本文選題：超級電容器　切入點：石墨烯/金屬硫化物　出處：《中國礦業(yè)大學》2017年碩士論文　論文類型：學位論文

【摘要】：超級電容器具有功率密度高、充放電時間短、循環(huán)壽命長、環(huán)保無污染等特點,有望成為下一代新型能量儲存裝置,是近些年來研究的熱點。在整個超級電容器裝置中,電極材料對超級電容器的性能起著決定性的影響。本文將具有高理論比電容的金屬硫化物和具有優(yōu)異循環(huán)穩(wěn)定性的石墨烯進行復(fù)合,制備了Ni_3S_2/石墨烯以及三元的金屬硫化物/石墨烯復(fù)合材料。研究了工藝參數(shù)對復(fù)合材料結(jié)構(gòu)與電化學性能的影響,分析了復(fù)合材料結(jié)構(gòu)與性能之間的關(guān)系,探討了金屬硫化物的生長機制。利用一步溶劑熱法制備了Ni_3S_2和石墨烯的復(fù)合材料(NF@rGO/Ni_3S_2)。厚層片狀Ni_3S_2均勻彌散地鑲嵌在連續(xù)的石墨烯層中,形成多孔的三維網(wǎng)狀結(jié)構(gòu)�；谝陨蟽�(yōu)異結(jié)構(gòu),該復(fù)合材料表現(xiàn)出良好的電化學性能:在5 mA·cm-2(0.98A·g-1)的電流密度下,復(fù)合材料的比電容可達到4048 mF·cm-2(816.8 F·g-1),遠高于單純Ni_3S_2的比電容(2335 mF·cm-2);經(jīng)過6000次循環(huán)充放電,比電容保持率為93.8%。本文進一步研究了反應(yīng)溫度和溶劑對NF@rGO/Ni_3S_2復(fù)合材料微觀結(jié)構(gòu)和電化學性能的影響。當反應(yīng)溫度為160℃,水和乙二醇的比例為1:1時,復(fù)合材料具有最佳的結(jié)構(gòu)和最優(yōu)的電化學性能。以該復(fù)合材料作為正極,氮摻雜的石墨烯(N-G)作為負極,組成了水系非對稱超級電容器,表現(xiàn)出良好的性能。0.5 A·g-1的電流密度下,其能量密度可以達到32.6 Wh·kg-1,相應(yīng)的功率密度為399.8 W·kg-1。在此基礎(chǔ)上,本文進一步優(yōu)化了上述復(fù)合材料的制備方法。首先制備了三維石墨烯基底(NF@rGO),然后利用液相沉淀法在石墨烯基底表面負載了Ni_3S_2納米顆粒。通過調(diào)整工藝參數(shù),可以實現(xiàn)Ni_3S_2顆粒在石墨烯基底上的可控合成,充分發(fā)揮兩種材料的最大潛能,以達到最合理的成分配比和最優(yōu)異的性能。該復(fù)合材料在1 A·g-1下的比電容可以達到1140.7 F·g-1。隨后,將復(fù)合硫化物(Ni_3S_2和Co_9S_8)負載到石墨烯基底上,制備了NF@rGO/Ni_3S_2/Co_9S_8復(fù)合材料。相比于NF@rGO/Ni_3S_2,后者表現(xiàn)出了更高的比電容和更加優(yōu)異的倍率性能,這歸因于石墨烯和金屬硫化物之間有益的協(xié)同效應(yīng)。同時,NF@rGO/Ni_3S_2/Co_9S_8//N-G非對稱超級電容器展現(xiàn)出了優(yōu)異的性能,0.5 A·g-1的電流密度下,其能量密度高達49.6 Wh·kg-1,功率密度為424.8 W·kg-1。
[Abstract]:Supercapacitors with high power density, short charge and discharge time, long cycle life, environmental protection and no pollution, are expected to become the next generation of new energy storage devices, is a hot research in recent years. Electrode materials play a decisive role in the performance of supercapacitors. In this paper, metal sulfides with high theoretical specific capacitance and graphene with excellent cyclic stability are recombined. Ni_3S_2/ graphene and ternary metal sulfide / graphene composites were prepared. The effects of process parameters on the structure and electrochemical properties of the composites were studied, and the relationship between the structure and properties of the composites was analyzed. The growth mechanism of metallic sulfides was discussed. The Ni_3S_2 and graphene composites were prepared by one-step solvothermal method. The thick lamellar Ni_3S_2 was uniformly embedded in the continuous graphene layer. Based on the above excellent structure, the composite exhibits good electrochemical properties: at the current density of 5 Ma 路cm-2(0.98A 路g -1, The specific capacitance of the composite is 4048mF 路cm-2(816.8 F 路g-1g ~ (-1), which is much higher than that of pure Ni_3S_2 (2335mF 路cm ~ (-2)). The effect of reaction temperature and solvent on the microstructure and electrochemical properties of NF@rGO/Ni_3S_2 composites was studied. When the reaction temperature was 160 鈩，

本文編號：1576376