PEO与Li1.3Al0.3Ti1.7(PO4)3络合的离子导体聚合物电解质

将实验室经固相反应的精细Li1．3Al0．3Ti1．7(PO4)3盐与聚氧化乙烯(PEO)按照不同，nEO／nLi摩尔比，通过溶液浇铸法制备了固态聚合物电解质。红外光谱分析表明Li1．3Al0．3Ti1．7(PO4)3盐与PEO之间有络合产生。SEM照片显示PEO晶体外层为无定形相所包覆形成的胞状结构。经电化学阻抗(简称EIS)法测试发现聚合物电解质膜的室温阻抗谱图是由高频处一压缩的半圆和低频下一条直线组成，而高温时的阻抗谱主要为一条直线。离子电导率的测试结果得到：当nEO／nLi=16时，聚合物电解质室温下电导率约为10^-6／cm，343K时达到10^-4s／cm。离子迁移率的数据表明聚合物电解质为离子和电子共混的导体，但在聚合物电解质体系中电荷的迁移主要是由离子作为载流子导电造成的，由测试结果可得此电解质为离子导体。     

Sol-gel synthesis of Li1.3Al0.3Ti1.7(PO4)3 solid electrolyte

A modified sol-gel process was studied as applied to synthesize a lithium-conducting solid electrolyte of composition Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP) using water-soluble salts Al(NO₃)₃ · 9H₂O, LiNO₃ · 3H₂O, and (NH₄)₂HPO₄ and a titanium(IV) citrate complex. As-synthesized samples were characterized using X-ray powder diffraction, DSC/TG, SEM, and impedance spectroscopy. Sintering of as-synthesized amorphous powders at 700°C was found to yield LATP with crystallite sizes of 42–48 nm. Ionic conductivity of the electrolyte measured in the frequency range 25–10⁶ Hz in disks having 86–90% density that were sintered at 1000°C was (3–4) × 10^?4 S/cm. Temperature-dependent ionic conductivity was studied in the range 25–200°C. The activation energy of conduction was determined for LATP.     

PEO-LiClO_4-ZSM5 composite polymer electrolyte (IV): Polarized optical microscopy study

All solid-state lithium polymer batteries may be one of the best choices for the future electrochemical power source, characterized by high energy densities, good cyclability, reliability and safety[1,2]. Owing to its potential capability to replace the t…     

Li1.3Ti1.7Al0.3(PO4)3与Na+的离子交换

锂离子传导材料Li_1.3Ti_1.7Al_0.3(PO₄)₃是具有NASICON结构的功能材料, 与Na⁺进行离子交换具有选择性高的特性. 研究了在不同温度条件下NaCl和LiCl水溶液中Li_1.3Ti_1.7Al_0.3(PO₄)₃上的Na/Li离子交换行为. 实验结果表明, 升高温度能显著提高Li_1.3Ti_1.7Al_0.3(PO₄)₃的Na/Li交换反应速率, 提高LiCl中杂质Na的分离效果.     

PEO-LiClO<Subscript>4</Subscript>-ZSM5 composite polymer electrolyte (IV): Polarized optical microscopy study

Polarized optical microscopy (POM) results show that ZSM5 has great influence on both the nucleation stage and the growth stage of PEO spherulites. Part of ZSM5 particles can act as the nucleus of PEO spherulites and thus increase the amount of PEO spherulites. On the other hand, ZSM5 can restrain the recrystallization tendency of PEO chains through Lewis acid-base interaction and hence decrease the growth speed of PEO spherulites. The increasing amount of PEO spherulites, decreasing size of PEO spherulites, and the incomplete crystallization are all beneficial for creating more continuous amorphous phases of PEO, which is very important for the transporting of Li⁺ ions. An adequate amount of ZSM5 can enhance the room temperature ionic conductivity of PEO-LiClO₄ based polymer electrolyte for more than two magnitudes.     

