【摘要】：近年來,隨著能源危機(jī)和環(huán)境污染兩大問題的日益嚴(yán)重,綠色能源的開發(fā)與利用越來越受到人們的重視。熱電材料是一種利用熱電技術(shù)實(shí)現(xiàn)電能與熱能相互轉(zhuǎn)換的環(huán)境友好型能源材料,廣泛應(yīng)用于溫差發(fā)電和熱電制冷領(lǐng)域。通常用ZT值(ZT=S2σT/k)來評(píng)價(jià)材料的熱電性能,由公式可知除溫度T外,熱電性能還與Seebeck系數(shù)S、電導(dǎo)率σ和熱導(dǎo)率k三個(gè)熱電參數(shù)有關(guān),其中,降低材料的熱導(dǎo)率k是優(yōu)化熱電性能的有效途徑之一。因此,如何構(gòu)筑低熱導(dǎo)率熱電材料,改善熱電性能的研究具有非常重要的意義。本文從選用特殊材料、構(gòu)筑特殊結(jié)構(gòu)、摻雜納米粒子等方法出發(fā),設(shè)計(jì)制備低熱導(dǎo)率熱電復(fù)合材料。具體研究?jī)?nèi)容和結(jié)論如下:(1)選用導(dǎo)電高分子聚(3,4-二氧乙撐噻吩):聚對(duì)苯乙烯磺酸(PEDOT:PSS)為原料,引入多壁碳納米管(MWCNTs)和Ag納米片,通過設(shè)計(jì)特殊結(jié)構(gòu)來制備低熱導(dǎo)率熱電材料。研究發(fā)現(xiàn)該材料具有三維網(wǎng)絡(luò)結(jié)構(gòu),其中MWCNTs構(gòu)筑孔洞結(jié)構(gòu),比表面積可達(dá)228m2/g。在Ag摻雜PEDOT:PSS/MWCNT(PCA)復(fù)合氣凝膠中,引入Ag納米片對(duì)熱導(dǎo)率影響較小,PCA氣凝膠熱導(dǎo)率變化范圍在0.06 W/mK~0.11 W/mK之間,與純的PEDOT:PSS(0.348±0.01 W/mK)相比,熱導(dǎo)率幾乎降低了一個(gè)數(shù)量級(jí)。此外,Ag納米片的添加有利于同時(shí)提高復(fù)合材料電導(dǎo)率和Seebeck系數(shù)。綜合三個(gè)因素的影響,制備的熱電材料室溫下PCA氣凝膠ZT值最高為7.56×10-3。(2)選用高Seebeck系數(shù)、高電導(dǎo)率的無機(jī)納米材料Bi_2Te_3與PEDOT:PSS復(fù)合制備PEDOT:PSS/Bi_2Te_3(PB)復(fù)合氣凝膠,并對(duì)熱電性能進(jìn)行了測(cè)試和分析。通過SEM表征發(fā)現(xiàn)純PEDOT:PSS氣凝膠內(nèi)部孔洞結(jié)構(gòu)清晰且完整,在PB復(fù)合氣凝膠中Bi_2Te_3粉體均勻的分散在高分子基體中,而且孔洞結(jié)構(gòu)沒有被破壞。室溫下,PB復(fù)合氣凝膠熱導(dǎo)率在0.15 W/mK~0.24 W/mK之間并隨著Bi_2Te_3含量的增加而增大。引入Bi_2Te_3導(dǎo)致復(fù)合氣凝膠電導(dǎo)率提高,Seebeck系數(shù)最大高達(dá)92.61μV/K。(3)以低導(dǎo)熱材料濾紙為基底,采用物理旋涂方法制PEDOT:PSS/MWCNTs(PMF)納米復(fù)合薄膜熱電材料。實(shí)驗(yàn)研究了原料比例、涂層數(shù)目及測(cè)試溫度對(duì)復(fù)合材料熱電性能的影響。研究發(fā)現(xiàn)MWCNTs在PEDOT:PSS中分散均勻且有良好的界面作用;室溫條件下,PMF復(fù)合材料熱導(dǎo)率較低,熱導(dǎo)率最高約為0.2 W/mK左右;原料配比為1:1時(shí),PMF薄膜整體導(dǎo)電性能最佳;隨著涂布層數(shù)的增加,電導(dǎo)率先增加后降低,當(dāng)原料配比1:1的PMF樣品在涂層數(shù)目為3層時(shí),電導(dǎo)率可高達(dá)3530.47 S/m,Seebeck系數(shù)為15μV/K到19μV/K。(4)采用水熱法合成碲化鉍粉體,將炭黑(CB)與其摻雜制備不同比例的碲化鉍-炭黑(Bi_2Te_3/CB)復(fù)合材料,研究了復(fù)合材料的熱電性能。同時(shí)采用TGA、SEM、XRD等分析方法表征復(fù)合材料的結(jié)構(gòu),探究了微觀結(jié)構(gòu)與熱電性能的關(guān)系。研究發(fā)現(xiàn):室溫下,CB的引入使復(fù)合材料的熱導(dǎo)率大大降低(從0.59 W/mK降到0.09 W/mK);隨著Bi_2Te_3含量的增加,復(fù)合材料的電導(dǎo)率、熱導(dǎo)率均增大,Seebeck系數(shù)先增加后降低;當(dāng)Bi_2Te_3含量為88.9 wt%時(shí),在558℃下燒結(jié)10 min復(fù)合材料室溫下的ZT值最大(ZT=0.21)。
[Abstract]:In recent years, with the energy crisis and environmental pollution becoming more and more serious, people pay more and more attention to the development and utilization of green energy. ZT=S2T/k) is used to evaluate the thermoelectric properties of materials. The formula shows that besides temperature T, the thermoelectric properties are also related to Seebeck coefficient S, conductivity_and thermal conductivity K. Reducing the thermal conductivity K of materials is one of the effective ways to optimize the thermoelectric properties. Therefore, how to construct low thermal conductivity thermoelectric materials and improve the thermoelectric properties are studied. In this paper, low thermal conductivity thermoelectric composites are designed and fabricated by selecting special materials, constructing special structures and doping nanoparticles. The specific research