石墨烯基复合电极在非对称超级电容器中的研究进展

非对称超级电容器(ASCs)因电化学性能更为优异而成为近几年来的研究热点,石墨烯作为一种新颖的二维碳材料,具有比表面积大、导电性高、力学性能好和化学稳定性优异等优点,是非对称超级电容器复合电极的一类理想载体材料。本文综述了近几年来石墨烯基复合电极在非对称超级电容器中的应用状况,认为比表面积更大、导电性更好的石墨烯将会促进石墨烯基复合电极在超级电容器中的应用与发展,也会提高石墨烯基非对称超级电容器的性能。指出将金属氧化物、导电聚合物、金属氢氧化物以及金属硫化物纳米化,使之兼具大的有效面积、丰富的氧化还原活性位点等特点,从而提高复合材料的比电容,是石墨烯基复合电极的研究重点。     

石墨烯与导电高分子复合材料及其电学性能研究进展

石墨烯作为单原子厚度的二维碳原子晶体,是具有优异的力学、热学、电学性能的新型纳米复合填料。近年来,石墨烯材料在化学和物理学界引起广泛关注。论述了石墨烯与导电高分子复合材料的制备,并对其在超级电容器、太阳能电池以及电化学传感器方面的应用。     

超级电容器用镍、钴基三维纳米材料的研究进展

过渡金属镍、钴资源广泛、价格低廉、环境友善,其氧化物和氢氧化物电化学性能良好,已成为优良的超级电容器电极材料。综述了在各类基底上三维生长的镍、钴基纳米材料在电化学超级电容器研究中的研究现状,并预测了未来电化学超级电容器的电极材料的研究方向。     

煤基石墨烯/炭纳米纤维复合材料的制备及其电化学性能

作为一种高性能新型储能器件,超级电容器具有功率密度高、充电时间短、绿色环保等诸多优点,决定超级电容器性能的关键因素是电极材料的性能。以煤为原料,通过高温热处理、化学氧化及等离子体还原技术制备得到煤基石墨烯;进一步将煤基石墨烯与聚丙烯腈(PAN)通过静电纺丝技术复合制备得到煤基石墨烯/炭纳米纤维(PM-CG)复合材料,以期借助于石墨烯所具备的高导电性、电子迁移率等性能获得具有优良电化学性能的电极材料。采用物理吸附仪、扫描电镜以及透射电镜等仪器对所制备的炭纳米纤维进行了表征,并通过电化学工作站研究了其作为超级电容器电极材料的电化学性能。结果表明,煤基石墨烯成功掺杂到炭纳米纤维中,所制备的PM-CG复合材料在6 mol/L KOH电解液中的比电容值可达225.1 F·g~(-1),是同样条件下纯PAN炭纳米纤维比电容值的2.57倍。     

电纺聚丙烯腈基碳纳米纤维在超级电容器中的应用

静电纺丝法制备聚丙烯腈（PAN）基纳米纤维具有较大的比表面积、较高的机械强度、优异的纳米结构及良好的化学稳定性。以PAN纳米纤维为基础,进行多方位设计与合成的电极材料在超级电容器中表现出优异的电化学性能,具有广阔的应用前景。本文根据电极材料分类,主要综述了近年来PAN基多孔结构电极材料、杂原子掺杂电极材料以及与碳系材料、导电聚合物、金属氧化物复合等电极材料的研究进展;讨论了电极材料的结构特征、制备方法及其提高电化学性能的原理;最后指出了上述研究中存在的问题,并对未来PAN基电极材料在超级电容器的发展前景进行了展望。     

一维有序聚苯胺纳米阵列在超级电容器中的研究进展

从聚苯胺（polyaniline, PANI）的结构特征和导电机理出发,详细叙述了一维有序PANI纳米阵列的优点及各种制备方法,指出了PANI纳米阵列作为超级电容器电极材料的优势。根据电极材料分类,重点综述了PANI阵列结构基与导电高分子材料、碳材料、金属氧化物复合作为超级电容器电极材料的应用情况;讨论了这些电极材料的结构特点、制备方法、提高电化学储能性的机理及上述研究中存在的问题;最后根据存在的问题,提出进一步优化PANI阵列结构基电极材料电化学性能的制备方法与策略,并对未来PANI阵列结构基电极材料在超级电容器的发展前景进行了展望。     

