新型化学储能器件——电化学电容

电化学电容是一种与电池和传统的电容都不同的新型储能器件。电化学电容具有比传统的电介质电容高 2 0到 2 0 0倍以上的质量比电容。研究证明 ,电化学电容所具有的大容量是由于电极表面的双电层电容和氧化还原反应导致的“假电容”的共同作用而引起的。系统的介绍了电化学电容器的广泛应用、发展历史、储能机理以及它和电池与传统电介质电容的区别 ,并且系统的介绍了影响电化学电容器性能的若干个主要因素。     

碳材料的微观结构与电容特性

超级电容器是介于传统电容器和蓄电池之间的一种新型储能装置,因其具有功率密度大、容量大、使用寿命长、免维护、经济环保等优点而成为世界各国近年来在新能源领域研究的热点。文章概述了由最基本的电极材料—碳材料组成的电化学双电层电容器的原理,分析了电化学双层电容器的实际和理论局限、碳材料的最大比电容、比表面积、能量密度及功率密度等性能参数。在阐述纳孔碳电容器的理论模型的基础上,详细介绍了双层电容器碳材料的孔尺寸与电解质溶液离子尺寸的关系。上述理论介绍与分析为电化学双层电容器今后的研究提供了依据。     

超级电容器电极材料的研究进展

超级电容器是一种介于电池和传统电容器的一种新的储能器件,也叫电化学超级电容器。介绍了目前国内外的超级电容器电极材料的研究现状以及展望,如碳材料、金属氧化物、导电聚合物。     

电介质储能材料

<正>电介质电容器是一种通过电介质在外加电场作用下的极化以及正负电荷的分离来储存能量的储能系统。与燃料电池、锂离子电池、超级电容器等通过离子迁移或化学反应实现能量转换的化学储能系统相比,电介质电容器由于其储能过程不涉及离子迁移扩散和化学反应,充放电反应迅速,功率密度极高,在许多需要快速充放电和高功率密度的应用场景中具有突出优势。同时,     

双碳基电极锂离子电容器的研究进展

锂离子电容器结合了锂离子电池和超级电容器的优点，可用于新能源储能等领域。双碳基电极锂离子电容器是现阶段的主要研究方向之一，其正负极均采用碳基电极材料，利用不同碳基材料的储能优势，不仅具有资源丰富、原料环保及安全性高的优点，而且具有优越的电化学性能。首先介绍了不同双碳基电极锂离子电容器的储能机理，并进一步阐述了各种碳基正极和负极材料的性能特点、改进方向和研究现状，最后展望了未来的研究方向及可行方案。     

金属化合物超级电容器电极材料研究现状

超级电容器是相比于锂离子电池等传统电池更具有优势的电容技术。电极材料是超级电容器中最重要的组成部分，它决定了超级电容器的性能，故在研究时引起了学者们的高度关注。由于电极材料的不同，在储能机理上具有不同的性质与差别。金属化合物作为电极材料中理论比电容优良的材料，具有很高的研究价值。着重围绕金属氧化物、金属硫化物以及金属氢氧化物3个方面分析，对当前金属化合物作为超级电容器电极材料发展方向和相应的研究进展进行归纳，目的是对金属化合物作超级电容器电极材料方面的优劣势进行一定的认识，从而在其发展研究上提供一些参考。     

有机介质体系锂离子电容器

锂离子电容器（lithium ion capacitor，LIC）是一种新型的电化学储能器件，可以填补锂离子电池和超级电容器两者之间的性能空白，是下一代高能量密度超级电容器的前进方向。本文首先介绍了锂离子电容器的储能原理分为电解液消耗机制、锂离子交换机制以及混合机制，并围绕高能量密度的有机介质体系锂离子电容器，着重阐述了各类电容及电池型正负极材料的性质特点、优化方向及其研究现状，指出不同材料的优缺点及改性方法。同时叙述了与产业应用相关的预嵌锂技术、隔膜、电解液以及体系匹配等方面的研究现状，总结归纳了这些部件的研究对于比能量、功率、安全、稳定性等性能的提升。在产业化应用方面，针对锂离子电容器不同于锂离子电池和传统超级电容器的性能指标，总结其在智能物流、起重机电源、机器人电源及轨道交通等方面独特的应用前景。最后展望了电极材料微观结构优化及功能集成、电解液专用化，预嵌锂成本进一步压缩、以及检测及原位表征方法的开发等锂离子电容器未来的发展方向。     