contents and conclusions are as follows: (1) Poly (3,4-dioxoethylene thiophene): poly (p-styrene sulfonic acid) (PEDOT: PSS) is selected as raw material to introduce multi-walled carbon nanoparticles. Low thermal conductivity thermoelectric materials were prepared by designing special structures of nanotubes (MWCNTs) and Ag nanosheets. It was found that the materials had three-dimensional network structure, in which MWCNTs had a pore structure with a specific surface area of 228 m2/g. In Ag-doped PEDOT: PSS / MWCNT (PCA) composite aerogels, the introduction of Ag nanosheets had little effect on the thermal conductivity, and the thermal conductivity of PCA aerogels was less affected. The thermal conductivity of PCA aerogels was almost one order of magnitude lower than that of pure PEDOT:PSS (0.348.01 W/mK). In addition, the addition of Ag nanosheets was beneficial to simultaneously improve the conductivity and Seebeck coefficient of the composites. PEDOT:PSS/Bi_2Te_3(PB) composite aerogel was prepared by using high Seebeck coefficient and high conductivity inorganic nano-material Bi_2Te_3 and PEDOT:PSS. The thermoelectric properties of the composite aerogel were tested and analyzed. The pore structure of pure PEDOT:PSS aerogel was clear and complete by SEM. At room temperature, the thermal conductivity of PB composite aerogel increases with the increase of Bi_2Te_3 content. The introduction of Bi_2Te_3 results in the increase of the conductivity of the composite aerogel, and the Seebeck coefficient is up to 92.61 mu V/K. PEDOT: PSS / MWCNTs (PMF) nanocomposites were prepared by physical spin-coating method. The effects of the ratio of raw materials, the number of coatings and the testing temperature on the thermoelectric properties of the composites were investigated experimentally. The highest conductivity is about 0.2 W/mK; when the ratio of raw materials is 1:1, the overall conductivity of PMF film is the best; with the increase of coating layers, the conductivity increases first and then decreases; when the ratio of raw materials is 1:1, the conductivity of PMF sample is as high as 3530.47 S/m, Seebeck coefficient is 15 to 19 uV/K. (4) Bismuth telluride is synthesized by hydrothermal method. Bi_2Te_3/CB composites were prepared by doping carbon black (CB) with CB. The thermoelectric properties of the composites were studied. The structure of the composites was characterized by TGA, SEM, XRD, and the relationship between microstructure and thermoelectric properties was investigated. The conductivity decreases greatly (from 0.59 W/mK to 0.09 W/mK); with the increase of Bi_2Te_3 content, the conductivity and thermal conductivity of the composites increase, and the Seebeck coefficient increases first and then decreases; when the content of Bi_2Te_3 is 88.9 wt%, the ZT value of the composites sintered at 558 for 10 minutes is the highest (ZT = 0.21).
【學(xué)位授予單位】：四川師范大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TB33