用于超级电容器的硫化钴/石墨烯气凝胶复合材料的研究

采用一步水热法,在乙二胺的辅助下,制备了硫化钴/石墨烯气凝胶(CoS/GA)复合材料。通过X射线衍射法(XRD)、扫描电镜(SEM)、电化学性能测试对材料进行了表征和测试。结果表明:制备的材料晶型规整,30～100 nm的CoS粒子均匀地分布在石墨烯气凝胶上。用作超级电容器时,在电流密度0.5 A/g时,CoS/GA复合材料比电容值达574 F/g,是纯CoS的1.4倍;充放电循环1 000次后,比电容保持率为94.4%。硫化钴/石墨烯复合材料的电化学性能较好,具有较大的比电容和较好的循环稳定性,是一种可用于超级电容器的较有潜力的电极材料。     

基于三维石墨烯/聚苯胺复合材料的制备方法及在超级电容器中的研究进展

三维石墨烯具有丰富的孔洞结构、大的比表面积、高的导电率、快的充电速率和长的循环寿命等优异性质,将其与聚苯胺复合制备三维石墨烯/聚苯胺复合材料可以充分发挥石墨烯和聚苯胺的优势性能,制得电化学性能优异的复合材料。该复合材料在超级电容器电极材料领域得到了广泛的关注。综述了三维石墨烯/聚苯胺复合材料的制备方法及其电化学性能,并针对复合材料研究中存在的问题、未来的研究方向进行了展望。     

石墨烯基材料在超级电容器中的研究进展

超级电容器作为一种新型的储能器件,具有广泛的应用前景。石墨烯基材料表现出优异的电化学性能,在超级电容器电极材料方面具有潜在的应用价值。文章简单对石墨烯/碳,石墨烯/金属氧化物,石墨烯/导电聚合物等三类石墨烯基超级电容器电极材料进行简单论述。     

钴酸镍基纳米材料在超级电容器中的研究进展

电极材料是决定超级电容器性能的关键因素。钴酸镍纳米材料因其合成简单,价格低廉,储量丰富且理论比电容较高等优点,成为超级电容器电极材料的研究热点。但钴酸镍纳米材料导电率较低、比表面积较小且电化学稳定性较差等缺点严重影响了其实际应用。本文简单介绍了钴酸镍纳米材料的晶体结构以及其作为超级电容器电极材料时的储能机理,同时结合一些示例归纳总结了钴酸镍基纳米材料的制备方法以及钴酸镍纳米材料的改性研究现状,包括形貌改性、复合改性及引入缺陷。最后指出,钴酸镍基纳米材料的环保且高效的制备方法,通过掺杂或缺陷等方法改善其电化学性能,增大其工作电压窗口以及探索适用于钴酸镍基超级电容器工作的电解液,将是未来研究的重点。     

Conducting Polymer Nanostructures and their Derivatives for Flexible Supercapacitors

This review provides a brief summary of the recent research developments in the fabrication and application of conducting polymer nanostructures and their derivatives as electrodes for flexible supercapacitors (SCs). By controlling the nucleation and growth process of polymerization, conducting polymers (CPs) with different nanostructures can be prepared by employing chemical polymerization, electrochemical polymerization and photo-induced polymerization. These CPs (such as polyaniline and polypyrrole) with special nanostructures possess high capacitance, superior rate capability ascribed to large electrochemical surface, and optimal ion diffusion path in the ordered nanostructures. The composites of nano-structured conducting polymer and some conductive flexible substrates (such as carbon nanotube film and graphene film) are proved to be ideal electrode materials for high performance flexible SCs. Furthermore, high N-containing CPs are very prospective for preparing N-doped carbon materials used as flexible electrodes for flexible SCs. With respect to the extra pseudo-capacitance induced by N atoms and superior stability derived from the conjugated graphitic structure of carbon materials, the obtained flexible SCs based on N-doped carbon materials could achieve high capacitance, high rate performance, and superior cycling stability.     

