过渡金属材料的电化学储能性能研究

超级电容器是一种电化学能量储存设备,具有功率密度高、充放电速率快、寿命长等优点.依照反应机理,电化学电容可以区分为双电层电容和赝电容.赝电容超级电容器的能量密度高于双电层电容器.过渡金属氧化物和氢氧化物是一类重要的赝电容器电极材料.为了提高赝电容器的性能,大量的研究工作集中在设计具有特殊结构和尺寸的过渡金属氧化物和氢氧化物电极材料方面.作者综述了电极材料的设计、制备以及性能等方面的研究进展,总结了过渡金属的氧化物和氢氧化物在超级电容器方面的研究与应用.     

超级电容器用金属层状双氢氧化物电极材料研究进展

金属层状双氢氧化物(LDHs)作为具有赝电容特性的电极材料,以法拉第反应机理为基础进行储能,其特殊的层状结构可以提供高比表面积和反应活性位点,从而实现高比容量,是一种理想的超级电容器电极材料.结合近几年的相关文献报道,综述金属层状双氢氧化物电极材料的机理特性、制备工艺、电化学性能,展望其在超级电容器领域的发展趋势.     

电沉积制备氮化钴纳米片超级电容器

采用一种简单的电化学沉积和退火方法,实现了在碳布基底上碳氮结构修饰氮化钴(CC@Co2 N@CN)材料的制备,并将其用于高性能超级电容器.氮化钴表面修饰的碳氮结构不仅可以提高整个电极的电容,而且可以缓解氮化钴的氧化,从而提高整体的导电性能.同时,CC@Co2 N@CN表现出极长的寿命,在10000次循环后容量仍能保持其初始值的77％.在电流密度为1 m A·cm-2时,该电极的面积电容最高可达429.4 m F·cm-2.因为具有较大的面积电容和良好的循环稳定性能,此类基于碳布基底的氮化钴碳氮结构超级电容器在储能领域具有广阔的应用前景.     

超级电容器电极材料的研究进展

超级电容器作为一种新型的电化学储能元件,以充放电效率高、循环寿命长等优点引起研究者的大量关注,而电极材料是决定超级电容器性能的一个关键性因素。常见的电极材料主要有:碳材料、金属化合物材料和导电聚合物材料三大类。当它们单独作为超级电容器电极材料时,碳材料展现高功率密度和优异的循环稳定性,但其比电容较低;而金属化合物和导电聚合物材料具有高比电容,但由于它们导电性差,致使其循环稳定性和倍率性能较差。因此,超级电容器电极材料的研究关注点是碳材料与其他材料组成复合材料,以制备出兼具高比电容、良好循环稳定性和倍率性能的超级电容器电极材料。     

浅谈电化学电容器

电化学电容器是一种不同于传统电容器和电池的新型储能装置.电化学电容器的超大容量来源于电极的双电层电容或者氧化还原反应导致的"赝电容".本文综述了电化学电容器的发展历史、储能机理及应用方面的研究进展.     

超级电容器电极材料研究进展

超级电容器因其高功率密度、长循环寿命,兼具传统电容高功率密度和电池高能量密度的优点,引起了人们的极大关注.超级电容器电极材料种类繁多,按储能原理可以分为双电层超级电容器、赝电容超级电容器和电池型超级电容器三类.双电层超级电容器介绍了几类主流的双电层电极材料的研究现状,同时很多研究者将赝电容电极材料和电池型电极材料混为一谈,本文对这两类材料的不同从原理上进行了区分,介绍各自的代表性材料,最后展望了超级电容器电极材料未来发展趋势.     

