液晶离聚物/PMMA多孔电解质膜

针对聚合物电解质膜电导率低、力学性能差的问题,用一种含磺酸基团的液晶离聚物(LCI)、聚甲基丙烯酸甲酯( PMMA)、高氯酸锂(LiCIO4)用溶液共混法制成多孔电解质膜.采用磺酸基团作为传输锂离子的体系,N-甲基吡咯烷酮(NMP)为增塑剂.孔隙率测定和扫描电镜表明:膜为多孔状结构,孔隙率为16.4％～29.3％.孔径...     

液晶离聚物/聚苯胺导电复合材料的研究

采用溶液共混,直接共混稀盐酸掺杂二种方法,制备出液晶离聚物(LCI)与聚苯胺(PAn)导电复合材料。红外光谱结果表明醌环模式振动红移了11 cm-1,峰形变宽,是-SO3-吸电子基团作用;DSC结果表明溶液共混复合材料为均相,且复合材料相容性增强;透射电镜结果表明溶液共混复合材料均匀分散且达到纳米级;交流阻抗结果表明直接共混HCl掺杂复合材料,LCI含量为10%时电导率最大为4.26×10-3 S/cm。     

全固态锂电池用聚合物电解质的研究

用碳酸乙烯酯、碳酸丙烯酯作为增塑剂制备了PEO-LiCl_4 聚合物电解质,实验结表明增塑剂不仅阻止了聚氧化乙烯结晶的生长,减小了聚合物的结晶度,降低了玻璃化温度,增加了聚合物分子链段的运动能力,而且促进了聚合物电解质中LiClO_4的电离,增加了聚合物电解质中的载流子数,因此提高了聚合物电解质的电导率.其室温下电导率可达到2X10~(-3)S/cm.讨论了改性聚合物电解质电导率提高的机理,在室温下测试了聚苯胺全固态锂电池的性能.     

PEO-LiClO4-Li4Ti5O12复合聚合物电解质性能研究

选用钛酸锂(Li4Ti5O12)纳米粒子作为填料对聚环氧乙烷(PEO)基聚合物电解质进行改性。通过交流阻抗谱(EIS),X射线衍射(XRD),扫描电镜(SEM)等手段对材料进行了表征,考察了Li4Ti5O12对聚合物电解质电化学性能的影响。研究表明,Li4Ti5O12的加入减小了聚合物的结晶度,提高了聚合物电解质的电导率,增加了聚合物中得载流子数,PEO16/LiClO4/15%Li4Ti5O12体系30℃电导率达到5.31×10-5S/cm,并初步研究了以此膜为电解质的复合锂硫电池的性能。     

溶剂对PEO基固态电解质制备与性能的影响

采用溶液浇铸法制备了PEO基聚合物固态电解质,并通过X射线衍射(XRD)、扫描电镜、交流阻抗法等方法对不同溶剂制备固态电解质的结构、形貌、电导率以及锂离子迁移数等进行分析表征。结果表明,溶剂对固态电解质的微观结构存在着较大的影响,以丙酮、乙腈为溶剂制备的固态电解质(S_A)表面致密,具有最低的结晶度,而以NMP、乙腈为溶剂制备的固态电解质(S_N)结晶度最高。固态电解质的微观结构直接决定了其机械性能和电化学性能,SA的抗拉强度为2.219 MPa,在80℃下的离子电导率可达到8.3×10~(–4)S/cm。所制备固态电解质可应用于锂离子固态电池的制备与研究中。     

PVA-PAAS基碱性聚合物电解质的制备及性能

采用溶液浇铸法制备了聚乙烯醇(PVA)-聚丙烯酸钠(PAAS)-KOH-H2O碱性聚合物电解质膜.膜的电导率与KOH和H2O含量密切相关,PAAS可明显改善PVA基碱性聚合物电解质膜的保水性能和机械性能,PAAS和KOH可使聚合物的结晶度和熔点降低.在20～50℃范围内,电解质膜的电导率与温度的关系符合Arrhenius方程.组成为PVA(以下均为质量分数)(13.84%)-PAAS(0.73%)-KOH(36.43%)-H2O(49%)电解质膜的室温电导率高达9.67×10-2S/cm,在不锈钢惰性电极上的电化学稳定电位范围约为1.6 V,可应用于活性炭超级电容器.     