A review of cobalt monoxide and its composites for supercapacitors

Cobalt monoxide is a low–valence compound with a face–centered cubic structure and has been deemed as a promising electrode material for energy storage, such as batteries and supercapacitors (SC). In this work, the recent progress of CoO and its composites for SC application is briefly reviewed. The preparation methods for CoO are summarized at first. With the development of nanotechnologies, various CoO nanostructures are thus synthesized for SC, but most architectures grown on conductive substrates show higher specific capacitance than the corresponding power materials. If integrated with some typical guest materials, such as transition metal oxides, hydroxides, sulfides, and carbon materials (including carbon nanotubes, graphene and porous carbon) as well as conductive polymers, the CoO composites usually deliver promoted electrochemical performances. Thus, much attention is focused on the composites of CoO. An outlook for future work is finally put forward.     

Electrochemically deposited hybrid nickel–cobalt hexacyanoferrate nanostructures for electrochemical supercapacitors

This study describes the use of electrodeposited nanostructured hybrid nickel–cobalt hexacyanoferrate in electrochemical supercapacitors. Herein, various compositions of nickel and cobalt hexacyanoferrates (Ni/CoHCNFe) nanostructures are electrodeposited on an inexpensive stainless steel substrate using cyclic voltammetric (CV) method. The morphology of the electrodeposited nanostructures is studied using scanning electron microscopy, while their electrochemical characterizations are investigated using CV, galvanostatic charge and discharge and electrochemical impedance spectroscopy. The results show that the nanostructures of hybrid metal cyanoferrate, shows a much higher capacitance (765 F g⁻¹) than those obtained with just nickel hexacyanoferrate (379 F g⁻¹) or cobalt hexacyanoferrate (277 F g⁻¹). Electrochemical impedance spectroscopy results confirm the favorable capacitive behavior of the electrodeposited materials. The columbic efficiency is approximately 95% based on the charge and discharge experiments. Long cycle-life and excellent stability of the nanostructured materials are also demonstrated during 1000 cycles.     

石墨烯/导电聚合物复合防腐蚀材料制备及应用研究进展

石墨烯/导电聚合物复合材料不仅具有石墨烯优异的屏蔽性能和导电聚合物良好的氧化还原特性,还能协同发挥二者的功能,在金属防腐蚀领域有着巨大的应用潜力。本文综述了石墨烯/导电聚合物复合防腐蚀材料的制备方法,包括电化学方法、化学氧化法、分散液混合法和化学气相沉积法（CVD）;并全面总结了石墨烯/导电聚合物复合材料在防腐蚀涂层中的应用及性能。制备的石墨烯/导电聚合物复合材料可以通过电化学方法、溶剂挥发法制成石墨烯/导电聚合物防腐蚀薄膜涂层,还可以混入成膜物树脂中制备树脂复合防护涂层。讨论了石墨烯/导电聚合物在制备过程、薄膜涂层和树脂复合涂层应用中的优势与不足,提出了构建结构可控、综合性能好的复合防腐涂层是石墨烯/导电聚合物复合防腐蚀材料的未来主要发展趋势。     

Phosphorus-doped Ni–Co sulfides connected by carbon nanotubes for flexible hybrid supercapacitor

As promising electrode materials for supercapacitors, nickel-cobalt bimetallic sulfides render the advantages of abundant redox reactions and inherently high conductivity. However, in general, unsatisfactory performance of low specific capacity, low rate capability, and fast capacity loss exist in Ni–Co sulfide electrodes. Herein, we rationally regulate phosphorus-doped nickel–cobalt sulfides (P-NCS) to enhance the electrochemical performance by gas–solid phosphorization. Moreover, carbon nanotubes (CNTs) as conductive additives are added to improve the cycle stability and conductivity and form the composite P-NCS/C/CNT. According to density functional theory, more electrons near the Fermi surface of P-NCS are demonstrated notionally than those of simple CoNi₂S₄. Electrochemical results manifest that P-NCS/C/CNT exhibits superior electrochemical performance, e.g., high specific capacity (932.0 C∙g^‒1 at 1 A∙g^‒1), remarkable rate capability (capacity retention ratio of 69.1% at 20 A∙g^‒1), and lower charge transfer resistance. More importantly, the flexible hybrid asymmetric supercapacitor is assembled using P-NCS/C/CNT and activated carbon, which renders an energy density of 34.875 W·h∙kg^‒1 at a power density of 375 W∙kg^‒1. These results show that as-prepared P-NCS/C/CNT demonstrates incredible possibility as a battery-type electrode for high-performance supercapacitors.     

