本文選題：超級電容器 + 過渡金屬��； 參考：《內(nèi)蒙古工業(yè)大學》2017年碩士論文

【摘要】：超級電容器作為一種新型綠色環(huán)保儲能器件,因其具有高比電容、高功率密度、快速充放電、循環(huán)壽命長以及比傳統(tǒng)電容器更高的能量密度等特點而被廣泛關(guān)注,在電動汽車、航空航天、起重機蓄電系統(tǒng)、新能源發(fā)電等領(lǐng)域應用前景廣闊,然而,與二次電池相比能量密度仍然較低,因此,提升能量密度是一直以來的研究重點。超級電容器的能量密度主要取決于比電容和電壓窗口,而比電容很大程度上取決于電極材料的結(jié)構(gòu)和形貌,因此,本文分別通過制備過渡金屬硒化物納米材料提升電極的導電性和比電容來改善超級電容器的能量密度,以及制備碳基納米復合材料并組裝成混合型超級電容器,從改進超級電容器結(jié)構(gòu)出發(fā)進行能量密度提升。實驗一通過溫和可控的水熱反應和硒代反應制得三維Ni_(0.85)Se納米陣列材料,特殊的三維結(jié)構(gòu)使Ni_(0.85)Se材料表現(xiàn)出良好的電化學性能。當電流密度為1 A·g~(-1)時,質(zhì)量比電容為1160.41 F·g~(-1),面電容為4.64 F·cm~(-2)。通過對比可知其電性能比Ni O和Ni S高出數(shù)倍,說明硒化物更具電化學優(yōu)勢。此外,三維Ni_(0.85)Se納米陣列材料具有良好的循環(huán)穩(wěn)定性,組裝成Ni_(0.85)Se//AC非對稱超級電容器后表現(xiàn)出一定的儲能特性。實驗二采用同樣的水熱反應和硒代反應制得了類珊瑚狀Ni_(0.9)Co_(1.92)Se_4納米材料,通過掃描電鏡、透射電鏡等表征確定了電極材料的形貌特征和結(jié)構(gòu)特點,隨后進行電化學測試和電性能分析。當電流密度為1 A·g~(-1)時,質(zhì)量比電容為1562.28 F·g~(-1),面電容為7.81 F·cm~(-2);盡管電流密度擴大到10 A·g~(-1),比電容保持率為69%,這在贗電容材料中處于較高水平,而且循環(huán)穩(wěn)定性高達88.4%。組裝成Ni_(0.9)Co_(1.92)Se_4//AC非對稱超級電容器后,1 A·g~(-1)電流密度下比電容能達到175.73 C·g~(-1),與Ni_(0.85)Se//AC和Co_(0.85)Se//AC相比具有明顯優(yōu)勢,尤其在大電流密度下能保持相對較高的比電容,同時,能量密度能達到40.42 Wh·kg~(-1),比當前多數(shù)超級電容器的儲能更好。實驗三采用聲波化學合成法制得了Mn_3O_4/AC納米復合材料,對其進行了基本的物相分析和形貌表征,并通過電化學測試得到材料在1 A·g~(-1)電流密度下,質(zhì)量比電容能達到359.90 F·g~(-1),是單純AC材料的2.2倍,即使電流密度擴大到10 A·g~(-1),比電容還能保持86%以上,說明復合材料保留了碳基材料倍率性能好的優(yōu)點。同時,組裝成Mn_3O_4/AC//1 M Li PF_6//Mn_3O_4/AC鋰離子混合型超級電容器后發(fā)現(xiàn),電容器的電壓窗口擴大到3 V,能量密度也隨之提升到54.20 Wh·kg~(-1),即使當功率密度擴大到9000W·kg~(-1),能量密度還能保持為31.68 Wh·kg~(-1),充分展現(xiàn)出Mn_3O_4/AC納米復合材料在超級電容器領(lǐng)域的良好應用。
[Abstract]:As a new type of green energy storage devices, supercapacitors have been widely concerned because of their high specific capacitance, high power density, rapid charge and discharge, long cycle life and higher energy density than traditional capacitors. Aerospace, crane power storage system, new energy generation and other fields have broad application prospects. However, compared with secondary batteries, energy density is still relatively low, so increasing energy density is always the focus of research. The energy density of supercapacitors depends mainly on the specific capacitance and voltage window, and the specific capacitance largely depends on the structure and morphology of the electrode material. In this paper, the energy density of supercapacitors was improved by the preparation of transition metal selenide nano-material lifting electrodes and the specific capacitance, and the carbon matrix nanocomposites were prepared and assembled into hybrid supercapacitors. In order to improve the structure of supercapacitor, the energy density is raised. In the first experiment, three dimensional Ni_(0.85)Se nanoarrays were prepared by moderate and controllable hydrothermal reaction and selenide reaction. The special three-dimensional structure made the Ni_(0.85)Se materials exhibit good electrochemical performance. When the current density