MnO2的制备及其在电化学电容器中的应用

在不同的pH值下，以KMnO4氧化Mn(NO3)2分别合成2种化学MnO2. 晶体结构和晶型经X射线衍射仪和X射线扫描电镜检测，表明pH值对晶体形成有一定的影响. 在-0.3~0.6 V(相对Hg/HgO电极电位)范围用循环伏安法研究两种材料的电化学性能，结果显示它们具有静电电容特征. 活性炭作为对电极组成混合型电化学电容器与MnO2相同电极对称型电化学电容器相比，工作电压窗口和比电容都得到了提高. 恒流充放电显示，对称结构电极比电容分别为262和302 F/g；不对称结构电极比电容为348和342 F/g，具有较好的大电流放电能力和循环寿命.     

二氧化锰基超级电容器研究进展

超级电容器又称电化学电容器,是一种比传统电容器能量密度高,比二次电池功率密度高的新型储能装置。目前被广泛应用于消费电子、交通工具、军事等多个领域。电极材料作为超级电容器的核心部件,决定着整个器件的电化学性能。文章综述了二氧化锰(Mn O2)基超级电容器的研究进展,指出了其未来发展方向。     

赝电容的起源和本体相赝电容的实现

因兼具高能量密度、高功率密度和长循环寿命,赝电容材料引领了近年来超级电容器的发展。然而,赝电容材料仍面临着储能机制认知不足、未来发展方向模糊等挑战。本文基于国家自然科学基金重点项目“高能量/高功率电池型超级电容器-离子插层储能的电极材料构筑”的部分研究成果以及最新的文献报道,以典型赝电容材料为纲,简要回顾赝电容材料发展历史、重点讨论赝电容材料的储能机制、指出其储能机制中亟待厘清的问题。并在此基础上,提出赝电容材料未来发展的新思路-本体相赝电容,讨论了实现本体相赝电容的关键着力点和初步策略。     

烟草加热器具供能元器件的创新思考及展望

供能元器件作为烟草加热器具的核心部件，决定了烟草加热器具的续航时间、充放电速度、预热等待时间以及使用寿命等关键参数。本文综述了电加热型烟草制品加热器具的供能元器件发展现状，分析了2种供能元器件存在的不足与潜在的研究方向。结果显示，锂离子电池作为电加热型卷烟加热器具中普遍使用的供能元器件，具有体积能量密度高且电流放电量大的特点，但是存在充放电速度慢、循环稳定性差、成本高以及存在安全隐患等劣势；介电电容器是一种电加热型卷烟加热器具的潜在供能元器件，具有充放电速度快、循环稳定性好、可靠性高、价格低廉以及安全性能好等特点，但是其体积能量密度亟待提高。供能元器件是烟草加热器具中的关键单元，重视供能元器件的开发和研究、提高供能元器件的工作性能，对促进我国新型烟草的高质量发展以及提升消费者体验具有重要意义。     

聚酯电容器与电容膜生产现状及发展趋势

介绍了国内外电容器市场态势和发展趋势,重点阐述了以聚酯和聚丙烯为代表的薄膜电容器的国内外市场状态和发展趋势,着重分析了聚酯电容器与电容膜的特性及应用,并与聚丙烯作了比较,以及聚酯电容膜在节能灯和片式化、小型化电容器领域的应用前景。     

Bi-modified SrTiO3-based ceramics for high-temperature energy storage applications

