PEO-LiClO4-ZSM5复合聚合物电解质Ⅱ.ZSM-5对离子电导率的影响

通过XRD,DSC,FT-IR和SEM等方法对PEO-LiClO₄-ZSM5复合电解质进行了研究,结果表明ZSM-5可以有效地降低PEO-LiClO₄-ZSM5复合电解质中PEO的结晶度和玻璃化温度,从而提高其低温区域的离子电导率.温度高于PEO的结晶熔融温度后,复合电解质离子电导率的提高则是由于在ZSM-5表面形成了有利于Li离子迁移的导电通道所引起的.较高的离子电导率和较宽的电化学稳定窗口表明PEO-LiClO₄-ZSM5复合电解质在全固态锂离子二次电池领域具有良好的应用前景.     

红外光谱研究PEO基离子液体聚合物电解质

以聚氧化乙烯(PEO)为聚合物基体, 双三氟甲基磺酸亚酰胺锂(LiTFSI)为锂盐, 加入不同量的离子液体(BMIMPF₆)为增塑剂, 制备离子液体聚合物电解质. 运用发射FTIR光谱技术实时监测所制备聚合物电解质的结构随温度的变化. 结合FTIR透射光谱\, SEM和XRD的研究结果分析了离子液体对离子电导率的影响, 并初步提出离子导电增强机制.     

PEO-LiClO_4-ZSM5复合聚合物电解质II.ZSM-5对离子电导率的影响

通过XRD ,DSC ,FT IR和SEM等方法对PEO LiClO4 ZSM5复合电解质进行了研究 ,结果表明ZSM 5可以有效地降低PEO LiClO4 ZSM5复合电解质中PEO的结晶度和玻璃化温度 ,从而提高其低温区域的离子电导率 .温度高于PEO的结晶熔融温度后 ,复合电解质离子电导率的提高则是由于在ZSM 5表面形成了有利于Li离子迁移的导电通道所引起的 .较高的离子电导率和较宽的电化学稳定窗口表明PEO LiClO4 ZSM5复合电解质在全固态锂离子二次电池领域具有良好的应用前景 .     

NASICON结构的锂离子导电微晶玻璃结构与电导率

通过对LixAlx-1Ge3-x(PO4)3(x=1.1～1.9)锂离子导电玻璃的差示量热扫描(DSC)数据,结合XRD及其Rietveld精修、FESEM和交流阻抗等测试方法,研究了该系微晶玻璃的物相组成、主晶相晶胞参数变化情况、微观结构形貌、锂离子电导率和电化学窗口等。结果表明:LixAlx-1Ge3-x(PO4)3(x=1.1～1.9)锂离子导电微晶玻璃析出导电主晶相为LiGe2(PO4)3。当x=1.5时,由于导电主晶相LiGe2(PO4)3晶粒充分长大、分布均匀,晶界清晰,LAGP导电微晶玻璃的室温电导率最高(可达5.3×10-4 S.cm-1),电化学窗口为7.2V,可以满足全固态锂离子电池对电解质高室温电导率和宽电化学窗口的应用要求。     

三维结构Li6.28La3Zr2Al0.24O12增强聚氧化乙烯基固态电解质的性能研究

通过牺牲模板法制备了一种三维框架Li_6.28La₃Zr₂Al_0.24O₁₂(3D-LLZAO)无机电解质,并将其用于构建聚氧化乙烯(PEO)基复合固态电解质膜.通过扫描电子显微镜(SEM)、X射线衍射(XRD)等物理表征及电化学阻抗谱(EIS)、线性扫描伏安(LSV)和充放电循环等电化学测试方法研究了PEO基固态电解质的性能.结果表明加入10%(w) 3D-LLZAO的PEO基复合固态电解质CPE-10具有较小的体电阻、较宽的电化学稳定窗口.复合电解质CPE-10室温下离子电导率为1.58×10-4 S·cm^-1,锂离子迁移数为0.26.利用复合固态电解质组装的锂锂对称电池可在室温下0.05 mA·cm^-2的电流密度条件下稳定循环1600 h.以磷酸铁锂(LFP)为正极组装的LFP/CPE-10/Li电池在0.5 C倍率下初始放电比容量为155.6m Ah·g^-1,循环100次后容量保持率为86%.     