Ionic transport studies on (PEO)6:NaPO3 polymer electrolyte plasticized with PEG400

Conduction characteristics of the poly(ethylene oxide) based new polymer electrolyte (PEO)₆:NaPO₃, plasticized with poly(ethylene glycol) are investigated. Free standing flexible electrolyte films of composition (PEO)₆:NaPO₃ + x wt.% PEG₄₀₀ (30 ? x ? 70) are prepared by solution casting method. A combination of X-ray diffraction (XRD), optical microscopy and differential scanning calorimetry (DSC) studies have indicated enhancement in the amorphous phase of polymer due to the addition of plasticizer. Further, a reduction in the glass transition temperature observed from the DSC result has inferred increase in the flexibility of the polymer chains. The cationic transport number (t_Na⁺) of 0.42 determined through combined ac-dc technique has confirmed ionic nature of conducting species. Ionic conductivity studies are carried out as a function of composition and temperature using complex impedance spectroscopy. The electrolyte with maximum PEG₄₀₀ content has exhibited an enhancement in the conductivity of about two orders of magnitude compared to the host polymer electrolyte. The complex impedance data is analyzed in conductivity, permittivity and electric modulus formalism in order to throw light on transport mechanism. A solid state electrochemical cell based on the above polymer electrolyte with a configuration Na|SPE|(I₂ + acetylene black + PEO) has exhibited an open circuit voltage of 2.94 V. The discharge characteristics are found to be satisfactory as a laboratory cell.     

偶联剂原位改性SiO2提高PEO/LiClO4/SiO2电导率

偶联剂原位改性SiO2提高PEO/LiClO4/SiO2电导率;PEO;聚合物电解质;偶联剂;SiO2;电导率     

Preparation and characterization of a new polymer electrolyte (PEO:NaClO3) for battery application

A new sodium-ion conducting thin-film polymer electrolyte based on the poly(ethylene oxide) (PEO) system has been prepared by a solution-casting method. Characterization by XRD, IR, and AC conductivity and Wagner's polarization were carried out on these thin-film electrolytes. From the transference number experiment it was found that the charge transport in these electrolytes is mainly due to ions. Conductivity studies show that the conductivity value of the PEO:NaClO₃ complex increases with the increase of salt concentration. An increase in the conductivity and a change in the cell parameters for the electrolyte system were found by the addition of the low molecular weight dimethylformamide or propylene carbonate as plasticizers. The cell parameters of these electrolyte systems were measured from a discharge study of the cell with the application of a load of 100 kΩ at room temperature in the common cell configuration Na|electrolyte|MnO₂. The open circuit voltage ranges from 2.02 V to 2.46 V and the short circuit current ranges from 570 μA to 1030 μA. Electronic Publication     

Melt crystallization and segmental dynamics of poly(ethylene oxide) confined in a solid electrolyte composite

The isothermal melt crystallization and the corresponding segmental dynamics, of a high molecular weight poly(ethylene oxide) (PEO) confined by Li₇La₃Zr₂O₁₂ (LLZO) particles in solid electrolyte composites, were monitored by differential scanning calorimetry (DSC) and dielectric relaxation spectroscopy (DRS), respectively. Our results show that the overall crystallinity is positively correlated with the surface area of LLZO particles. The primary and secondary crystallization processes are identified by a modified Avrami equation, while two dynamic modes, the α relaxation and α′ relaxation, were in the DRS measurements. The results reveal an unambiguous correlation between the primary crystallization and the α relaxation, while a correlation between the second crystallization and the α′ relaxation concurrently exist in the electrolyte composites. © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020 , 58, 466–477     

Single-ion and salt conductor polymer electrolytes based on poly(4-vinylpyridine) quaternized with poly(ethylene oxide) side chains

A new type of single-ion conductor with fixed cation was synthesized by spontaneous anionic polymerization of 4-vinylpyridine in the presence of short polyethylene oxide ( PEO ) chains as alkylating agents. These comblike polymers have low T_gs and are amorphous with the shorter PEO s. Their conductivities are unaffected by the nature of the anion ( Br ⁻, ClO ₄⁻, and tosylate) and are controlled by the free volume and the mobility of the pendant cation. By comparison of the results at constant free volume, it is shown that the charge density decreases with the increasing length of pendant PEO demonstrating that PEO acts only as a plasticizing agent. Best conductivity results (σ = 10⁻⁵ S cm⁻¹ at 60°C) are obtained with PEO side chains of molecular weight 350. With this sample, the conductivity in the presence of various amounts of added salt (LiTFSI) was studied. A best value of 10⁻⁴ S cm⁻¹ at 60°C is obtained with a molar ratio EO/Li of 10. It is shown that, over the range of examined concentrations (0.2–1.3 mol Li kg⁻¹), the reduced conductivity σ_r/c increases linearly with increasing salt concentration showing that the ion mobility increases continuously. Such behavior is quite unusual since in this concentration range a maximum is generally observed with PEO systems. To interpret this result and by analogy with the behavior of this type of polymer in solution, it is proposed that the conformation of these polymers in the solid state is segregated with the P4VP skeleton more or less confined inside the dense coils surrounded by the PEO side chains. Under the influence of the increasing salt concentration, this microphase separation vanishes progressively: The LiTFSI salt exchanges with the tosylate anions and acts as a miscibility improver agent. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2719–2728, 1997     

