增塑剂PC掺杂（PEO）_8-LiClO_4-SiO_2电解质体系的性能研究

以增塑剂碳酸丙烯酯（PC）作为掺杂物,混于（PEO）8-LiClO4-SiO2固体电解质体系中。得到厚度约为350μm性能良好的聚合物电解质薄膜,利用交流阻抗法测定聚合物电解质的电导率,通过XRD对聚合物电解质薄膜的物相结构进行分析研究。结果表明掺杂后（PEO）8-LiClO4-SiO2-PC固体电解质的室温电导率较（PEO）8-LiClO4-SiO2体系有了进一步提高,在PC质量分数为40%时最高,达到3.083×10-6 S.cm-1;电导率与温度关系遵循Arrhenius方程。温度的升高有利于电导率的提升,在80℃时体系的离子电导率为1.180×10-5 S.cm-1。XRD分析表明,加入PC后PEO的结晶度进一步减小,体系不定形相增加,有利于离子电导率的提高。     

DDBA改性纤维对PEO聚合物电解质性能的影响

针对聚环氧乙烷(PEO)基聚合物电解质室温易结晶的问题，将4-4-二羟基-α,α’-二甲基卞联氮(DDBA)改性芳纶纤维(DF)掺杂在基体中，抑制PEO结晶，提高其离子电导率。通过交流阻抗、差式扫描量热等方法进行表征。结果表明：制备的聚合物电解质在少量DF掺杂时离子电导率有所改善，其中掺杂质量分数2.0%DF的电解质电化学性能最好，在25℃下电导率达到1.5×10^-5 S/cm，离子迁移数提高至0.30。     

LCI-PEO/PLA固态聚合物电解质电导率的研究

针对聚氧化乙烯(PEO)聚合物电解质室温电导率较低的问题,设计掺杂液晶离聚物(LCI)改善PEO/PLA共混相结构以提高聚合物室温电导率。通过差示扫描量热分析、偏光显微镜技术、扫描电子显微镜技术、电化学阻抗测试等对其进行表征。结果表明:制备的固态聚合物电解质在较低的LCI掺杂下显示出显著的电导率改善。掺杂1.0wt.%LCI在17℃下电导率达到3.58×10~(-5) S/cm,相比于PEO电解质电导率提高了三个数量级。     

PVDF/PEO/PS交联复合型凝胶聚合物电解质薄膜的制备及性能测试

采用相反转法和聚苯乙烯原位交联制备了一系列聚偏氟乙烯(PVDF)、聚氧化乙烯(PEO)和聚苯乙烯(PS)交联复合型凝胶聚合物电解质薄膜,测定了它们的孔隙率、吸液率、离子电导率等性能,并通过扫描电镜对其形貌进行了分析。结果表明,PVDF-30%(PEO/PS)薄膜中当PS含量达到PEO/PS总含量的25%时薄膜具有较高的孔隙率、吸液率和电导率,孔隙率达到67.4%,吸液率高达184.3%,离子电导率为4.4×10~(-3)S/cm。     

新型聚合物固体电解质的导电性研究

采用溶液浇铸法制得以偏二氟乙烯与六氟丙烯共聚物P(VdF-HFP)为基质的聚合物固体电解质,并测定了该类电解质的电导率。讨论了锂盐浓度、增塑剂配比、纳米SiO2粉末掺入以及温度对膜的离子电导率的影响;结果表明:以P(VdF-HFP)为基质的电解质的室温电导率最高达到2.81×10-3S·cm-1。利用红外分析对聚合物固体电解质的导电性进行分析,探讨了聚合物固体电解质膜的各组分间相互作用的规律。     

快冷对PEO/LiClO_4固态电解质的晶型与导电性的影响

聚合物电解质的离子电导率是电解质的一个重要参数 ,与聚合物电解质中的非晶态的存在有很大的关系。在本文中 ,以X射线衍射 (XRD)、差热分析 (DTA)和交流阻抗 (Acimpedance)为研究手段 ,研究了快冷对聚合物电解质的晶型转变和对聚合物电解质室温离子电导率的影响。在快速冷却的条件下 ,质量比为1∶1的PEO/LiClO4聚合物电解质的室温离子电导率可达 1 6 1x 10 -7S/cm ,比慢冷处理的相同体系的室温离子电导率提高了 1个数量级。实验证明 ,快速冷却可破坏聚合物的结晶性 ,提高聚合物电解质的离子电导率。     

