本文選題：多孔碳電極 + 氧化還原活性電解液　； 參考：《武漢理工大學(xué)》2015年博士論文

【摘要】：設(shè)計制備能同時實現(xiàn)高功率密度、高能量密度的超級電容器是新能源領(lǐng)域的重要發(fā)展方向和研究熱點。基于雙電層儲能的多孔碳材料,由于其表面積高,導(dǎo)電性好,因而被廣泛應(yīng)用于超級電容器中。研究表明,除了雙電層儲能,碳材料表面的活性官能團可以發(fā)生氧化還原反應(yīng)而提供額外的容量;然而,碳材料表面活性官能團與電解液離子之間的反應(yīng)通常不夠穩(wěn)定,導(dǎo)致其循環(huán)性能差,電荷存儲受限。另一種增加碳材料氧化還原活性的方法是使用具有氧化還原活性的電解液,此類電解液在電池中發(fā)生額外的氧化還原反應(yīng)因而可以存儲額外的電荷。但是它們在循環(huán)反應(yīng)過程中主要缺點是有限的氧化還原反應(yīng)和循環(huán)穩(wěn)定性差。本文針對以上問題,提出了通過在多孔碳微球表面引入功能化含氧基團,與具有高氧化還原活性的電解液協(xié)同作用,來大幅提高其能量密度與功率密度。此策略為新型儲能器件的設(shè)計提供了一種有效的方法,且對于高性能超級電容器的發(fā)展有巨大的促進作用,并獲得以下創(chuàng)新性成果:(1)我們提出了一種新的有效策略,在無需加入粘結(jié)劑的情況下,利用電解液中的Cu2+與多孔碳電極表面氧化還原反應(yīng),實現(xiàn)了超過傳統(tǒng)電解液體系高達10倍的比容量(4700 F g-1)。三電極體系中在60 A g-1的大電流密度下充放電循環(huán)5000次后,容量保持率高達99.4%。在二電極體系中材料比容量仍可達1010 F g-1。大幅提升的電化學(xué)性能歸因多孔碳電極超低的電荷轉(zhuǎn)移阻抗(0.04?),以及電解液離子與表面氧分子之間的協(xié)同作用。(2)在使用CuCl2這一新型氧化還原電解液時,對稱兩電極超級電容器也展現(xiàn)出很好電化學(xué)性能�？稍趯崿F(xiàn)7 kW kg-1的功率密度的同時,獲得高的能量密度(73 W h kg-1)與比容量(294 F g-1)。(3)混合型超級電容器在能源存儲領(lǐng)域體現(xiàn)了優(yōu)異的電化學(xué)性能。然而,基于微型多孔碳電極的對稱式超級電容器要實現(xiàn)高的輸出電壓和高的比容量仍然是一個巨大的挑戰(zhàn)�；谶@一挑戰(zhàn),我們進一步設(shè)計了微型無粘結(jié)劑對稱式超級電容器。通過設(shè)計相互交錯的微型多孔碳電極,在電解液中加入對苯二酚和藍胭脂紅,顯著提升了電化學(xué)性能。在中性的水系電解液中,電容器的工作電壓達到了2.5 V。在氧化還原酸性電解液中,其面積比容量提升了3倍。這種氧化還原電解液導(dǎo)致性能的提升歸因于對苯二酚的存在,其加速了電荷轉(zhuǎn)移的過程。
[Abstract]:Designing and fabricating supercapacitors with high power density and high energy density is an important development direction and research hotspot in the field of new energy. Porous carbon materials based on double layer energy storage are widely used in supercapacitors because of their high surface area and good conductivity. It has been shown that, in addition to the double layer energy storage, the active functional groups on the surface of carbon materials can undergo redox reactions to provide additional capacity; however, the reaction between the active functional groups on the surface of carbon materials and electrolyte ions is usually not stable. It leads to poor cycle performance and limited charge storage. Another way to increase the redox activity of carbon materials is to use redox active electrolytes which can store extra charges by additional redox reactions in the battery. However, their main shortcomings in the process of cyclic reaction are limited redox reaction and poor cycle stability. Aiming at the above problems, it is proposed that the energy density and power density can be greatly increased by introducing functionalized oxygen-containing groups on the surface of porous carbon microspheres and cooperating with the electrolyte with high redox activity. This strategy provides an effective method for the design of new energy storage devices, and has a great role in promoting the development of high performance supercapacitors, and obtains the following innovative results: 1) We propose a new and effective strategy. Using Cu2 in electrolyte and surface redox reaction of porous carbon electrode without adding binder, a specific capacity of 4700F g ~ (-1) is achieved, which is 10 times higher than that of traditional electrolyte system. After 5000 cycles at high current density of 60 A g ~ (-1) in the three-electrode system, the capacity retention rate is 99.4%. In the two-electrode system, the specific capacity of the material can still reach 1010 F g -1. The greatly improved electrochemical performance is attributed to the extremely low charge transfer impedance of the porous carbon electrode, and the synergistic effect between electrolyte ions and surface oxygen molecules. 2) when using CuCl2, a new redox electrolyte, Symmetrical two-electrode supercapacitors also show good electrochemical performance. The hybrid supercapacitors with high energy density (73W / h 路kg ~ (-1) and specific capacity (294F / g ~ (-1) 路L ~ (3) have excellent electrochemical performance in the field of energy storage while realizing the power density of 7 kW kg-1. However, the realization of high output voltage and high specific capacity for symmetric supercapacitors based on micro porous carbon electrodes is still a great challenge. In view of this challenge, we have further designed miniature binder-free symmetric supercapacitors. By designing interlaced micro porous carbon electrode and adding hydroquinone and blue carmine into the electrolyte, the electrochemical performance was improved significantly. In neutral aqueous electrolyte, the working voltage of the capacitor is up to 2.5 V. In the redox acidic electrolyte, the area specific capacity was increased by three times. This redox electrolyte leads to the improvement of performance due to the presence of hydroquinone, which accelerates the process of charge transfer.
【學(xué)位授予單位】：武漢理工大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：TQ127.11;TM53

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本文編號：1835124