聚氧化乙烯基聚合物电解质中离子缔合与结晶状态的傅立叶变换红外光谱(FTIR)研究

通过FTIR光谱技术对P(EO)_nLiX [X＝N(SO₂CF₃)₂, SCN, ClO₄] (n＝4～60)聚合物电解质的离子缔合行为进行了研究, 结果表明在PEO-LiSCN体系中缔合现象较为严重. 在高浓度时LiSCN主要以离子对、离子簇以及二聚体形式存在, 自由离子含量较少. 而对于LiTFSI和LiClO₄体系, 则以自由离子形式为主. 随着锂盐的加入, 由于其阴离子的增塑作用使聚氧化乙烯(PEO)中的晶相成分逐渐向无定形相转化. 当锂盐含量增加到一定程度, 体系中会有不同晶相复合物的形成.     

基于Li6.4La3Zr1.4Ta0.6O12/聚合物复合固态电解质的制备及电化学性能

采用溶液浇注法制备以Li_(6.4)La_3Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)为填料、聚氧化乙烯(PEO)与聚碳酸亚丙酯(PPC)共混的固态复合电解质膜,探讨了LLZTO含量和PPC/PEO比例对复合固态电解质离子电导率的影响。研究发现,当LLZTO含量为30%(w/w)及PPC/PEO质量比为1∶1时,固态复合电解质室温离子电导率最高,达到1.14×10~(-4)S·cm~(-1)。LLZTO和PPC的加入,降低了PEO基电解质的结晶性,提高了离子电导率、电化学稳定窗口(4.7 V)和锂离子迁移数(0.25),并改善了电解质与金属锂的化学稳定性。该固态复合电解质与LiFePO_4/Li组装固态锂电池,室温下在0.1C循环70次后容量保持率82%,60℃下0.1C循环100次后容量保持率79%,0.5C和1C倍率下放电比容量仍能达到120.7和112.6 mAh·g~(-1)。     

PEO-12-钨磷酸质子导电聚合物电解质膜

以聚氧乙烯(PEO)为基质, 在其中掺杂适量的钨磷酸, 制备PEO-H₃PW₁₂O₄₀质子导电聚合物电解质膜. XRD及IR测试表明体系中Keggin阴离子与PEO链相互作用形成新的化合物; Keggin阴离子的存在有利于水合质子的形成. PEO-H₃PW₁₂O₄₀复合膜的电导率室温最高可达4.0×10^－3 S•cm^－1.     

一种双锂盐梳状聚合物电解质的制备及电化学性能

将聚乙二醇单甲醚(MPEG)接枝在聚(异丁烯-alt-马来酸酐)(PIAMA)上合成梳状锂单离子导体PIAMA-g-MPEG, 并与双(三氟甲基磺酰)亚胺锂(LiTFSI)复合制成双锂盐梳状聚合物电解质薄膜. 用核磁共振波谱 (¹H NMR)、 热重分析(TG)、 扫描电子显微镜(SEM)、 电化学阻抗(EIS)和电池充放电测试等方法对聚合物基体和电解质的物化性质和电化学性能进行了研究.结果表明, 设计的双锂盐梳状聚合物电解质能够有效解离并传输锂离子, 70 ℃下离子迁移数(t_Li⁺)为0.32, 离子电导率(σ)为1.5×10^-4 S/cm, 电化学稳定窗口为0~4.9 V (vs. Li/Li⁺). 组装Li|PIAMA-g-MPEG|Li电池并进行70 ℃恒电流充放电电压极化测试, 结果表明, 电解质与金属锂负极兼容性较好, 能够有效抑制锂枝晶的生长.组装LiFePO₄|PIAMA-g-MPEG|Li电池进行70 ℃长循环及倍率性能测试, 电解质表现出了优异的高温性能.     