Li1.5Al0.5Ge1.5(PO4)3基固体复合电解质的制备及锂离子导电行为

将聚氧化乙烯(PEO)和二(三氟甲基磺酰)亚胺锂(LiTFSI)混合(固定EO/Li摩尔比为13)后, 采用溶液浇注法制备了一系列不同Li_1.5Al_0.5Ge_1.5(PO₄)₃(LAGP)与PEO质量比的LAGP-PEO(LiTFSI)固体复合电解质体系. 结合电化学阻抗法、 表面形貌表征以及与惰性陶瓷填料(SiO₂, Al₂O₃) 性能的对比分析, 探讨了LAGP在固体复合电解质中的作用机理以及锂离子的导电行为. 结果表明, 在以LAGP为主相的固体复合电解质中, PEO主要处于无定形态, 整个体系主要为PEO与LiTFSI的络合相、 LAGP与PEO(LiTFSI)相互作用形成的过渡相和LAGP晶相. 其中LAGP作为主要的导电基体不仅起到降低PEO结晶度、 改善两相导电界面的作用; 同时自身也可以作为离子传输的通道, 降低锂离子迁移的活化能, 从而使离子电导率得到提高. 当LAGP与PEO的质量比为6:4时, 固体复合电解质的成膜性能最好, 离子电导率最高, 在30 ℃时为2.57×10^-5 S/cm, 接近LAGP的水平, 电化学稳定窗口超过5 V.     

The effect of crosslinked networks with poly(ethylene glycol) on sulfonated polyimide for polymer electrolyte membrane fuel cell

To investigate the effect of crosslinking by a hydrophilic group on a sulfonated polyimide electrolyte membrane, sulfonated polyimide end‐capped with maleic anhydride was synthesized using 1,4,5,8‐naphthalenetetracarboxylic dianhydride, 4,4′‐diaminobiphenyl, 2,2′‐disulfonic acid, 2‐bis [4‐(4‐aminophenoxy)phenyl] hexafluropropane and maleic anhydride. The sulfonated polyimides end‐capped with maleic anhydride were self‐crosslinked or crosslinked with poly(ethylene glycol) diacrylate. A series of the crosslinked sulfonated polyimides having various ratios of sulfonated polyimide and poly(ethylene glycol) diacrylate were prepared and compared with uncrosslinked and self‐crosslinked sulfonated polyimides. The synthesized sulfonated polyimide films were characterized for FTIR spectrum, thermal stability, ion exchange capacity, water uptake, hydrolytic stability, morphological structure, and proton conductivity. The formation of sulfonated polyimide was confirmed in FTIR spectrum. Thermal stability was good for all the sulfonated polyimides that exhibited a three‐step degradation pattern. Ion exchange capacity was the same for both the uncrosslinked and the self‐crosslinked sulfonated polyimides (1.30 mEq/g). When the crosslinked sulfonated polyimides with poly(ethylene glycol) were compared, the ion exchange capacity was decreased as 1.27 > 1.25 > 1.23 mEq/g and water uptake was increased as 23.8 < 24.0 < 24.3% with the increase in poly(ethylene glycol) diacrylate content. All the crosslinked sulfonated polyimides with poly(ethylene glycol) diacrylate were stable for over 200 h at 80 °C in deionized water. Morphological structure and mean intermolecular distance were obtained by WAXD. Proton conductivities were measured at 30, 50, 70, and 90 °C. The proton conductivity of the crosslinked sulfonated polyimides with poly(ethylene glycol) diacrylate increased with the increase in poly(ethylene glycol) diacrylate content despite the fact that the ion exchange capacity was decreased. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1455–1464, 2005     

