共查询到20条相似文献,搜索用时 734 毫秒
1.
2.
与传统能量存储设备相比,超级电容器因具备比电容高、充放电快、绿色环保并且循环稳定性能优异等优点,在移动通信、电动汽车、国防和航空航天领域具有广阔的应用前景,已成为世界范围内的研究焦点。其中,超级电容器的电极材料是其性能的决定因素,常见的超级电容器电极材料包括碳材料、过渡金属氧化物和导电聚合物等。不同的电极材料的电荷储存机理不同,过渡金属氧化物具有典型的赝电容行为,依赖可逆的氧化还原反应和化学吸附/脱附过程来储存电荷,理论比电容高。然而,过渡金属氧化物同时存在导电性能差,循环稳定性不佳的缺点。碳材料主要表现双电层电容特性,依靠材料表面和电解质离子间的可逆物理吸附/脱附过程储存电荷,具有优异的倍率性能,符合实际生产和应用中对于超级电容器器件高寿命的要求,但其自身比电容相对较低。与单一属性的材料相比,复合材料往往表现出更加优异的电化学性能,大量的研究表明,过渡金属氧化物与碳材料的复合是解决上述问题的有效途径。碳材料因具有来源丰富、价格低廉、质量轻盈、比表面积高以及热稳定性好与电化学性能稳定等优点,日益受到重视,是构建赝电容电容器电极的首选基底材料。碳材料结构多样,近年来,零维的碳量子点、碳球,一维的碳纳米管、碳纳米纤维,二维的石墨烯、氧化石墨烯,三维的石墨烯泡沫、碳泡沫/海绵等均被成功地用于构建碳基复合电极材料,并取得了丰硕的成果。零维碳纳米材料具有高比表面积,提供了调节多孔性的灵活度,可以获得适合各自电解质溶液的最优化条件。一维碳纳米结构一般具有高长宽比和良好的电子传输性能,可以促进超级电容器电极的电荷转移。二维碳纳米结构具有比表面积大与导电性高、力学性能优良等特点,具备潜在赝电容行为,并且能增强超级电容器电极间的充放电反应动力学。利用三维导电材料作为模板,沉淀赝电容材料,可以构建高性能超级电容器电极。本文概述了不同维度碳材料负载过渡金属氧化物作为赝电容的电极材料及其电容性能,并对电极材料储能方面存在的不足和未来的研究方向做出了总结和展望,以期为制备性能优良、环境友好和高寿命的超级电容器提供参考。 相似文献
3.
4.
5.
6.
超级电容器导电聚合物电极材料的研究进展 总被引:2,自引:0,他引:2
导电聚合物是一类重要的超级电容器电极材料,其电容主要来自于法拉第准电容.采用不同掺杂方式的导电性聚合物(n型或p型)作为电极材料使相应的超级电容器分为3种基本类型,这3种类型的超级电容器各具有不同的导电结构及特性.介绍了超级电容器导电聚合物的工作原理和导电聚合物电极材料的研究进展. 相似文献
7.
非对称型超级电容器结合了双电层电容器和法拉第准电容器的优点,具备高能量密度和功率密度、循环寿命长等特性,成为近年来超级电容器领域的研究热点。非对称型超级电容器电极材料包括碳材料/过渡金属氧化物体系、碳材料/导电聚合物体系和金属氧化物/导电聚合物体系,综述了非对称型超级电容器电极材料的类型及研究进展。 相似文献
8.
9.
电化学超级电容器电极材料的研究进展 总被引:11,自引:0,他引:11
电化学超级电容器以其独特的大容量、大电流快速充放电和高的循环使用寿命等特点,受到世人的青睐,致使许多新型的电化学超级电容器电极材料相继被发现和应用.为进一步促进电化学超级电容器的发展,在综述了近年来出现的各种电化学超级电容器电极材料的基础上,提出按材料种类将其分为四大系列:碳材料系列、过渡金属氧化物系列、有机导电聚合物系列和其他系列.并就其各自的特点和性能进行了分析比较,得出了碳材料系列主要向高比表面积和可控微孔孔径方向发展和过渡金属氧化物系列主要向提高材料本身的利用率方向发展以及导电聚合物系列主要向无机、有机杂化方向发展的结论. 相似文献
10.
超级电容器是一种介于电池和传统物理电容器之间的新型环保储能器件,近年来得到了研究者的广泛关注。电极材料是超级电容器的核心部分,因此具有更高的研究价值。聚丙烯腈基碳纳米纤维因具有良好的静电纺丝性、较高的碳化产率、优异的纳米结构、超高的比表面积以及优良的导电性和稳定性,已经成为超级电容器电极材料的研究热点。本文主要介绍了聚丙烯腈基交联结构和多孔结构碳纳米纤维电极材料,元素掺杂电极材料以及与碳材料、导电聚合物、金属氧化物复合的电极材料,并对聚丙烯腈基碳纳米纤维电极材料未来的研究方向进行了展望。 相似文献
11.
