【摘要】：目前，，能源短缺和環(huán)境污染是人類社會面臨的兩大難題，研究可持續(xù)的清潔能源能夠逐漸緩解日益嚴重的能源和環(huán)境危機。鋰硫電池作為新一代高能量密度的儲能裝置受到了廣泛關(guān)注，這是因為單質(zhì)硫具有低成本、環(huán)境友好和高能量密度等優(yōu)勢。然而，鋰硫電池目前仍存在一定的技術(shù)瓶頸，主要由于單質(zhì)硫的不導(dǎo)電性和充放電中間產(chǎn)物在電解液中的易溶性，導(dǎo)致活性材料利用率較低、電池循環(huán)壽命較短以及庫侖效率較低，嚴重地制約著鋰硫電池的發(fā)展。 本文主要針對鋰硫電池存在的活性材料利用率低以及電池循環(huán)性能差兩大問題，挑選了一種高比表面中微雙級孔碳即活性炭作為正極載體（BET：2200m2g-1）。分別研究了載體材料顆粒大小、比表面積和孔容以及硫-碳復(fù)合材料的制備方法對鋰硫電池的影響，改進了蒸汽-熔融法制備中微孔材料-硫復(fù)合材料。結(jié)果表明，高比表面中微雙孔碳-硫復(fù)合正極材料的最佳制備工藝條件為：較小的活性炭顆粒、較大的比表面積和孔容、蒸汽-熔融法制備中微孔碳-硫復(fù)合材料。該工藝條件下制備的Sv-m-E/HACP復(fù)合物所制得的鋰硫電池在0.5C下的初始放電比容量為920mAh g-1，100圈的容量保持率為90%。 本文通過利用碳纖維紙做鋰硫電池正極集流體，構(gòu)建了碳纖維與活性炭顆粒形成的三維導(dǎo)電網(wǎng)狀，結(jié)合該三維導(dǎo)電網(wǎng)絡(luò)與上述Sv-m-E/HACP復(fù)合物制備的Li-(S/HAC-CPF)電池具有優(yōu)良的電化學(xué)性能。Li-(S/HAC-CPF)電池首圈的放電比容量高達1692mA hg-1，在0.5C、1C、2C、3C、6C下的放電比容量分別是1088mAh g-1、1013mAh g-1、895mAh g-1、829mAh g-1、660mAh g-1，比相同條件下鋁片為集流體的鋰硫電池相應(yīng)的放電比容量要分別高出15%、41%、45%、48%、50%。
[Abstract]:At present, energy shortage and environmental pollution are two major problems facing human society. The study of sustainable clean energy can gradually alleviate the increasingly serious energy and environmental crisis. As a new generation of high energy density energy storage devices, lithium sulfur batteries have attracted much attention because of their advantages of low cost, environmental friendliness and high energy density. However, there are still some technical bottlenecks in lithium-sulfur batteries at present, mainly due to the unconductivity of elemental sulfur and the easy solubility of the intermediate products of charge and discharge in the electrolyte, which leads to the low utilization of active materials. The short cycle life and low Coulomb efficiency seriously restrict the development of lithium-sulfur batteries. Aiming at the two problems of low utilization ratio of active materials and poor cycle performance of lithium-sulfur batteries, a kind of micro-double-pore carbon (activated carbon) in high specific surface was selected as positive electrode carrier (BET:2200m2g-1). The effects of particle size, specific surface area, pore volume and the preparation method of sulfur / carbon composites on lithium-sulfur batteries were studied respectively. The results show that the optimum preparation conditions of microporous carbon-sulfur composite cathode material in high specific surface are: smaller activated carbon particle, larger specific surface area and pore volume, and mesoporous carbon-sulfur composite prepared by steam melting method. The initial discharge specific capacity of the lithium-sulfur battery prepared by the Sv-m-E/HACP complex at 0.5 C is 90% for the 920mAh g-1100 cycle. In this paper, a three-dimensional conductive network formed by carbon fiber and activated carbon particles was constructed by using carbon fiber paper as the positive current collector of lithium-sulfur battery. The Li- (S/HAC-CPF) battery prepared by combining the 3D conductive network with the Sv-m-E/HACP complex has excellent electrochemical performance. The discharge specific capacity of the first cycle of Li- (S/HAC-CPF) battery is as high as that of 1692mA hg-1, at 0.5CU 1CU 2CU 3C 3C, respectively, which is 1088mAh g-1n 1013mAh g-1895mAh g-1829mAh g-1660mAh g-1, which is higher than that under the same conditions. The specific discharge capacity of the lithium-sulfur battery with aluminum as a fluid collector should be 15% higher than that of 41% and 45% 48.50% higher than the corresponding discharge capacity.
【學(xué)位授予單位】：華南理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TM912;TB332

【參考文獻】

相關(guān)期刊論文 前5條

1 屈偉平;;鋰電池的發(fā)展概述[J];城市車輛;2009年05期

2 閆強;陳毓川;王安建;王高尚;于汶加;陳其慎;;我國新能源發(fā)展障礙與應(yīng)對:全球現(xiàn)狀評述[J];地球?qū)W報;2010年05期

3 于雪云;;簡述循環(huán)伏安法實驗技術(shù)的應(yīng)用[J];德州學(xué)院學(xué)報;2012年S1期

4 胡林彥,張慶軍,沈毅;X射線衍射分析的實驗方法及其應(yīng)用[J];河北理工學(xué)院學(xué)報;2004年03期

5 陳強;努麗燕娜;楊軍;凱麗比努爾·克日木;王久林;;集流體對可充鎂電池電解液電化學(xué)性能的影響[J];物理化學(xué)學(xué)報;2012年11期

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