离子液体在超级电容器中的应用

超级电容器作为一种清洁和可持续的能源储存设备,因其功率密度高、循环使用寿命长及应用温度范围宽等特点被广泛应用于军事装备、航空航天、交通运输等领域.本文介绍了超级电容器和离子液体的特性,综述了离子液体作为超级电容器电解质材料的应用,同时特别介绍了近年来在实验以及分子动力学模拟方面的一些重要研究成果,并分析了离子液体基超级...     

超级电容器电解质研究进展

简述了近年来国内外超级电容器各种电解质,包括水系、有机体系、离子液体、固态、氧化还原等电解质的最新研究进展以及重要的理论和技术突破,着重对离子液体、水溶液及有机电解质作为超级电容器电解质的性能进行了比较,并对杂质离子的穿梭效应引起的自放电进行了讨论。最后总结指出开发具有低黏度、高电导率和高电化学稳定性的离子液体电解质是将来超级电容器在基础领域中研究的重点,并有望成为有机电解液的替代者。此外离子液体与混合有机溶剂多种成分的优化组合也是电解质的发展趋势。     

氰酸盐离子液体在石墨烯基超级电容器中的应用

将石墨烯电极与离子液体N-甲基-N-丙基吡咯烷氰酸盐（[C₃mpyr][OCN]）/碳酸丙烯酯（PC）混合电解液组装成超级电容器,采用循环伏安（CV）、交流阻抗（EIS）、恒电流充放电（GCD）等方法研究了其在50、60、70℃环境下的电化学性能。结果表明：该体系在较高温度下的电化学性能优异,70℃下其比容量最高可达295 F·g^-1,能量密度可达118 W·h·kg^-1,且恒电流充放电循环稳定性较好。     

超级电容器电解质的研究进展

综述了超级电容器电解质的研究现状,重点介绍了适用于新型电极材料的水系电解质以及目前已实现商业化的有机电解质,对离子液体电解质、固体和凝胶电解质的产业化提出了展望。     

纳米SiO2填料对离子凝胶电解质及高压超级电容器性能的影响

以SiO2纳米颗粒为填料,通过溶液浇筑法合成了纳米复合离子凝胶电解质,研究了SiO2填料对离子输运的影响规律。基于离子凝胶电解质构筑了准固态电容器,探讨了无机填料对电容器性能的影响,以活性炭为电极、凝胶电解质为隔膜,构筑了准固态双电层电容器。结果表明,SiO2的加入没有改变隔膜电解质的微观形貌,但有效改善了浸润性,提高了离子电导率。高SiO2添加量的隔膜电解质电化学性能更优,当添加8wt% SiO2时凝胶电解质电化学性能最优。SiO2的加入可有效提高活性炭准固态电容器的性能,电容器的比容提升约15%,经4000次循环后容量保持可达100%。电解质高温稳定性良好,器件最高使用温度可达60℃。基于该复合电解质构筑的电容器具有良好的高温性能,电容器比容随温度升高而逐渐提升,60℃时能量密度可达81.36 Wh/kg。     

超级电容器电极材料制备与性能研究

用恒电位沉积法在不锈钢电极上制备了MnO2薄膜,测试了循环伏安曲线及充放电性能。测试结果表明,充放电电压随时间呈线性变化,循环伏安曲线无明显的氧化还原峰,说明制备的MnO2具有良好的电容特性。     

超级电容器电极材料的研究发展

电极是超级电容器一个重要的组成部分,电极材料是决定超级电容器性能最重要的因素。本文主要综述了超级电容器的性能优点、工作原理、应用前景,并详细介绍了碳素材料、过渡金属氧化物、导电聚合物等三类超级电容器电极材料的研究进展。     

