PEO基纳米复合聚合物电解质电化学性质的研究

以PEO8 LiClO4作母体,纳米SiO2为填料,制成PEO8 LiClO4 SiO2(x%)系列复合聚合物电解质,测定这该电解质的电导率、锂离子迁移数和电化学稳定窗口,并对其晶态结构作差热分析表征.结果表明,纳米SiO2的引入,显著提高了电解质的电导率,在22℃时达到4.3×10-5S·cm-1.此外,还探讨了填料对复合聚合物电解质电导率提高的影响机理.     

聚合物电解质膜燃料电池薄电极制备技术的研究

为降低聚合物电解质膜燃料电池 (PEMFC)电极中铂的载量 ,本文建立一种新的薄电极制备技术 (TEFT) ,制备了表面平滑、颗粒分布均匀的低铂载量电极 .结果表明当电极的铂载量为 1mg/cm2 ,用Nafion 117膜作电解质时 ,电池的最大功率密度达 0 30W·cm-2 .系统地考察了阴极中不同PTFE和Nafion含量对PEMFC性能的影响 .     

碳酸丙烯酯分子凝胶电解质的电化学行为

碳酸丙烯酯 (PC)在凝胶因子 4 ,4′ 二 (硬脂酰胺基 )二苯醚 (BSDE)的作用下形成分子凝胶。交流阻抗法研究发现 ,含二 (三氟甲基磺酰 )亚胺锂 (LiTFSI)的PC分子凝胶在室温下的电导率达 5 .5 6× 1 0 -3 S·cm-1 。在较低温度下 (≥ - 35℃ ) ,温度对分子凝胶电导率的影响比其溶液电解质的影响大。在 - 35℃时 ,含LiTFSI的PC分子凝胶的电导率为 5 .91× 1 0 -5S·cm-1 。以不锈钢电极为工作电极 ,锂电极为参比电极 ,用循环伏安法 ,测定PC分子凝胶电解质体系的电化学稳定窗口为 0 .0～ 4 .7V。     

电化学混合电容器用新型聚吡咯/介孔碳纳米复合电极

采用介孔碳CMK-3作为载体,通过化学原位聚合的方法制备出一种新型的聚吡咯/介孔碳(PPy-CMK-3)纳米复合材料.将该纳米复合材料作为正极,配以介孔碳CMK-3为负极和1.0mol·L-1NaNO3中性电解液,组装成为电化学混合电容器.电化学测试表明:在5.0mA·cm-2电流密度和1.4V充放电电位条件下,其放电比容量达57F·g-1,电容器功率密度为2.5×102W·kg-1,能量密度达17Wh·kg-1.当电流密度从5.0mA·cm-2增加至50mA·cm-2时,电容器的容量保持率在80%以上,显示高倍率充放电特性优异.此外,聚吡咯-介孔碳/介孔碳电化学混合电容器易活化,并具有优异的充放电效率和良好的循环稳定性能.     

三氟化硼乙醚/乙酸混合电解质中芴的电化学聚合

在三氟化硼V(乙醚):V(乙酸)=4:5的混合电解质体系中直接氧化芴,获得芴聚合物膜,其电导率为0.5 S cm-1,高于在纯三氟化硼乙醚中制得的聚芴的电导率0.25 S cm-1.在三氟化硼乙醚:乙酸=4:5的混合电解质体系中获得的聚芴膜具有良好的电化学性质和化学稳定性.FTIR,1H-NMR和量化计算表明反应发生在...     

用于柔性超级电容器的凝胶聚合物电解质膜的制备

以聚乙烯吡咯烷酮(PVP)提高戊二醛(GA)交联的聚乙烯醇(PVA)凝胶在1 mol/L的H2SO4溶液中的溶胀度,制备出一种用于柔性超级电容器的凝胶聚合物电解质膜,并对该电解质膜的结构、形貌、溶胀度、力学性能和电导率等进行了表征.在此基础上,组装了一种基于石墨烯电极的柔性超级电容器.结果表明:随着PVP用量的增加,膜孔数量增多且孔径增大,溶胀度增加,电导率提高,但力学强度下降.电解质膜中PVP质量分数为20％时,所组装的柔性超级电容器的比电容为111 F/g,其电化学性能的温度依赖性较低,稳定性较好.     

