电解质非水溶液导热系数计算方法

根据电解质非水溶液导热系数的变化规律 ,发展了一种根据电解质非水溶液的组成计算其导热系数的普适方法。对不同温度下 191个电解质非水溶液体系的计算结果表明 ,导热系数计算值与文献值的一致性令人满意 ,平均误差 3.4 8%。     

有机物水溶液导热系数的关联

根据对有机物水溶液导热系数影响因素的分析,在Horvath液体导热系数关系式的基础上,导出了估算有机物水溶液导热系数的计算模型;利用该模型计算了14个体系中447个数据点的不同温度和组成的二元水溶液导热系数;结果表明,计算值与实验数据吻合很好,其与实验值的总平均相对偏差为1.03％,计算准确性优于文献方法。本文计算方法简单方便,只需知道水溶液各组分的临界温度、临界体积和导热系数数据,就可以直接预测各种温度和组成的有机物水溶液混合物的导热系数。     

一种预测电解质溶液密度的新方法

根据对应状态原理的基本思想本文提出了一种预测电解质溶液密度的新方法。以CaCl2 溶液作为参考流体 ,本文得到了溶液渗透压和溶剂水的表观摩尔体积的定量关系。假定该关系对所有电解质水溶液都是适用的 ,则由离子半径和溶液组成 ,就可以计算单一电解质溶液和预测混合电解质溶液在全浓度和 2 73K～ 373K范围内的密度。模型的可靠性通过 30个二元电解质溶液在 2 98 1 5K和 1 1个单一电解质溶液在 2 73K～ 373 1 5K范围内密度的预测进行了检验。采用与温度和浓度无关的离子半径的优化值 ,本文对密度预测的总平均相对偏差小于 1 %。该方法公式简单 ,计算精度可以满足工业设计计算的要求     

离子选择性电极测定混合电解质溶液中离子活度系数

应用离子选择性电极法测定混合电解质溶液中离子活度系数,由实验结果对该方法的可行性和混合电解质水溶液活度系数随温度和浓度的变化关系进行了讨论,并对单一电解质溶液和混合电解质溶液中离子的活度系数进行了对比分析。结果表明,该方法快速、简便、灵活、成本低,是测定混合电解质溶液离子活度系数的有效方法。     

利用变阱宽方阱链流体状态方程计算1：1电解质溶液热力学性质

将变阱宽方阱链流体状态方程拓展到1：1强电解质水溶液热力学性质的计算中,通过关联溶液的平均离子活度系数和溶剂的渗透系数得到了22种离子的链节直径和方阱能量参数,40余种电解质溶液的平均离子活度系数和溶剂渗透系数的总平均相对偏差分别为6.03%和5.83%。计算结果表明,建立的电解质型状态方程可以满意预测电解质溶液的密度和宽广温度下溶液的蒸气压,总体平均相对偏差分别为0.22%和4.69%。进一步说明模型参数的可靠性。     

多元电解质水溶液的值计算法

本文探讨了有关多元电解质水溶液的炯值计算法。提出根据溶液蒸汽压或离子平均活度系数γ±计算二元电解质水溶液(火用)值的公式。多元溶液的(火用)由相同离子强度的二元溶液的(火用)计算。给出海水淡化系统的(火用)数据和脱盐最小功。     

甲醇和乙醇的水溶液粘度、密度和导热系数的估算

根据作者导出的非电解质水溶液的粘度模型,提出了估算低压下甲醇和乙醇水溶液粘度的估算式,并根据对实验数据的回归分析,提出了甲醇和乙醇水溶液的密度和导热系数估算式。利用这些计算式计算了不同温度和组成下的甲醇水溶液和乙醇水溶液的132个粘度数据、130个密度数据和32个导热系数数据,计算值与实验值的平均计算偏差分别为1.888%、0.540%和0.969%;计算了不同温度和组成下的甲醇-乙醇-水三元溶液的115个粘度数据和116个密度数据,计算值与实验值的平均相对偏差分别为2.556%和0.351%。计算结果表明,计算值与实验数据吻合很好。     

溴化锂水溶液分子扩散系数的计算方法

本文从电解质溶液理论出发,导出了不同温度和不同浓度下溴化锂水溶液的平均活度系数的计算表达式。又借助于Gorden半经验公式,得到了计算溴化锂水溶液分子扩散系数的理论计算公式。计算结果与T.Kashiwagi等采用全息干涉法所观测到的结果完全吻合。     

水泥石导热系数的计算模型

测试了不同水灰比、不同养护龄期水泥石的导热系数,并对比了并联模型、串联模型、Maxwell模型、Mori-Tanaka模型、有效介质理论模型和Self-consistent模型对水泥石导热系数的预测效果。利用分子动力学方法计算了水泥石中各相的导热系数。结果表明:水泥石的导热系数随着养护龄期和水灰比的增大而减小。SC模型适用于不同水灰比和养护龄期水泥石导热系数的计算,其计算结果与试验值的相对误差在0.3%～4.7%之间。Maxwell模型和MT模型可以用于对水灰比较大且养护龄期较长的水泥石的导热系数进行计算。     

