本文選題：鋁離子電池　切入點：高質(zhì)量石墨烯設(shè)計　出處：《浙江大學(xué)》2017年博士論文　論文類型：學(xué)位論文

【摘要】：鋁離子電池是一種以金屬鋁為負極,鋁基離子液體為電解質(zhì)的新型電化學(xué)儲能器件,具有負極容量高,安全性好及成本低等優(yōu)點。而目前鋁離子電池的發(fā)展主要受限于其正極性能,如容量低,循環(huán)性差等,這限制了其進一步發(fā)展和未來的實際應(yīng)用。因此尋找合適的鋁離子電池正極材料,特別是性能相對突出的石墨烯正極材料,并深入研究反應(yīng)機理以提高鋁離子電池的性能是目前鋁離子電池研究方向的重中之重。石墨烯是一種在電學(xué)、力學(xué)、光學(xué)及柔性等方面均展現(xiàn)出了卓越性能的新型二維碳材料。優(yōu)異的導(dǎo)電率、極高的二維材料寬厚比和表面積使得石墨烯目前已經(jīng)在能源存儲材料領(lǐng)域展現(xiàn)出了非常重要的應(yīng)用價值。因此,探究石墨烯本身的核心參數(shù)與電極反應(yīng)中的重要因素之間的關(guān)系是目前推進石墨烯在能源領(lǐng)域應(yīng)用的關(guān)鍵。為此本論文瞄準(zhǔn)“高質(zhì)量石墨烯設(shè)計”,以鋁離子電池中的“短板”正極為切入點,通過針對性的立足于完美石墨烯中關(guān)鍵性的“無缺陷”和“低堆疊”特征與電極性能之間的關(guān)系,極大的提高了鋁離子電池中石墨烯正極的電化學(xué)性能并探究相關(guān)機理,并擴展至其他電池電極的設(shè)計中。主要內(nèi)容如下:1.提出針對鋁離子電池石墨烯正極的首要“無缺陷原則”:缺陷越少,電化學(xué)性能越好。開發(fā)一種可大規(guī)模制備的無缺陷石墨烯氣凝膠正極,其比容量可達100mAhg-1,可在7.2秒內(nèi)充滿電(最高電流密度達100Ag-1),且可在25,000圈循環(huán)內(nèi)保持容量穩(wěn)定。通過計算知其能量密度可達60 Wh kg-1,功率密度可達30 kW kg-1,均達到甚至超出商業(yè)化超級電容器的水平。通過原位實驗證明石墨烯中的缺陷的存在導(dǎo)致電化學(xué)性能的降低,缺陷的產(chǎn)生導(dǎo)致循環(huán)中容量的衰減。同時證明該種鋁離子電池的原型具有快充慢放、柔性折疊及耐火安全的優(yōu)點,在未來可穿戴、高功率密度或需要高安全性的電化學(xué)儲能領(lǐng)域均可發(fā)揮極大作用。2.提出“高質(zhì)量石墨烯設(shè)計”,通過針對性的褶皺引入和高溫?zé)徇�原等關(guān)鍵技術(shù)創(chuàng)新,實現(xiàn)了可大量制備的無缺陷、低堆疊、高連續(xù)的石墨烯微花粉體材料,并闡明了其中“無缺陷”和“低堆疊”因素對鋁離子電池中的石墨烯正極的電化學(xué)性能起到的決定性作用。無缺陷石墨烯微花應(yīng)用于鋁離子正極時比容量可達100mAh g-1,在5,000圈循環(huán)內(nèi)保持容量穩(wěn)定,最快可在18秒內(nèi)充滿電(最高電流密度達20 A g-1),遠遠超出低質(zhì)量石墨烯正極的電化學(xué)性能。同時作者也將該原則延伸至鋰硫電池中的硫正極中。無缺陷石墨烯微花-硫復(fù)合物正極的面容量最高可達5.2 mAh cm-2,超出低質(zhì)量石墨烯材料-硫復(fù)合物的電化學(xué)性能,證明了該“高質(zhì)量石墨烯設(shè)計”為普適性原則。3.首次證明在以室溫離子液體為電解質(zhì)、鋁箔為負極的鋁離子電池中枝晶現(xiàn)象的存在。發(fā)現(xiàn)了表面天然氧化膜在抑制枝晶生長、維持負極穩(wěn)定方面的重要作用;闡明了在表面致密氧化膜均勻的保護下,金屬鋁箔與離子液體電解液反應(yīng)的機理,有助于推動鋁離子電池的進一步深入思考和實用化發(fā)展。
[Abstract]:Aluminum ion battery is a kind of metal aluminum as anode, aluminum based ionic liquid as a new electrochemical electrolyte energy device having a negative high capacity, good safety and low cost. At present, the aluminum ion battery development is mainly limited to the positive performance, such as low capacity, poor circulation, which limits its further development and application in the future. So looking for a suitable cathode material for aluminum ion batteries, especially graphene anode material properties are relatively prominent, and in-depth study of the reaction mechanism is the priority among priorities at the direction of aluminum ion battery to improve the performance of the aluminum ion battery. Graphene is a kind of electrical. The mechanical, optical and flexible aspects show a new two-dimensional carbon material with superior performance. Excellent conductivity, high ratio and thickness of two-dimensional material surface area makes graphene has been in the energy storage materials. The domain shows very important value. Therefore, the relationship between the important factors and the key parameters of the electrode reaction of graphene itself is the key to promote the application of graphene in the field of energy. This paper aimed at the design of high quality graphene, with aluminum ion battery in the "short board" positive as the breakthrough point, through targeted based on perfect graphene key "defect free" and "low stack" characteristics and the relationship between the electrode performance, greatly improve the electrochemical performance of aluminum ion battery cathode in graphene and explore the related mechanism, designed and extended to other battery electrodes. The main contents are as follows: 1. proposed aluminum ion battery graphene anode first "defect free" principle: the fewer defects and better electrochemical performance. The development of a large scale preparation of defect free graphene aerogel is 鏋，

本文編號：1628810