空心六边形镍钴硫化物/RGO复合物的合成及其超级电容性能

通过两步法制备了一种空心六边形镍钴硫化物（HHNCS）与还原氧化石墨烯（RGO）的纳米复合材料HHNCS/RGO。利用XRD,SEM,TEM和Raman光谱等对复合物进行表征,发现镍钴硫化物为空心六边形结构,并且均匀地附着在RGO的表面。该纳米复合物用作超级电容器电极表现出优异的电化学性能。在电流密度为1 A·g^-1时比电容为927 F·g^-1;当电流密度增大到20 A·g^-1时,比电容仍高达724 F·g^-1,表明材料拥有较好的倍率性能。此外,在电流密度5 A·g^-1下循环2000次后比电容保留有初始值的93%,显示出优异的循环稳定性。HHNCS/RGO优异的电容性能主要是由于RGO的存在不仅增强了材料的导电性,而且作为理想的载体分散HHNCS纳米片。HHNCS/RGO纳米复合物优异的电化学性能使其在超级电容器电极材料领域具有应用前景。     

氧化镍/碳纳米管复合型超级电容器的研制

通过电化学阴极还原的方法制备了氧化镍电极材料。经250℃脱水处理后氧化镍材料表现出法拉第赝电容的电化学特性且材料单电极比容量达到210F·g^-1，优于普通活性炭材料。本文采用催化裂解法制备了碳纳米管电极材料，比容量达到了42F·g^-1。提出了采用电化学法沉积氧化镍和碳纳米管分别作为电容器正负极的新工艺，该工艺制备的复合型超级电容器的工作电位达到了1.6V，且具有良好的大电流放电特性。实验还表明该型氧化镍超级电容器具有极低的自放电率。     

碳纳米管在室温熔盐中的电容特性

研究了碳纳米管在室温熔盐二(三氟甲基磺酸酰)亚胺锂(LiTFSI)-乙酰胺中的电容特性. 将碳纳米管制成薄膜电极, 以LiTFSI-乙酰胺为电解液, 装配成模拟电容器, 用循环伏安和恒流充放电法研究其电化学性能. 结果表明, 碳纳米管在室温熔盐中表现出典型的电容特性, 其比电容为22 F•g^-1, 模拟电容器的工作电压可达2.0 V, 具有非常好的循环性能, 循环充放电1000次后容量损失仅10%, 表明室温熔盐是超级电容器非常有前景的新型电解液.     

石墨烯-聚苯胺类超级电容器复合电极材料

聚苯胺理论比容量高、易合成,是一种理想的电极材料,但其循环寿命差,而石墨烯具有高的理论比表面积,将二者复合,充分利用两者之间的协同效应,能够使复合材料具有优异的电化学电容性能。本文回顾了近几年石墨烯-聚苯胺纳米复合材料在超级电容器中的最新研究结果及其制备方法,并对如何优化电极的结构与性能进行讨论,同时介绍了石墨烯-聚苯胺类电极材料在有机超级电容器中的应用进展,最后对石墨烯-聚苯胺复合材料的前景进行了展望。超级电容器用石墨烯-聚苯胺纳米复合材料的发展取决于其合理的微观结构设计,构建理想的三维多孔结构以避免聚苯胺的膨胀与收缩现象是研究的方向之一,此外,在改善石墨烯和聚苯胺间弱的界面相互作用的同时寻求石墨烯性能与功能化的平衡仍是难点,机械性能优异的聚苯胺纳米复合材料对于柔性全固态超级电容器的研究也会起到关键作用。     

聚苯胺共价接枝碳纳米管复合材料的制备及其超电容性能的研究

以氨基化的碳纳米管为基体, 通过低温原位聚合的方法将聚苯胺共价接枝于碳纳米管表面, 通过透射电镜(TEM)、X射线衍射(XRD)、紫外可见光(UV-vis)、傅里叶红外(FT-IR)、拉曼(Raman)及电化学方法对复合材料进行了表征. 结果表明通过低温原位聚合的方法可以使聚苯胺均匀接枝于碳纳米管表面. 电化学测试结果表明, 碳纳米管共价接枝聚苯胺作为超级电容器材料在0.5 A/g条件下聚苯胺的电容贡献值为754.8 F/g, 同时其倍率性能以及循环稳定性方面都明显优于聚苯胺非共价修饰的碳纳米管复合材料.     