Hierarchical 3D All‐Carbon Composite Structure Modified with N‐Doped Graphene Quantum Dots for High‐Performance Flexible Supercapacitors 下载免费PDF全文
Zhen Li Xiang Liu Liang Wang Fan Bu Junjie Wei Dengyu Pan Minghong Wu 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(39)
Flexible supercapacitors have shown enormous potential for portable electronic devices. Herein, hierarchical 3D all‐carbon electrode materials are prepared by assembling N‐doped graphene quantum dots (N‐GQDs) on carbonized MOF materials (cZIF‐8) interweaved with carbon nanotubes (CNTs) for flexible all‐solid‐state supercapacitors. In this ternary electrode, cZIF‐8 provides a large accessible surface area, CNTs act as the electrical conductive network, and N‐GQDs serve as highly pseudocapactive materials. Due to the synergistic effect and hierarchical assembly of these components, N‐GQD@cZIF‐8/CNT electrodes exhibit a high specific capacitance of 540 F g?1 at 0.5 A g?1 in a 1 m H2SO4 electrolyte and excellent cycle stability with 90.9% capacity retention over 8000 cycles. The assembled supercapacitor possesses an energy density of 18.75 Wh kg?1 with a power density of 108.7 W kg?1. Meanwhile, three supercapacitors connected in series can power light‐emitting diodes for 20 min. All‐solid‐state N‐GQD@cZIF‐8/CNT flexible supercapacitor exhibits an energy density of 14 Wh kg?1 with a power density of 89.3 W kg?1, while the capacitance retention after 5000 cycles reaches 82%. This work provides an effective way to construct novel electrode materials with high energy storage density as well as good cycling performance and power density for high‐performance energy storage devices via the rational design. 相似文献
12.
One-dimensional alkali metal titanates containing potassium,sodium,and lithium are of great concern owing to their high ion mobility and high specific surface area.When those titanates are combined with conductive materials such as graphene,carbon nanotube,and carbon nanofiber,they are able to be employed as efficient electrode materials for supercapacitors.Potassium hexa-titanate(K2Ti6O13,KTO),in particular,has shown superior electrochemical properties compared to other alkali metal titanates because of their large lattice parameters induced by the large radius of potassium ions.Here,we present porous rGO crumples(PGC)decorated with KTO nanoparticles(NPs)for application to supercapacitors.The KTO NP/PGC composites were synthesized by aerosol spray pyrolysis and post-heat treatment.KTO NPs less than 10 nm in diameter were loaded onto PGCs ranging from 3 to 5μm.Enhanced porous structure of the composites was obtained by the activation of rGO by adding an excessive amount of KOH to the composites.The KTO NP/PGC composite electrodes fabricated at the GO/KOH/TiO2 ratio of 1:3:0.25 showed the highest performance(275 F g−1)in capacitance with different KOH concentrations and cycling stability(83%)after 2000 cycles at a current density of 1 A g−1. 相似文献
13.
A nanocomposite of nickel oxide/carbon nanotubes was prepared through a simple chemical precipitation followed by thermal annealing. The electrochemical capacitance of this electrode material was studied. When the mass fraction of CNTs (carbon nanotubes) in NiO/CNT composites increases, the electrical resistivity of nanocomposites decreases and becomes similar to that of pure CNTs when it reaches 30%. The specific surface area of composites increases with increasing CNT mass fraction and the specific capacitance reaches 160 F/g under 10 mA/g discharge current density at CNT mass fraction of 10%. 相似文献
14.
Inspired by the high specific capacitances found using ultrathin films or nanoparticles of manganese oxides (MnO(x)), we have electrodeposited MnO(x) nanoparticles onto sheets of carbon nanotubes (CNT sheets). The resulting composites have high specific capacitances (C(sp) ≤ 1250 F/g), high charge/discharge rate capabilities, and excellent cyclic stability. Both the C(sp) and rate capabilities are controlled by the average size of the MnO(x) nanoparticles on the CNTs. They are independent of the number of layers of CNT sheets used to form an electrode. The high-performance composites result from a synergistic combination of large surface area and good electron-transport capabilities of the MnO(x) nanoparticles with the good conductivity of the CNT sheets. Such composites can be used as electrodes for lithium batteries and supercapacitors. 相似文献
15.