一种复合聚合物电解质的性质表征

基于新的微孔膜成型工艺制备了一种复合聚合物电解质,聚合物基质为聚乙烯基吡咯烷酮(PVP)与聚偏氟乙烯(PVDF)的复合物。对所制聚合物电解质的离子迁移性质和电化学稳定性做了表征。采用稳态电流法测量了聚合物电解质中锂离子的迁移数,测试结果为0.2。利用交流阻抗技术对聚合物电解质的电导率进行测试,室温下电导率可达到1.6mS·cm-1。锂盐的扩散系数由对称电池的限制扩散法测得,结果为4.8×10-7cm2·S-1。由线性伏安扫描实验测试了该聚合物电解质体系的电化学稳定性,结果表明在5.1V以下电解质性质稳定。     

硅钨酸锂在聚合物电解质中的应用

采用萃取法制备了具有微孔结构的偏二氟乙烯-六氟丙烯共聚物[P(VDF-HFP)]膜,其中掺杂不同质量分数的硅钨酸锂(Li4SiW12O40),吸附碳酸丙烯酯(PC)后,具有10-4 S·cm-1的离子电导率。DSC分析结果显示,聚合物电解质的结晶度随Li4SiW12O40掺杂量的增加而降低。利用电化学阻抗法测试了聚合物电解质的离子电导率,发现当聚合物膜中掺杂8.5%(质量百分数)的Li4SiW12O40时,聚合物电解质具有较高的离子电导率(3.56×10-4 S·cm-1)。采用交流阻抗与直流极化相结合的方法测试了聚合物电解质的离子迁移数,随Li4SiW12O40的掺杂质量分数的增加,Li 离子迁移数逐渐降低。通过分析聚合物膜掺杂Li4SiW12O40前后的FTIR光谱图,发现Li4SiW12O40与P(VDF-HFP)共聚物分子链之间存在氢键和配位作用。     

PEO-LiXSiO2复合聚合物电解质电导率的研究

为了提高基于聚氧化乙烯(PEO)的聚合物电解质的室温电导率,以PEO为聚合物主体、LiClO4或LiN(CF3SO2)2为盐、SiO2为填充剂,以溶液浇铸法制备了它的复合聚合物电解质.电导率测试表明,PEO15LiN(CF3SO2)2-10%SiO2在30℃的电导率为4.67×10-5S/cm.     

原位制备P(VDF-HFP)/SiO_2复合聚合物电解质及其性能研究

通过倒相法原位制备P(VDF-HFP)/SiO_2复合聚合物电解质膜,将其于1.0 mol/L LiPF_6/(EC+DMC+EMC)中浸泡30 min即得复合聚合物电解质。采用扫描电子显微镜法(SEM)、X射线衍射光谱法(XRD)、线性扫描法(LSV)和交流阻抗法(EIS)分别对复合电解质的形貌、结晶度和电化学性能进行表征。SEM结果表明SiO_2溶胶原位制备的P(VDF-HFP)/SiO_2复合膜的膜层表面微孔丰富且相互连通,XRD表明其结晶度较纯P(VDF-HFP)膜减小;LSV和EIS结果表明复合膜的电化学稳定窗口为5.0 V,室温离子电导率高达3.134×10~(-3) S/cm,且其界面阻抗较直接添加SiO_2粉末制备的复合膜的920Ω下降至850Ω。     

离子液体聚合物电解质的研究进展

离子液体聚合物电解质具有电导率高、力学性能和稳定性能好等特点.综述了离子液体聚合物电解质的分类、制备方法及其在电池中的应用现状,包括含浸离子液体的聚合物电解质和聚合物分子上引入离子液体结构得到的离子液体聚合物电解质.对离子液体聚合物电解质的未来发展进行了展望.     

低温SOFC的SDC-碳酸盐复合物电解质

采用钐掺杂的氧化铈(SDC)-碳酸盐复合物作为低温固体氧化物燃料电池电解质。分别采用燃烧法和共沉淀法制备SDC,记为NSDC和CSDC。将这两种SDC分别与Li2CO3-Na2CO3二元共熔物复合制备了SDC-碳酸盐复合电解质材料。通过X射线衍射(XRD)、扫描电子显微镜(SEM)和电导率测试对两种复合电解质材料的结构、形貌和电性能进行了表征,并考察了燃料电池输出性能。结果表明,氧化物的制备方法影响复合电解质的形貌和电性能;复合大大提高了电解质的电导率,复合电解质的电导率在碳酸盐熔融点附近突然增大;NSDC-碳酸盐复合物具有更高的电导率,以H2和空气为燃料和氧化气体的电池性能测试显示,600℃时开路电压为1.02V,最大比功率为473mW/cm2。     

Substrate effect on the electrical properties of sputtered YSZ thin films for co-planar SOFC applications

The physical and electrical properties of sputtered YSZ thin films on various substrates were investigated. The in-plane electrical properties of the films were measured for evaluating YSZ thin film for co-planar SOFC electrolytes. The conductance measured on YSZ over Si substrates was significantly affected by the buffer layer thickness and exhibited higher values than that of YSZ on sapphire. This indicates that electrical leakage occurred through the substrate when Si substrates were utilized. Nevertheless, pure ionic conduction was observed in YSZ/sapphire regardless of the film thickness. It implies that much care should be taken for the selection of substrate materials in measuring or utilizing in-plane conductivity, especially for high temperature applications.     