Dielectric capacitors with high energy storage performance are in great demand for emerging advanced energy storage applications. Relaxor ferroelectrics are one type dielectric materials possessing high energy storage density and energy efficiency simultaneously. In this study, 0.9(Sr_0.7Bi_0.2)TiO₃–0.1Bi(Mg_0.5Me_0.5)O₃ (Me = Ti, Zr, and Hf) dielectric relaxors are designed and the corresponding energy storage properties are investigated. The excellent recoverable energy density of 3.1 J/cm³ with a high energy efficiency of 93% is achieved at applied electric field of 360 kV/cm for 0.9(Sr_0.7Bi_0.2)TiO₃–0.1Bi(Mg_0.5Hf_0.5)O₃ (0.9SBT–0.1BMH) ceramic. High breakdown strength of 460 kV/cm in 0.9SBT–0.1BMH ceramic is obtained by Weibull distribution with satisfied reliability. In addition, 0.9SBT–0.1BMH shows outstanding thermal stability of energy storage performance up to 200°C, with the variation being less than 5%, together with satisfying cycling stability and high charge-discharge rate, making the 0.9SBT–0.1BMH ceramic a potential lead-free candidate for high power energy storage applications at elevated temperature.     

Design strategies of perovskite energy-storage dielectrics for next-generation capacitors

The next-generation capacitors have placed higher requirements on energy-storage dielectrics, such as high temperature, high frequency and high voltage. Perovskite dielectrics possess various kinds of polar structures, such as ferroelectric domains, polar nano-regions (PNRs), and anti-polar structure as well, which exhibit various responses to external stimulations (temperature, electric field, mechanical loadings). Its design inspires development strategies to improve their energy-storage properties for capacitors involving chemical composition, fabrication process, computer simulation, and even measurement strategies for validation. In this article, we reviewed the recent design strategies and the perovskite dielectrics (covering linear, ferroelectric, relaxor ferroelectric, anti-ferroelectric, even some composite materials, such as glass-ceramics and polymer). This review spans from the atomic to millimeter-scale strategies of property optimization to provide accurate and comprehensive information for researchers in this field. Some novel proposals for overcoming the barriers between materials and properties are presented to accelerate the applications of the next-generation capacitors. Therefore, this review should help to identify the best approach for transferring the new perovskite dielectrics into next-generation capacitor applications.     

PLZST antiferroelectric ceramics with promising energy storage and discharge performance for high power applications

Capacitors are widely used as energy storage elements in electric vehicles (EVs) and pulsed power. At present, it is still challenging to develop capacitor dielectrics with good energy storage and discharge performance. In this work, antiferroelectric (AFE) ceramics (Pb_0.94La_0.04)[(Zr_0.6Sn_0.4)_0.92Ti_0.08]O₃ with enhanced antiferroelectricity were fabricated by a rolling process. The obtained ceramics have a high recoverable energy density of 5.2 J/cm³ and an extremely high efficiency of 91.2% at 327 kV/cm. The ceramics have good energy storage and discharge performance in the temperature range from −40°C to 100°C due to the existence of AFE phase. An energy density of 3.7 J/cm³ can be released at 200 kV/cm in less than 500 ns and the discharge current keeps stable after 1000 charge-discharge cycles. By direct short experiment, a current density of 1657 A/cm², which is the highest result in recently developed AFE ceramics, and a power density of 228 MW/cm³ were achieved. The possibility of using AFEs at low temperature was confirmed. The excellent energy storage and discharge performance prove the great potential of the obtained ceramics in high energy and power density applications.     

