复杂电渗泵系统的输液特征

基于对电渗泵中压强产生原理的讨论, 对新兴的复杂串、并联电渗泵系统的流体输液特征加以研究. 在多级串联电渗泵系统中, 可以通过增加电渗泵的级数或操作电压来提高泵系统产生的压强, 但是单一流路的输液能力有限. 而在多级并联电渗泵系统中, 输液量也可以通过增加电渗泵的级数或操作电压得到提高. 在这一体系中, 尽管输液量的叠加有利于其在更为广泛的领域中应用, 但是因Joule热产生的电场强度与电渗流速度线性关系的偏离也使得其线性范围变小, 不利于操作条件的控制.     

基于有机和组合电解液的锂空气电池研究进展

发展纯电动汽车与混合动力汽车是解决能源危机与环境问题的有效途径,这对新能源材料及储能设备提出了更高的要求. 其中以金属锂作为负极、以空气中的氧气作为正极活性物质组成的锂-空气二次电池具有很高的理论比能量,因在纯电动汽车、混合动力汽车方面有很好的应用前景而受到人们的广泛关注. 根据工作环境及介质条件,目前研究最多的锂-空气电池主要包括有机电解液、有机-水组合电解液及全固态电解质三种类型. 由于锂-空气电池的发展历史较短,目前仍处于起步阶段,在电池的正极、负极、电解液（质）及综合性能等方面均存在诸多的困难与挑战. 本文从作者课题组对有机电解液及组合电解液型锂-空气电池方面的研究出发,旨在向读者简单介绍锂-空气电池的发展历史,研究现状及未来努力的方向.     

金属空气电池阴极氧还原催化剂研究进展

随着能源危机加剧和生态环境恶化, 可持续发展能源受到更大的重视. 金属空气电池作为一种绿色能源是具有很大发展潜力的新一代电池. 与传统电池相比, 此类电池有着更高的理论能量密度, 尤其是锂空电池, 能量密度可达3505 Wh/kg, 然而阴极缓慢的氧还原反应成为制约其发展的关键因素之一. 在简要介绍氧还原反应机理基础上, 着重介绍了近年来氧还原催化剂如贵金属及其合金、过渡金属氧化物/硫化物、功能化碳材料和金属氮化物的研究进展, 并根据目前所存在问题指出未来研究方向, 包括深入研究氧还原反应机理, 明确催化剂活性位; 研究催化剂结构等对催化活性的影响, 优化制备条件, 以提高催化活性和稳定性; 根据氧还原机理设计开发新型氧还原催化剂.     

不可燃氟代碳酸酯基钠离子电池电解液

Lithium-ion batteries (LIBs) are widely used in cellphones, laptops, and electric cars owing to their high energy density and long operational lifetime. However, their further deployment in large-scale energy storage systems is restricted by the uneven distribution of lithium resources (~0.0017% (mass fraction, w) in the Earth's crust). Therefore, alternative energy storage systems composed of abundant elements are of urgent need. Recently, sodium-ion batteries (SIBs) have attracted significant attention and are considered to be a potential alternative for next-generation batteries owing to abundant sodium resources (~2.64% (w) of the Earth's crust), suitable potential (−2.71 V), and low cost. SIBs are similar to LIBs in terms of their physical and electrochemical properties. Previous studies have mainly focused on SIB storage materials, including hard carbon, alloys, and hexacyanoferrate, while the safety of SIBs remains largely unexplored. Similar to LIBs, the current electrolytes used in SIBs are mainly composed of flammable organic carbonate solvents (or ether solvents), sodium salts, and functional additives, which pose possible safety issues. Moreover, the chemical activity of sodium is much higher than that of lithium, leading to a higher risk of fire, thermal runaway, and explosion. To overcome this problem, herein we propose a fluorinated non-flammable electrolyte composed of 0.9 mol∙L⁻¹ NaPF₆ (sodium hexafluorophosphate) in an intermixture of di-(2, 2, 2 trifluoroethyl) carbonate (TFEC) and fluoroethylene carbonate (FEC) in a 7 : 3 ratio by volume. Its physical and electrochemical properties were studied by ionic conductivity, direct ignition, cyclic voltammetry, and charge/discharge measurements, demonstrating excellent flame-retarding ability and outstanding compatibility with sodium electrodes. The electrochemical tests showed that the Prussian blue cathode retained a capacity of 84 mAh∙g⁻¹ over 50 cycles in the prepared electrolyte, in contrast to the rapid capacity degradation in a flammable conventional carbonate electrolyte (74 mAh∙g⁻¹ with 57% capacity retention after 50 cycles). To test the practical application of the proposed electrolyte, a hard carbon anode was used and exhibited exceptional performance in this system. The enhancement mechanism was further verified by Fourier transform infrared (FTIR), X-ray diffraction (XRD), and scanning emission microscopy (SEM) investigations. Polycarbonate on the surface of the cathode played an important role for the studied electrolyte system. The polycarbonate may originate from FEC decomposition, which can enhance the ionic conductivity of the solid electrolyte interface (SEI) layer and reduce impedance. Hence, we believe that this proposed electrolyte may provide new opportunities for the design of robust and safe SIBs for next-generation applications.     