兼具高质量和高体积能量密度的水系全金属氧化物不对称超级电容器（英文）

超级电容器只有兼具高质量和高体积能量密度才能拥有更广泛的应用价值.本文采用具有纳米结构及高填充密度的RuO_2(纳米球,1.69 g·cm-3)和Co-Ni氧化物(纳米片,2.14 g·cm-3)分别作为负极和正极材料,成功地构筑了氧化物非对称超级电容器.所得不对称超级电容器具有高电压窗口、高质量比容量(217.5 F·g-1)和高体积比容量(412.3 F·cm-3)、高质量能量密度(61.8 Wh·kg-1)和高体积能量密度(121Wh·L-1)的优良性能,在1.4 V的电压下以2 A·g-1的电流密度历经5000次循环后比容量保持率为87%.     

含二茂铁离子液体电容器的电化学性能

对以含二茂铁(ferrocene, Fc)离子液体1-乙基-3-甲基咪唑四氟硼酸盐(1-ethyl-3-methylimidazolium tetra-fluoroborate, [BMIm]BF4)作为电解液, 高比表面积的多孔炭作为电极材料构成的电容器的电化学行为进行了探讨. 循环伏安和恒流充放电测试结果表明,含二茂铁离子液体在多孔炭中发生氧化还原反应, 并且该氧化还原反应是扩散控制, 高度可逆的过程. 0.01 mol·L-1 [BMIm]BF4/Fc在电流密度为1 mA·cm-2时的平均比电容为163 F·g-1, 比纯[BMIm]BF4的比电容高63%. 平均比电容的增加表明由Fc参与的氧化还原反应生成的法拉第电容对电容器的总电容有很大的贡献. 同时, 以0.01 mol·L-1 [BMIm]BF4/Fc作电解液的电容器的功率密度为400 W·kg-1, 能量密度高达37.5 Wh·kg-1, 达到了电池的水平.     

Ce_(0.8)Nd_(0.2)O_(1.9)-La_(0.95)Sr_(0.05)Ga_(0.9)Mg_(0.1)O_(3-δ)固体复合电解质的结构和电性能

采用溶胶-凝胶法分别制备La0.95Sr0.05Ga0.9Mg0.1O3-δ(LSGM)和Ce0.8Nd0.2O1.9(NDC)电解质,并在NDC溶胶中加入0-15%(w,质量分数)的LSGM预烧粉体制得NDC-LSGM复合电解质,研究不同质量比复合电解质的结构和电性能.采用X射线衍射(XRD)、场发射扫描电子显微镜(FE-SEM)和X能量色散谱仪(EDS)对样品进行结构表征,交流(AC)阻抗谱测试样品导电性能.结果表明:NDC-LSGM复合体系主要由立方萤石结构相、钙钛矿结构相和杂质相组成;LSGM的添加可促进晶粒的生长,产生大量相界面,清除或降低SiO2有害影响,明显提高晶界导电性;LSGM质量分数为10%的样品NL10具有最高晶界电导率和总电导率,400°C时NL10的晶界电导率σgb和总电导率σt分别为12.15×10-4和3.49×10-4S cm-1,与NDC的σgb(1.41×10-4S cm-1)和σt(1.20×10-4S cm-1)相比分别提高了7.62和1.91倍,总电导率的提高主要归因于晶界电导率的影响.     

离子液体/凝胶聚合物电解质的制备及其与LiFePO_4的相容性

以1-甲基-3-乙基咪唑六氟磷酸盐(EMIPF6)、聚偏氟乙烯-六氟丙烯(P(VDF-HFP))和六氟磷酸锂(LiPF6)为原料,采用溶液浇铸法制备了离子液体/凝胶聚合物电解质(ILGPE).通过循环伏安(CV)、计时电流法、恒流充放电、电化学阻抗法(EIS)研究了该电解质的离子传输特性以及与锂离子电池正极材料LiFePO4的相容性.结果表明,离子液体/凝胶聚合物电解质的室温电导率为1.650×10-3S·cm-1,电化学稳定窗口达到5.0V.在充放电循环过程中,电极表面形成的钝化膜改善了锂离子脱、嵌可逆性和电极/电解质的界面性质.     

锂离子电池凝胶聚合物电解质研究进展

使用聚合物电解质可以避免传统液态锂离子电池的漏液问题,提高电池的安全性能和能量密度,并可实现电池的薄型化、轻便化和形状可变等优点.目前,聚合物电解质的研究集中在凝胶型的复合和多孔聚合物电解质两大类.本文对各类凝胶聚合物电解质的特点、功能及研究情况逐一进行了介绍,对凝胶聚合物电解质的发展趋势进行了展望.     

