Characterization of plasticized PMMA-LiBF4 based solid polymer electrolytes

Polymer electrolyte films prepared from poly(methyl methacrylate) and LiBF₄ with different concentrations of plasticizer (DBP) are described. The formation of polymer-salt complex has been confirmed by FTIR spectral studies. The temperature dependence of conductivity of polymer films seems to obey the VTF relation. Values of conductivities of the polymer complexes are presented and discussed.     

Correlation between ionic conductivity and fluidity of polymer gel electrolytes containing NH4CF3SO3

Nonaqueous polymer gel electrolytes containing ammonium triflate (NH₄CF₃SO₃) and dimethylacetamide (DMA) with polymethylmethacrylate (PMMA) as the gelling polymer have been synthesized which show high value of conductivity (~ 10^-2 S/cm) at 25°C. The conductivity of polymer gel electrolytes containing different concentrations of NH₄CF₃SO₃ shows a small decrease with the addition of PMMA and this has been correlated with the variation of fluidity of these gel electrolytes. The small decrease in conductivity with PMMA addition shows that polymer plays the role of stiffener and this is supported by FTIR results which also indicates the absence of any active interaction between polymer and NH₄CF₃SO₃ in these gel electrolytes.     

Performance characteristics of guanine incorporated PVDF-HFP/PEO polymer blend electrolytes with binary iodide salts for dye-sensitized solar cells

In this work, we have investigated the influence of guanine as an organic dopant in dye-sensitized solar cell (DSSC) based on poly(vinylidinefluoride-co-hexafluoropropylene) (PVDF-HFP)/polyethylene oxide (PEO) polymer blend electrolyte along with binary iodide salts (potassium iodide (KI) and tetrabutylammonium iodide (TBAI)) and iodine (I₂). The PVDF-HFP/KI + TBAI/I₂, PVDF-HFP/PEO/KI + TBAI/I₂ and guanine incorporated PVDF-HFP/PEO/KI + TBAI/I₂ electrolytes were prepared by solution casting technique using DMF as solvent. The PVDF-HFP/KI + TBAI/I₂ electrolyte showed an ionic conductivity value of 9.99 × 10⁻⁵ Scm⁻¹, whereas, it was found to be increased to 4.53 × 10⁻⁵ Scm⁻¹ when PEO was blended with PVDF-HFP/KI + TBAI/I₂ electrolyte. However, a maximum ionic conductivity value of 3.67 × 10⁻⁴ Scm⁻¹ was obtained for guanine incorporated PVDF-HFP/PEO/KI + TBAI/I₂ blend electrolyte. The photovoltaic properties of all these polymer electrolytes in DSSCs were characterized. As a consequence, the power conversion efficiency of the guanine incorporated PVDF-HFP/PEO/KI + TBAI/I₂ electrolyte based DSSC was significantly improved to 4.98% compared with PVDF-HFP/PEO/KI + TBAI/I₂ electrolyte based DSSC (2.46%). These results revealed that the guanine can be an effective organic dopant to enhance the performance of DSSCs.     

Electromagnetic interference shielding properties of polymer derived SiC-Si_3N_4 composite ceramics

SiC-Si₃N₄ composite ceramics are successfully fabricated by pyrolysis of ferrocene-modified polycarbosilane (PCS) mixed with inert filler Si₃N₄ powders, followed by thermal treatment from 1100 °C to 1400 °C in Ar atmosphere. The porosity of SiC-Si₃N₄ ceramics decreases to 6.4% due to the addition of inert filler Si₃N₄. And the content and crystallization degree of free carbon and SiC derived from PCS are improved simultaneously with the increase of thermal treatment temperature. Finally, the free carbon and SiC interconnect, forming the conductive network. As a result, the electromagnetic interference (EMI) shielding performance of the as-prepared ceramic annealed at 1400 °C reaches up to 36 dB, meaning more than 99.9% of EM energy is shielded. The low porosity and high EMI shielding performance enable SiC-Si₃N₄ composite ceramics to be a promising electromagnetic shielding and structural material.     

Effect of MnO2 on the electrical conductivity of ZrO2

Electrical conductivity of ZrO₂ doped with MnO₂ has been measured at various temperatures for different molar ratios. The conductivity increases due to hopping of oxygen into neighboring vacancies, created by doping. Increase in temperature increases the rate of hopping, which results in the rise in conductivity and after attaining a maximum the conductivity, decrease due to collapse of the fluorite framework. All compositions show phase transition in ZrO₂ from monoclinic to tetragonal at 746 K. The XRD, DTA, and FT-IR studies were carried out for confirming the doping effect and transition in ZrO₂. The text was submitted by the authors in English.     

