本文選題：高電壓鋰離子電池 + 隔膜��； 參考：《青島大學(xué)》2017年碩士論文

【摘要】：鋰離子電池正在逐步應(yīng)用在移動(dòng)智能設(shè)備、電動(dòng)汽車、航空航天、航海、以及眾多大型工業(yè)中。發(fā)展高電壓、高能量的鋰離子電池體系迫在眉睫,隔膜和電解質(zhì)作為鋰離子電池中重要組成部分之一,在高電壓鋰離子電池發(fā)展中起著十分關(guān)鍵的作用。因此,研發(fā)新型寬電化學(xué)窗口、高離子電導(dǎo)率和安全性能的耐高電壓隔膜和電解質(zhì)是高電壓鋰離子電池研究的重點(diǎn)。本文選用可再生的,具有良好的熱穩(wěn)定性的海藻酸鹽無(wú)紡布膜作為5 V高電壓鋰離子電池隔膜。通過(guò)測(cè)試發(fā)現(xiàn):海藻酸鹽隔膜最大拉伸強(qiáng)度為37 MPa,具有良好的機(jī)械性能,在150 oC以下熱穩(wěn)定性好,尺寸不發(fā)生收縮。30 oC時(shí)的離子電導(dǎo)率為1.4×10-3 S/cm。用海藻酸鹽隔膜組裝的5 V LiNi0.5Mn1.5O4(LNMO)/Li電池在55oC下200圈的循環(huán)保持率為79.6%,高于同等條件下的PP2500的半電池(69.3%)。除此之外,海藻酸鹽隔膜組裝的LiFePO4/Li半電池在150 oC下能夠正常充放電。因此,海藻酸鹽隔膜能夠應(yīng)用在5 V高電壓鋰離子電池隔膜領(lǐng)域。以三乙二醇二甲基丙烯酸酯(TEGDMA)為單體,碳酸丙烯酯(PC)為增塑劑,鋰鹽選用二氟草酸硼酸鋰(LiDFOB)配制前聚體溶液,引發(fā)劑選用偶氮二異丁腈(AIBN),通過(guò)原位聚合方法制備三乙二醇二甲基丙烯酸酯聚合物(CTE)凝膠態(tài)聚合物電解質(zhì)。合成的CTE凝膠聚合物電解質(zhì)在25 oC下的離子電導(dǎo)率為1.64×10-4 S cm-1。電化學(xué)窗口為2.5 V-4.75 V,離子遷移數(shù)為0.62。該電解質(zhì)組裝的LCoO2/Li半電池在25oC下具有良好的倍率性能和循環(huán)性能。這歸功于電解質(zhì)較高的離子電導(dǎo)率和離子遷移數(shù)以及較好的界面穩(wěn)定性。由此可見(jiàn)CTE凝膠聚合物電解質(zhì)能夠適用于高電壓LiCoO2鋰離子電池電解質(zhì)領(lǐng)域。本文提出的海藻酸鹽隔膜和CTE凝膠態(tài)聚合物電解質(zhì)具有良好的電化學(xué)穩(wěn)定性,應(yīng)用在高電壓鋰離子電池中表現(xiàn)出較好的循環(huán)和倍率性能,十分適用于高電壓鋰離子電池領(lǐng)域,對(duì)高電壓鋰離子電池的發(fā)展具有重要意義。
[Abstract]:Lithium-ion batteries are being used in mobile smart devices, electric vehicles, aerospace, navigation, and many large industries. It is urgent to develop high voltage and high energy lithium ion battery system. As one of the important components of lithium ion battery, diaphragm and electrolyte play a very important role in the development of high voltage lithium ion battery. Therefore, the research and development of new high voltage barrier and electrolyte with wide electrochemical window, high ionic conductivity and safety performance are the focus of research on high voltage lithium ion batteries. In this paper, a regenerative alginate nonwoven film with good thermal stability is used as a 5 V high voltage lithium ion battery diaphragm. The results show that the maximum tensile strength of alginate separator is 37 MPA, and it has good mechanical properties, and the ionic conductivity is 1.4 脳 10 ~ (-3) S-1 路cm ~ (-1) under 150oC, and the ionic conductivity is 1.4 脳 10 ~ (-3) S-1 路cm ~ (-1) when the size does not shrink. The cycle retention rate of the 5 V LiNi0.5Mn1.5O4(LNMO)/Li cell assembled with alginate diaphragm at 200 cycles under 55oC was 79.6, which was higher than that of the half-cell of PP2500 under the same conditions. In addition, the alginate membrane assembled LiFePO4/Li semi-cells can charge and discharge normally at 150oC. Therefore, alginate separator can be used in the field of 5 V high voltage lithium ion battery diaphragm. The prepolymer solution was prepared by using triethylene glycol dimethacrylate (TEGDMA) as monomer and propylene carbonate (PC) as plasticizer, and lithium salt was prepared with lithium difluorooxalate borate (LiDFOB). The gel polymer electrolyte of triethylene glycol dimethacrylate polymer (CTE) was prepared by in-situ polymerization with azodiisobutyronitrile (AIBN) as initiator. The ionic conductivity of the synthesized CTE gel polymer electrolyte is 1.64 脳 10 ~ (-4) S / cm ~ (-1) at 25oC. The electrochemical window is 2.5 V-4.75 V and the ion mobility is 0.62V. The LCoO2/Li half-cell assembled by the electrolyte has good performance of rate and cycle under 25oC. This is due to the high ionic conductivity, ionic mobility and better interfacial stability of the electrolyte. Therefore, CTE gel polymer electrolyte can be used in high voltage LiCoO2 lithium-ion battery electrolyte field. The alginate separator and CTE gel polymer electrolyte presented in this paper have good electrochemical stability, and have been applied to high voltage lithium ion batteries with good cycling and rate performance, and are very suitable for high voltage lithium ion batteries. It is of great significance to the development of high voltage lithium ion battery.
【學(xué)位授予單位】：青島大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：O646;TM912

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 Weizhai Bao;Zhian Zhang;Yongqing Gan;Xiwen Wang;Jie Lia;;Enhanced cyclability of sulfur cathodes in lithium-sulfur batteries with Na-alginate as a binder[J];Journal of Energy Chemistry;2013年05期

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本文編號(hào)：1834978