生物礦化多孔碳微管及其復(fù)合材料的制備與其超級(jí)電容器性能的研究
發(fā)布時(shí)間：2018-09-11 17:33
【摘要】：隨著經(jīng)濟(jì)的快速發(fā)展,具有快速充放電,長(zhǎng)久循環(huán)壽命,高功率密度的超級(jí)電容器逐漸作為能源儲(chǔ)存中不可或缺的設(shè)備之一。然而其較低的容量性質(zhì)以及較低的能量密度成為制約超級(jí)電容器發(fā)展的主要因素。超級(jí)電容器性能的好壞主要由電極材料自身的性質(zhì)及其結(jié)構(gòu)所決定。電極材料的選擇以及電極結(jié)構(gòu)的合理設(shè)計(jì)將有利于超級(jí)電容器性能的提高。本論文以天然生物質(zhì)作為前驅(qū)體,將高溫煅燒得到的中空碳微管,分別通過(guò)KOH與空氣活化的方式獲得具有較大比表面積的多孔材料,并與具有高導(dǎo)電性的金屬硫化物進(jìn)行復(fù)合,設(shè)計(jì)合成具有特殊結(jié)構(gòu)的納米復(fù)合材料,提高電極材料的整體性能。具體內(nèi)容如下:(1)以燈芯草作為前驅(qū)體,通過(guò)高溫煅燒獲得三維中空的生物碳微管,在此基礎(chǔ)上,分別通過(guò)KOH活化以及空氣活化的方式得到具有高比表面積的多孔活性炭。并將其應(yīng)用于對(duì)稱超級(jí)電容器中,研究發(fā)現(xiàn),通過(guò)空氣活化得到的多孔碳管很大程度上能夠保持材料原有的骨架結(jié)構(gòu),實(shí)現(xiàn)對(duì)雙電層電容性質(zhì)的改善。(2)以上述制得的生物碳微管作為基底,采用兩步水熱法,合成具有不同結(jié)構(gòu)的C/Ni Co2S4復(fù)合材料�；诳驴线_(dá)爾效應(yīng),通過(guò)改變第二步水熱的反應(yīng)時(shí)間,控制合成具有管中管結(jié)構(gòu)的復(fù)合材料。對(duì)該電極的結(jié)構(gòu)以及組成進(jìn)行詳細(xì)的表征,研究發(fā)現(xiàn)Ni、Co、S均勻的分布在碳管的周圍,而Ni Co2S4納米管像草一樣附著在碳管的內(nèi)側(cè)與外壁。通過(guò)BET表征發(fā)現(xiàn)其復(fù)合結(jié)構(gòu)具有較大的比表面積以及豐富的孔洞分布。將其用作超級(jí)電容器電極材料,探究其電化學(xué)性能。研究表明,含特殊管狀結(jié)構(gòu)的C/Ni Co2S4表現(xiàn)出較快的反應(yīng)動(dòng)力學(xué),受益于結(jié)構(gòu)的優(yōu)勢(shì),管中管復(fù)合材料可獲得較高的容量以及較好的倍率性能和循環(huán)穩(wěn)定性。這項(xiàng)研究為特殊形貌結(jié)構(gòu)的設(shè)計(jì)以及高性能電極材料的制備提供了有價(jià)值的思路。(3)以上述制得的多孔碳微管作為基底,通過(guò)水熱法以及高溫硫化法,控制Ni/Co的摩爾比例,獲得一系列具有不同形貌的C/NixCo1-x S1.097(0≤x1)復(fù)合材料。相關(guān)的物相表征表明,當(dāng)x值為0.6時(shí),C/Ni0.6Co0.4S1.097具有穩(wěn)定的納米線結(jié)構(gòu)和較高的結(jié)晶度。將C/NixCo1-x S1.097(0≤x1)分別用作超級(jí)電容器電極材料,通過(guò)三電極體系電化學(xué)表征對(duì)比發(fā)現(xiàn),C/Ni0.6Co0.4S1.097具有較好的電化學(xué)性能。將其組裝為器件,結(jié)果表明C/Ni0.6Co0.4S1.097//AC表現(xiàn)出較高的比容量,優(yōu)異的倍率性能以及較高的能量密度,可作為一種新的有前景的超級(jí)電容器器件。
[Abstract]:With the rapid development of economy, supercapacitors with rapid charge and discharge, long cycle life and high power density are becoming one of the indispensable equipments in energy storage. However, its low capacity and low energy density are the main factors restricting the development of supercapacitors. The performance of supercapacitors is mainly determined by the properties and structure of electrode materials themselves. The selection of electrode materials and the reasonable design of electrode structure will benefit the performance of supercapacitors. In this paper, the hollow carbon microtubules calcined at high temperature were used as precursors to obtain porous materials with large specific surface area by KOH and air activation, and the hollow carbon microtubules were compounded with metal sulfides with high conductivity. Nanocomposites with special structure were designed and synthesized to improve the overall properties of electrode materials. The main contents are as follows: (1) porous activated carbon with high specific surface area was obtained by KOH activation and air activation by calcination of three dimensional hollow carbon microtubules. It is found that the porous carbon tube obtained by air activation can maintain the original skeleton structure of the material to a large extent. The properties of double-layer capacitance were improved. (2) C/Ni Co2S4 composites with different structures were synthesized by two-step hydrothermal method using the biocarbon microtubules prepared above as the substrate. Based on the Kokkendal effect, the composite with tube structure was synthesized by changing the reaction time of the second step. The structure and composition of the electrode were characterized in detail. It was found that Ni,Co,S distributed uniformly around the carbon tube, while Ni Co2S4 nanotubes adhered to the