有限域聚合法制备碳纳米管-聚苯胺复合材料及其电化学性能

通过有限域聚合法将聚苯胺(PANI)均匀地生长在碳纳米管(CNTs)表面, 得到CNTs-PANI纳米复合材料. 通过透射电子显微镜(TEM)、扫描电子显微镜(SEM)、傅立叶变换红外(FTIR)光谱对样品的形貌及成分进行表征. 将得到的复合材料组装成电化学超级电容器, 进行电化学的循环伏安和恒流充放电测试. 结果显示, 运用此有限域聚合法所制备的复合材料中PANI 可以非常均匀地包裹在CNTs表面, 复合材料的比容量可以达到117.7 F·g-1(有机电解液), 远远高于所用纯碳纳米管(25.0 F·g-1)和纯聚苯胺(65.0 F·g-1)的比容量, 从而表明有限域聚合法是一良好的纳米复合材料的制备方法.     

单壁碳纳米管用做超级电容器的电极材料

摘要本文研究了采用电弧放电法大规模合成的单壁碳纳米管（SWNT）用作超级电容器电极材料的电化学性能。N₂吸脱附测试表明SWNT既有发达的微孔，又有发达的中孔，其比表面为435 m².g^-1。由于既有双电层电容，又有表面官能团产生的准电容，采用浓硝酸处理后的单壁碳纳米管在水相电解液中的比电容达到105 F/g。基于SWNT的超级电容器也有着良好的充放电可逆性和循环稳定性。     

聚苯胺改性氮掺杂碳纳米管制备及其超级电容器性能

利用苯胺原位化学聚合合成聚苯胺包覆碳纳米管(CNTs), 再炭化处理制备氮掺杂碳纳米管(NCNTs).激光拉曼(Raman)光谱和X射线光电子谱(XPS)分析及透射电镜(TEM)观察表明, 苯胺包覆碳纳米管经炭化处理后, 得到以碳纳米管为核、氮掺杂碳层为壳, 具有核-壳结构的氮掺杂碳纳米管, 而碳纳米管本征结构未遭破坏. 研究表明, 随着苯胺用量的增大, 氮掺杂碳纳米管的氮掺杂碳层变厚, 氮含量从7.06%(质量分数)增加到8.64%, 而作为超级电容器电极材料, 随着氮掺杂碳层厚度降低, 氮掺杂碳纳米管在6 mol·L^-1氢氧化钾电解液中的比容量从107 F·g^-1增大到205 F·g^-1, 远高于原始碳纳米管10 F·g^-1的比容量, 且聚苯胺改性氮掺杂碳纳米管表现出较好的充放电循环性, 经1000次充放电循环后仍保持初始容量的92.8%~97.1%, 表明氮掺杂碳纳米管不仅通过表面氮杂原子引入大的法拉第电容和改善亲水性使电容量显著增大, 其具有的核壳结构特征也使循环稳定性增强。     

以多层次聚苯胺颗粒为电极活性物质的超级电容器的电化学性能

以(NH₄)₂S₂O₈为氧化剂用化学氧化法合成了具有多层次结构的聚苯胺颗粒，其二次颗粒由一次颗粒集结而成，一次颗粒的粒径基本上在1 μm以下，一次颗粒由多层微小薄片叠合而成. 用这种聚苯胺为活性物质制成电极，以2 mol•L^-1的H₂SO₄水溶液作电解液，组装成了聚苯胺电极超级电容器. 用循环伏安法、电化学阻抗谱和恒电流充放电技术测试了该超级电容器的电化学性能.在7 mA的充放电电流下，它的比能量可达6.35 Wh•kg^-1，比功率可达132 W•kg^-1，电极材料的比容量可达408 F•g^-1. 在20 mA的充放电电流下，它的比能量可达4.39 Wh•kg^-1，比功率可达328 W•kg^-1，电极材料的比容量可达324 F•g^-1. 在100次的充放电循环中，聚苯胺电极超级电容器的电容量没有下降，电荷充放电效率一直保持在95%左右.     

