本文選題：超級電容器　切入點：電極材料　出處：《吉林大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

【摘要】：在眾多活性電極材料中,氫氧化鎳以其低價無毒比容量高的特性,成為了超級電容器電極材料的理想選擇。而目前在對氫氧化鎳電極材料的研究主要集中在了晶體相而很少有人關(guān)注非晶或者弱結(jié)晶狀態(tài)的Ni(OH)2以及他們的復(fù)合物。本文通過不同的實驗方法制備出非晶氫氧化鎳、非晶鎳-鈷氫氧化物復(fù)合材料以及弱結(jié)晶狀態(tài)下的鎳基氫氧化物、鎳-鈷復(fù)合氫氧化物。通過SEM、TEM、XRD、XPS等檢測方法對材料的微觀形貌和結(jié)構(gòu)特征進(jìn)行分析。利用循環(huán)伏安法、恒定流充放電法、交流阻抗法等電化學(xué)分析方法對制備的材料進(jìn)行電化學(xué)性能分析。本文采用一種綠色無毒的電化學(xué)方法制備了非晶Ni(OH)2、非晶鎳-鈷復(fù)合氫氧化物。鈷的加入很好的改善了非晶氫氧化鎳的電化學(xué)性能。鈷的加入使非晶氫氧化鎳原本納米微球的均勻分布狀態(tài)變?yōu)楦嗟男〖{米微球均勻的分布在樣品表面。其一,在提高電導(dǎo)率的同時改善了材料利用率;其二,由于鈷的加入很好的抑制了γ-Ni OOH的形成,優(yōu)化了原有材料的穩(wěn)定性;第三,改變了材料氧化還原電位,對充放電效率也有改善。鈷的加入使非晶氫氧化鎳材料的比容量由1692 F·g-1提高到1769 F·g-1(5 m V·s-1),3000圈后循環(huán)性能由73%提高到83%。采用水熱法制備了弱結(jié)晶狀態(tài)的Ni(OH)2,以及不同比例鎳-鈷氫氧化物。我們發(fā)現(xiàn)水熱法制備的鎳基氫氧化物在90℃反應(yīng)6 h可以獲得最佳的性能,所有材料微觀形貌都是表面帶有褶皺的薄片結(jié)構(gòu)。隨著鈷含量的增多復(fù)合材料的片層厚度先減小后增大,在最薄時為2 nm左右,褶皺的分布也更加均勻。說明鈷的加入對材料的結(jié)構(gòu)分布有一定的影響。在鈷含量為7%,電流密度為1 A·g-1時,材料的比電容由純氫氧化鎳的1145 F·g-1增加到了1852 F·g-1。1000圈后的保持率也由52.7%升高到91%。此外,本文還分別以綠色環(huán)保電化學(xué)方法制備的非晶Ni(OH)2、非晶鎳-鈷氫氧化物材料作為正極材料,活性炭作為負(fù)極材料制備紐扣式非對稱超級電容器件,所用電解液為3 M KOH溶液,在0.0-1.3V的電勢窗口內(nèi)進(jìn)行測試,表現(xiàn)出了良好的比電容及循環(huán)性能,最高比電容為106 F·g-1,最高能量密度為25 Wh kg-1。在功率密度為1.56 k W kg-1時能量密度仍能保持在19.1 Wh kg-1。性能優(yōu)于很多已經(jīng)報道的以碳基材料與氫氧化鎳材料組裝的非對稱電容器。此外鎳-鈷氫氧化物復(fù)合材料比純氫氧化鎳材料制備的電容器件擁有更好的循環(huán)性能,循環(huán)3000圈后仍有81%的容量保持率。
[Abstract]:Among many active electrode materials, nickel hydroxide is characterized by its low price and high specific capacity. It has become an ideal choice of electrode materials for supercapacitors, but the current research on nickel hydroxide electrode materials is mainly focused on the crystalline phase and few people pay attention to amorphous or weakly crystallized Ni(OH)2 and their complexes. In this paper, amorphous nickel hydroxide was prepared by different experimental methods. Amorphous nickel-cobalt hydroxide composites and Ni-base hydroxides and nickel-cobalt composite hydroxides in weakly crystallized state. The microstructure and structural characteristics of the materials were analyzed by means of SEMMOTEMX XRDX XPS, and cyclic voltammetry was used. Constant current charge-discharge method, The electrochemical properties of the prepared materials were analyzed by electrochemical analysis methods such as AC impedance method. In this paper, a green and non-toxic electrochemical method was used to prepare amorphous NiOH2, amorphous nickel-cobalt complex hydroxides. The addition of cobalt is very good. The electrochemical performance of amorphous nickel hydroxide is improved. The addition of cobalt makes the uniform distribution of amorphous nickel hydroxide nanoparticles into more and more small nanometer-sized microspheres uniformly distributed on the surface of the sample. The conductivity is increased and the material utilization rate is improved. Secondly, the formation of 緯 -Ni OOH is restrained and the stability of the original material is optimized because of the addition of cobalt. Thirdly, the redox potential of the material is changed. The specific capacity of amorphous nickel hydroxide material was increased from 1692F 路g-1 to 1769F 路g -1 5mV 路s-1C ~ (3 000) from 73% to 833. The weakly crystallized NiOH2 was prepared by hydrothermal method, and the specific ratio of NiOH2 was increased to 833F 路g ~ (-1) by the addition of cobalt, and the specific capacity of amorphous nickel hydroxide was increased from 1692 F 路g ~ (-1) to 1769 F 路g ~ (-1) ~ (-1) from 73% to 83. For example, Ni-Co hydroxide. We found that the best performance of nickel-base hydroxide prepared by hydrothermal method can be obtained at 90 鈩，

本文編號：1633384