超级电容器极化电极材料的研究进展

超级电容器作为储能元件，具有重要的战略意义，与常规的电解电容器相比，明显地提高了比容量、比能量；而与电池相比，虽然比能量较低，但其比功率却是电池的数量级倍数。目前用于制备超级电容在的极化电极材料主要分为碳素材料、金属氧化物材料和导电聚合物材料。简要地介绍了这三类材料的制备、结构、改性、工作原理以及电化学特性，评述了这三类材料的研究进展，这三类材料制作的电容器具有超大功率，长循环寿命等特点，为电动车（EV）以及其他储能器的发展奠定了基础。     

超级电容器用钒基纳米电极材料的研究进展

超级电容器因其优越的性能已成为近些年的研究热点.电极材料是决定超级电容器电化学性能的关键,研究者们对各种超级电容器电极材料进行了广泛的研究.钒元素具有可变价态,使得钒基化合物具有理论比容量高、电化学可逆性良好等优点,是一类极具潜力的超级电容器电极材料.为了提升钒基电极材料的电化学性能,研究者们将其制备为纳米结构,或进一步与其他材料复合制备纳米复合材料.归纳总结了近年来国内外对零维、一维、二维、三维钒基纳米材料作为超级电容器电极材料的研究进展,以期为超级电容器用钒基纳米电极材料的发展提供参考.     

弱结晶二氧化锰超级电容器充放电分析

以等物质的量的高锰酸钾和乙酸锰为原料,采用机械化学法制备出弱结晶型α-MnO2超级电容器电极材料.在1.2V电压内,200mA·g-1电流密度下对对称型超级电容器进行恒流充放电测试.采用XRD法、循环伏安及交流阻抗法对充放电前后电极材料的结构以及电化学性能进行表征,首次采用求斜率法对充放电曲线分析.结果表明:超级电容器表现出法拉第电容与双电层电容的双重特征;在循环过程中,电化学惰性物质Mn3O4生成,循环伏安图中氧化还原峰逐渐消失;充放电曲线的法拉第电容特征逐渐消失而接近双电层电容理想曲线;超级电容器的比容量、等效串联电阻发生了对应的变化,其最大电极比容量达到416F·g-1,经过近500次循环后,比容量为220F·g-1.     

柚皮活性炭/纳米Fe_2O_3的制备及其在超级电容器中的应用

具有高比表面积和低成本的活性炭是理想的超级电容器电极材料,但其作为电极材料时与金属氧化物电极相比电荷储存能力有所不足,因此通过对活性炭进行改性以提高其比电容成为研究焦点.以柚皮为碳源、硝酸铁为铁源制备柚皮活性炭/纳米Fe_2O_3复合材料,并通过系统表征研究其形态、结构和电化学性能.结果表明:引入纳米Fe_2O_3提高了活性炭的电化学性能,在电流密度为1A/g时,活性炭的比电容为159.6F/g,而复合材料的比电容增至276.0F/g;此外在对称超级电容器中,360W/kg功率密度下的复合材料获得了9.39Wh/kg的能量密度.     

Advanced materials for aqueous supercapacitors in the asymmetric design

Supercapacitors have been recognized as one of the promising energy storage devices in the future energy technology. In this perspective, rapid progress is made in the development of fundamental and applied aspects of supercapacitors. Various techniques have been developed specifically to estimate the specific capacitance. Numerous efforts have been made in the literature to increase the specific capacitance of electrode materials. Recently, researchers pay more attention on designing supercapacitors of asymmetric type with extending cell voltage and dissimilar materials with complementary working potentials. Researchers try to increase the specific energy of asymmetric supercapacitors (ASCs). Conversely, it is still a challenge to find a suitable operation conditions for ASCs in various designs, especially for the one with battery type electrode. In this review, we describe our recent research works and other reports on the preparation of various nanostructured electrode materials and the performances of both symmetric and asymmetric supercapacitors. Finally, we demonstrate effects of charge balance on the capacitive performances of ASCs which consist of one electrode material of the battery type and one capacitive material. We also demonstrate how to evaluate the charge capacities of both positive and negative electrode materials for this ASC application.     