Li ion battery materials with core-shell nanostructures

Nanomaterials have some disadvantages in application as Li ion battery materials, such as low density, poor electronic conductivity and high risk of surface side reactions. In recent years, materials with core-shell nanostructures, which was initially a common concept in semiconductors, have been introduced to the field of Li ion batteries in order to overcome the disadvantages of nanomaterials, and increase their general performances in Li ion batteries. Many efforts have been made to exploit core-shell Li ion battery materials, including cathode materials, such as lithium transition metal oxides with varied core and shell compositions, and lithium transition metal phosphates with carbon shells; and anode materials, such as metals, alloys, Si and transition metal oxides with carbon shells. More recently, graphene has also been proposed as a shell material. All these core-shell nanostructured materials presented enhanced electrochemical capacity and cyclic stability. In this review, we summarize the preparation, electrochemical performances, and structural stability of core-shell nanostructured materials for lithium ion batteries, and we also discuss the problems and prospects of this kind of materials.     

Si基锂离子电池负极材料研究进展

硅具有高的理论比容量、较低的嵌锂电位、来源广泛且环境友好等优点,被认为是下一代锂离子电池负极材料的有力竞争者。然而,在锂离子脱嵌过程中巨大的体积膨胀引起了活性材料的粉化和破裂,这带来了电极循环性能差、容量衰减快甚至电极失效等一系列问题。迄今为止,有大量关于改性硅基材料的报道。本文将重点介绍硅基材料的纳米结构化设计和硅/碳材料的结合。首先,分析了硅的储锂及失效机制,从机理上理解硅的失效对其电化学性能的影响。其次,从理论上阐述了纳米级硅材料对缓解体积效应的机理,从结构设计、材料合成、形态特征和电化学性能等方面论证了纳米硅材料的优势。随后,从缓解体积膨胀、提高电导率和形成稳定的固体电解质（SEI）膜等方面总结了硅碳复合材料的研究进展。此外,还讨论了将导电聚合物和金属引入硅基材料的电化学性能增强机理。最后,从提高首次库仑效率、SEI膜稳定性和质量负载量等方面对硅基材料的产业化应用提出几点建议。     

导电水凝胶的制备及应用研究进展

导电水凝胶是一类将亲水性基质和导电介质有机结合的新型水凝胶,具有较高的柔韧性、可调的力学性能和优异的电化学性能,在柔性电子设备等领域具有广阔的应用前景。本文综述了导电水凝胶材料的研究前沿和动态,介绍了导电水凝胶的分类及制备方法,讨论了导电水凝胶的结构设计与性能,重点阐述了导电水凝胶材料的应用研究进展,归纳了导电水凝胶材料面临的问题与挑战,并展望了导电水凝胶材料的发展趋势,指出采用天然可再生资源为原料开发具有高导电性、力学性能稳定、耐极端温度、生物相容性和生物可降解的导电水凝胶将成为下一步研究重点,同时优化柔性电子装置、提高器件输出稳定性也将成为重要的研究方向之一。导电水凝胶的制备及应用研究将促进柔性电子功能材料领域的快速发展。     

Preparation of graphene supported porous Si@C ternary composites and their electrochemical performance as high capacity anode materials for Li-ion batteries

Graphene supported porous Si@C ternary composites had been synthesized by various routes and their structural, morphological and electrochemical properties were investigated. Porous Si spheres coated with carbon layer and supported by graphene have been designed to form a 3D carbon conductive network. Used as anode materials for lithium ion batteries, graphene supported porous Si@C ternary composites demonstrate excellent electrochemical performance and cycling stability. The first discharge capacity is 2184.7 mA h/g at a high current density of 300 mA/g. After 50 cycles, the reversible capacity is 652.4 mA h/g at a current density of 300 mA/g and the coulomb efficiency reaches at 98.7%. Due to their excellent electrochemical properties, graphene supported porous Si@C ternary composites can be a kind of promising anode materials for lithium ion batteries.