非均相电解质溶液导热系数的测定

基于瞬态热丝法原理，将ＫＤＲ－１Ｂ导热系数测定仪的探头作绝缘处理后，测定了１０种非均相电解质溶液的导热系数，实验数据的重复性较好，平行试验的误差小于５％。不同温度下的实验数据用经验关联式关联，精度满足工程设计要求。     

GENERALIZED CORRESPONDING STATES CORRELATIONS FOR THE VISCOSITY AND THERMAL CONDUCTIVITY OF AQUEOUS ELECTROLYTE SOLUTIONS

Corresponding slates correlations have been developed for the viscosity and thermal conductivity of aqueous electrolyte solutions for a wide range of temperatures, pressures, and concentrations. For viscosity, the Vogel-Tamann-Fulcher equation has been generalized using the corresponding states theory, and extended to include pressure effects. Twenty six aqueous electrolyte solutions, including both monovalent and multivalent electrolytes, have been studied and a generalized correlation has been developed for viscosity, with four system dependent parameters. For thermal conductivity, a similar corresponding states based correlation has been developed. Twenty three aqueous electrolyte solutions were studied for thermal conductivity and a generalized equation was obtained that requires only two System dependent parameters. With both correlations, the maximum error is usually within 10% of the experimental values, with the average errors being much less. Additional systems can also be included in both correlations in a straightforward manner.     

固体电解质的制备及其在锂氧电池性能研究

本文提出了将高离子电导率的全固态电解质Li1.4Al0.4Ti1.6(PO3)4(LATP)用于锂氧电池。用Pechini法成功的合成了全固态电解质，采用X射线荧光衍射(XRD)、场发射扫描电子显微镜(SEM)和电化学性能分析其性能。结果显示，LATP不仅具有较高的离子导电性，而且LATP作为固体电解质，具有更高的放电平台。同时，LATP固体电解质能降低电解质的分解，从而能够减少放电产物的生成。因此，LATP玻璃陶瓷固体用于锂氧电池提高了锂氧电池的热稳定性并且降低了锂氧电池热膨胀。LATP固体电解质利用在可再充电锂氧电池中具有良好的前景。     

Stable zirconium hydrogen phosphate-silica nanocomposite membranes with high degree of bound water for fuel cells

Zirconium hydrogen phosphate (ZrP)-silica nanocomposite polymer electrolyte membranes (PEMs) were prepared by sol-gel method in aqueous media. Hydrophilic and hydrophobic regions of PEMs were tailored by molecular level of architecture to introduce proton conducting pathways and methanol impervious nature. ZrP-silica nanocomposite PEMs showed improved thermal, mechanical, oxidative and hydrolytic stabilities along with high conductivity, methanol retention capacity, which are essential requirements. Furthermore, high degree of bound water content in membrane matrix indicates suitability of reported PEMs under anhydrous or low-humidity conditions. These PEMs were well processed as self-supporting film, and exhibited high selectivity parameter in comparison to Nafion117 membrane for direct methanol fuel cell (DMFC) applications.     

Effect of methylsisesquioxane filler on the properties of ionic liquid based polymer electrolyte

Composite electrolyte comprising methylsisesquioxane (MSQ) filler and 1-butyl-3-methyl-imidazolium-tetrafluoroborate (BMImBF₄) ionic liquid (IL) in poly(2-hydroxyethyl methacrylate) (PHEMA) matrix had been prepared. The polymer matrix was formed by free radical polymerization of HEMA macromer, and MSQ was produced in situ from methyl-trimethoxysilane by the sol-gel method. Infrared spectroscopy and dynamic mechanical analysis were employed to give insight into the interactions among the methylsisesquioxane filler, BMImBF₄ and the PHEMA polymer matrix. The PHEMA-IL-MSQ hybrids and the PHEMA-IL electrolyte without MSQ were investigated regarding their ionic conductivity and thermal and electrochemical properties. BMImBF₄ increased the thermal stability of the polymer and provided the ion conductivity; MSQ filler as the additive increased the mechanical strength of the polymer and provided the ion conductive pathway. The electrolyte with MSQ at the 10 wt% showed the highest ionic conductivity of 5×10⁻⁴ S cm⁻¹ which was five times higher than that of the electrolyte without MSQ, and the electrochemical window was up to 3.6 V.     

