本文選題：MCMB + 甲醛�。� 參考：《福州大學(xué)》2010年碩士論文

【摘要】：本文研究了在酸性催化劑的條件下采用甲醛對煤瀝青進(jìn)行聚合改性，然后對改性瀝青進(jìn)行熱解制備出中間相炭微球（MCMB）。研究了改性煤瀝青的中間相轉(zhuǎn)化行為，探索了MCMB的制備工藝與結(jié)構(gòu)和性能之間的關(guān)系。以MCMB為原料，對MCMB進(jìn)行熱處理，將處理過的炭微球應(yīng)用于鋰離子電池的負(fù)極材料，并分析了MCMB的結(jié)構(gòu)和粒徑分布與電化學(xué)性能之間的關(guān)系。 采用FT-IR、1H-NMR、XRD、TG和流變儀對改性煤瀝青的結(jié)構(gòu)和性能進(jìn)行了分析。結(jié)果表明：甲醛在草酸的作用下與煤瀝青中的多環(huán)芳烴發(fā)生親電取代反應(yīng)，進(jìn)一步的環(huán)化和芳構(gòu)化，形成分子量大的多核芳烴化合物。改性后煤瀝青的殘?zhí)柯屎蛙浕c(diǎn)都有了明顯的提高，同時(shí)它的耐熱性和流變性能都有了很大的改善，表現(xiàn)出非牛頓流體行為的性質(zhì)，并且改性后煤瀝青的粘流活化能降低，表現(xiàn)出對溫度的不敏感性。 采用FT-IR、SEM、TEM和偏光顯微鏡對中間相轉(zhuǎn)化過程中的結(jié)構(gòu)和形貌進(jìn)行了觀察。研究表明：在炭化過程中，C-H、C-C鍵斷裂形成具有自由活性的自由基，隨著溫度的升高，，分子結(jié)構(gòu)發(fā)生重排，進(jìn)一步稠化、脫氫縮聚反應(yīng)，形成分子量更大的平面稠環(huán)芳烴化合物，在表面張力的作用下，形成MCMB。 采用SEM、XRD、粒度分析儀等分析手段，研究了MCMB的制備工藝、組成與性能的關(guān)系。結(jié)果表明：不同的工藝條件對于MCMB的結(jié)構(gòu)和性能均有不同程度的影響，特別是炭化溫度和保溫時(shí)間的影響更為顯著，在460℃下炭化保溫2h，MCMB的收率達(dá)到30.23%，并且球形度好，粒徑分布均勻；炭黑在炭微球的形成過程中起到了成核的作用，并且阻止了炭微球的融并，使MCMB粒徑分布更均勻。 通過電化學(xué)性能測試考察了MCMB作為鋰離子電池負(fù)極材料的性能，研究了熱處理溫度以及粒徑對其電化學(xué)性能及循環(huán)性能的影響。研究表明：MCMB的可逆容量和不可逆容量，都隨著熱處理溫度的升高而降低，而庫侖效率升高；同時(shí)電化學(xué)性能隨粒徑的變化而表現(xiàn)出一定的規(guī)律。隨著平均粒徑的增大，可逆容量和不可逆容量逐漸減小，庫侖效率則升高。將1000℃熱處理的炭微球制成鋰離子負(fù)極材料，經(jīng)過30次充放電循環(huán)后，容量下降僅為6.5%。
[Abstract]:This paper studied the polymerization modification of coal tar pitch with formaldehyde under the condition of acid catalyst. Then the mesophase microsphere (MCMB) was prepared by pyrolysis of modified bitumen. The intermediate phase transformation behavior of modified coal tar pitch was studied. The relationship between the preparation process of MCMB and the structure and energy of the asphalt was explored. The MCMB was used as the raw material to heat the MCMB. The treated carbon microspheres were applied to the anode materials of lithium ion batteries, and the relationship between the structure and particle size distribution of MCMB and the electrochemical performance was analyzed.
The structure and performance of modified coal tar pitch were analyzed by FT-IR, 1H-NMR, XRD, TG and rheometer. The results showed that formaldehyde was electrophilic substitution reaction with polycyclic aromatic hydrocarbons in coal tar pitch under the action of oxalic acid, further cyclization and aromatization, and formed a polyarene compound with large molecular weight. The residual carbon rate and softening of modified coal bitumen. At the same time, the heat resistance and rheological properties have been greatly improved, and the properties of non Newton fluid behavior are shown, and the viscous flow activation energy of the modified coal bitumen is reduced and the temperature is insensitive to the modified coal tar.
The structure and morphology of the mesophase transformation were observed by FT-IR, SEM, TEM and polarizing microscope. The results showed that in the carbonization process, the free radicals were formed with the free activity of C-H and C-C bonds. With the increase of temperature, the molecular structure rearranged, further thickened, dehydrogenized and condensed, and formed a larger molecular weight plane. Polycyclic aromatic hydrocarbons form MCMB. under the action of surface tension.
By means of SEM, XRD and particle size analyzer, the relationship between the preparation process and the composition of MCMB is studied. The results show that the different technological conditions have different influence on the structure and properties of MCMB, especially the influence of carbonization temperature and holding time, and the heat preservation of 2H at 460 C and the yield of MCMB is 30.2. 3%, the sphericity is good and the particle size distribution is uniform. Carbon black plays a nucleation role in the formation of carbon microspheres, and prevents the melting of carbon microspheres, so that the distribution of MCMB particle size is even more uniform.
The performance of MCMB as a anode material for lithium ion batteries was investigated by electrochemical performance test. The effects of heat treatment temperature and particle size on its electrochemical performance and cyclic properties were investigated. The results showed that the reversible capacity and irreversible capacity of MCMB decreased with the increase of heat treatment temperature, and the coulomb efficiency increased; With the increase of the average particle size, the reversible capacity and irreversible capacity gradually decrease with the increase of the average particle size, and the coulomb efficiency increases. The carbon microspheres treated at 1000 C are made of lithium ion anode material. After 30 charging and discharging cycles, the capacity drop is only 6.5%.