新型室温熔盐二(三氟甲基磺酸酰)亚胺锂-乙酰胺/乙烯脲体系的研究

制备了二(三氟甲基磺酸酰)亚胺锂[LiN(SO₂CF₃)₂,LiTFSI]与乙酰胺和乙烯脲形成的新型室温熔盐,分析了其热学和电化学性能.LiTFSI-乙酰胺体系的热学稳定性好,低共熔温度为-62.18℃.电化学测试表明,LiTFSI-乙酰胺体系的电导率较高,n(LiTFSI):n(Acetamide)=1:6.5样品的室温电导率为1.08×10^-3S/cm,60℃时电导率为5.35×10^-3S/cm;摩尔比为1:4.0样品的电化学稳定电位窗为3V左右.     

PEO-LITFSI-SiO2-SN System Promotes the Application of Polymer Electrolytes in All-Solid-State Lithium-ion Batteries

All-solid-state polymer lithium-ion batteries are ideal choice for the next generation of rechargeable lithium-ion batteries due to their high energy, safety and flexibility. Among all polymer electrolytes, PEO-based polymer electrolytes have attracted extensive attention because they can dissolve various lithium salts. However, the ionic conductivity of pure PEO-based polymer electrolytes is limited due to high crystallinity and poor segment motion. An inorganic filler SiO₂ nanospheres and a plasticizer Succinonitrile (SN) are introduced into the PEO matrix to improve the crystallization of PEO, promote the formation of amorphous region, and thus improve the movement of PEO chain segment. Herein, a PEO₁₈−LiTFSI−5 %SiO₂−5 %SN composite solid polymer electrolyte (CSPE) was prepared by solution-casting. The high ionic conductivity of the electrolyte was demonstrated at 60 °C up to 3.3×10⁻⁴ S cm⁻¹. Meanwhile, the electrochemical performance of LiFePO₄/CSPE/Li all-solid-state battery was tested, with discharge capacity of 157.5 mAh g⁻¹ at 0.5 C, and capacity retention rate of 99 % after 100 cycles at 60 °C. This system provides a feasible strategy for the development of efficient all-solid-state lithium-ion batteries.     

含锂沸石Li-FER提高PEO复合聚合物电解质电导率

通过离子交换方法使锂部分取代了镁碱沸石（FER）孔道壁上羟基中的氢，制得含锂沸石Li-FER. 将这种沸石作为无机填料加入到PEO/LiClO₄聚合物电解质中，可以使其室温电导率提高三个数量级以上. 电化学测量表明， 锂离子与PEO和含锂沸石中氧的相互作用提高了聚合物电解质中锂离子的迁移数. 另一方面， 采用XRD, DSC, PLM等方法研究了电解质的结晶状况.结果表明, Li-FER可以作为PEO链段结晶的成核剂，使PEO电解质的晶粒得到细化， 结晶度降低，为Li⁺的传输提供了更多的非晶区通道. 这是Li-FER的加入促使PEO聚合物电解质电导率提高的两个主要原因.     

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…     

PEO-LiClO4-ZSM-5复合聚合物电解质——ZSM-5对锂离子选择通过的影响

通过溶液浇铸法制得了一系列以不同分子筛和蒙脱土为填料的PEO基复合聚合物电解质,利用交流阻抗-稳态电流方法研究了填料对复合聚合物电解质锂离子迁移数(TLi+)的影响.实验结果表明,所有填料都有利于同时提高复合聚合物电解质的TLi+和离子电导率,但以Li-ZSM-5为填料时TLi+最高,这是因为ZSM-5的特殊二维孔道结构有利于阳离子Li+的进入,而排斥阴离子ClO4-的通过.较高的TLi+和室温离子电导率说明PEO-LiClO4-ZSM-5有可能作为全固态锂离子聚合物电池的电解质材料.     