沸石咪唑骨架衍生空心纳米电极材料可控制备及其电化学性能研究

超级电容器是介于可充电电池和传统电容器之间的一种新型储能器件。它具有高功率密度、快速充放电和环境友好等优点。在众多应用于超级电容器的电极材料中,金属有机骨架材料因具有大的比表面积,可灵活调控的组成和结构,是十分理想的电极材料之一,又由于其易于合成、独特的结构和反应特性,也是制备纳米结构电极材料的理想模板之一。以沸石咪唑骨架（zeolitic lmidazolate framework,ZIF）-67为前驱体,采用二水合钼酸钠盐溶液刻蚀的方法成功制备了空心CoMo 层状双金属氢氧化物（layered double hydroxides, LDH）纳米笼结构,同时还讨论了钼酸钠的用量对最终产物形貌和性能的影响。当用作超级电容器电极材料时,所制备的空心Co₁Mo₅ LDH在1 A/g的时候最多可提供578 F/g的比电容,当电流密度增加到10 A/g时,比电容保持在346 F/g。与活性炭组装成非对称超级电容器后,该储能器件在功率密度750 W/kg时,能量密度最大可达到21.25 W·h/kg。在5 A/g的电流密度下,经过15 000次充放电循环后,仍保持了90%的初始容量。     

石墨烯基电极材料在超级电容器中的应用

随着能源消耗的日渐增长,寻找低成本、环保、寿命长的储能设备迫在眉睫。在超级电容器领域,石墨烯电极材料以其高比电容、优异倍率性能、良好导电性等优势而受到广泛关注。对石墨烯材料的制备方法、电化学性能及相关机制做了总结,目的是研究不同结构的石墨烯材料对超级电容器性能的影响,并找到性能较为优异的石墨烯基材料。最后分析了石墨烯基电极材料发展中存在的问题,并对其研究前景进行了展望。     

镍基电极材料在超级电容器中的制备与应用

Ni因其价格低廉和对环境友好,被视为具有发展潜力的超级电容器电极材料之一;且它与其他电极材料复合可以有效阻止团聚反应的发生,能大大改善材料的电化学性能。近年来Ni的（氢）氧化物与碳材料、聚合物等复合制备新的电极材料已经成为储能领域研究的热点。介绍了Ni的化合物作为电极材料储能的机制以及在复合电极材料中的应用,综述了近年来国内外报道的各类镍基复合电极材料的研究进展,并对其今后的发展趋势进行了展望。     

Direct growth of Fe3O4-MoO2 hybrid nanofilm anode with enhanced electrochemical performance in neutral aqueous electrolyte

To enhance the electrochemical energy storage performance of supercapacitors(SCs), the current researches are general directed towards the cathode materials. However, the anode materials are relatively less studied. In the present work, Fe_3O_4-MoO_2(FO-MO) hybrid nano thin film directly grown on Ti substrate is investigated, which is used as high-performance anode material for SCs in Li_2SO_4 electrolyte with the comparison to pristine Fe_3O_4 nanorod array. The areal capacitance of FO-MO hybrid electrode was initially found to be 65.0 m F cm~(-2)at 2 m Vs~(-1)and continuously increased to 260.0% after 50 cycles of activation. The capacitance values were considerably comparable or higher than many reported thinfilm iron oxide-based anodes in neutral electrolyte. With the protection of MoO_2 shell, the FO-MO electrode developed in this study also exhibited excellent cyclic stability(increased to 230.8% after 1000cycles). This work presents a promising way to improve the electrochemical performance of iron oxidebased anodes for SCs.     

具有微纳结构的FeS_2的制备及其储锂性能研究

金属硫化物具有较大的理论容量,有望成为下一代的锂电池负极材料,但是充放电过程中材料发生严重的膨胀/收缩、晶体粉化,使得材料的比容量迅速衰减.本文以铁醇盐为原料制备具有花状微纳结构的FeS_2,以达到抑制材料粉化效果.结果显示,300℃热处理得到的FeS_2样品能够充分保持中间体铁醇盐的花状微纳结构,结晶度高.450℃处理得到的样品表面为多孔状结构,而800℃处理未得到目标产物,样品分子式是Fe_9S_(10).电化学测试结果表明:300℃所得产物具有1 484.3mA·h/g的放电比容量,高于450℃的产物(1 326.7mA·h/g);在电流密度为200mA/g条件下,100次充放电循环后,300℃所得产物的放电比容量为480.8mA·h/g,远高于450℃所得产物的放电比容量(215.8mA·h/g).研究结果表明具有花状微纳结构对材料的粉化现象有较好的抑制作用.     

