关键词： Solid polymer electrolytes   Polyhedral oligomeric silsesquioxane (PUSS)   Organic/inorganic hybrid materials  

摘要： A series of composite electrolytes (CEs) consisting of organic/inorganic hybrid star-shaped polymer (SPP13), plasticizer (PEG-functionalized PUSS derivatives), and lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) were prepared to investigate the effects of the composite compositions and PEG chain length of PEs on the properties of CEs. SPP13 was prepared via ATRP from poly(ethylene glycol) methyl ether methacrylate (PEGMA) and methacryl-cyclohexyl-POSS (MA-PUSS) using an octafunctional initiator, and the PEG-functionalized PUSS derivatives were synthesized by the hydrosilylation reaction of octakis(dimethylsilyloxy)silsesquioxane (OHPS) and allyl-PEG. The CEs were found to be dimensionally-stable enough to separate the electrodes in batteries, but they still possessed high mobility of ion-conducting P(PEGMA) segments, as estimated by the low glass transition temperatures (T-g). The CEs having solid-state show quite high ionic conductivity (4.5 x 10(-5) S cm(-1) at 30 degrees C) which is about three times of magnitude larger than that of the matrix polymer (SPP13) electrolyte (1.5 x 10(-5) S cm(-1) at 30 degrees C). The CEs were electrochemically stable up to +4.2 V without the decomposition of electrolytes. An all-solid-state lithium battery prepared from the CEs exhibited larger discharge capacity than that prepared from the SPP13 electrolyte at 60 degrees C. (C) 2013 Elsevier Ltd. All rights reserved.

关键词： 锂电池   聚氧化乙烯   聚合物电解质   复合材料   复合聚合物电解质  

摘要： 介绍了锂电池用聚氧化乙烯(PEO)基固态聚合物电解质的研究进展,论述了国内外在PEO改性、锂盐改进和制备PEO-无机复合聚合物电解质等三方面在提高其电导率、电化学稳定窗口和离子迁移数等性能进行的研究,综述了PEO基聚合物电解质的应用情况。

关键词： atomic force microscopy   catalysis   differential scanning calorimetry   ionic conductivity   phase separation   polymer blends   polymer electrolytes   polymer films   polymerisation   secondary cells   solid electrolytes   transmission electron microscopy   voltammetry (chemical analysis)  

摘要： A star-shaped copolymer, poly (styrene)-block-poly[poly(ethylene glycol) methyl ethyl methacrylate (PS-block-PPEGMA(2))(8), was synthesized by the combination of living anionic polymerization of styrene and ruthenium-catalyzed living radical polymerization of poly(ethylene glycol) methyl ether methacrylate. The prepared star- shaped copolymer was characterized to evaluate its use as a solid polymer electrolyte (SPE) in lithium-ion batteries. The star polymer comprised a hard, condensed poly (styrene) part at the center, which enhanced the mechanical properties of the solid-state polymer, and a soft, mobile poly[poly(ethylene glycol) methyl ethyl methacrylate] (PPEGMA) outer part that was responsible for the high ionic conductivity of the SPE. The design of this star polymer resulted in a well-ordered spherical microphase separation structure, in which the individual star polymers were systematically ordered to form the PPEGMA continuous phase distinctly observed in transmission electron microscopy and atomic force microscopy images. The SPE containing the lithium bis (pentafluoroethanesulfonyl) imide salt exhibited high ionic conductivities due to the unique morphology of the polymer;the ionic conductivity of this salt was 10(-4) S cm(-1) at 30 degrees C and 10(-5) S cm(-1) at 5 degrees C at [Li ]/[EO] = 0.03. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3129245] All rights reserved.