Influence of DC electric field on both crystalline structure and conductivity of poly(ethylene oxide)10:LiClO4 electrolyte

The dynamic ionic conductivity and polarizing morphology of poly(ethylene oxide)₁₀:LiClO₄ (PEO₁₀:LiClO₄) electrolyte membranes under different direct current electric fields (EFs) were simultaneously investigated. PEO molecular chains were found to rearrange during the migration of charge carriers, and the rearrangement of PEO molecular chains dramatically affected the conductivity of the electrolyte membrane. No noticeable differences of conductivity and polarizing morphology between the heating and cooling process were observed when the EF was absent. However, the conductivity of the membrane was remarkably enhanced after applying an EF and after carrying out a heating–cooling loop. Differential scanning calorimetry and wide‐angle X‐ray diffraction of the sample with different treatments of both EFs and heating–cooling loops showed that the conductivity enhancement or reduction after loading special EFs and heating–cooling loops were attributed to the change of both the crystallite size of certain diffraction planes and the thickness of PEO lamellae. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012     

原位复合法制备(PEO)8LiClO4/TiO2聚合物电解质的研究

以聚氧化乙烯/高氯酸锂复合物[(PEO)8LiClO4]为基体,通过钛酸丁酯的水解缩合反应在其中原位生成TiO2,制备了(PEO)8LiClO4/TiO2复合聚合物电解质,采用SEM、DSC和交流阻抗方法研究了聚合物电解质的形态、玻璃化转变温度(Tg)、结晶度(Xc)和离子导电性能.结果表明原位生成的TiO2在基体中分散均匀,加入TiO2后聚合物电解质体系的Tg和Xc均有所降低,而电导率明显提高,当TiO2添加量为ω=0.05时电导率达到最大值5.5×10-5S·cm-1(20℃).     

Synthesis of sulfonated poly(imidoaryl ether sulfone) membranes for polymer electrolyte membrane fuel cells

New sulfonated poly(imidoaryl ether sulfone) copolymers derived from sulfonated 4,4′‐dichlorodiphenyl sulfone, 4,4′‐dichlorodiphenyl sulfone, and imidoaryl biphenol were evaluated as polymer electrolyte membranes for direct methanol fuel cells. The sulfonated membranes were characterized with Fourier transform infrared spectroscopy, thermogravimetric analysis, and proton nuclear magnetic resonance spectra. The state of water in the membranes was measured with differential scanning calorimetry, and the existence of free water and bound water was discussed in terms of the sulfonation level. The 10 wt % weight loss temperatures of these copolymers were above 470 °C, indicating excellent thermooxidative stability to meet the severe criteria of harsh fuel‐cell conditions. The proton conductivities of the membranes ranged from 3.8 × 10^?2 to 5 × 10^?2 S/cm at 90 °C, depending on the degree of sulfonation. The sulfonated membranes maintained the original proton conductivity even after a boiling water test, and this indicated the excellent hydrolytic stability of the membranes. The methanol permeabilities ranged from 1.65 × 10^?8 to 5.14 × 10^?8 cm²/s and were lower than those of other conventional sulfonated ionomer membranes, particularly commercial perfluorinated sulfonated ionomer (Nafion). The properties of proton and methanol transport were discussed with respect to the state of water in the membranes. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5620–5631, 2005     

Ionic conductivity of complexes of novel multiarmed polymers with phosphazene core and LiClO4