Oxidative Intercalation for Monometallic Ni2+‐Ni3+ Layered Double Hydroxide and Enhanced Capacitance in Exfoliated Nanosheets 下载免费PDF全文
Feng Gu Xing Cheng Shufen Wang Xu Wang Pooi See Lee 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(17):2044-2050
Monometallic Ni2+‐Ni3+ layered double hydroxide (LDH) is prepared using a simple oxidative intercalation process and may be further exfoliated into positively charged Ni(OH)2 unilamellar sheets. The superior capacitive behavior of the unilamellar sheets stranded in carbon nanotubes (CNTs) networks is achieved because of the complete interfacial charge storage arising from the confined Faradaic reactions at the interfacial region. 3D nanosheet/CNT composites are prepared using an in situ electrostatic assembly of positive charged sheets with CNTs bearing negative charges. The restacking of active nanosheets during electrochemical cycling is effectively prohibited. Consequently, the outstanding specific capacitance and remarkable rate capability of the nanosheet/CNT hybrid electrodes are demonstrated, making them promising candidates for high performance supercapacitors, combining high‐energy storage densities with high levels of power delivery. 相似文献
16.
17.
18.
High‐Performance Two‐Ply Yarn Supercapacitors Based on Carbon Nanotube Yarns Dotted with Co3O4 and NiO Nanoparticles 下载免费PDF全文
Yarn supercapacitors are promising power sources for flexible electronic applications that require conventional fabric‐like durability and wearer comfort. Carbon nanotube (CNT) yarn is an attractive choice for constructing yarn supercapacitors used in wearable textiles because of its high strength and flexibility. However, low capacitance and energy density limits the use of pure CNT yarn in wearable high‐energy density devices. Here, transitional metal oxide pseudocapacitive materials NiO and Co3O4 are deposited on as‐spun CNT yarn surface using a simple electrodeposition process. The Co3O4 deposited on the CNT yarn surface forms a uniform hybridized CNT@Co3O4 layer. The two‐ply supercapacitors formed from the CNT@Co3O4 composite yarns display excellent electrochemical properties with very high capacitance of 52.6 mF cm?2 and energy density of 1.10 μWh cm?2. The high performance two‐ply CNT@Co3O4 yarn supercapacitors are mechanically and electrochemically robust to meet the high performance requirements of power sources for wearable electronics. 相似文献
19.
《Advanced Powder Technology》2019,30(12):3079-3087
In recent years, supercapacitors have received considerable research attention for energy storage systems due to their high-power density, fast charge-discharge processes, and long cycle life. The superior performance of supercapacitors is considerably dependent on the electrode materials. Among electrode materials, graphene balls (GBs) and their composites have recently attracted strong interest. They are considered ideal for the fabrication of electrode materials because of their unique characteristics of large specific surface area and superior electric conductivity, which should make them very effective for use in supercapacitors. In particular, GBs and their microstructured composites have recently been proven promising candidates for supercapacitor electrodes. Their unique 3D morphology provides highly porous graphene structures for decoration with active materials. In this perspective, recent studies were highlighted and discussed that focus on GBs and their composites for the potential energy storage devices called supercapacitors, (i.e., electric double layer capacitors and pseudocapacitors). 相似文献
20.
Binder-free activated carbon/carbon nanotube paper electrodes for use in supercapacitors 总被引:1,自引:0,他引:1
Guanghui Xu Chao Zheng Qiang Zhang Jiaqi Huang Mengqiang Zhao Jingqi Nie Xianghua Wang Fei Wei 《Nano Research》2011,4(9):870-881
Novel inexpensive, light, flexible, and even rollup or wearable devices are required for multi-functional portable electronics
and developing new versatile and flexible electrode materials as alternatives to the materials used in contemporary batteries
and supercapacitors is a key challenge. Here, binder-free activated carbon (AC)/carbon nanotube (CNT) paper electrodes for
use in advanced supercapacitors have been fabricated based on low-cost, industrial-grade aligned CNTs. By a two-step shearing
strategy, aligned CNTs were dispersed into individual long CNTs, and then 90 wt%–99 wt% of AC powder was incorporated into
the CNT pulp and the AC/CNT paper electrode was fabricated by deposition on a filter. The specific capacity, rate performance,
and power density of the AC/CNT paper electrode were better than the corresponding values for an AC/acetylene black electrode.
The capacity reached a maximum value of 267.6 F/g with a CNT loading of 5 wt%, and the energy density and power density were
22.5 W·h/kg and 7.3 kW/kg at a high current density of 20 A/g. The AC/CNT paper electrode also showed a good cycle performance,
with 97.5% of the original capacity retained after 5000 cycles at a scan rate of 200 mV/s. This method affords not only a
promising paper-like nanocomposite for use in low-cost and flexible supercapacitors, but also a general way of fabricating
multi-functional paper-like CNT-based nanocomposites for use in devices such as flexible lithium ion batteries and solar cells.
相似文献