Preparation and supercapacitor performance of assembled graphene fiber and foam

Graphene-based materials have been full of vigor and tremendous potentiality for application in supercapacitors due to its variety of unique properties such as electronic properties, simple synthesis, etc. In developing new macroscopic nanostructured graphene materials for supercapacitors, considerable efforts have been made by the scientist including our research group. In this account, we describe our development of the construction of the assembled graphene especially fiber and foam, which have great potential in addressing the challenges in the synthesis of graphene-based electrode materials for supercapacitors. As the supercapacitors are reviewed in this article, they are accordant with the rapid development of flexible, lightweight, and wearable-electronic devices, overcoming the major some drawbacks of conventional bulk supercapacitors. We hope that this summary will benefit the further research of graphene-based materials for the applications in electrochemical energy storage devices and beyond.     

复合导电剂在超细炭微球超级电容器中的应用研究

导电剂能否在电极材料中形成良好的导电网络是影响超级电容器性能的关键因素之一. 以改进St?ber法合成了高比表面积且具有多级孔结构的超细空心炭微球,以其为电极材料,对比研究了碳纳米管/炭黑复合导电剂与单一导电剂对基于超细空心炭微球超级电容器性能的影响. 研究发现,在0.2 A/g的电流密度下,采用复合导电剂时其比电容为205.7 F/g,远高于单一导电剂时的比电容. 尤其在100 A/g的大电流密度下,采用复合导电剂时的比电容高达104.0 F/g,相比炭黑导电剂提高了275%. 分析表明,纤维状的碳纳米管和炭黑可在本身易团聚的超细空心炭微球中形成点-线协同作用的导电网络,这是提升超级电容器性能的主要原因.      

Synthesis of Porous Hollow Micro spheres of BiVO_4 Based on EDTA and SDBS via Hydro thermal Method

Porous hollow microspheres of bismuth vanadate(BiVO_4) were successfully synthesized with the assistances of ethylenediamine tetraacetic(EDTA) and sodium dodecylbenzene sulfonate(SDBS) via hydrothermal method.The as-prepared BiVO_4 samples were characterized by X-ray diffraction(XRD),field-emission scanning electron microscopy(FE-SEM) and UV-vis diffuse reflectance spectra(DRS).It was found that the ratio of EDTA and SDBS had a significant impact on the crystalline structure,size and morphology of BiVO_4 photocatalyst.The crystal phase could be adjusted by changing the mass ratio of EDTA and SDBS.The photocatalytic activities of different BiVO_4 samples were investigated through the degradation of RhB in the presence of H_2O_2 under visible light irradiation.The results indicated that the photocatalytic performance of the BiVO_4 microstructures was greatly influenced by the porous structure,morphology and band gap.The BiVO_4 sample prepared with the EDTA and SDBS ratio of 2:1 and total amount of 1.5 g have shown superior photocatalytic performance for its unique morphology,good porous structure and low band gap energy.     

Ultrafastly activated needle coke as electrode material for supercapacitors

The uniform porous structure makes activated porous carbons (APCs) superior electrode material. Traditionally, APCs are produced by a combination of time-consuming high-temperature heat treatment and activation, with a production time of up to several hours. The produced APCs have relatively low specific surface area (SSA) and porosity. Therefore, the electrochemical performance is poor, which limits its application in high-power energy storage devices. Here, APCs materials are directly synthesized by a high temperature shock (HTS) strategy using needle coke as a precursor. The structure of as-prepared APC is characterized by XRD, SEM and Raman, and electrochemical tests confirmed its good electrochemical performance. In the two-electrode system, the supercapacitor with HTS-APC as the electrode material provides a high energy density of 35 ?Wh kg^?1 and a high power density of 875 ?W ?kg^?1 in EMIMBF₄ ionic liquid. This work is instructive for the rapid synthesis of electrode materials, and also provides guidance for the large-scale application of porous carbon materials.