超级电容器中的二维材料

以石墨烯为代表的具有层状结构的二维材料因具有大比表面积等特性成为超级电容器电极材料的热门候选。文章着眼于针对诸如石墨烯、过渡金属二硫族化合物、过渡金属碳/氮化物、层状过渡金属氧化物/氢氧化物等二维材料在超级电容器领域应用的研究,尝试总结了其制备方法、产物形貌特征以及作为电极的性能等,并对这一领域的未来发展和面临的挑战提出了看法与预测。     

超级电容器中的二维材料

以石墨烯为代表的具有层状结构的二维材料因具有大比表面积等特性成为超级电容器电极材料的热门候选.文章着眼于针对诸如石墨烯、过渡金属二硫族化合物、过渡金属碳/氮化物、层状过渡金属氧化物/氢氧化物等二维材料在超级电容器领域应用的研究,尝试总结了其制备方法、产物形貌特征以及作为电极的性能等,并对这一领域的未来发展和面临的挑战提出了看法与预测.     

静电纺丝技术在超级电容器中的应用

静电纺丝是一种新型的非纺织成丝技术,具有适用材料体系广泛、纤维尺寸结构可控、工艺简便等特点,是制备连续纳米纤维的重要方法.静电纺丝技术制备的纳米纤维薄膜因具有巨大的纳米表面和网状孔隙结构可调等优势,在超级电容器领域显示出诱人的应用前景.综述了近年来静电纺丝技术在超级电容器电极材料和隔膜材料方面的研究进展,介绍了碳基、金属氧化物和聚合物电极材料高活性纳米纤维的制备方法及电化学行为,以及静电纺丝无纺布作为隔膜材料显示出的巨大优势,并总结了制约静电纺丝走向商业化的不利因素,如产率低、薄膜强度不足、喷丝不稳定等,最后介绍了近年来静电纺丝技术在结构可控、规模化制备的产业进展,并展望了其在超级电容器领域中的商业化应用前景.     

TiN Paper for Ultrafast-Charging Supercapacitors

Ultrafast-charging energy storage devices are attractive for powering personal electronics and electric vehicles.Most ultrafast-charging devices are made of carbonaceous materials such as chemically converted graphene and carbon nanotubes.Yet,their relatively low electrical conductivity may restrict their performance at ultrahigh charging rate.Here,we report the fabrication of a porous titanium nitride(TiN)paper as an alternative electrode material for ultrafast-charging devices.The TiN paper shows an excellent conductivity of 3.67×104 S m−1,which is considerably higher than most carbon-based electrodes.The paper-like structure also contains a combination of large pores between interconnected nanobelts and mesopores within the nanobelts.This unique electrode enables fast charging by simultaneously providing efficient ion diffusion and electron transport.The supercapacitors(SCs)made of TiN paper enable charging/discharging at an ultrahigh scan rate of 100 V s−1 in a wide voltage window of 1.5 V in Na2SO4 neutral electrolyte.It has an outstanding response time with a characteristic time constant of 4 ms.Significantly,the TiN paper-based SCs also show zero capacitance loss after 200,000 cycles,which is much better than the stability performance reported for other metal nitride SCs.Furthermore,the device shows great promise in scalability.The filtration method enables good control of the thickness and mass loading of TiN electrodes and devices.     

物理气相沉积薄膜超级电容器

超级电容器作为一种可以快速充放电的储能器件,在电动汽车、微储能电子器件、航空航天等领域有广泛的应用前景。金属氮/氧化物薄膜电极具有优良的电化学性能以及稳定的机械性能,使其成为一种极具发展潜力的超级电容器电极材料。物理气相沉积(PVD)制备的薄膜具有成分结构易调控,膜层与基体结合力好,且可规模化生产等优点,可应用在超级电容器领域,特别是柔性薄膜超电电极的制备。本文论述了PVD在制备氮/氧化物薄膜电极方面的研究进展,并详细探讨了通过PVD制备的金属氮氧化物以及多元金属氮化物薄膜电极的可行性以及PVD柔性薄膜电极的发展前景。     

Supercapacitors based on pillared graphene nanostructures

We describe the fabrication of highly conductive and large-area three dimensional pillared graphene nanostructure (PGN) films from assembly of vertically aligned CNT pillars on flexible copper foils for applications in electric double layer capacitors (EDLC). The PGN films synthesized via a one-step chemical vapor deposition process on flexible copper foils exhibit high conductivity with sheet resistance as low as 1.6 ohms per square and possessing high mechanical flexibility. Raman spectroscopy indicates the presence of multi walled carbon nanotubes (MWCNT) and their morphology can be controlled by the growth conditions. It was discovered that nitric acid treatment can significantly increase the specific capacitance of the devices. EDLC devices based on PGN electrodes (surface area of 565 m2/g) demonstrate enhanced performance with specific capacitance value as high as 330 F/g extracted from the current density-voltage (CV) measurements and energy density value of 45.8 Wh/kg. The hybrid graphene-CNT nanostructures are attractive for applications including supercapacitors, fuel cells and batteries.     