超级电容器电极材料二氧化锰的合成和性能研究

高锰酸钾和硫酸锰混合液,在高压反应釜内通过不同的水热时间合成了纳米级α-二氧化锰。借助X射线衍射（XRD）、扫描电镜（SEM）和比表面积（BET法）分析手段,对样品的结构和性能进行了表征。研究结果表明：水热时间为9 h的样品,扫描电镜检测结果显示,合成的粉体是纳米粉体,粒径为50～60 nm;X射线衍射检测结果表明,合成的粉体为α-二氧化锰;合成粉体的比表面积达到53.66 m2/g。以该二氧化锰为工作电极、饱和甘汞电极（SCE）为参比电极、铂丝电极为辅助电极的三电极体系中,以1 mol/L的硫酸钠溶液为电解液,通过循环伏安和计时电位法研究电化学行为,结果表明：在电位窗口为0～0.8 V（相对于饱和甘汞电极）、扫描速度为2 mV/s时,其比电容达到76 F/g,循环伏安曲线接近于矩形。     

A novel nickel-based mixed rare-earth oxide/activated carbon supercapacitor using room temperature ionic liquid electrolyte

Mesopore nickel-based mixed rare-earth oxide (NMRO) and activated carbon (AC) with rich oxygen-contained groups were prepared as electrode materials in a supercapacitor using room temperature ionic liquid (RTIL) electrolyte. These electrode materials were characterized by XPS, XRD, N₂ adsorption, SEM as well as various electrochemical techniques, and showed good properties and operated well with RTIL electrolyte. A 3 V asymmetrical supercapacitor was fabricated, which delivered a real power density of 458 W kg⁻¹ as well as a real energy density of 50 Wh kg⁻¹, and during a 500-cycle galvanostatic charge/discharge measurement, no capacity decay was visible. Such promising energy-storage performance was to a large extent ascribed to nonvolatile RTIL electrolyte with wide electrochemical windows and high stable abilities worked with both electrode materials.     

高温质子交换膜燃料电池用离子液体聚合物电解质的研究进展

综述了近十几年来高温质子交换膜燃料电池用离子液体聚合物电解质的研究进展及其在高温质子交换膜燃料电池中的应用进展,指出了此类电解质目前存在的亟待解决的两个问题：咪唑类离子液体毒化Pt基催化剂和复合膜中离子液体的长期稳定性。最后对高温质子交换膜燃料电池用离子液体聚合物电解质的发展前景作了展望,即开发与Pt基催化剂相容的离子液体聚合物电解质以及预防复合膜内离子液体的流失,即提高高温质子交换膜燃料电池的性能及长期稳定性,最终提高高温燃料电池的寿命。     

Application of room temperature ionic liquids to Li batteries

Novel electrolyte materials, room temperature ionic liquids (RTILs) were applied to the Li battery system and their characteristics in Li-metal batteries are discussed, partly reviewing authors work in the past. Quaternary ammonium (QA) cation-imide RTIL was focused on because of the excellent stability in cathodic environment of Li. Li/LiCoO₂ cell performance and Li cycling efficiency using the selected QA-imide RTIL was almost satisfactory. In addition, thermal stability of selected QA-imide RTIL with the charged positive electrode and Li was the advantage for Li battery. On the other hand, further improvement in the conducting properties is required with balanced approach for both electrochemical stability and thermal stability in order to use the RTIL electrolyte practically in batteries.     

室温离子液体室

介绍了主要由烷基咪唑盐阳离子及氟阴离子组成的室温离子液体的制备、物理性质、化学性质及其在常温条件下的应用.     

Design of highly stretchable deep eutectic solvent-based ionic gel electrolyte with high ionic conductivity by the addition of zwitterion ion dissociators for flexible supercapacitor

Nonvolatile deep eutectic solvent (DES) electrolytes with good electrochemical stability have recently emerged as promising electrolytes for energy storage devices. In this report, for the first time a polymerized zwitterionic molecule was introduced and a series of hybrid cross-linked zwitterion-containing copolymer DES gels are synthesized via UV initiated free-radical copolymerization of acrylic acid (AA), sulfobetaine vinylimidazole (VIPS) and poly(ethylene glycol) diacrylate (PEGDA) monomers, in situ within DES, which is prepared from 1:2 M ratio of choline chloride and ethylene glycol. Systematically varying the AA:VIPS molar ratio and copolymer contents within the copolymer network enables one to widely tune the mechanical properties and ionic conductivity of the poly(AA-co-VIPS) DES gels. The tensile strength of P(AA-co-VIPS) DES gels significantly increased from 28 kPa to 176 kPa with fracture strain from 720% to 1370%, while the ionic conductivity of copolymer DES gels remains high from 2.7 to 4.1 mS cm⁻¹ with the increase of copolymer content from 25 wt % to 45 wt%. A copolymer DES gel not only enables a supercapacitor deliver high capacitance of 71.52 F g⁻¹ at 0.5 A g⁻¹, and retains ∼97% of its capacitance after 2000 cycles, but also achieves outstanding capacitive performance over wide temperature range.     

