電解液添加劑對(duì)檸檬酸鹽基炭材料的超電容性能影響研究
發(fā)布時(shí)間:2018-10-24 08:31
【摘要】:本論文主要利用模板炭化法制備一系列具有不同內(nèi)部結(jié)構(gòu)和電化學(xué)性能的納米多孔炭材料,考察了炭化溫度和模板類型對(duì)炭材料性能的影響。在此基礎(chǔ)上,通過引入一系列不同的氧化還原添加劑進(jìn)一步提高超級(jí)電容器電化學(xué)性能,對(duì)其反應(yīng)機(jī)理進(jìn)行詳細(xì)的研究。具體內(nèi)容如下:1.引入氧化還原添加劑鈣試劑羧酸鈉(簡(jiǎn)稱CS)到KOH電解質(zhì)中提高超級(jí)電容器的電化學(xué)性能。實(shí)驗(yàn)中,首先在800 ℃下直接炭化檸檬酸鉀得到Carbon-800樣品。然后在三電極系統(tǒng)中測(cè)量電化學(xué)性能,以6 mol L-1 KOH為電解液,測(cè)得該樣品在3 Ag-1 電流密度下的質(zhì)量比電容為128 F g-1。為了進(jìn)一步提升超級(jí)超級(jí)電容器的電容性能,在KOH電解液中引入一系列濃度的鈣試劑羧酸鈉。結(jié)果表明,當(dāng)6 mol L-1 KOH電解液中加入15 mmol L-1鈣試劑羧酸鈉,Carbon-800-15樣品在3Ag-1的電流密度下顯示出了較高的質(zhì)量比電容237F g-1,是Carbon-800樣品質(zhì)量比電容的2.1倍。除此之外,在二電極系統(tǒng)中,Carbon-800-15樣品在1.5 kW kg-1的功率密度下能量密度高達(dá)11.4 Wh kg-1,遠(yuǎn)大于在相同功率密度Carbon-800樣品的能量密度7.3 Wh kg-1。提高的比電容主要來源于電極/電解液表面質(zhì)子與電子的快速氧化還原反應(yīng)。由此可見,鈣試劑羧酸鈉在提高超級(jí)電容器的性能方面具有潛在的應(yīng)用價(jià)值。2.以檸檬酸三鈉為唯一碳源在800 ℃下炭化,制備新型的二維非晶炭材料(樣品命名為SC-blank),該樣品比表面積和孔隙體積分別高達(dá)1015.8 m2 g-1和2.0 m3 g-1。此外,我們應(yīng)用了一種炭化和石墨化同步的方法合成部分石墨化炭材料。首先,在800 ℃下炭化檸檬酸三鈉和硝酸鎳的混合物(質(zhì)量比為7:1),得到SC-7:1樣品,由于石墨化程度的增加促使其比表面積減少到682.8 m2 g-1,質(zhì)量比電容也有所減小,但該樣品具有了更好的倍率性能。更為重要的是,引入一定量的氧化還原添加劑對(duì)磺基苯偶氮變色酸鈉(簡(jiǎn)稱SAA)到KOH電解液中提高超級(jí)電容器的電化學(xué)性能。當(dāng)電流密度為3 A g-1時(shí),SC-blank樣品在KOH和對(duì)磺基苯偶氮變色酸鈉混合電解液中的質(zhì)量比電容高達(dá)200 F g-1,相對(duì)于在傳統(tǒng)KOH電解液中測(cè)得的比電容(66 Fg-1)有了很大幅度的提高。總之,對(duì)磺基苯偶氮變色酸鈉是一種可以有效提高電容的氧化還原添加劑。3.引入一種簡(jiǎn)單高效的氧化還原添加劑鄰苯二酚紫(簡(jiǎn)稱PCV)到不同的水質(zhì)電解液(H2SO4、Na2SO4、KOH)中提高超級(jí)電容器的電化學(xué)性能,這種性能的提升主要來源于電子和質(zhì)子在電極/電解液界面快速的氧化還原反應(yīng)。實(shí)驗(yàn)表明鄰苯二酚紫的濃度對(duì)超級(jí)電容器電化學(xué)性能具有重要的影響。在二電極系統(tǒng)中,當(dāng)把0.006 mol的鄰苯二酚紫加入到1mol L-1 H2SO4電解液中,超級(jí)電容器的電容達(dá)到200 F g-1,其是初始質(zhì)量比電容的2.6倍。此外,對(duì)應(yīng)的能量密度也高達(dá)28Wh kg-1 (增加了兩倍)。鄰苯二酚紫也被進(jìn)一步加入到Na2SO4和KOH介質(zhì)中,其電容和能量密度也都有顯著的提高,進(jìn)一步證明鄰苯二酚紫的高效性和普適性。實(shí)驗(yàn)結(jié)果表明具有突出電化學(xué)可逆性、良好普適性和較高溶解度的鄰苯二酚紫是一種非常高效的氧化還原添加劑。
[Abstract]:In this paper, a series of nano-porous carbon materials with different internal structure and electrochemical properties were prepared by template carbonization, and the influence of carbonization temperature and template type on the properties of carbon materials was investigated. On this basis, the electrochemical performance of super capacitor is further improved by introducing a series of different redox additives, and the reaction mechanism is studied in detail. The specific content is as follows: 1. The electrochemical performance of the super capacitor is improved by the introduction of the redox additive calcium reagent caustic soda (CS) into the KOH electrolyte. In the experiment, potassium citrate was first carbonized at 800 鈩,
本文編號(hào):2290871
[Abstract]:In this paper, a series of nano-porous carbon materials with different internal structure and electrochemical properties were prepared by template carbonization, and the influence of carbonization temperature and template type on the properties of carbon materials was investigated. On this basis, the electrochemical performance of super capacitor is further improved by introducing a series of different redox additives, and the reaction mechanism is studied in detail. The specific content is as follows: 1. The electrochemical performance of the super capacitor is improved by the introduction of the redox additive calcium reagent caustic soda (CS) into the KOH electrolyte. In the experiment, potassium citrate was first carbonized at 800 鈩,
本文編號(hào):2290871
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