發(fā)布時(shí)間：2018-05-14 17:26

  本文選題：Li-S電池 + 碳紙阻隔層�。� 參考：《青島科技大學(xué)》2017年碩士論文

【摘要】：鋰硫電池的理論能量密度高達(dá)2600 Wh kg-1,作為最具競(jìng)爭(zhēng)力的下一代可充電電池之一,鋰硫電池引起了極大的關(guān)注。除了高能量密度外,硫單質(zhì)作為鋰硫電池的陰極還有自然界中儲(chǔ)存豐富,成本低和無(wú)毒的優(yōu)點(diǎn),開(kāi)發(fā)此類電池具有巨大的優(yōu)勢(shì)。但受現(xiàn)在研究水平和技術(shù)水平的限制,鋰硫電池中現(xiàn)存的問(wèn)題還無(wú)法得到徹底的解決,其中“穿梭效應(yīng)”被認(rèn)為是鋰硫電池實(shí)際應(yīng)用的主要障礙之一,可導(dǎo)致鋰硫電池容量的快速衰減和庫(kù)侖效率低。本研究針對(duì)“穿梭效應(yīng)”問(wèn)題,提出并制備了多功能碳紙和新型凝膠聚合物電解質(zhì)(PEGPE),從而顯著改善了鋰硫電池性能。(1)針對(duì)“穿梭效應(yīng)”,我們研究了多功能碳紙阻隔層。以導(dǎo)電劑和金屬氧化物混合材料為涂層修飾的碳紙制備多功能碳紙阻隔層,將其插在正極和隔膜之間,作為溶解的多硫化物阻擋層。配備多功能碳紙阻隔層的鋰硫電池展現(xiàn)出優(yōu)異的長(zhǎng)循環(huán)性能(0.5 C下,初始放電比容量1250 mAh g-1,400次循環(huán)后放電比容量為900 mAh g-1),通過(guò)掃描電鏡和元素分布圖譜分析,證明了多功能碳紙阻隔層對(duì)多硫化物具有阻擋作用。(2)為解決“穿梭效應(yīng)”問(wèn)題,本文研究并制備了一種新型凝膠電解質(zhì)PEGPE來(lái)替代鋰硫電池中傳統(tǒng)的液態(tài)電解質(zhì)。該凝膠電解質(zhì)以聚乙烯(PE)隔膜為支撐體,通過(guò)季戊四醇四丙烯酸酯(PETEA)與己二酸乙烯基酯(Ester)聚合形成。以PEGPE為電解質(zhì)的鋰硫電池顯示出優(yōu)異的循環(huán)穩(wěn)定性,在0.5 C電流密度下300次循環(huán)后,保持343 mAh g-1可逆放電比容量,同時(shí)具有高于92%的庫(kù)侖效率。該鋰硫電池的良好的循環(huán)性能主要源于PEGPE封閉多硫化物梭和非常穩(wěn)定的電極與電解質(zhì)的界面。
[Abstract]:The theoretical energy density of lithium-sulfur batteries is as high as 2600 Wh 路kg -1. As one of the most competitive next generation rechargeable batteries, lithium-sulfur batteries have attracted great attention. In addition to high energy density, sulfur as the cathode of lithium-sulfur batteries has the advantages of rich storage, low cost and non-toxic in nature, so the development of this kind of batteries has great advantages. However, limited by the current research level and technical level, the existing problems in lithium-sulfur batteries can not be completely solved, among which "shuttle effect" is considered as one of the main obstacles to the practical application of lithium-sulfur batteries. It can lead to rapid attenuation of lithium-sulfur battery capacity and low Coulomb efficiency. In order to solve the problem of "shuttle effect", the multifunctional carbon paper and a new gel polymer electrolyte PEGPEN were proposed and prepared in this study, which significantly improved the performance of lithium-sulfur batteries. (1) in view of the "shuttle effect", we studied the multifunctional carbon paper barrier layer. The multifunctional carbon paper barrier layer was prepared by carbon paper coated with conductive agent and metal oxide mixture. The barrier layer was inserted between the positive electrode and the diaphragm as the dissolved polysulfide barrier layer. The lithium-sulfur battery equipped with multifunctional carbon-paper barrier layer showed excellent long cycle performance at 0.5C. The initial discharge specific capacity of 1250 mAh g-1400 cycles was 900 mAh g-1g ~ (-1), which was analyzed by scanning electron microscopy (SEM) and elemental distribution spectra. In order to solve the problem of "shuttle effect", a new gel electrolyte, PEGPE, was studied and prepared to replace the traditional liquid electrolyte in lithium-sulfur battery. The gel electrolyte was prepared by polymerization of pentaerythritol tetraacrylate (PETEAA) and vinyl adipate (Ester). The lithium-sulfur battery with PEGPE as electrolyte showed excellent cycle stability. After 300 cycles at 0.5C current density, the specific capacity of reversible discharge was maintained at 343 mAh g ~ (-1) and the Coulomb efficiency was higher than 92%. The good cycling performance of the lithium-sulfur battery is mainly due to the PEGPE closed polysulfide shuttles and the very stable interface between electrode and electrolyte.
【學(xué)位授予單位】：青島科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TM912
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本文編號(hào)：1888812