Efficient capture of CO2 from flue gas at high temperature by tunable polyamine-based hybrid ionic liquids

For an ideal absorbent for CO₂ capture from flue gas, there are some key features including easy preparation, high stability, low absorption enthalpy, high capacity at high temperature and excellent reversibility. Herein, several polyamine-functionalized ionic liquids (ILs) were easily prepared from cheap polyamines and lithium salts, which exhibited significantly improved stability due to the presence of multisite coordinating interactions. The viscosity was reduced by introducing polyalcohol-based ILs, leading to polyamine-based hybrid ILs. Interestingly, these polyamine-based hybrid ILs exhibited high CO₂ capacity (4.09 mmol/g, 0.1 bar) at high temperature (80°C) and excellent reversibility in the presence of H₂O and O₂, which is superior to many other good absorbents. Moreover, these ILs also showed good performance for CO₂ capture from stimulated air (2.10 mmol/g, 380 ppm). We believe that this method with easy preparation, low cost, high efficiency and excellent reversibility has a great potential in the industrial capture of CO₂ from flue gas.     

Crack initiation of natural rubber under high temperature fatigue loading

Vulcanized natural rubber (NR) under quiescent thermal oxidation aging and high temperature fatigue loading with small strain amplitude was investigated by the infrared spectroscopy, scanning electron microscopy, and positron annihilation lifetime spectroscopy measurements. IR results demonstrated the thermal oxidation degradation process of vulcanized NR at 85°C. During high temperature fatigue loading, nanoscale cracks and voids that are generated by the combined impact of thermal oxidation and cyclic loading were detected. Further investigation suggests that the nucleation effect of dissolved vapor and gas in the low molecular weight domains of the NR under fatigue loading accounts for the appearance of nanocracks. This work provides some new insight into the crack initiation mechanism of NR during high temperature fatigue loading, which has not been clearly understood. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

萃取还原法制备离子液体基银纳米流体

在1-(2-羟基乙基)-3-甲基咪唑六氟磷酸/硫酸铵 双水相体系中,以双硫腙为萃取剂,将水相中的银离子萃取到离子液体相中.在超声辅助条件下通过对离子液体相中银离子的还原,制备了在亲水性离子液体中稳定的纳米银流体.用纳米粒度仪、透射电子显微镜对该流体进行表征,结果表明,纳米银微粒的平均粒度在29 nm左右,在离子液体中分布均匀.红外光谱分析结果表明,双硫腙与纳米银微粒之间存在一定的化学键作用,双硫腙对纳米银起到表面修饰的作用,这使得纳米银微粒在离子液体中有良好的分散性和稳定性.     

高温辐射环境中液滴的沸腾效应

建立了液滴在高温对流和辐射环境中的受热和蒸发模型,结合液滴均质沸腾模型,编制了计算程序。以正十二烷液滴为例,考虑液滴的膨胀效应以及液滴与周围气流的热物性变化,数值模拟了高温辐射与对流加热下的液滴升温和蒸发过程。分析了不同对流和高温辐射条件下,液滴内部是否能够发生沸腾。研究表明,液滴在高温辐射和对流加热下,蒸发伴随热膨胀;高温热辐射加热可导致液滴内部温度高于表面温度,升温到一定程度后可达到液滴内部沸腾状态;影响液滴沸腾的因素有液滴半径、辐射温度、环境气流温度等;同时,随着液滴蒸发,高温环境中液滴的沸腾过热度逐渐增大。