Biomass-derived materials for electrochemical energy storages

During the past decade humans have witnessed dramatic expansion of fundamental research as well as the commercialization in the area of electrochemical energy storage, which is driven by the urgent demand by portable electronic devices, electric vehicles, transportation and storage of renewable energy for the power grid in the clean energy economy. Li-secondary batteries and electrochemical capacitors can efficiently convert stored chemical energy into electrical energy, and are currently the rapid-growing rechargeable devices. However, the characteristic (including energy density, cost, and safety issues, etc.) reported for these current rechargeable devices still cannot meet the requirements for electric vehicles and grid energy storage, which are mainly caused by the limited properties of the key materials (e.g. anode, cathode, electrolyte, separator, and binder) employed by these devices. Moreover, these key materials are normally far from renewable and sustainable. Therefore great challenges and opportunities remain to be realized are to search green and low-cost materials with high performances. A large number of the properties of biomass materials-such as renewable, low-cost, earth-abundant, specific structures, mechanical property and many others-are very attractive. These properties endow that biomass could replace some key materials in electrochemical energy storage systems. In this review, we focus on the fundamentals and applications of biomass-derived materials in electrochemical energy storage techniques. Specifically, we summarize the recent advances of the utilization of various biomasses as separators, binders and electrode materials. Finally, several perspectives related to the biomass-derived materials for electrochemical energy storages are proposed based on the reported progress and our own evaluation, aiming to provide some possible research directions in this field.     

Review of recent advances of polymer based dielectrics for high-energy storage in electronic power devices from the perspective of target applications

Polymer-based dielectric capacitors are widely-used energy storage devices.However,although the functions of dielectrics in applications like high-voltage direct current transmission projects,distributed energy systems,high-power pulse systems and new energy electric vehicles are similar,their requirements can be quite different.Low electric loss is a critical prerequisite for capacitors for electric grids,while high-temperature stability is an essential pre-requirement for those in electric vehicles.This paper reviews recent advances in this area,and categorizes dielectrics in terms of their foremost properties related to their target applications.Requirements for polymer-based dielectrics in various power electronic equipment are emphasized,including high energy storage density,low dissipation,high working temperature and fast-response time.This paper considers innovations including chemical structure modification,composite fabrication and structure re-design,and the enhancements to material performances achieved.The advantages and limitations of these methods are also discussed.     

Review on doping strategy in Li4Ti5O12 as an anode material for Lithium-ion batteries

Lithium-Ion Batteries (LIBs) as rechargeable energy storages play a key role in saving oil and decreasing exhaust emissions which are used for many applications including electric vehicles and electronic devices. Lithium titanate (LTO) as a promised anode material provides not only the Li-ion extraction and intercalation reversibility but also low volume changing during Li transmission. Nevertheless, LTO has some limitations which can be improved by some strategies such as doping. Dopants as a substation in the crystal structure of LTO could result in better performance in LIBs. In this report, doping of LTO with all kinds of dopants and with different fabrication methods is reviewed.     

Multifunctional BaTiO3-(Bi0.5Na0.5)TiO3-based MLCC with high-energy storage properties and temperature stability

BaTiO₃-(Bi_0.5Na_0.5)TiO₃ (BTBNT)-based multilayer ceramic capacitor (MLCC) chips with the inner electrodes being Ag0.6/Pd0.4 are prepared by a roll-to-roll casting method. The BTBNT-based MLCC chips with ten-dielectric layers can be sintered very well at a low temperature of 1130°C via two-step sintering (TSS). X-ray diffraction (XRD) and transmission electron microscope (TEM) results show that MLCC chips are a core-shell structure with two phases coexistence. The core exhibits a tetragonal phase at room temperature and then gradually changes into a cubic phase when the temperature increases above T_c (175°C). While, the shell exhibits a pseudocubic phase at all tested temperature from 25°C to 500°C. BTBNT-based MLCC chips exhibit a broad temperature stability and meet the requirement of Electronic Industries Association (EIA) X9R specifications. In terms of energy storage performance, a large discharge energy density of 3.33 J/cm³ can be obtained at 175°C under the applied electric field of 480 kV/cm. Among all tested temperature ranging from −50°C to 200°C, the energy efficiency of all chips is higher than 80%, even under a high applied electric field. The experimental results indicate that this novel BTBNT-based X9R MLCCs can be one of the most promising candidates for energy storage applications, especially operated in high temperature.