纳米纤维素基多层级孔道结构碳气凝胶的制备及在锂电池中的应用

发布时间：2018-02-26 01:36

本文关键词： 纳米纤丝化纤维素气凝胶碳化多层级结构锂离子电池　出处：《高等学校化学学报》2017年11期 　论文类型：期刊论文

【摘要】：采用纳米精磨法对商品桉木浆进行纳米纤丝化处理,得到了高长径比、尺寸均一的纳米纤丝化纤维素(NFC),平均直径为230.10 nm,长度达数十微米.将其组装、干燥后制得具有大量介孔的纳米纤丝化纤维素气凝胶(NFCA).将NFCA在氮气氛围下高温碳化制得碳气凝胶(CNFA),或在氢氧化钾条件下辅助碳化制得具有多层级孔道结构的碳气凝胶(CNFA-A),在保留的碳气凝胶骨架结构上进行孔洞构建.通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)表征及Nanomeasure溲统计分析,发现NFC的平均直径经碳化后减小到53.16 nm.利用X射线衍射(XRD)、BET比表面积测试和拉曼光谱揭示了碳化处理对纳米纤维素结构、比表面积、石墨化程度和缺陷的影响.结果表明,KOH辅助碳化处理后的碳气凝胶不仅保留了纤维素气凝胶前驱体的网络结构,还在其骨架上二次构建了更多的微孔和介孔,其比表面积高达488.92 m2/g,总孔容为0.404 cm3/g,所得的碳骨架被部分石墨化,具有良好的导电性.这类源于生物质的高比表面积碳气凝胶在被用作锂离子电池(LIB)负极材料时表现出优异的电化学性能,在电流密度1 A/g下连续充放电1000次后比容量达到409 m A·h/g,在电流密度高达20 A/g下,比容量还能维持在219 m A·h/g.
[Abstract]:The commercial eucalyptus wood pulp was treated with nanoscale fine grinding method. The average diameter of NFC was 230.10 nm and the length was tens of microns. After drying, nanofilament cellulose aerogels with a large number of mesoporous particles were prepared. Carbon aerogels were prepared by carbonization of NFCA in nitrogen atmosphere at high temperature, or carbon gas with multi-layer pore structure was prepared by carbonization under the condition of potassium hydroxide. The pore structure of carbon aerogel was constructed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Nanomeasure statistical analysis. It was found that the average diameter of NFC was reduced to 53.16 nm after carbonization. The specific surface area and specific surface area of nano-cellulose treated by carbonation were revealed by X-ray diffraction (XRD) and Raman spectroscopy. The results showed that the carbon aerogel not only retained the network structure of cellulose aerogel precursor, but also constructed more micropores and mesoporous cells on its skeleton. Its surface area is as high as 488.92 m2 / g, the total pore volume is 0.404 cm / 3 / g, and the resulting carbon skeleton is partially graphitized. High specific surface area carbon aerogels derived from biomass exhibit excellent electrochemical properties when used as anode materials for lithium-ion battery libs. When the current density is up to 20 A / g, the specific capacity can be maintained at 219 Ma 路h / g.
【作者单位】：青岛大学材料科学与工程学院;中国林业科学研究院木材工业研究所;青岛大学环境科学与工程学院;
【基金】：国家自然科学基金(批准号:31500468) 中央级公益性科研院所基本科研业务费专项(批准号:CAFYBB2016QB012)资助~~
【分类号】：TM912;TQ427.26

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