化學(xué)界面的方法策略。在制備的過程中,原位自組裝生成的碳包覆在二氧化錫納米顆粒表面,形成SnO_2@C納米簇,由于界面上碳修飾層的存在,穩(wěn)定了電化學(xué)界面,在隨后的制備過程中,SnO_2@C納米簇均勻地分散在硫摻雜的石墨烯氣凝膠網(wǎng)絡(luò)中,最終成功構(gòu)建了SnO_2@C@S-GAs材料,硫摻雜石墨烯氣凝膠的三維導(dǎo)電網(wǎng)絡(luò),有利于鋰離子、電子的快速傳輸和與電解液的充分接觸。該材料展示出了非常優(yōu)異的倍率和循環(huán)穩(wěn)定性能。在0.8、1.6、4.0、8.0和16.0A/g的電流密度下,放電容量分別為721、594、510、398和271 mAh/g。在4 A/g放電狀態(tài)下,經(jīng)1000次充放電循環(huán)后放電容量仍然高達(dá)537 mAh/g。(4)采用噴墨打印的方法,以PEDOT:PSS作為導(dǎo)電墨水,在柔性基底構(gòu)筑圖案化超級(jí)電容器,該方法突破了傳統(tǒng)的圖案制備方法存在制備周期長(zhǎng)、步驟繁瑣等局限,同時(shí)代替了以往方法必須采用的貴金屬做為引線。所制備的柔性器件展示出了很好的柔性和電容放電特性,在0.1 mA/cm~2的電流密度下,電容值為2.8mF/cm~2,在20 mV/s的掃速下具有高達(dá)6.2 mF/cm~2的電容值。
[Abstract]:The widespread use of traditional fossil energy has brought about environmental pollution and depletion of resources. The use of renewable energy, represented by solar and wind energy, has attracted increasing attention. At the same time, the development of the associated energy storage system is the key to solve the problem of intermittent and decentralized renewable energy. As the core of the energy storage system, a kind of energy storage system with high energy storage density is developed. In this paper, based on the advantages of 蟺 conjugated materials in energy storage, the structure optimization design of 蟺 conjugated materials is taken as the direction. A series of composite energy storage materials based on 蟺 -conjugated system were prepared to improve the electrochemical properties of energy storage materials, including: 1) based on the 蟺-蟺 interaction between graphene (GNS) and methylene blue (MBM) dyes. The dye molecules are adsorbed on the surface of graphene, and the restacking of graphene lamellae is limited. A new type of super capacitor material is obtained, which goes through 800 cycles at a charge / discharge rate of 1 A / g. The specific capacitance can still be kept at 187 F / g, and the capacitance retention ratio is greater than 98. 2) A solvothermal self-assembly method has been developed to prepare nanoclusters of Fe_3O_4/GAs composites, such as Fe3O4 nanoclusters, which are uniformly dispersed in the graphene aerogel three-dimensional conductive network. Among them, Fe_3O_4 nanoclusters reduce the path of lithium ion transport, which is conducive to the rapid transport of lithium ions during charge and discharge. The porous graphene aerogel ensures sufficient contact between the active material and the electrolyte and effectively buffers the volume expansion of the electrode. The performance of Fe_3O_4/GAs composite electrode was greatly improved at the rate of 12 C and 35 C, and the discharge capacity was 1221 渭 g / g and 118 mg / g, respectively, at the discharge rate of 6 C, and the discharge capacity of the composite electrode was 122mAh/ g at the rate of 12 鈩，

本文編號(hào)：1570582