新型二元熔盐电解质LiTFSI/NaTf的热学和电化学性能

制备了由二（三氟甲基磺酰亚胺）锂（LiTFSI）和三氟甲基磺酸钠（NaTf）形成的二元低温熔盐电解质材料,采用差热分析、电化学阻抗和循环伏安法分别对熔盐电解质体系的热学性质、电导率和电化学窗口等进行了研究。测试结果表明,LiTFSI/NaTf熔盐体系的最低共熔温度为188℃,而且具有很高的热稳定性,在300℃以内没有明显热分解的迹象;LiTFSI/NaTf熔盐体系具有较好的电导率,电导率随着LiTFSI浓度的增加而减小;温度为230℃、摩尔配比为1∶3的LiTFSI/NaTf熔盐体系的电化学窗口为4.7 V,且随着温度的升高,电化学窗口减小幅度较小,表明该体系具有良好的电化学稳定性。     

石榴石固态电解质的冷烧结工艺制备及性能

以LiNO3、Al(NO3)3·9H2O、La(NO3)3·6H2O、ZrO(NO3)2·5H2O为原料,采用溶胶-凝胶法制备Li5.95Al0.35La3Zr2O12粉体,随后加入聚乙烯醇（PVA）水溶液作为液相介质,通过冷烧结工艺制备Li5.95Al0.35La3Zr2O12石榴石固态电解质。冷烧结工艺后采用后续热处理改善离子传导性能。采用质量体积法和电化学阻抗谱对Li5.95Al0.35La3Zr2O12石榴石固态电解质的体积密度和离子电导率进行了测试,采用XRD与SEM进行晶体结构与形貌表征。结果表明,冷烧结时间和压力对样品的晶体结构几乎没有影响。冷烧结时间过长会导致样品开裂,在15~30 min时,冷烧结时间对样品的致密性和电导率影响不大,在烧结时间较短的样品中发现了杂相。提高冷烧结压力可明显提高样品的致密性和电导率,在200℃、510 MPa、30 min的冷烧结条件下可以获得具有较高离子电导率（2.66×10-6 S/cm）的Li5.95Al0.35La3Zr2O12石榴石固态电解质,此时材料的晶界电阻较小。但继续增加冷烧结压力,由于热处理过程中第二相的分解和晶粒生长受到抑制,样品的致密性和电导率反而下降。     

Effect of electrolyte concentration on the properties of the electropolymerized polypyrrole films

The effect of electrolyte concentration on the electropolymerization of pyrrole was investigated by studies of conductivity, tensile strength, and absorption spectra, etc., of polypyrrole films prepared from electrolyte aqueous solutions. The electrolyte salts used in the studies include sodium p-toluenesulfonate (TsONa), NaClO₄, NaNO₃, and KCl. Cyclic voltammetry and elemental analysis were also performed in the studies of the effect of the NaNO₃ concentration. The conductivity, tensile strength, and the counteranion doping degree of conducting polypyrrole films increased obviously with increase of the electrolyte concentration of their polymerization solutions from 0.2 to 1 mol L⁻¹. Further increase of the concentration over 1 mol L⁻¹ has a weak effect on the further improvement of the film quality of polypyrrole. So, 1 mol L₋₁ was recommended for the electrolyte concentration of the polymerization aqueous solutions of pyrrole. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2739–2744, 1997     

原位聚合有机累托石/聚甲基丙烯酸甲酯凝胶聚合物电解质的性能

以有机增塑剂聚碳酸丙烯酯(propylene carbonate,PC)为聚合反应溶剂,通过自由基引发原位聚合法制备了有机累托石/聚甲基丙烯酸甲酯(organic-modified rectorite/polymethyl methacrylate,OREC/PMMA)纳米复合凝胶聚合物电解质(nanocomposite gel polymer electrolyte,NGPE).用交流阻抗法分析了凝胶电解质的电性能,并研究了温度对电性能的影响.通过红外光谱分析其组分间的相互作用.用差示扫描量热分析和热失重分析分析凝胶电解质的热稳定性.结果表明:OREC/PMMA组成的NGPE的本体阻抗值随OREC添加量的增加呈现出先减小后增大的趋势,当OREC的添加质量为5%时,NGPE在不同温度下均具有最大的离子电导率(σ).OREC与PC,PMMA及锂盐之间存在一定的相互作用,从结构的角度解释了OREC添加提高体系σ的机理.添加OREC能在一定程度上改善体系的凝胶热稳定性.     

Crosslinked quaternized poly(arylene ether sulfone) copolymer membrane applied in an electric double-layer capacitor for high energy density

The low energy density of supercapacitors, especially supercapacitors based on aqueous electrolytes, is the main factor limiting their application, and the energy density is closely related to the operating potential window of the supercapacitor. The polymer electrolyte is the main contributor to the safe operation and good ion conductivity of the supercapacitor. In this study, a crosslinked quaternized poly(arylene ether sulfone) (PAES) membrane was prepared via crosslinking during membrane formation with a thermal-only treatment and applied in an electric double-layer capacitor (EDLC). The pre-prepared PAES membrane formed a polymer electrolyte with 1 mol/L Li₂SO₄ and was then fabricated into an EDLC single cell. The properties of both the membrane and ELDC were investigated. The preferred cPAES-N-0.2 polymer electrolyte showed an ionic conductivity of 1.18 mS/cm. The optimized EDLC exhibited a single-electrode gravimetric capacitance of 104.92 F/g at a current density of 1.0 A/g and a high operating potential window (1.5 V); it, thereby, achieved a high energy density of 8.20 W h/kg. The EDLC also exhibited excellent cycling properties over 3000 charge–discharge cycles. The crosslinked structures promoted the tensile strength and thermal stability of the PAES membranes; this was accompanied by a slight decrease in the ionic conductivity. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47759.