Novel multiarmed polymers with ethylene oxide units, [( CH₂CH₂O)_n : 7, n = 3; 8, n= 7.2; 9, n = 11.8, and 12, n = 11.8] were prepared from the reaction of polyethylene glycol monomethyl ethers with acid chlorides of hexakis(3,5-dicarboxyphenoxy)-( 6 ) and hexakis(4-carboxyphenoxy)cyclotriphosphazenes ( 11 ) and conductivities of their Li⁺ salt complexes were investigated. The glass transition temperatures of the salt-free polymers are in the temperature range −59 to −54°C, indicative of a high degree of reorientational mobility of the arms. When LiClO₄ was added to the multiarmed polymers, the T_g values raised monotonically. The extent of T_g elevation was affected by the length of arms and the number of oxygen atoms around cyclotriphosphazene core and increased in the order 7 > 8 > 12 > 9 . The conductivities increased in the order 9 > 8 = 12 > 7 and the maximum conductivities of 4.0 × 10⁻⁵ S/cm at 30°C and 6.0 × 10⁻⁴ S/cm at 90°C have been achieved for the 9 -Li⁺ complex with Li⁺/O = 0.03. Interestingly, the conductivity of 9 -Li⁺ complexes at constant reduced temperatures increased in the whole concentrations of LiClO₄ examined (Li⁺/O = 0.01–0.2), although the degree of increase in conductivity above Li⁺/O = 0.06 became small. From the behaviors of T_g and the conductivity of multiarmed polymer–LiClO₄ complexes, it appears that the conductivity is governed by relative concentrations of inter- and intramolecular complexes in the polymer matrix. The influence of structural change of the comb-shaped to multiarmed polymers on the conductivity is described. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 1839–1847, 1997     

Solid polymer electrolytes I,preparation, characterization,and ionic conductivity of gelled polymer electrolytes based on novel crosslinked siloxane/poly(ethylene glycol) polymers

A series of crosslinked siloxane/poly(ethylene glycol) (Si–PEG) copolymers were synthesized from the reactive methoxy‐functional silicone resin (Si resin) and PEGs with different molecular weights via two kinds of crosslinking reactions during an in situ curing stage. One of the crosslinking reactions is the self‐condensation between two methoxy groups in the Si resin, and another one is an alkoxy‐exchange reaction between the methoxy group in the Si resin and the OH group in PEG. The synthesized crosslinked copolymers were characterized by Fourier transform infrared spectroscopy, DSC, and ¹³C NMR. The crosslinked copolymers were stable in a moisture‐free environment, but the Si? O? C linkages were hydrolyzed in humid conditions. The gel‐like solid polymer electrolytes (SPEs) were prepared by impregnating these crosslinked Si–PEG copolymers in a propylene carbonate (LiClO₄/PC) solution. The highest conductivity reached 2.4 × 10^?4 S cm^?1 at 25 °C and increased to 8.7 × 10^?4 S cm^?1 at 85 °C. The conductivities of these gel‐type SPEs were affected by the content of LiClO₄/PC, the molecular weights of PEGs, and the weight fraction of the Si resin. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2051–2059, 2004     

Poly(ethylene oxide)/poly(2vinylpyridne)/lithium perchlorate blends as solid polymer electrolytes: Composition/property/structure interrelationship

Poly(ethylene oxide) (MW 600,000)/poly(2vinylpyridine) (MW 200,000)/LiClO₄ blends have been prepared by the solution blending process. The ionic conductivities of the blends containing lower weight fractions (15, 17.5, 20 and 22.5%) of poly (2vinylpyridine) initially increases as the salt content is increased, reaches a maximum at an ethylene oxide/Li⁺ mole ratio of 10 and decreases as the salt content is further increased. Blends, which have higher weight fractions of poly(2vinylpyridine) (25 and 35%) display different electric behavior, i.e., the ionic conductivity continously increased as the salt content is increased to an ethylene oxide/Li⁺ mole ratio of 2. Thermal, ⁷Li solidstate NMR and semiempirical MNDO molecular orbital studies indicate that this contrasting behavior may be explained by the structure and ratios of the solvates (mixed solvate or homosolvate) of LiClO₄ present in the blends. © 1995 John Wiley & Sons, Inc.     

Brønsted acid-base polymer electrolyte membrane based on sulfonated poly(phenylene oxide) and imidazole

The Brønsted acid-base polymer electrolyte membrane was prepared by entrapping imidazole in sulfonated poly(phenylene oxide) at the molar ratio of Im/SPPO = 2:1. The hybrid showed a high thermal stability up to 200 °C and peroxide tolerance. Differential scanning calorimetry shows that glass transition temperature is 232 °C. The conductivity increases with temperature exceeding 10⁻³ S/cm above 120 °C and a high conductivity of 6.9 × 10⁻³ S/cm was obtained at 200 °C under 33% RH conditions.