NaOH电解液改善MH/Ni电池自放电性能的机理研究

以NaOH电解液代替KOH能够明显改善MH/N i电池的自放电性能和高温(60℃)充电效率.电化学阻抗和循环伏安测试表明,NaOH电解液的作用可能是改变了H原子于负极表面的吸(脱)附行为,并在一定程度上抑制了负极的析氢过程,从而改善了电池的自放电性能.     

示波极谱法直接快速测定痕量锑的研究

在0.06 mol.L-1硫酸溶液中,Sb(Ⅲ)与焦性没食子酸络合物产生一个灵敏的导数极谱波,峰电位为-0.4 V(vs.SCE),有微量Se(Ⅳ)存在下,灵敏度大为提高,锑浓度在0.03~1.2 mg.L-1范围内峰高与浓度呈线性关系,应用于锌电解液中痕量锑的测定。检出限为0.004 mg.L-1,RSD为1.8%~2.2%,回收率为95.0%~105.0%。     

1,3-二氧戊环基LiCF3SO3电解液对锂硫电池正极材料单质硫的电化学性能影响

测试了二元和多元溶剂组分的1,3-二氧戊环基LiCF3SO3电解液的粘度、离子电导率和单质硫的溶解度. 研究结果表明, 由较强的给电子能力溶剂组成的低粘度电解液较容易提高单质硫的氧化还原反应活性和可逆性能, 有利于提高单质硫在2.10 V附近的低放电平台电位和放电比容量. DOL-DME LiCF3SO3电解液能够较好地改善单质硫电极的表面钝化层结构, 促进电活性物质离子扩散和降低界面电荷传递阻抗, 从而表现出很好的放电倍率特性. 在室温下充放电流密度分别为0.1和0.2 mA/cm2时, 单质硫的首次放电比容量为792 mA·h/g, 第29次放电比容量达到412 mA·h/g.     

高活性硫化铅电极的制备及在量子点敏化太阳能电池中的应用

为了提高量子点敏化纳晶薄膜太阳能电池的光电转换效率,我们通过连续在酸和多硫溶液中处理铅片制备了对多硫电解液具有高电催化活性的硫化铅电极.通过电化学阻抗谱测试评价所制备硫化铅电极的催化活性,从而确定制备高效硫化铅电极的最佳条件.以在最佳条件下制备的硫化铅为对电极、CdSe量子点敏化TiO2纳晶薄膜为工作电极和多硫电解液组装成量子点敏化太阳能电池.光电性能测试结果表明所制备的电极具有良好的催化活性和光电转换性能.与已报导的方法相比,新方法大幅度地减少制备过程所需的时间,但却提高了所制备的硫化铅对电极的催化活性.通过X射线衍射和扫描电镜测试表征了硫化铅的生成过程,探讨了催化活性提高的原因.     

Synthesis and Ionic Conductivity of Network Polymer Electrolytes with Internal Plasticizers

Network polymer electrolytes with free oligo(oxyethylene) chains as internal plasticizers were prepared by cross-linking poly(ethylene glycol) acrylates. The effects of salt concentration and properties of internal plasticizers on ionic conductivity were studied.     

Ionic Liquid Based Electrolyte with Mesoporous Silica SBA-15 as Framework for Quasi-solid-state Dye-sensitized Solar Cells

Quasi-solid-state electrolytes were fabricated with mesoporous silica SBA-15 as a framework material. Ionic conductivity measurements revealed that SBA-15 can enhance the conductivity of the quasi-solid-state electrolyte. The diffusion coefficients of polyiodide ions such as Ⅰ3ˉ and Ⅰ5ˉ which were confirmed by Raman spectroscopic measurement, were about twice larger than that of I-. The optimized photoenergy conversion efficiency of dye-sensitized solar cells （DSSC） with the quasi-solid-state electrolyte was 4.3% under AM 1.5 irradiation at 75 mW·cm^-2 light intensity.