链珠状氢氧化亚镍的准电容特性及其在复合型超电容器中的应用(英)

本文采用溶胶凝聚方法制备了超细氢氧化亚镍电极材料并通过在其中掺加适量碳纳米管的方法大大提高了电极的比容量并有效改善了电极材料的阻抗特性。掺有20%碳纳米管的氢氧化亚镍复合电极材料的单电极比容量可达到320 F·g^-1。本文分别采用氢氧化亚镍/碳纳米管复合电极作为正极，活性炭作为负极，6 mol·L^-1 KOH作为电解液制备了复合型电化学电容器。采用上述方法制备的复合型电容器工作电压达到1.6 V，电容器质量比容量达到60 F·g^-1。复合型电容器能量密度达到20.11 Wh·kg^-1，最大功率密度达到8.6 kW·kg^-1,兼具高能量特性和优良的大电流放电特性。     

High Performance Supercapacitors Based on Mesopore Structured Multiwalled Carbon Nanotubes

A 3D CNT/few layered graphene construct (CNT−FLG) with mesopore structure was fabricated and applied in supercapacitors. The structure was acquired through a two-step method. Firstly, commercial multiwalled carbon nanotubes (MCNTs) were oxidized in a mixed solution of concentrated acid and modified with a couple of long-chain organic ions. Second, the above resultant product was carbonized at a high temperature. The achieved structure offers a 3D interconnected electrically conductive network as well as mesopore structure. It also significantly improves the specific surface area of MCNTs. Result of BET tests showed that the specific surface area of CNT−FLG reached to 2235 m²/g. When acted as electrode materials in a supercapacitor structure, specific capacitance was approximately 531.2 F/g at a current density of 0.8 A/g. At current density of 50 A/g, specific capacitance remained 204.4 F/g. Besides, the capacitance retention was as high as 96.18 % after 10000 cycles at the current density of 5 A/g.     

碳纳米管-聚(3',4'-亚乙基二氧-2,2':5',2"-三噻吩)复合材料的制备及其电化学性能研究

通过Stille反应合成了3',4'-亚乙基二氧-2,2':5',2"-三噻吩(TET),并以其作为单体,采用化学氧化原位聚合方法在碳纳米管(CNT)的表面包覆新型聚(3',4'-亚乙基二氧.2,2':5',2"-三噻吩)(FTET),制备了PTET-CNT纳米复合材料.通过TEM、SEM和IR对其进行了表征,并利用循环伏安、交流阻抗、恒电流充放电等电化学测试方法,比较研究了复合材料以及碳纳米管在0.1 mol/L四乙基四氟硼酸铵(Et_4NPF_4)的乙腈溶液中的电化学行为.实验结果表明,在电流密度为3 mA/cm~2时,PTET-CNT复合材料的比电容为86 F/g,比原碳纳米管比电容20 F/g提高了3.3倍.基于这种复合材料的电容器的能量密度达到2.02 Wh/kg.     