Electrochemical investigation of gel polymer electrolytes based on poly(methyl methacrylate) and dimethylacetamide for application in Li-ion batteries

In the present work, gel polymer electrolytes (GPEs) were prepared using poly(methyl methacrylate) (PMMA), lithium perchlorate (LiClO₄) and dimethylacetamide as a plasticizer. Solution-casting technique was used to fabricate GPEs containing different weight percentage of PMMA. The degree of crystallinity of GPE samples was studied by X-ray diffraction (XRD) analysis. Fourier transform infrared (FT-IR) spectroscopy was applied to study the level of interactions between lithium salt and PMMA in the prepared GPEs. Electrochemical properties were studied by electrochemical impedance spectroscopy, linear sweep voltammetry and DC polarization techniques. Lithium ion conductivity of GPEs was determined by calculating the bulk resistance of polymer electrolytes from Nyquist plot. Increasing PMMA content of GPEs resulted in an improvement in the electrochemical potential window from 4.2 to 4.5 V. The highest lithium transference number (0.42) and also the best electrochemical properties were obtained for GPE containing 0.75 M LiClO₄ and 10 wt% PMMA. Scanning electron microscopy images of the optimized GPE showed a porous and heterogeneous surface structure which is desirable for application in Li-ion batteries.     

PEO/LiClO_4纳米SiO_2复合聚合物电解质的电化学研究

将实验室制备的纳米二氧化硅和市售纳米二氧化硅粉末与PEO LiClO4复合 ,制得了复合PEO电解质 .它们的室温离子电导率可比未复合的PEO电解质提高 1～ 2个数量级 ,最高可以达到 1 2 4× 10 - 5S cm .离子电导率的提高有两方面的原因 :一是无机二氧化硅粉末的加入抑制了PEO的结晶 ,是二氧化硅粉末和聚合物电解质之间形成的界面对电导率的提高也有一定的作用 .在进一步加入PC EC(碳酸丙烯酯 碳酸乙烯酯 )混合增塑剂后制得的复合凝胶PEO电解质 ,可使室温离子电导率再提高 2个数量 ,达到 2× 10 - 3 S cm .用这种复合凝胶PEO电解质组装了Li|compositegelelectrolyte|Li半电池 ,并测量了该半电池的交流阻抗谱图随组装后保持时间的变化 ,实验观察到在保持时间为 144h以内钝化膜的交流阻抗迅速增大 ,但在随后的时间内逐渐趋于平稳 ,表明二氧化硅粉末的加入可以有效地抑制钝化膜的生长     

FT‐IR Studies of Plasticization of Propylene Carbonate and Ethylene Carbonate in PEO‐NaSCN Polymer Electrolytes

The FT‐IR spectra of poly(ethylene oxide) (PEO)‐based gel polymer electrolytes (GPEs), PEO‐NaSCN‐propylene carbonate (PC) and PEO‐NaSCN‐ethylene carbonate (EC), were measured at room temperature. Along with the FT‐IR spectra of NaSCN‐PC, PEO‐PC, and PEO‐EC, the interactions in the GPEs and the plasticizations of PC and EC are revealed. It is shown that the coordination of ether oxygen in PEO with NaSCN is the preferential solvation, whereas the interactions of PC and EC with NaSCN are relatively weak in the GPEs. However, both PC and EC play an important role in inhibiting the formation of crystalline complexes and high ionic aggregations, in addition to the ability of transformation of PEO from crystal to amorphism. It is further observed that EC exhibits the stronger ability to transform PEO crystalline into amorphism than PC when the plasticizer content in PEO is more than 25%, and also the far stronger ability to decompose the crystalline complexes, in particular, in polymer electrolytes with high salt content.     