Effect of complexing salt on conductivity of PVC/PEO polymer blend electrolytes

Solid polymer electrolyte membrane comprising poly(vinyl chloride) (PVC), poly(ehylene oxide) (PEO) and different lithium salts (LiClO₄, LiBF₄ and LiCF₃SO₃) were prepared by the solution casting technique. The effect of complexing salt on the ionic conductivity of the PVC/PEO host polymer is discussed. Solid polymer electrolyte films were characterized by X-ray diffraction, FTIR spectroscopy, TG/DTA and ac impedance spectroscopic studies. The conductivity studies of these solid polymer electrolyte (SPE) films are carried out as a function of frequency at various temperatures ranging from 302 K to 353 K. The maximum room temperature ionic conductivity is found to be 0·079 × 10^?4 S cm^?1 for the film containing LiBF₄ as the complexing salt. The temperature dependence of the conductivity of polymer electrolyte films seems to obey the Vogel-Tamman-Fulcher (VTF) relation.     

空心玻璃微珠对PMMA/SAN共混体系相分离的影响

运用小角激光光散射(SALS)和透射电镜(TEM)等测试方法,考察了空心玻璃微珠(HGB)的含量及粒子尺寸对PMMA/SAN共混体系相分离的影响。结果表明,微米级粒子HGB粒子的填充不影响聚合物基体的相分离机理,填充和未填充体系的相行为均遵循spinodal(SD)相分离机理,但HGB粒子对组成不同的PMMA/SAN共混物基体会产生不同程度的诱导作用。HGB粒子的加入会使60/40PMMA/SAN基体相分离初期的扩散系数降低,减缓了相分离进程。微米级HGB粒子的加入对共混物基体的相形态与结构影响不显著。     

聚合物凝胶电解质在镍氢电池中的应用

研究了一系列交联聚丙烯酸与KOH形成的水凝胶电解质的电化学特性。研究表明,聚合物凝胶电解质具有和KOH水溶液十分接近的离子电导率和稳定的电化学窗口,而且用聚合物凝胶电解质制作的Ni／MH试验电池具有更好的充放电循环特性。扫描电镜研究也证明,使用聚合物凝胶电解质的电池正负极材料腐蚀较小,没有明显的粉化,因此在Ni／MH电池领域将有广阔的应用前景。     

Conductivity studies on poly(methyl methacrylate)–Li2SO4 polymer electrolyte systems

Thin-film ion-conducting polymer electrolytes based on poly(methyl methacrylate) (PMMA) complexed with Li₂SO₄ have been prepared using the solution casting technique. The complexation of salt with PMMA was confirmed by structural and thermal studies. The results of the electrical conductivity measurements in these electrolytes are reported. A Vogel–Tammann–Fulcher-like temperature dependence of ionic conductivity implies coupling of the ion movement with the segmental motion of the polymer chains in the cross-linked environment. Predominant formation of contact ion pairs of Li₂SO₄ has been consistently observed through conductivity, X-ray diffraction, Fourier transformation and thermal analysis studies.     

Composite electrolytes of polyethylene glycol methyl ether and TiO2 for dye-sensitized solar cells—Effect of heat treatment

For solid-state dye-sensitized solar cells (DSSCs), a composite electrolyte of polyethylene glycol methyl ether (PEGME) and titania (TiO₂) nanoparticles was prepared and characterized by Fourier transform-infra red (FT-IR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and Raman spectroscopy. The heat treatment on PEGME and TiO₂ composite was found to be an essential step to improve morphology, amorphicity and ionic conductivity of PEGME–TiO₂ composite electrolytes. It was attributed to the increased bond strength of OC–O–Ti between PEGME and TiO₂ and increased surface roughness of composite materials, which may help to absorb a large amount of iodide couple and effective generation of I₃⁻ ions. A DSSC fabricated with heat treated PEGME–TiO₂ composite electrolyte showed significantly enhanced overall conversion efficiency of 3.1%, which was 20% higher than that of the DSSC fabricated with bare PEGME–TiO₂ composite electrolyte.     

增塑剂对聚合物电解质性能的影响

对PVB＋LiClO4 PC组成的聚合物电解质体系,探讨了增塑剂PC对聚合物电解质性能的影响。随着增塑剂浓度的增加,聚合物电解质的玻璃化转变温度下降,加快了高分子的链段运动,使聚合物的电导率增加;同时,PC也起到了溶剂化的作用,使LiClO4的溶解度增大。但PC浓度的增加,使聚合物电解质为力学性能下降。     

Effect of ion bombardment on the optical properties of LDPE/EPDM polymer blends

Ion bombardment is a suitable tool to improve the physical properties of polymers. In the present study, the effect of ion bombardment on the optical properties of low density polyethylene (LDPE)/Ethylene propylene diene monomer (EPDM) blend (LDPE/EPDM) was studied. Polymer samples was bombarded with 130 keV He and 320 keV Ar ions at fluencies levels ranging from 1 × 10¹³ to 2 × 10¹⁶ ions/cm². The untreated and ion beam bombarded samples were investigated using ultraviolet-visible (UV-Vis) spectrophotometry. The optical band gap (E_g), was decreased from ∼2.9 eV for the pristine sample down to 1.7 eV for the samples bombarded with He and Ar ions at the highest fluences. Change in the optical gap indicates the presence of a gradual phase transition for the polymer blends. Activation energy has been investigated as a function of the ion fluences. With increasing ion fluence, a decrease in both the energy gap and the activation energy was observed. The number of carbon atoms (N) in a formed cluster is determined according to the modified Tauc's equation.     

