本文關(guān)鍵詞：氧化鋁陶瓷涂層對鋰離子電池性能影響的研究　出處：《中南大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 納米氧化鋁 陶瓷涂層 循環(huán)性能 鋰離子電池安全性

【摘要】：摘要：安全性能是制約鋰離子電池大型化發(fā)展的關(guān)鍵,影響鋰離子電池安全性能因素有很多。陶瓷涂層具有良好的電解液浸潤性和耐高溫性能,是提高電池電化學(xué)性能和安全性能的一種途徑。本文從鋰離子電池電極的角度出發(fā),研究成本低并與電池兼容性好的陶瓷涂層,旨在提高鋰離子電池的電化學(xué)性能和安全性能。 本文在查閱文獻(xiàn)的基礎(chǔ)上,優(yōu)選了工業(yè)化原料納米氧化鋁為陶瓷原料,研究了納米氧化鋁的物化性能和粘結(jié)劑的種類比例對陶瓷涂層的影響,陶瓷涂層與石墨的相容性以及對全電池電化學(xué)性能和安全性能的影響。采用了循環(huán)伏安法(CV)、交流阻抗(EIS)、恒流充放電和掃描電子顯微鏡(SEM)、X射線衍射(XRD)等測試表征手段,研究了陶瓷涂層理化性能及其對電池性能的影響,獲得的主要結(jié)果如下： 1)納米氧化鋁顆粒的分散性能直接影響陶瓷涂層的均勻性。采用粒徑小、分散均勻的氧化鋁能夠有效防止?jié){料團(tuán)聚,油系陶瓷涂層與水系石墨負(fù)極相容性最好。高溫干燥后的陶瓷涂層具有納米級微孔,有利于電解液浸潤和吸收。 2)陶瓷涂層中氧化鋁顆粒與粘結(jié)劑比例對電池性能有重要影響。比較氧化鋁顆粒與聚合物粘結(jié)劑比例分別為9：1(AG-T1)和8：2(AG-T2), AG-T1的首次充放電效率為83.3%,與普通石墨負(fù)極的82.9%相當(dāng),而AG-T2的首次效率為80.4%�？凼诫姵匮h(huán)結(jié)果表明,T1能夠提高電池循環(huán)性能,T2降低電池循環(huán)性能�？凼诫姵氐慕涣髯杩购脱h(huán)伏安圖譜表明,T1涂層與電池負(fù)極的相容性好。 3)吸液和保液率測試表明,陶瓷涂層有利于電解液吸收和保存。負(fù)極涂覆陶瓷涂層后,循環(huán)500次容量保持率在88.6%,相比普通電池容量保持率為85.3%。陶瓷涂層也在一定程度上提高了電池的倍率性能和低溫性能。在針刺、短路、擠壓、重物沖擊、熱箱安全實(shí)驗(yàn)中,陶瓷涂層電池均未出現(xiàn)熱失控,而普通電池在針刺、重物沖擊、熱箱試驗(yàn)中均起火爆炸,說明陶瓷涂層能夠提高電池的安全性能。陶瓷涂層電池在循環(huán)300次后電池保持較好的安全性能,但沒有通過500次循環(huán)后的安全試驗(yàn)。負(fù)極極片電鏡表明,500次循環(huán)后陶瓷涂層出現(xiàn)剝離,這是造成安全性能下降的主要原因。
[Abstract]:Abstract: safety performance is the key to the development of lithium-ion batteries. There are many factors affecting the safety performance of lithium-ion batteries. Ceramic coatings have good electrolyte wettability and high temperature resistance. It is a way to improve the electrochemical performance and safety performance of the battery. From the point of view of the lithium ion battery electrode, the ceramic coating with low cost and good compatibility with the battery is studied in this paper. The aim of this paper is to improve the electrochemical and safety performance of lithium ion batteries. On the basis of literature review, the industrial raw material nano-alumina was selected as ceramic material, and the effects of physical and chemical properties of nano-alumina and the proportion of binder on ceramic coating were studied. The compatibility of the ceramic coating with graphite and its effect on the electrochemical and safety properties of the whole battery were investigated by cyclic voltammetry (CV) and AC impedance spectroscopy (EIS). The physical and chemical properties of ceramic coatings and their effects on battery performance were studied by means of constant current charge-discharge and scanning electron microscopy (SEM). The main results were as follows:. 1) the dispersion properties of nano-alumina particles directly affect the uniformity of ceramic coatings. Using alumina with small particle size and uniform dispersion can effectively prevent slurry agglomeration. The oil system ceramic coating has the best compatibility with the aqueous graphite negative electrode, and the ceramic coating after high temperature drying has nanometer micropores, which is favorable for electrolyte infiltration and absorption. 2) the ratio of alumina particle to binder in ceramic coating has an important effect on the performance of battery. The ratio of alumina particle to polymer binder is 9: 1 / AG-T1) and 8: 2 / 2 AG-T2 respectively. . The first charge and discharge efficiency of AG-T1 is 83.3, which is equivalent to that of normal graphite anode 82.9%, while the first efficiency of AG-T2 is 80.4. T1 can improve the cycle performance of the battery and T2 can reduce the cycle performance of the battery. The AC impedance and cyclic voltammetry of the buttoned battery show that the compatibility of the T1-coating with the negative electrode of the battery is good. 3) the liquid absorption and retention rate test showed that the ceramic coating was beneficial to the absorption and preservation of electrolyte. After coating the ceramic coating on the negative electrode, the capacity retention rate of 88.6% cycles was obtained. Compared with the ordinary battery capacity retention rate is 85.3. Ceramic coating also improves the battery performance and low temperature performance to a certain extent. In needle piercing, short circuit, extrusion, heavy impact, hot box safety experiments. Ceramic coated batteries did not appear heat out of control, but ordinary batteries in acupuncture, heavy impact, hot box test are all on fire and explosion. The results show that ceramic coating can improve the safety performance of the battery, and the ceramic coating battery keeps a good safety performance after 300 cycles. The negative electrode sheet electron microscope showed that the ceramic coating was peeled off after 500 cycles, which was the main reason for the deterioration of safety performance.
【學(xué)位授予單位】：中南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TM912

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