本文選題：二氧化錳 + 聚苯胺��； 參考：《東華大學(xué)》2015年碩士論文

【摘要】：作為一種新興的能源存儲(chǔ)裝置，超級(jí)電容器具有比電池更高的功率密度、更短的充電/放電時(shí)間和較長(zhǎng)的循環(huán)壽命，擁有很好的發(fā)展前景。柔性超級(jí)電容器在可穿戴、小型化、便攜式電子設(shè)備的儲(chǔ)能元件上有潛在的應(yīng)用價(jià)值，其中電極材料是決定超級(jí)電容器性能的關(guān)鍵。將一種或多種具有高贗電容的物質(zhì)與不同結(jié)構(gòu)碳材料通過一定的加工工藝制備成復(fù)合材料，有望使兩者得到優(yōu)勢(shì)互補(bǔ)，從而制備具有較高電化學(xué)性能的新型電極材料。以不同結(jié)構(gòu)的碳材料如石墨烯、碳納米管、活性炭、碳纖維等作為基材制備自支撐電極材料受到較多關(guān)注，同時(shí)二氧化錳（MnO2）由于具有高比電容、資源廣、價(jià)格低廉、制備簡(jiǎn)單和環(huán)境友好等特點(diǎn)，而聚苯胺（PANI）不僅具有上述優(yōu)點(diǎn)外還具有高導(dǎo)電性，因此均受到廣泛研究。本文選擇具有一定機(jī)械強(qiáng)度、柔韌性和高導(dǎo)電的碳布（CC）作為碳材料基體，在其表面通過一定的化學(xué)及電化學(xué)合成方法分別制備了MnO2/CC、PANI/CC、MnO2/PANI/CC和PANI/MnO2/CC自支撐復(fù)合電極材料，并對(duì)其不同的形貌、結(jié)構(gòu)及電化學(xué)性能進(jìn)行了研究表征。 首先將CC通過等離子體表面蝕刻處理后，以5mM KMnO4溶液作為錳源，CC同時(shí)作為還原劑和碳基體材料，采用水熱反應(yīng)制備MnO2/CC復(fù)合材料。通過控制水熱反應(yīng)時(shí)間，制備了一系列不同厚度的MnO2/CC復(fù)合材料，采用FESEM、Raman、XRD、XPS等手段對(duì)其結(jié)構(gòu)和形貌進(jìn)行了表征，并通過循環(huán)伏安、恒流充放電、交流阻抗等測(cè)試方法對(duì)其電化學(xué)性能進(jìn)行了研究。結(jié)果表明，水熱法制備復(fù)合材料MnO2形貌很難控制且分布不均勻，容易受到反應(yīng)條件的影響，當(dāng)反應(yīng)時(shí)間為0.5h時(shí)，碳布表面形成球狀花瓣二氧化錳，隨著反應(yīng)時(shí)間增加到1h MnO2在自身表面繼續(xù)生長(zhǎng)易形成棒狀二氧化錳，并且雜亂無(wú)規(guī)地生長(zhǎng)于碳布的表面。隨著反應(yīng)時(shí)間的增加，復(fù)合材料的比電容逐漸增加，但MnO2的利用率逐漸下降，當(dāng)反應(yīng)時(shí)間為0.5h時(shí)，材料的面積比電容達(dá)到76.9mF/cm2，而且循環(huán)1700圈后比電容仍保留89%，顯示了較好的電化學(xué)性能。 為了改善MnO2/CC復(fù)合材料表面MnO2的分布均勻性和形貌可控操作性，采用電化學(xué)沉積法，通過改變電化學(xué)沉積時(shí)間，制備出一系列不同厚度的MnO2/CC復(fù)合材料。實(shí)驗(yàn)結(jié)果表明，電化學(xué)沉積法制備的MnO2呈納米球片狀的形貌，而且在碳布纖維表面均勻分布，當(dāng)沉積100s材料表面基本已經(jīng)被MnO2包裹；隨著沉積時(shí)間的延長(zhǎng)，所沉積MnO2的片層結(jié)構(gòu)變大，材料的比電容也隨著MnO2負(fù)載量增加而增大。當(dāng)沉積時(shí)間為2000s時(shí)復(fù)合材料的面積比電容可達(dá)291.7mF/cm2，但是MnO2表現(xiàn)出來(lái)的比電容隨著MnO2層厚度的增加而降低，沉積400s時(shí)，在1A/g的電流密度下，MnO2表現(xiàn)出很高的比電容，為413.7F/g。材料的循環(huán)穩(wěn)定性表現(xiàn)出一開始升高而后面穩(wěn)定保持不變的趨勢(shì)，在循環(huán)2000圈后比電容達(dá)到初始值得113%，顯示了較好的循環(huán)穩(wěn)定性，且相對(duì)于水熱法制備得到的復(fù)合材料其穩(wěn)定性有所提高。 由于MnO2的導(dǎo)電性較差，負(fù)載導(dǎo)電聚合物有望改善復(fù)合材料的導(dǎo)電性，從而進(jìn)一步提高材料的電化學(xué)性能。通過控制苯胺單體與氧化劑濃度，在一定的反應(yīng)溫度和時(shí)間下，采用原位聚合法制備了一系列PANI/CC復(fù)合材料。結(jié)果表明，，當(dāng)單體與氧化劑摩爾比為3：1時(shí)有利于納米線狀聚苯胺的形成，當(dāng)單體濃度超過0.015mmol/mL時(shí)，表面生長(zhǎng)的聚苯胺薄膜形貌會(huì)坍塌。隨著單體反應(yīng)濃度的增加，復(fù)合材料的電化學(xué)性能出現(xiàn)先增大后減小的趨勢(shì)，在單體濃度為1mmol/mL時(shí)，所制備的PANI/CC復(fù)合材料在0.2mA/cm2下的比電容高達(dá)225mF/cm2，但是倍率性較差，循環(huán)穩(wěn)定性差循環(huán)1600圈比電容僅保持初始的63%。 為進(jìn)一步改善MnO2/CC復(fù)合材料的導(dǎo)電性和PANI/CC復(fù)合材料的循環(huán)穩(wěn)定性，將MnO2和PANI按不同的順序負(fù)載于CC表面，利用兩者的協(xié)同作用進(jìn)一步提高復(fù)合材料的電學(xué)性能。選用前期研究的較佳實(shí)驗(yàn)條件分別制備PANI/MnO2/CC、MnO2/PANI/CC兩種不同層結(jié)構(gòu)復(fù)合材料，結(jié)果表明，PANI/MnO2/CC材料中兩種物質(zhì)能夠很好地相互嵌入交聯(lián)，其中球狀MnO2為PANI的生長(zhǎng)提供了較大的生長(zhǎng)空間，同時(shí)MnO2球間隙由納米線狀PANI連接，既起到增強(qiáng)兩者粘結(jié)力又能提供高導(dǎo)電通道；而MnO2/PANI/CC中兩種物質(zhì)則是形成相對(duì)獨(dú)立的存在，沉積時(shí)間較短時(shí)MnO2花球錯(cuò)落在PANI表面，當(dāng)沉積時(shí)間達(dá)到400s時(shí)最外層的MnO2就把PANI層完全包覆。在三電極測(cè)試體系下以0.2mA/cm2掃速進(jìn)行充放電測(cè)試， PANI/MnO2/CC的比電容達(dá)到421.6mF/cm2，而MnO2/PANI/CC只有284.7mF/cm2，且通過比較兩種電極的倍率性能發(fā)現(xiàn)，前者在電流密度擴(kuò)大5倍時(shí)比電容仍保持原來(lái)的63%，顯示出良好的倍率性能，而后者只有原來(lái)的48.6%。