Compact Assembly and Programmable Integration of Supercapacitors

Microsized supercapacitors (mSCs) with small volume, rapid charge–discharge rate, and ultralong cyclic lifetime are urgently needed to meet the demand of miniaturized portable electronic devices. A versatile self-shrinkage assembling (SSA) strategy to directly construct the compact mSCs (CmSCs) from hydrogels of reduced graphene oxide is reported. A single CmSC is only 0.0023 cm³ in volume, which is significantly smaller than most reported mSCs in fiber/yarn and planar interdigital forms. It exhibits a high capacitance of up to 68.3 F cm⁻³ and a superior cycling stability with 98% capacitance retention after 25 000 cycles. Most importantly, the SSA technique enables the CmSC as the building block to realize arbitrary, programmable, and multi-dimensional integration for adaptable and complicated power systems. By design on mortise and tenon joint connection, autologous integrated 3D interdigital CmSCs are fabricated in a self-holding-on manner, which thus dramatically reduces the whole device volume to achieve the high-performance capacitive behavior. Consequently, the SSA technique offers a universal and versatile approach for large-scale on-demand integration of mSCs as flexible and transformable power sources.     

Carbons and Electrolytes for Advanced Supercapacitors

Electrical energy storage (EES) is one of the most critical areas of technological research around the world. Storing and efficiently using electricity generated by intermittent sources and the transition of our transportation fleet to electric drive depend fundamentally on the development of EES systems with high energy and power densities. Supercapacitors are promising devices for highly efficient energy storage and power management, yet they still suffer from moderate energy densities compared to batteries. To establish a detailed understanding of the science and technology of carbon/carbon supercapacitors, this review discusses the basic principles of the electrical double‐layer (EDL), especially regarding the correlation between ion size/ion solvation and the pore size of porous carbon electrodes. We summarize the key aspects of various carbon materials synthesized for use in supercapacitors. With the objective of improving the energy density, the last two sections are dedicated to strategies to increase the capacitance by either introducing pseudocapacitive materials or by using novel electrolytes that allow to increasing the cell voltage. In particular, advances in ionic liquids, but also in the field of organic electrolytes, are discussed and electrode mass balancing is expanded because of its importance to create higher performance asymmetric electrochemical capacitors.     

石墨烯在超级电容器中的研究进展

石墨烯因其优异的物理、化学性能,自发现以来一直是研究的热点。介绍了石墨烯作为超级电容器电极材料的优势,简单阐述了超级电容器的分类和机理,重点分析了特殊结构石墨烯单质材料、石墨烯复合材料作为超级电容器电极材料的研究进展。     

Transparent and Flexible Supercapacitors with Networked Electrodes

Transparent and flexible energy storage devices have received immense attention due to their suitability for innovative electronics and displays. However, it remains a great challenge to fabricate devices with high storage capacity and high degree of transmittance. This study describes a simple process for fabrication of supercapacitors with ≈75% of visible transparency and areal capacitance of ≈3 mF cm^?2 with high stability tested over 5000 cycles of charging and discharging. The electrodes consist of Au wire networks obtained by a simple crackle template method which are coated with MnO₂ nanostructures by electrodeposition process. Importantly, the membrane separator itself is employed as substrate to bring in the desired transparency and light weight while additionally exploiting its porous nature in enhancing the interaction of electrolyte with the active material from both sides of the substrate, thereby enhancing the storage capacity. The method opens up new ways for fabricating transparent devices.     

超级电容器电解质研究进展

电解质作为超级电容器的重要组成部分,对器件性能起着关键性作用。本文对近些年来超级电容器各种电解质,包括水系、有机液体、离子液体、固态/准固态聚合物电解质和氧化还原体系电解质的特点和最新研究成果进行了描述;重点介绍了固态/准固态聚合物电解质的分类及其性能研究概况。提出了发展电位窗口宽、离子电导率高、电化学性能稳定的离子液体和机械强度等综合性能优良的凝胶聚合物电解质是将来超级电容器电解质发展领域的趋势,最后对超级电容器电解质的发展前景进行了展望。     

超级电容器聚合物电解质研究进展

由于聚合物电解质具有较高的稳定性、较好的机械加工性能和安全性能,因而受到广泛关注.根据制备方法与物理状态分类,综述了近年来聚合物凝胶电解质、复合聚合物电解质以及浸入型聚合物电解质的研究进展,并展望了聚合物电解质的应用前景.