碳量子点/聚环氧乙烷固态电解质的制备

针对聚氧化乙烷(PEO)基固态电解质室温电导率较低的问题，通过在PEO中掺杂碳量子点(CQDs)作为填料，制备出不同CQDs含量的PEO基固态电解质，通过差示扫描量热分析技术、X射线衍射技术、扫描电子显微镜(SEM)技术等对其进行表征。结果表明：与PEO基固态电解质相比，掺杂CQDs的PEO基固态电解质的结晶度有明显的下降趋势；通过电化学阻抗测试(EIS)得出，PEO-LITFSI-5%CQDs固态电解质在室温下的离子电导率为2.01×10^-5 S/cm,与PEO-LiTFSI-0%CQDs室温下的离子电导率相比，有明显的提升。     

PEO基聚合物复合电解质的制备及性能研究

将不同含量的单宁酸加入到聚环氧乙烷(PEO)和双三氟甲磺酰胺亚胺锂(Li TFSI)体系中,采用流延法来制备聚合物电解质膜。在氢键的作用下破坏PEO的结晶度来提高聚合物电解质的离子电导率。通过X射线衍射、差示扫描量热仪、热重分析仪、力学性能、表面形貌以及交流阻抗法等对聚合物电解质膜进行表征。结果表明,随着单宁酸(TA)含量的增加,结晶度下降,断裂伸长率提高,最高达到了675%,热力学性能也有很大的改善。室温下,当单宁酸含量为1%时,拉伸强度达到0.22 MPa,离子电导率最大达到了3.4×10-5S/cm。     

新能源汽车固态电池中的锂枝晶抑制研究

相比于商业化的锂离子电池,固态电池具有更高的能量密度和更好的安全性。然而,固体电解质依旧面临锂枝晶生长的问题。以目前已大规模工业化的聚氧化乙烯(PEO)基电解质作为研究对象,通过将PEO与高杨氏模量的石榴石型电解质复合,抑制了锂枝晶在PEO基复合电解质中的生长,不仅使电解质膜的离子电导率从9.8×10-6S/cm增加到了3.8×10-4S/cm,还使锂/锂对称电池的临界电流密度从0.4 m A/cm²提高到1.6 mA/cm²。与此同时,组装的基于金属锂负极与传统石墨负极的软包电池可分别获得334.5 W·h/kg与218.2 W·h/kg的能量密度。其中,钴酸锂/复合电解质/石墨软包全电池循环1 000次后的容量保持率可达92.3%,能够满足新能源汽车的需求。     

Mn_3CoO_8复合纳米线改性PEO基全固态聚合物电解质

采用水热法和溶液浇铸法制备了复合纳米线-聚氧化乙(PEO)聚合物电解质。研究了不同纳米线的添加量对PEO基复合电解质表面形貌、离子电导率、电压窗口及循环稳定性的影响。研究表明,纳米线添加量在3%时性能最优,此复合固态电解质在60℃的离子电导率为9.1*10~(-5)S/cm,电压窗口达到4.7V,0.5C电流下循环100圈容量为143.7mAh/g,容量保持率达到96%。     

PMMA-[BMIM]PF_6-非质子溶剂复合型凝胶电解质的制备和性能

采用烯类单体MMA在离子液体[BMIM]PF6和PC、DMC等形成的混合溶液中聚合,合成一系列PMMA-[BMIM]PF6-非质子溶剂复合型凝胶电解质,并对其性能进行了研究。结果表明,当m([BMIM]PF6)∶m(PC)=45∶55时,凝胶电解质PMMA-PC-[BMIM]PF6的室温电导率值为3.44×10-3S/cm,当m([BMIM]PF6)∶m(DMC-PC)=35∶65时,PMMA-LiPF6-(PC-DMC)-[BMIM]PF6的室温电导率值为10.05×10-3S/cm,并随温度升高而增加,变化规律符合VTF方程。凝胶电解质热分解温度都在250℃以上,在80℃时热失重小于0.97%。锂离子的迁移数约为0.3。电化学窗口高达5.1V。     

应用于氧化还原电池正极的Fe2+/Fe3+胶体电解质研究

设计了一种新的Zn-Fe氧化还原胶体电池。研究了胶凝剂气相SiO2含量对胶体电解质特性的影响。SiO2含量愈高,电解质愈粘稠,电导率愈低。采用循环伏安法研究了Fe3+/Fe2+电对在胶体电解质中的电化学行为。结果表明,该体系中Fe3+/Fe2+在Pt电极上的电极反应属于准可逆过程。计算得到Fe3+的扩散系数为2.29×10-6 cm2/s。组装的Zn/Fe胶体电池具有较好的循环性能,其平均库仑效率达94.83%,平均能量效率为44.61%。     

Study of poly(organic palygorskite-methyl methacrylate)/poly(ethylene oxide) blended gel polymer electrolyte for lithium-ion batteries

