本文選題：石墨烯 + 聚乙烯醇��； 參考：《東南大學(xué)》2017年碩士論文

【摘要】：泡沫石墨烯是具有三維結(jié)構(gòu)的石墨烯組裝體,既有石墨烯優(yōu)秀的物理化學(xué)性質(zhì),又具有三維多孔結(jié)構(gòu)的比表面積大、機(jī)械強(qiáng)度可控以及傳質(zhì)快速等優(yōu)點(diǎn)。這些獨(dú)特的性質(zhì)使泡沫石墨烯及其復(fù)合材料備受關(guān)注。本課題采用氧化石墨烯(GO)為前驅(qū)體,制備了氧化石墨烯/聚乙烯醇(GO/PVA)三維復(fù)合材料,通過(guò)熱還原法制備了 r-GO/PVA材料,并系統(tǒng)研究了材料的成分、微觀結(jié)構(gòu)及力學(xué)性能。為探索復(fù)合材料在高性能鋰離子電池上的應(yīng)用,本文采用水熱法合成了 Sn02納米粒子,研究了水熱溫度對(duì)其形貌、性能的影響。在此基礎(chǔ)上,制備了石墨烯/二氧化錫/聚乙烯醇r-GO/SnO_2/PVA三維多孔材料,研究了其電化學(xué)性能。本論文主要研究?jī)?nèi)容和結(jié)果如下:(1)通過(guò)冷凍干燥法制備了二元復(fù)合GO/PVA泡沫材料,其內(nèi)部具有均勻的孔洞,且可通過(guò)改變PVA加入量調(diào)節(jié)孔徑,材料的抗壓強(qiáng)度和彈性模量隨PVA含量增加而提高。在氬氣下300 ℃還原后,得到r-GO/PVA,材料的導(dǎo)電性能提高,強(qiáng)度和模量均低于同比例的GO/PVA材料。(2)采用水熱法制備了 Sn02納米材料,并對(duì)其進(jìn)行系統(tǒng)表征。結(jié)果表明,隨水熱溫度提高,SnO_2由納米顆粒轉(zhuǎn)變成納米棒狀結(jié)構(gòu)。將240 ℃下得到的納米棒狀SnO_2用作鋰電負(fù)極材料,具有較高的首次放電容量(1401 mAh/g),在500 mA/g電流密度下循環(huán)100次后,放電比容量在350 mAh/g左右。(3)將SnO_2納米棒均勻地分散在GO溶液中,采用冷凍干燥法制備了r-GO/SnO_2/PVA,將其用作鋰離子電池負(fù)極材料時(shí),表現(xiàn)出優(yōu)異的電化學(xué)性能。首次庫(kù)倫效率大于60%,循環(huán)100次后放電比容量保持在709.9 mAh/g以上,且此材料具有優(yōu)秀的倍率性能,在4A/g的電流密度下充放電,放電比容量在～500 mAh/g左右。
[Abstract]:Foamed graphene is an assembly of graphene with three dimensional structure. It has excellent physical and chemical properties, large specific surface area of three-dimensional porous structure, controllable mechanical strength and rapid mass transfer. These unique properties have attracted much attention to graphene foam and its composites. In this paper, the graphene oxide / polyvinyl alcohol (GOP / PVA) three dimensional composites were prepared by using graphene oxide (GOO) as the precursor. The r-GO/PVA materials were prepared by thermal reduction method. The composition, microstructure and mechanical properties of the composites were systematically studied. In order to explore the application of composite materials in high performance lithium-ion batteries, Sn02 nanoparticles were synthesized by hydrothermal method, and the effects of hydrothermal temperature on their morphology and properties were studied. On this basis, three dimensional porous materials of graphene / tin dioxide / polyvinyl alcohol (r-GO/SnO_2/PVA) were prepared and their electrochemical properties were studied. The main contents and results of this paper are as follows: (1) binary composite GO/PVA foam materials were prepared by freeze-drying method. The internal pores were uniform and the pore size could be adjusted by changing the amount of PVA. The compressive strength and elastic modulus of the material increase with the increase of PVA content. After reduction at 300 鈩，

本文編號(hào)：1825099