关键词： rechargeable lithium batteries   composite solid-state polymer electrolyte   PEO   SBA-15   interfacial stability  

摘要： Functionalized molecular sieve SBA-15 with trimethylchlorosilane was used as an inorganic filler in a poly(ethyleneoxide) (PEO) polymer matrix to synthesize a composite solid-state polymer electrolyte (CSPE) using LiClO4 as the doping salts, which is designated to be used for rechargeable lithium batteries. The methyl group-functionalized SBA-15 ((f)SBA-15) powder possesses more hydrophobic characters than SBA-15, which improves the miscibility between the (f)SBA-15 filler and the PEO matrix. The interaction between the (f)SBA-15 and PEO polymer matrix was investigated by scanning electron microscopy, X-ray diffraction, and differential scanning calorimetry. Linear sweep voltammetry and electrochemical impedance spectroscopy were employed to study the electrochemical stability windows, ionic conductivity, and interfacial stability of the CSPE. The temperature dependence of the change of the PEO polymer matrix in the CSPE from crystallization to amorphous phase was surveyed, for the first time, at different temperature by Fourier transform infrared emission spectroscopy. It has demonstrated that the addition of the (f)SBA-15 filler has improved significantly the electrochemical compatibility of the CSPE with a lithium metal electrode and enhanced effectively the ion conductivity of the CSPE.

关键词： Lithium batteries  

摘要： Solid polymer nanocomposite electrolytes composed of polyethylene oxide (PEO) macromolecules, LiN(CF3SO2)(2) (LiTFSI) and polyether-grafted nano-ZnO (designated ZnO(PEGME)), are prepared and characterized in comparison with the prototypical PEO-LiTFSI film and that doped with conventional acetate group modified ZnO nanoparticles (designated ZnO(Ac)). High resolution transmission electron microscopic (HRTEM) results show that ZnO nanoparticles are dispersed homogeneously in the present PEO-LiTFSI-ZnO(PEGME) films, while those particles in PEO-LiTFSI-ZnO(Ac) aggregate badly. Atomic force microscopic (AFM) analyses prove that after storage at room temperature for a month, PEO-LiTFSI forms large dendrites while only a small amount of tiny crystals can be observed in the PEO-LiTFSI-ZnO(PEGME) film. In contrast, ZnO(Ac) particles agglomerate around the PEO-LiTFSI dendrites and separate from the original phase. This is the first direct observation on the micromorphology of the SPE films after long-term storage, which elucidates why the PEO LiTFSI-ZnO(PEGME) electrolyte is much more stable than its counterparts. Conductivity evolutions, Li+ transport number measurements and cycle performances of the above-mentioned three typical films in all-solid-state lithium batteries also suggest that the structural merits of the polyether-grafted nanoparticles render this type of SPEs attractive in the future applications.

关键词： 锂电池   聚合物   固态电解质  

摘要： 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.

摘要： Several methods have been developed to dimensionally stabilize polymer electrolytes based on poly-[bis((methoxyethoxy)ethoxy)phosphazene] (MEEP). In contrast to the poor dimensional stability exhibited by complexes of MEEP with most Li salts, those prepared with LiAlCl4 have been isolated as the first example of free-standing MEEP-(LiX)n films. The mechanical properties of dimensionally unstable MEEP-(LiX)n complexes can be significantly improved by forming composites with polymers such as poly(ethylene oxide), poly(propylene oxide), poly(ethylene glycol diacrylate) and poly(vinylprrolidinone). The conductivity of 6.7 x 10(-5) OMEGA-1 cm-1 at 25-degrees-C exhibited by 55 wt% MEEP/45 wt% PEO-[LiN(CF3SO2)2]0.13 is among the highest values reported to date for a dimensionally stable electrolyte. The preparation and conductivity, calorimetric, and electrochemical studies of these electrolytes are described. Cyclic voltammetric data indicated that they are anodically stable at least up to 4.5 V versus Li+/Li. They have shown excellent compatibility with Li metal, making them suitable for use as Li+ conductive solid electrolytes in solid-state Li batteries. Li/TiS2 solid-state cells utilizing some of these electrolytes have exceeded 200 cycles.