[Abstract]:As a new energy storage device, the supercapacitor has a higher power density than the battery, a shorter charge / discharge time and a longer cycle life. It has a good prospect of development. The flexible supercapacitor has potential application value in the wearable, miniaturized and portable electronic devices, in which the electrode materials are used. It is the key to determine the performance of supercapacitor. One or more materials with high pseudo capacitance and different structural carbon materials are prepared by a certain processing technology. It is expected to make the two more complementary and prepare a new electrode material with high electrochemical properties. Rice tube, activated carbon and carbon fiber have been paid more attention to the preparation of self supporting electrode materials as base materials. At the same time, manganese dioxide (MnO2) has the characteristics of high capacitance, wide resources, low price, simple preparation and friendly environment, and polyaniline (PANI) not only has the above advantages but also has high conductivity, so it has been widely studied in this paper. Carbon cloth (CC) with a certain mechanical strength, flexibility and high conductivity was selected as the matrix of carbon material. The self supported composite electrode materials of MnO2/CC, PANI/CC, MnO2/PANI/CC and PANI/MnO2/CC were prepared on its surface by chemical and electrochemical synthesis methods, and their different morphology, structure and electrochemical properties were studied. Sign.
After the CC is etched by plasma surface, 5mM KMnO4 solution is used as manganese source and CC is used as reducing agent and carbon matrix material to prepare MnO2/CC composites by hydrothermal reaction. A series of MnO2/CC composites with different thickness are prepared by controlling the time of hydrothermal reaction. The structure of the composite is composed of FESEM, Raman, XRD and XPS. The morphology was characterized and its electrochemical performance was studied by cyclic voltammetry, constant current charge discharge, and AC impedance. The results showed that the MnO2 morphology of the composites prepared by hydrothermal method was difficult to control and distributed unevenly, and was easily affected by the reaction conditions. When the reaction time was 0.5h, the spherical petals formed on the surface of the carbon cloth. As the reaction time increases to 1H MnO2, it is easy to form rod like manganese dioxide on its own surface, and it grows on the surface of carbon cloth randomly. With the increase of reaction time, the specific capacitance of the composite increases gradually, but the utilization of MnO2 gradually decreases. When the reaction time is 0.5h, the area of the material is higher than the capacitance. To 76.9mF/cm2, and after 1700 cycles, the capacitance is still 89%, indicating better electrochemical performance.
In order to improve the distribution uniformity and controllability of the surface MnO2 on the surface of MnO2/CC composite, a series of MnO2/CC composites with different thickness were prepared by electrochemical deposition and the electrochemical deposition time was changed. The results showed that the MnO2 prepared by electrochemical deposition was in the shape of nanospheres and on the carbon fiber sheet. The surface of the 100s material is evenly distributed when the surface of the deposited material is basically MnO2 wrapped. As the deposition time prolongs, the lamellar structure of the deposited MnO2 becomes larger and the specific capacitance of the material increases with the increase of the load of MnO2. When the deposition time is 2000s, the area of the composite can reach 291.7mF/cm2, but the specific capacitance shown by the MnO2 is followed by the capacitance. With the increase of the thickness of the MnO2 layer, when the current density of 1A/g is deposited, the MnO2 shows a high specific capacitance at the current density of 1A/g. It shows a trend that the cyclic stability of the 413.7F/g. material rises at the beginning and the stability remains unchanged at the back. After the cycle 2000 cycles, the specific capacitance is worth 113%, showing a better cycle stability and relative stability. The stability of the composites prepared by hydrothermal method has been improved.