单分散SiO2纳米颗粒复合凝胶电解质的应用

以单分散程度较高的SiO₂纳米颗粒(约130 nm)作为填料,聚偏氟乙烯-六氟丙烯(PVDF-HFP)作为聚合物基质,采用简便的物理共混法制备出了一种单分散SiO₂纳米颗粒复合凝胶聚合物电解质(MCGPEs)并将其应用于锂电池中。扫描电镜结果表明,SiO₂纳米颗粒在聚合物基体中分散均匀。与传统凝胶聚合物电解质(GPEs)和商业SiO₂颗粒复合凝胶电解质(CGPEs)相比,MCGPEs有着更高的电解液吸液能力和离子电导率,并且具备更强的锂离子迁移能力。此外,使用MCGPEs作为电解质的锂电池,在1.0C下历经300次循环后仍然保持了121.1 mAh·g^-1的较高比容量,表现出了优异的循环性能。同时,其倍率性能也十分优异,在10C倍率下获得了135 mAh·g^-1的比容量,远高于GPEs锂电池(76.2 mAh·g^-1)。     

不同热引发剂对凝胶态聚合物电解质性能的影响

采用热重/差热分析方法研究了两种热聚合引发剂: AIBN和BPO. 它们通常用于制备锂离子二次电池凝胶态聚合物电解质. 采用不同引发剂制备的凝胶态聚合物电解质具有不同的特性并影响聚合物锂离子二次电池的性能, 例如倍率性能, 高低温性能和循环性能. 为凝胶态聚合物电解质体系选择了一种合适的热引发剂.     

Effect of solvents on properties of polymer gel-electrolyte based on polyester diacrylate

New polymer gel electrolytes based on polyester diacrylates and LiClO₄ salt solutions in organic solvents are developed for lithium ion and lithium polymer batteries with a high ionic conductivity up to 2.7 × 10^?3 Ohm^?1cm^?1 at the room temperature. To choose the optimum liquid electrolyte composition, the dependence is studied of physico-chemical parameters of new gel electrolytes on the composition of the mixture of aprotic organic solvents: ethylene carbonate, propylene carbonate, and λ-butyrolacton. The bulk conductivity of gel electrolytes and exchange currents at the gel electrolyte/Li interface are studied using the electrochemical impedance method in symmetrical cells with two Li electrodes. The glass transition temperature and gel homogeneity are determined using the method of differential scanning calorimetry. It is found that the optimum mixture is that of propylene carbonate and λ-butyrolacton, in which a homogeneous polymer gel is formed in a wide temperature range of ?150 to +50°C.     

PREPARATION OF STAR NETWORK PEG-BASED GEL POLYMER ELECTROLYTES FOR ELECTROCHROMIC DEVICES

An amorphous,colorless,and highly transparent star network polymer with a pentaerythritol core linking four PEG-block polymeric arms was synthesized from the poly(ethylene glycol)(PEG),pentaerythritol,and dichloromethane by Williamson reaction.FTIR and ~1H-NMR measurement demonstrated that the polymer repeating units were C[CH_2-OCH_2O-(CH_2CH_2O)_m-CH_2O-(CH_2CH_2O)_n-CH_2O]_4.The polymer host held well mechanical properties for pentaerythritol cross-linking.The gel polymer electrolytes based on Lithium...     

Polymer Electrolytes – New Opportunities for the Development of Multivalent Ion Batteries

Batteries, as highly concerned energy conversion system, have a great development prospect in various fields, especially in the field of energy powered vehicles. Multivalent ion batteries are getting more attention due to their low cost, high abundance in earth crust, high capacity and safety compared with Lithium batteries. Despite above advantages, several problems still need to be solved before multivalent ion batteries achieve large-scale application, such as interfacial parasitic reaction, anode passivation, and dendrites. The replacement of liquid electrolytes with gel polymer electrolytes (GPEs) which pose high safety, high mechanical strength and simplified battery system, is an effective strategy to inhibit dendrite growth and improve electrochemical performance. This review mainly discusses the advantages and challenges of multivalent ion batteries including zinc, magnesium, calcium and aluminum batteries. Meanwhile, the major targets of this review are introducing the recent developments and making a summary of the future trends of GPEs in the multivalent ion batteries.     

增塑聚合物电解质电化学性能

以GBL/EC复配体系为增塑剂, PVDF HFP和PMMA为聚合物基体制备胶态聚合物电解质. 研究聚合物电解质的离子传输特性和电化学稳定性. 实验表明,室温离子电导率达到 1. 2mS·cm-1, 电化学稳定窗口在 4. 5V以上. 以GBL/EC增塑聚合物电解质与表面经修饰的锂金属电极组成锂金属聚合物电池,其电极稳定性较好,充放电循环寿命得到很大的提高.