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 孫希靜;魏燕紅;李娟娟;趙敬紅;趙麗娟;李權(quán);;銀摻雜PEDOT:PSS/碳納米管超輕導(dǎo)電氣凝膠熱電材料(英文)[J];Science China Materials;2017年02期

2 孫希靜;趙敬紅;劉艷玲;李娟娟;趙麗娟;李權(quán);;Bi_2Te_3/炭黑復(fù)合材料的制備及熱電性能[J];復(fù)合材料學(xué)報(bào);2017年05期

3 陳明禮;;炭素材料的研究熱點(diǎn)和發(fā)展趨勢(shì)[J];科技創(chuàng)新與應(yīng)用;2016年04期

4 趙麗娟;孫希靜;趙敬紅;胡楠;李權(quán);;聚(3,4-乙烯二氧噻吩)-聚苯乙烯磺酸類熱電材料研究進(jìn)展[J];四川師范大學(xué)學(xué)報(bào)(自然科學(xué)版);2015年04期

5 王綱;姜成群;高彩艷;王新;陳光明;;導(dǎo)電聚合物PEDOT在有機(jī)溶劑中的分散性研究[J];高分子學(xué)報(bào);2014年11期

6 趙敬紅;胡楠;趙麗娟;李權(quán);;高分子熱電材料研究進(jìn)展[J];塑料工業(yè);2014年08期

7 馮堅(jiān);馮軍宗;姜勇剛;張長(zhǎng)瑞;;碳?xì)饽z的傳熱規(guī)律及其在防隔熱中的應(yīng)用[J];宇航材料工藝;2012年02期

8 周歡歡;檀柏梅;張建新;牛新環(huán);王如;潘國峰;;Bi_2Te_3熱電材料研究現(xiàn)狀[J];半導(dǎo)體技術(shù);2011年10期

9 陳立東;熊震;柏勝強(qiáng);;納米復(fù)合熱電材料研究進(jìn)展[J];無機(jī)材料學(xué)報(bào);2010年06期

10 馮堅(jiān);高慶福;馮軍宗;姜勇剛;;纖維增強(qiáng)SiO_2氣凝膠隔熱復(fù)合材料的制備及其性能[J];國防科技大學(xué)學(xué)報(bào);2010年01期

相關(guān)博士學(xué)位論文 前1條

1 張麗麗;P型中溫碲化物溫差電材料制備與性能研究[D];天津大學(xué);2014年

相關(guān)碩士學(xué)位論文 前2條

1 馮倩;高溫溫差發(fā)電半導(dǎo)體焊層應(yīng)力場(chǎng)分析及疲勞壽命研究[D];燕山大學(xué);2013年

2 劉聰聰;聚3，，4-二氧乙撐噻吩：聚苯乙烯磺酸及其復(fù)合材料的熱電性能研究[D];江西科技師范學(xué)院;2011年

本文編號(hào)：2188317