【摘要】：隨著可穿戴、輕薄和柔性電子產品的迅速發(fā)展,開發(fā)具有高功率、高能量密度的柔性儲能器件已經成為儲能領域的研究熱點。然而,常規(guī)的電極制備需要加入導電劑、粘結劑和金屬集流體。其中,導電劑和粘結劑是非活性成分,會降低電極的比容量,而金屬集流體則會降低電極的整體能量密度和機械柔性,導致傳統(tǒng)的儲能器件無法滿足柔性電子設備的要求。因此,設計和開發(fā)具有高比容量、質輕、自支撐的柔性電極材料是發(fā)展柔性儲能器件的關鍵所在。目前,柔性電極材料遇到的瓶頸,主要體現(xiàn)在以下兩個方面:1)材料制備方法復雜,成本較高;2)電池的電化學性能仍未達到傳統(tǒng)鋰離子電池水平,無法滿足實際應用的要求。針對上述問題,本論文設計、開發(fā)了兩種兼具柔性和三維多孔結構的氮摻雜網狀碳材料,研究了其在氧氣還原電催化(ORR)和柔性鋰離子電池電極材料方面的應用,并探究其結構與性能之間的關系。具體工作如下:(1)以三聚氰胺泡沫為前驅體,采用預氧化和高溫熱解兩步法制備了一種多孔氮摻雜碳泡沫(NCFs)。考察了預氧化過程及溫度(250,300℃)對NCFs形貌、結構和性能的影響。形貌和結構表征顯示,NCFs碳骨架具有較高的石墨化程度和豐富的多級孔結構,比表面積可以達到980 m2 g~(-1)。力學性能測試結果表明,NCFs在80%的壓縮形變下能回復到原狀而不發(fā)生任何塑性形變,具有優(yōu)異的彈性性能。NCF-300~(-1)000用作ORR催化電極時,在堿性介質中表現(xiàn)出優(yōu)越的催化活性,起始電位與商業(yè)化Pt/C催化劑相當。同時,它還具有優(yōu)于Pt/C催化劑的循環(huán)穩(wěn)定性和抗甲醇中毒性。如此優(yōu)異的電催化性能主要歸功于NCFs的多級孔結構提供了豐富的催化活性位點以及三維石墨化碳結構保證了優(yōu)越的電荷傳遞通道。(2)采用簡單的壓力輔助熱解法,制備了一種兼具柔性和高密度的氮摻雜碳紙(NCPs)�？疾炝藟毫Υ笮�(600,400,200和0 kPa)對NCPs結構和性能的影響。研究發(fā)現(xiàn),隨著壓力的增大,NCP的三維網狀結構越來越密集,密度和導電性逐漸升高。三點彎曲測試結果顯示,NCPs具有優(yōu)異的機械柔性。將NCP-600k直接用于鋰電池負極材料,表現(xiàn)出良好的循環(huán)性能和倍率性能。在0.05和0.5 A g~(-1)的電流密度下循環(huán)200圈,NCP-600k的放電比容量分別為480和329.8 mA h g~(-1);甚至在8.0 A g~(-1)電流密度下循環(huán)500圈,放電比容量仍然能夠保留126.5 mA h g~(-1),保留率可以達到98.8%。如此優(yōu)異的電化學性能源于NCPs具有良好的三維導電網絡,促進了電荷的高效傳遞;以及碳纖維骨架上的多孔結構和氮原子的摻雜提供了豐富的儲鋰活性位點,提高了鋰離子的存儲能力。
[Abstract]:With the rapid development of wearable, thin and flexible electronic products, the development of flexible energy storage devices with high power and high energy density has become a research hotspot in the field of energy storage. However, conventional electrode preparation requires the addition of conductors, binders, and metallic fluid traps. Among them, the conductive agent and binder are inactive components, which will reduce the specific capacity of the electrode, while the metal collector will reduce the overall energy density and mechanical flexibility of the electrode, resulting in the traditional energy storage device can not meet the requirements of flexible electronic equipment. Therefore, the design and development of flexible electrode materials with high specific capacity, light weight and self support is the key to the development of flexible energy storage devices. At present, the bottleneck of flexible electrode material is mainly reflected in the following two aspects: 1) the preparation method of the material is complex and the cost is high. The electrochemical performance of the battery is still not up to the level of the traditional lithium ion battery, which can not meet the requirements of practical application. In order to solve the above problems, two kinds of nitrogen-doped reticular carbon materials with flexible and three-dimensional porous structure were designed and developed in this paper. The applications of these materials in oxygen reduction electrocatalytic (ORR) and flexible lithium ion battery electrode materials were studied. The relationship between structure and performance is explored. The main works are as follows: (1) using melamine foam as precursor, a porous nitrogen-doped carbon foam (NCFs). Was prepared by pre-oxidation and pyrolysis at high temperature. The effects of preoxidation process and temperature (250300 鈩，

本文編號：2141138