【學(xué)位授予單位】：福州大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2010
【分類號(hào)】：TQ522.65

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 楊俊和;金鳴林;;中間相炭微球(MCMB)的制備與應(yīng)用[J];材料導(dǎo)報(bào);2001年08期

2 王文志;林起浪;李鐵虎;馮子煜;;炭微球制備技術(shù)的研究動(dòng)態(tài)[J];材料導(dǎo)報(bào);2004年07期

3 任呈強(qiáng);李鐵虎;林起浪;李昊;孫效燕;;煤瀝青中間相的研究進(jìn)展[J];材料導(dǎo)報(bào);2005年02期

4 李新貴,黃美榮;高性能中介相瀝青基碳微球及碳片[J];材料科學(xué)與工藝;1997年03期

5 王惠,喬占平,董發(fā)昕,冉新權(quán);石油瀝青制備中間相瀝青[J];材料科學(xué)與工程;2001年02期

6 王成揚(yáng),李明偉,郭崇濤,稻垣道夫;不同形狀中間相瀝青炭纖維的橫斷面結(jié)構(gòu)(英文)[J];材料研究學(xué)報(bào);2000年04期

7 冀勇斌;李鐵虎;艾艷玲;程有亮;方長青;;中間相炭微球的制備及結(jié)構(gòu)研究[J];功能材料;2006年11期

8 張懷平,劉春林,呂春祥,李開喜,凌立成;空氣氧化法制備的煤焦油瀝青的性質(zhì)研究[J];新型炭材料;2000年03期

9 王成揚(yáng),姜卉,李鵬,鄭嘉明;原生QI成核中間相炭微球的結(jié)構(gòu)[J];新型炭材料;2000年04期

10 呂永根,凌立成,吳世e

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