is 1 A / g ~ (-1), the mass specific capacitance is 1160.41 F / g ~ (-1) and the surface capacitance is 4.64 F / cm ~ (-2) ~ (-1). Compared with Ni O and Ni S, the electrical properties of selenides are several times higher than that of Ni O and Ni S, indicating that selenides have more electrochemical advantages. In addition, the three-dimensional Ni_(0.85)Se nanoarrays have good cyclic stability and exhibit certain energy storage characteristics after assembling into Ni_(0.85)Se//AC asymmetric supercapacitors. In experiment 2, coral-like Ni_(0.9)Co_(1.92)Se_4 nanomaterials were prepared by the same hydrothermal reaction and selenium reaction. The morphology and structure of the electrode materials were determined by SEM and TEM. Then electrochemical test and electrical performance analysis were carried out. When the current density is 1 A / g ~ (-1), the mass specific capacitance is 1562.28 F / g ~ (-1) and the surface capacitance is 7.81 F / cm ~ (-1) ~ (-1). Although the current density is increased to 10 A / g ~ (-1), the specific capacitance retention rate is 69 ~ (th), which is relatively high in the pseudo-capacitance materials, and the cycle stability is up to 88.4%. The specific capacitance of Ni_(0.9)Co_(1.92)Se_4//AC asymmetric supercapacitor can reach 175.73 C / g ~ (-1) at current density, which has obvious advantages over Ni_(0.85)Se//AC and Co_(0.85)Se//AC, especially it can keep a relatively high specific capacitance at high current density. The energy density can reach 40.42 Wh / kg ~ (-1), which is better than that of most supercapacitors. In experiment 3, Mn_3O_4/AC nanocomposites were synthesized by acoustic chemical synthesis. The phase and morphology of the composites were analyzed and characterized. The current density of Mn_3O_4/AC nanocomposites was obtained by electrochemical measurement at 1 A g ~ (-1). The mass specific capacitance can reach 359.90 F / g ~ (-1) ~ (-1), which is 2.2 times as high as that of pure AC material. Even if the current density is increased to 10 A / g ~ (-1), the specific capacitance can be maintained by more than 86%, which indicates that the composite retains the advantage of good performance of carbon based material. At the same time, after assembling Mn_3O_4/AC//1 M Li PF_6//Mn_3O_4/AC lithium ion hybrid supercapacitors, When the voltage window of the capacitor is enlarged to 3 V, the energy density increases to 54.20 Wh / kg ~ (-1). Even if the power density is increased to 9 000 W / kg ~ (-1), the energy density can be maintained at 31.68 Wh / kg ~ (-1), which fully demonstrates the good application of Mn_3O_4/AC nanocomposites in the field of supercapacitors.
【學位授予單位】：內(nèi)蒙古工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TM53;TB383.1

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相關(guān)期刊論文 前4條

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本文編號：1857230