Due to the poor conductivity of MnO2, the load conducting polymer is expected to improve the conductivity of the composite material and further improve the electrochemical performance of the material. By controlling the concentration of aniline monomer and oxidant, a series of PANI/CC composites are prepared by in-situ polymerization at a certain reaction temperature and time. The results show that the monomer and the monomer are used as the monomers. When the molar ratio of oxidizer is 3:1, it is beneficial to the formation of nanoscale polyaniline. When the monomer concentration exceeds 0.015mmol/mL, the surface morphology of the polyaniline film will collapse. With the increase of the monomer reaction concentration, the electrochemical performance of the composite increases first and then decreases. When the monomer concentration is 1mmol/mL, the prepared PANI/CC is made. The specific capacitance of the composite material under 0.2mA/cm2 is as high as 225mF/cm2, but the rate is poor, and the cycle stability is poor. Compared to the 1600 cycle cycle, the capacitance keeps only the initial 63%..
In order to further improve the conductivity of MnO2/CC composites and the cyclic stability of PANI/CC composites, MnO2 and PANI are loaded on the CC surface in different order, and the electrical properties of the composites are further improved by the synergistic effect of both. The better experimental conditions of the previous study are made to prepare PANI/MnO2/CC and MnO2/PANI/CC in two different kinds. The results show that the two materials in the PANI/MnO2/CC material can be intercalalized well with each other, in which the spherical MnO2 provides a larger growth space for the growth of PANI, and the MnO2 sphere gap is connected by the nanoscale PANI, which can enhance both the bonding force and the high conduction channel, while the two in MnO2/PANI/CC. The quality is a relatively independent existence, when the deposition time is shorter, the MnO2 flower ball falls on the PANI surface. When the time of deposition reaches 400s, the PANI layer is completely covered with the PANI layer. Under the three electrode test system, the charge and discharge test is carried out at 0.2mA/cm2 sweep speed, PANI/MnO2/CC's specific electrical capacity reaches 421.6mF/cm2, and MnO2/PANI/CC only 284.7mF/cm is 284.7mF/cm. 2, and by comparing the ratio performance of the two electrodes, it is found that the former is still 63% when the current density is 5 times larger than the capacitance, showing a good multiplier performance, and the latter only has the original 48.6%..
【學(xué)位授予單位】：東華大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TB383.1;TB33

【參考文獻(xiàn)】

相關(guān)期刊論文 前2條

1 吳徹平;彭家惠;;納米二氧化錳的可控制備及其電化學(xué)儲(chǔ)能機(jī)理研究[J];功能材料;2011年02期

2 肖迎紅,王靜,孫曉亮,車劍飛,汪信;導(dǎo)電聚吡咯的電化學(xué)行為及表面形貌研究[J];南京理工大學(xué)學(xué)報(bào)(自然科學(xué)版);2005年04期

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