Graphene and carbon nanotube composite electrodes for supercapacitors with ultra-high energy density

We describe a graphene and single-walled carbon nanotube (SWCNT) composite film prepared by a blending process for use as electrodes in high energy density supercapacitors. Specific capacitances of 290.6 F g(-1) and 201.0 F g(-1) have been obtained for a single electrode in aqueous and organic electrolytes, respectively, using a more practical two-electrode testing system. In the organic electrolyte the energy density reached 62.8 Wh kg(-1) and the power density reached 58.5 kW kg(-1). The addition of single-walled carbon nanotubes raised the energy density by 23% and power density by 31% more than the graphene electrodes. The graphene/CNT electrodes exhibited an ultra-high energy density of 155.6 Wh kg(-1) in ionic liquid at room temperature. In addition, the specific capacitance increased by 29% after 1000 cycles in ionic liquid, indicating their excellent cyclicity. The SWCNTs acted as a conductive additive, spacer, and binder in the graphene/CNT supercapacitors. This work suggests that our graphene/CNT supercapacitors can be comparable to NiMH batteries in performance and are promising for applications in hybrid vehicles and electric vehicles.     

基于玉米秸秆合成的多孔生物质炭材料及其电化学储能

以玉米秸秆为原料,合成了高比表面积(2167 m²/g)的多孔生物质炭材料。 优化实验条件即可获得性能最佳的生物质炭电极材料,其在电流密度为1 A/g时的比电容高达390 F/g。 更重要的是,以所得最佳多孔生物质炭为电极材料,3 mol/L 的KOH溶液为电解质,组装了液相对称超级电容器。 该超级电容器在功率密度为818 W/kg时,其能量密度高达7 Wh/kg,在循环10000圈后的电容保持率为91.1%。 同时,将两个这种超级电容器串联充电之后,能够点亮15个LED灯并驱动小风扇正常工作。 这些结果表明,将基于玉米秸秆的多孔生物质炭作为先进电极材料应用于超级电容器具有较大的实际应用价值。     

A wide potential window aqueous supercapacitor based on LiMn<Subscript>2</Subscript>O<Subscript>4</Subscript>–rGO nanocomposite

Aqueous supercapacitors based on neutral solutions have the advantages of high-ionic conductivity, being environmentally friendly, safe, and low cost. However, the operating potential window for most aqueous electrolytes is far lower than that of organic electrolytes that are commonly used in commercial supercapacitors. In this work, we report on the fabrication of a wide potential window, high-energy aqueous asymmetric supercapacitor, without sacrificing power, by using a nanostructured LiMn₂O₄/reduced graphene oxide (LMO–rGO) nanocomposite. We synthesized the uniformly distributed LMO in the LMO–rGO nanocomposite using a co-precipitation route followed by a low-temperature hydrothermal treatment. In a three-electrode cell setup, the specific capacitance of the LMO–rGO nanocomposite electrode at 1 A/g (1.2 mA/cm²) is 268.75 F/g (258 mF/cm²), which shows a dramatic improvement over the sum of the specific capacitances of pristine LMO (162.5 F/g) and pure rGO (29.94 F/g) electrodes in their relative ratios, when used alone. This finding suggests a synergistic coupling of LMO and rGO in the nanocomposite. We also assembled the LMO–rGO nanocomposite, as the positive electrode, with activated carbon, as the negative electrode, into an asymmetric cell configuration. The device shows an ultra-wide potential window of 2.0 V in a neutral aqueous Li₂SO₄ electrolyte, with a maximum energy density of 29.6 Wh/kg (which approaches the commercial lead-acid batteries), power density of up to 7408 W/kg, and an excellent cycle life (5% loss after 6000 cycles). These findings confirm that an LMO–rGO nanocomposite is a promising material to meet the demands of real world energy storage.     

Electrodeposition of MnO2 nanowires on carbon nanotube paper as free-standing,flexible electrode for supercapacitors

MnO₂ nanowires were electrodeposited onto carbon nanotube (CNT) paper by a cyclic voltammetric technique. The as-prepared MnO₂ nanowire/CNT composite paper (MNCCP) can be used as a flexible electrode for electrochemical supercapacitors. Electrochemical measurements showed that the MNCCP electrode displayed specific capacitances as high as 167.5 F g⁻¹ at a current density of 77 mA g⁻¹. After 3000 cycles, the composite paper can retain more than 88% of initial capacitance, showing good cyclability. The CNT paper in the composite acted as a good conductive and active substrate for flexible electrodes in supercapacitors, and the nanowire structure of the MnO₂ could facilitate the contact of the electrolyte with the active materials, and thus increase the capacitance.     