Composite Electrolytes for Lithium Rechargeable Batteries

The paper reviews and presents attributes of emerging polymer-ceramic composite electrolytes for lithium rechargeable batteries. The electrochemical data of a diverse range of composite electrolytes reveal that the incorporation of a ceramic component in a polymer matrix leads to enhanced conductivity, increased lithium transport number, and improved electrode-electrolyte interfacial stability. The conductivity enhancement depends upon the weight fraction of the ceramic phase, annealing parameters, nature of polymer-ceramic system, and temperature. The ceramic additive also increases the effective glass transition temperature and thus decouples structural and electrical relaxation modes which in turn increases the lithium transport number. The ceramic additives also provide a range of free energy of reactions with lithium. A few of the ceramic materials (MgO, CaO, Si₃N₄) have positive free energy of reaction and they should not passivate lithium electrodes.     

Preparation, microstructure and electrical properties of Li1.4Al0.4Ti1.6(PO4)3 nanoceramics

NASICON-type Li_1.4Al_0.4Ti_1.6(PO₄)₃ solid electrolytes were prepared by various processes, such as crystallization of glasses, spark plasma sintering (SPS) and conventional sintering process from nanosized precursor powders synthesized by a sol–gel route. The experimental results showed that grain size and relative density were the main factors determining the ionic conductivity of the bulk materials. The SPS technique produced ceramics with nearly 100% of the theoretical density. Maximum room temperature conductivities, 1.39?×?10^?3 S cm^?1 and 1.12?×?10^?3 S cm^?1 of grain boundary conductivity and total conductivity, respectively were obtained which were the highest values for Li⁺ inorganic oxide conductors as reported. Crystallization of ceramics from a glass was also certified as a favorable route to fabricate a bulk material with high conductivity.     

A case study of replacing steam turbines with LCI-typevariable-speed drives

The problems and experiences associated with the installation, start-up, and operation of 7000 HP 1800 r/min and 3600 HP 6000 r/min synchronous motors using load commutated inverter (LCI) variable-speed controllers are examined. The application of new technology in existing process units can present some unusual and sometimes perplexing challenges. The steep learning curve, and the fact that most projects are time and money driven, all contribute to the hurdles that must be overcome. The described application of LCI variable-speed drives covered all of the factors. Some of the problems and concerns encountered with this project resulted from equipment previously installed, coupled with the dynamics of the electrical, instrumentation, and process systems. When planning the application of variable-speed drives, factors such as electrical system disturbances, impact of harmonics on the existing equipment, training, commissioning, operator acceptance, craft training, and spare parts all need to be taken into consideration     

AN、DME对锂电池电解液电导率的影响

研究了乙腈(AN)和乙二醇二甲醚(DME)对六氟磷酸锂(LiPF6)电解液电导率的影响.结果表明:在同一温度下,电导率随AN添加量的增加而增大,而DME的添加则使电导率先增加后趋于稳定.在AN和DME添加量一定的情况下,电导率均随温度的升高而增大.电导率与物质的量比和温度之间的关系分别可用函数δ=A+B1x+B2x2和...     

Mixed Electronic-Ionic Conductivity of Cobalt Doped Cerium Gadolinium Oxide

The effect of small amounts (<5 mol %) of cobalt oxide on the electrical properties of cerium oxide solid solutions has been evaluated. Ce_0.8Gd_0.2O_2-x (CGO) powder with an average crystallite size of 20 nm served as a model substance for the electrolyte material with a high oxygen ion conductivity and low electronic conductivity in its densified state. Doping the CGO powder by transition metal oxides (MeO) with concentrations below 2 mol % did not change the ionic conductivity nor the electrolytic domain boundary. After long sintering times (2 h) at temperatures above 900°C, MeO and CeO₂ form solid solutions. However, short sintering times or high dopant concentrations lead to an electronic conducting grain boundary phase short circuiting the ionic conductivity of the CGO grains. Choosing proper doping levels, sintering time and temperature allows one to tailor mixed conducting oxides based on CGO. These materials have potential use as electrolytes and/or anodes in solid oxide fuel cells and ion separation membranes.