In this study, the composite polymer was prepared by blending poly(ethylene oxide) (PEO) and POPM (the copolymer of methyl methacrylate [MMA] and organically modified palygorskite), and then the composite polymer based membrane was obtained by phase-inversion method. The scanning electron microscopy results showed that the composite polymer membrane has a three-dimensional network structure. X-ray diffraction results indicated that the crystalline region of PEO is disappeared when introduction of a certain amount of the PEO. Meanwhile, the elongation of composite polymer membrane increased when increasing PEO concentration, but the value of tensile strength of PEO-POPM membrane decreased. When the mass fraction of PEO was 24%, the porosity and maximum value of ionic conductivity of the composite polymer membrane were 54% and 2.41 mS/cm, respectively. The electrochemical stability window of Li/gel composite polymer electrolyte/stainless steel batteries was close to 5.3 V (vs. Li⁺/Li), and the battery of Li/gel composite polymer electrolyte/LiFePO₄ showed good cycling performance and the discharge capacity of the battery were between 169.8 and 155 mAh/g. Meanwhile, the Coulombic efficiency of the battery maintained over 95% during the 80 cycles.     

Effect of nano‐TiO2 dispersion on PEO polymer electrolyte property

Polymer electrolyte membranes based on poly(ethylene oxide) (PEO) doped with TiO₂ nanoparticles were synthesized by simple solution cast technique. Mesoporous TiO₂ film was prepared by doctor‐blade method. The modified polymer membranes and the mesoporous films were characterized by SEM, TEM, AFM, ionic conductivity, and J‐V measurements. Dye‐sensitized solar cells (DSSC) have been fabricated in which PEO‐polymer electrolyte doped with and without nano‐TiO₂ were sandwiched between porous TiO₂ and counter electrodes. The DSSC with nano‐TiO₂ doped polymer electrolyte shows better performance (1.68%) in comparison with pristine polymer electrolyte (1.07%), which is due to improved ionic conductivity value in polymer electrolyte system by nano‐TiO₂ doping. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Ionic conductivity in polyethylene-b-poly(ethylene oxide)/lithium perchlorate solid polymer electrolytes

The ionic conductivity and phase arrangement of solid polymeric electrolytes based on the block copolymer polyethylene-b-poly(ethylene oxide) (PE-b-PEO) and LiClO₄ have been investigated. One set of electrolytes was prepared from copolymers with 75% of PEO units and another set was based on a blend of copolymer with 50% PEO units and homopolymers. The differential scanning calorimetry (DSC) results, for electrolytes based on the copolymer with 75% of PEO units, were dominated by the PEO phase. The PEO block crystallinity dropped and the glass transition increased with salt addition due to the coordination of the cation by PEO oxygen. The conductivity for copolymers 75% PEO-based electrolyte with 15 wt% of salt was higher than 10⁻⁵ S/cm at room temperature and reached to 10⁻³ S/cm at 100 °C on a heating measurement. The blend of PE-b-PEO (50% PEO)/PEO/PE showed a complex thermal behavior with decoupled melting of the blocks and the homopolymers. Upon salt addition the endotherms associated with PEO domains disappeared and the PE crystals remained untouched. The conductivity results were limited at 100 °C to values close to 10⁻⁴ S/cm and at room temperature values close to 3 × 10⁻⁶ S/cm were obtained for the 15 wt% salt electrolyte. Raman study showed that the ionic association of the highly concentrated blend electrolytes at room temperature is not significant. Therefore, the lower values of conductivity in the case of the blend with 50% PEO can be assigned to the higher content of PE domains leading to a morphology with lower connectivity for ionic conduction both in the crystalline and melted state of the PE domains.     

Studies of dielectric relaxation and a.c. conductivity in [(100−<Emphasis Type="Italic">x</Emphasis>)PEO + <Emphasis Type="Italic">x</Emphasis>NH<Subscript>4</Subscript>SCN]: Al-Zn ferrite nano composite polymer electrolyte

Present work deals with findings on dielectric behaviour and a.c. conduction in a ferrite doped polymer nano composite electrolyte system, namely [(100−x) PEO + xNH₄SCN]: ferrite. The formation of nano composite and structural behavior of electrolyte was studied by XRD and SEM images. The effect of salt and ferrite on conductivity behaviour of PEO based nano composite polymer electrolyte has been investigated by the impedance spectroscopy at room temperature. The variation of dielectric permittivity and dielectric loss with frequency was carried out at ambient temperature. The a.c. conductivity seems to follow the universal power law.     

电纺EVOH磺酸锂/TiO_2聚合物电解质电性能的研究

将纳米二氧化钛加入到EVOH-SO3Li中制备纺丝液,利用高压静电纺丝法制备EVOH-SO3Li/TiO2复合膜。组装扣式电池,测试EVOH-SO3Li/TiO2聚合物电解质的电化学稳定窗口及离子电导率。结果表明:复合薄膜的电化学性能稳定,离子电导率达到0.96×10-3s/cm。