發(fā)布時間：2018-03-10 00:25

  本文選題：氧化還原穿梭　切入點：噻蒽　出處：《復旦大學》2014年碩士論文　論文類型：學位論文

【摘要】：近幾年來,氧化還原穿梭限壓添加劑的研制逐漸成為鋰離子蓄電池限壓一致性的研發(fā)重點,該種方法具有以下幾點優(yōu)勢：(1)可以在電池內(nèi)部建立一種防過充過放的電化學自我保護機制,在發(fā)揮保護作用的過程中,不會對電池體系造成任何不可逆損害,對電池的保護作用是可恢復性的；(2)穿梭所起的電化學反應是可逆的,因此,穿梭的添加量少,使用壽命長；(3)制造工藝簡單,生產(chǎn)成本低。目前,電池一致性問題一直限制著我公司鋰離子二次電池在筆記本電腦、電動工具、電動汽車等領(lǐng)域中的發(fā)展,特別是在電動汽車等大型動力系統(tǒng)中各單體電池的電壓一致性是我們迫切需要解決的問題。鑒于上述情況,我們開展了氧化還原穿梭添加劑研究,目的開發(fā)出幾種可應用于實際LiFePO4/C電池體系的氧化還原穿梭添加劑。在第一階段的研究工作中,我們探討了氧化還原穿梭作用的動力學過程、其在石墨負極上的得失電子原理以及在實際電池組中的作用效果,初步篩選了十種4V級氧化還原穿梭添加劑,分別對其物理特性、電化學性能、限壓性能及電池的常規(guī)性能進行了實驗研究。對比結(jié)果表明,噻蒽具有合適的氧化還原電位,較高的分解反應速率,對電池其它電性能和安全性能沒有影響,是一種優(yōu)良的LiFePO4/C電池體系電解液氧化還原穿梭添加劑。在第二階段的研究工作中,深入研究了噻蒽限壓能力的發(fā)揮、衰減、恢復、受外界因素的影響程度,總結(jié)了噻蒽在一些實際電池產(chǎn)品中的應用結(jié)果,實驗驗證了噻蒽消耗后對電池常規(guī)性能的影響。研究表明噻蒽是一種適用于LiFePO4/C電池體系的氧化還原穿梭限壓添加劑,可顯著提高串聯(lián)電池組中單體電池的一致性。通過模擬筆記本電腦長時間待機過程的實驗發(fā)現(xiàn),噻蒽在循環(huán)使用的過程中,損失衰減速度相對較慢,具有良好的循環(huán)使用壽命,從而使得電池組具有優(yōu)異的循環(huán)性能。雖然,噻蒽的限壓內(nèi)能力受過充電流大小和環(huán)境溫度的雙重影響,但可通過提高添加劑濃度、減小極片及隔膜厚度等方法,提高氧化還原穿梭的分子擴散速率,從而改善穿梭在不同電流和溫度下的限壓性能。此外,噻蒽的在電池體系內(nèi)的引入,不僅對電池的常規(guī)性能(特別是自放電性能)沒有任何不利影響,而且,當噻蒽的限壓作用消耗殆盡后,噻蒽添加劑在“氧化一還原”循環(huán)過程中產(chǎn)生的不可逆反應副產(chǎn)物,亦不會對電池的常規(guī)性能有任何不利影響。
[Abstract]:In recent years, the development of redox shuttle voltage limiting additives has gradually become the focus of research and development of the voltage limiting consistency of lithium ion batteries. This method has the following advantages: 1) it can establish an electrochemical self-protection mechanism against overcharge and overdischarge within the battery, and will not cause any irreversible damage to the battery system in the process of exerting its protective effect. The electrochemical reaction to the battery protection is recoverable. The electrochemical reaction is reversible. Therefore, the added amount of shuttle is less, the service life is long, the manufacturing process is simple, and the production cost is low. Battery consistency has been limiting the development of lithium ion secondary batteries in notebook computers, electric tools, electric vehicles, etc. Especially in large power systems such as electric vehicles, the voltage consistency of individual cells is an urgent problem that we need to solve. In view of the above situation, we have carried out a study on redox shuttle additives. Objective to develop several redox shuttle additives that can be used in practical LiFePO4/C battery systems. In the first stage of the study, we discussed the kinetic process of redox shuttling. The principle of electron gain and loss on graphite negative electrode and its effect on actual battery pack. Ten kinds of 4V redox shuttle additives were preliminarily selected, and their physical properties and electrochemical properties were studied. The experimental results show that thianthracene has a suitable redox potential and a high decomposition rate, and has no effect on other electrical and safety properties of the battery. It is an excellent oxidation-reduction shuttle additive for electrolyte of LiFePO4/C battery system. In the second stage of the research work, the exertion, attenuation, recovery and influence of external factors on the limiting capacity of thianthracene were deeply studied. The application results of thianthracene in some practical battery products are summarized, and the effect of thianthracene consumption on the conventional performance of the battery is verified. The results show that thianthracene is a kind of redox shuttle limiting voltage additive suitable for LiFePO4/C battery system. By simulating the long standby process of notebook computer, it is found that the loss attenuation rate of thianthracene is relatively slow, and it has a good cycle life. Although the pressure limiting capacity of thianthracene is influenced by the charge current size and ambient temperature, it can be reduced by increasing the concentration of additives, reducing the thickness of the electrode and diaphragm, etc. Increase the molecular diffusion rate of the redox shuttle, thus improving the voltage limiting performance of the shuttle at different current and temperature. In addition, the introduction of thianthracene in the battery system, Not only does it have no adverse effect on the conventional performance (especially self-discharge performance) of the battery, but also, when the pressure limiting effect of thianthracene is exhausted, the by-product of the irreversible reaction produced by the thianthracene additive during the "oxidation-reduction" cycle, Nor will there be any adverse effect on the conventional performance of the battery.
【學位授予單位】：復旦大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TM912

【參考文獻】

相關(guān)期刊論文 前2條

1 莊全超,武山,劉文元,陸兆達;二次鋰電池過充電保護添加劑[J];電池工業(yè);2003年04期

2 盧星河;鄭立娟;崔旭軒;;動力型鋰離子電池的研究進展[J];化工新型材料;2010年03期

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本文編號：1590961