苯基硅树脂改性锂离子电池聚合物电解质的电导率和热稳定性

通过水解缩聚法合成苯基硅树脂微球(PPSQ),使用TEM、TGA、XRD、XPS等方法对PPSQ进行表征,结果表明,PPSQ的结构规整,粒径分布均匀,且耐热性能非常优异;以聚(甲基丙烯酸甲酯-醋酸乙烯酯)[P(MMA-VAc)]为基体制备PPSQ/P(MMAVAc)凝胶型聚合物电解质,研究了PPSQ的加入对聚合物电解质性能产生的影响。热失重测试和电导率测试结果表明,当PPSQ含量达到7%(质量分数)时,体系的热失重曲线向高温方向偏移,同时电导率也达到最大值3.17×10-5S/cm,聚合物电解质的综合性能达到最佳。     

锂离子电池用固态偏氟乙烯-六氟丙烯共聚物电解质的研究进展

固体聚合物电解质具有质轻、安全、易加工等优点,在锂离子电池中具有极大的应用价值.综述了以偏氟乙烯-六氟丙烯(PVDF-HFP)共聚物为基的聚合物电解质的研究工作,介绍了PVDF-HFP固体电解质的制备方法,分析了影响此聚合物电解质性能的因素,并讨论了PVDF-HFP电解质的改性措施,对今后的发展方向作了简要展望.     

聚离子液体型聚合物电解质的制备及表征

以N-乙烯基咪唑、溴乙酸甲酯和二（三氟甲基磺酰亚胺）锂（LiTFSI）为原料,采用溶液聚合法制备了聚（1-乙烯基-3-乙酸甲酯基咪唑二（三氟甲基磺酰亚胺））（PMVIm-TFSI）。将其与LiTFSI和聚（甲基丙烯酸甲酯-醋酸乙烯酯）（P（MMA-VAc））共混制得了不同质量比的聚合物电解质。核磁共振（1 HNMR）、红外光谱（FT-IR）、示差扫描量热计（DSC）、热重分析（TGA）、X射线衍射（XRD）、扫描电镜（SEM）、交流阻抗（AC impedance）等对电解质的测试结果表明,PMVIm-TFSI掺杂到P（MMA-VAc）和LiTFSI组成的电解质中后其电导率得到了极大的改善,30℃下最高可达4.71×10-4S/cm,同时热稳定性也得到了极大的提高。此外,该共混电解质（透过率≥90%）还可以运用到电致变色器件（ECD）导电离子材料中,也显示出了优良的电化学性能。     

Integration of polymer electrolytes in dye sensitized solar cells by initiated chemical vapor deposition

The mesoporous titanium dioxide electrode of dye sensitized solar cells (DSSC) has been successfully filled with polymer electrolyte to replace the conventional liquid electrolyte. Polymer electrolyte was directly synthesized and deposited using the initiated chemical vapor deposition (iCVD) process, and an iodide-triiodide redox couple in different redox solvents was then incorporated into the polymer. We have investigated different candidate polymer electrolytes, including poly(2-hydroxyethyl methacrylate) (PHEMA). The open circuit voltage of cells fabricated with iCVD PHEMA was found to be higher when compared with a liquid electrolyte that is attributed to a lower rate of electron recombination.     

石墨烯基聚合物复合电解质的设计、性能及其应用研究进展

固态电化学器件具有柔性好、安全性能高及能量密度高等优点,属于极有前景的新一代化学能源器件.固态电解质是实现电化学器件固态化的关键,其中石墨烯基聚合物复合电解质由传统聚合物电解质发展而来,是一类含有石墨烯纳米填料和聚合物基体的新型固态电解质,具有较高的离子电导率、良好的加工性能及优异的界面特性,现已成为固态电化学器件研发...     

ZrO2的加入对(CeO2)0.86(SmO1.5)0.14陶瓷性能的影响

探讨了添加 ＺｒＯ_２对 ＣｅＯ_２／Ｓｍ_２Ｏ₃体系电导率和力学性能的影响,并用 ＸＲＤ、ＳＥＭ等对材料的微观性能进行了试验分析．结果发现,添加 ＺｒＯ_２使材料的电导率降低,主要是因为ＺｒＯ_２的固清使得ＣｅＯ_２电解质材料的晶格常数减小,活化能增加造成的;添加 ＺｒＯ_２可提高材料的断裂强度,使材料断裂以穿晶断裂为主,其原因可能是ＺｒＯ_２的固溶强化了晶界;添加 ＺｒＯ_２促进了致密烧结,使晶界结合紧密．实验确定,外加 ２．５ｍｏｌ％ ＺｒＯ_２的 ＣｅＯ_２电解质具有适中的强度和电导率,可以作为电解质材料应用．