inner and outer walls of the carbon tube like grass. It was found by BET that the composite structure had a large specific surface area and abundant pore distribution. It is used as electrode material of supercapacitor to study its electrochemical performance. The results show that the C/Ni Co2S4 with special tubular structure exhibits faster reaction kinetics, and can obtain higher capacity, better rate performance and better cyclic stability. This study provides valuable ideas for the design of special morphologies and the preparation of high performance electrode materials. (3) the porous carbon microtubules prepared above are used as substrates, and the molar ratio of Ni/Co is controlled by hydrothermal method and high temperature vulcanization. A series of C/NixCo1-x S1.097 (0 鈮，
本文編號(hào)：2237380
[Abstract]:With the rapid development of economy, supercapacitors with rapid charge and discharge, long cycle life and high power density are becoming one of the indispensable equipments in energy storage. However, its low capacity and low energy density are the main factors restricting the development of supercapacitors. The performance of supercapacitors is mainly determined by the properties and structure of electrode materials themselves. The selection of electrode materials and the reasonable design of electrode structure will benefit the performance of supercapacitors. In this paper, the hollow carbon microtubules calcined at high temperature were used as precursors to obtain porous materials with large specific surface area by KOH and air activation, and the hollow carbon microtubules were compounded with metal sulfides with high conductivity. Nanocomposites with special structure were designed and synthesized to improve the overall properties of electrode materials. The main contents are as follows: (1) porous activated carbon with high specific surface area was obtained by KOH activation and air activation by calcination of three dimensional hollow carbon microtubules. It is found that the porous carbon tube obtained by air activation can maintain the original skeleton structure of the material to a large extent. The properties of double-layer capacitance were improved. (2) C/Ni Co2S4 composites with different structures were synthesized by two-step hydrothermal method using the biocarbon microtubules prepared above as the substrate. Based on the Kokkendal effect, the composite with tube structure was synthesized by changing the reaction time of the second step. The structure and composition of the electrode were characterized in detail. It was found that Ni,Co,S distributed uniformly around the carbon tube, while Ni Co2S4 nanotubes adhered to the inner and outer walls of the carbon tube like grass. It was found by BET that the composite structure had a large specific surface area and abundant pore distribution. It is used as electrode material of supercapacitor to study its electrochemical performance. The results show that the C/Ni Co2S4 with special tubular structure exhibits faster reaction kinetics, and can obtain higher capacity, better rate performance and better cyclic stability. This study provides valuable ideas for the design of special morphologies and the preparation of high performance electrode materials. (3) the porous carbon microtubules prepared above are used as substrates, and the molar ratio of Ni/Co is controlled by hydrothermal method and high temperature vulcanization. A series of C/NixCo1-x S1.097 (0 鈮，
本文編號(hào)：2237380
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