Design and Preparation of Graphene/Fe2O3 Nanocomposite as Negative Material for Supercapacitor

The development of high specific capacitance electrode materials with high efficiency, scalability and economic feasibility is significant for the application of supercapacitors, however, the synthesis of electrode material still faces huge challenges. Herein, graphene(G)/Fe₂O₃ nanocomposite was prepared via a simple hydrothermal method connected with subsequent thermal reduction process. Scanning electron microscopy(SEM) and transmission electron microscopy(TEM) results showed rod-like Fe₂O₃ nanoparticles were prepared and well-dispersed on graphene layers, providing a rich active site and effectively buffering the aggregation of Fe₂O₃ nanoparticles in the process of electrochemical reaction. The specific capacitance of the obtained G/Fe₂O₃ nanocomposite as negative electrode for supercapacitor was 378.7 F/g at the current density of 1.5 A/g, and the specific capacitance retention was 88.76% after 3000 cycles. Furthermore, the asymmetric supercapacitor(ASC) was fabricated with G/Fe₂O₃ nanocomposite as negative electrode, graphene as positive electrode, which achieved a high energy density of 64.09 W∙h/kg at a power density of 800.01 W/kg, maintained 30.07 W∙h/kg at a power density of 8004.89 W/kg, and retained its initial capacitance by 78.04% after 3000 cycles. The excellent result offered a promising way for the G/Fe₂O₃ nanocomposite to be applied in high energy density storage systems.     

Enriching redox active sites by interconnected nanowalls-like nickel cobalt phospho-sulfide nanosheets for high performance supercapacitors

Although transition metal phospho-sulfides deliver outstanding electrochemical performance, complex preparation methods hindered their further development. Herein, we report a facile one-step electrodeposition approach to deposit interconnected nanowalls-like nickel cobalt phospho-sulfide (Ni-Co-P-S) nanosheets onto the surface of carbon cloth. The thin Ni-Co-P-S nanosheets with multi-components and synergetic effects delivered rich active sites, further enhancing reversible capacitance. Therefore, the as-prepared Ni-Co-P-S electrode materials exhibit excellent electrochemical performance in a three-electrode system, showcasing a high specific capacitance of 2744 F/g at 4 A/g. The full supercapacitors based on Ni-Co-P-S as positive electrode and active carbon as negative electrode showcase a high specific capacitance of 110.9 F/g at 1 A/g, impressive energy density of 39.4 Wh/kg at a power density of 797.5 W/kg in terms of excellent cycling stability (91.87% retention after 10,000 cycles). This simple electrode position strategy for synthesizing Ni-Co-P-S can be extended to prepare electrode materials for various sustainable electrochemical energy storage/conversion technologies.     

微波辐射合成钌／碳纳米复合材料及其在电化学超级电容器的应用

以RuCl_3的乙二醇溶液作为产驱体，利用微波辐射技术合成了Ru/C(19.1 wt%) 纳米复合材料。TEM观察表明这些纳米粒子具有均匀的尺寸，其平均粒径为3.2 nm ，并均匀地分散在纳米碳的表面。Ru/C纳米复合在电化学氧化后可以作为电化学超 级电容器的电极材料，循环伏安实验表明其比电容为144 F/g，而未负载纳米钌的 XC-72碳的比电容为31 F/g。     

Flower-like Cu5Sn2S7/ZnS nanocomposite for high performance supercapacitor

Due to the synergistic effect between ZnS and Cu₅Sn₂S₇, the ZnS can enhance electrochemical performance of pristine Cu₅Sn₂S₇.