Cold Sintering of Li6.4La3Zr1.4Ta0.6O12/PEO Composite Solid Electrolytes

Ceramic/polymer composite solid electrolytes integrate the high ionic conductivity of in ceramics and the flexibility of organic polymers. In practice, ceramic/polymer composite solid electrolytes are generally made into thin films rather than sintered into bulk due to processing temperature limitations. In this work, Li_6.4La₃Zr_1.4Ta_0.6O₁₂ (LLZTO)/polyethylene-oxide (PEO) electrolyte containing bis(trifluoromethanesulfonyl)imide (LiTFSI) as the lithium salt was successfully fabricated into bulk pellets via the cold sintering process (CSP). Using CSP, above 80% dense composite electrolyte pellets were obtained, and a high Li-ion conductivity of 2.4 × 10⁻⁴ S cm^–1 was achieved at room temperature. This work focuses on the conductivity contributions and microstructural development within the CSP process of composite solid electrolytes. Cold sintering provides an approach for bridging the gap in processing temperatures of ceramics and polymers, thereby enabling high-performance composites for electrochemical systems.     

PEO/LiClO_4纳米SiO_2复合聚合物电解质的电化学研究

将实验室制备的纳米二氧化硅和市售纳米二氧化硅粉末与PEO LiClO4复合 ,制得了复合PEO电解质 .它们的室温离子电导率可比未复合的PEO电解质提高 1～ 2个数量级 ,最高可以达到 1 2 4× 10 - 5S cm .离子电导率的提高有两方面的原因 :一是无机二氧化硅粉末的加入抑制了PEO的结晶 ,是二氧化硅粉末和聚合物电解质之间形成的界面对电导率的提高也有一定的作用 .在进一步加入PC EC(碳酸丙烯酯 碳酸乙烯酯 )混合增塑剂后制得的复合凝胶PEO电解质 ,可使室温离子电导率再提高 2个数量 ,达到 2× 10 - 3 S cm .用这种复合凝胶PEO电解质组装了Li|compositegelelectrolyte|Li半电池 ,并测量了该半电池的交流阻抗谱图随组装后保持时间的变化 ,实验观察到在保持时间为 144h以内钝化膜的交流阻抗迅速增大 ,但在随后的时间内逐渐趋于平稳 ,表明二氧化硅粉末的加入可以有效地抑制钝化膜的生长     

Ion conducting properties of poly(ethylene oxide)-based electrolytes incorporating amorphous silica attached with imidazolium salts

Poly(ethylene oxide) (PEO)-based polymer electrolytes containing amorphous silica attached ionic liquid (IL) were studied in order to improve electrochemical and interfacial properties. An imidazolium salt such as IL was attached to modified ceramic fillers. The modified ceramic fillers were amorphous silica with the immobilized 1-methyl-3-propyl-imidazolium bromide (MPIm-AS). PEO-based polymer electrolytes were prepared by using the solution casting technique. In order to investigate the ionic conductivity, studies on the modified filler addition effects on the ion-conducting behavior of polymer electrolytes having specific amounts of MPIm-AS were carried out. The addition of MPIm-AS in polymer electrolytes has resulted in higher ionic conductivity at room temperature. The structure, crystallinity, and morphology of the solid polymer electrolytes were evaluated using X-ray diffraction, differential scanning calorimetry, and scanning electron microscope measurement. The ionic conductivity was measured by an AC impedance method. The enhanced conductivity was dependent on the decreased crystallinity and the changed morphologies of composites.     

PEO基聚合物电解质及其锂硫电池性能研究

锂硫电池由于具有高的理论比能量引起了广泛关注,然而传统液态锂硫电池由于多硫化物的“穿梭效应”以及安全问题而限制了其应用,全固态锂硫电池可显著提高电池安全性能并有望解决多硫化物的穿梭问题. 本文采用传统的溶液浇铸法制备了具有不同的[EO]/[Li⁺]的PEO-LiTFSI聚合物电解质,并将其应用于锂硫电池. 研究发现,虽然[EO]/[Li⁺] = 8的聚合物电解质具有更高的离子电导率,但是[EO]/[Li⁺] = 20的电解质与金属锂负极间的界面阻抗更低,界面稳定性更好. Li|PEO-LiTFSI([EO]/[Li⁺]=20)|Li对称电池在60 °C,电流密度为0.1 mA·cm^-2时可稳定循环超过300 h,而Li|PEO-LiTFSI ([EO]/[Li⁺]=8)|Li对称电池循环75 h就出现了短路现象. 基于PEO-LiTFSI([EO]/[Li⁺]=20)电解质的锂硫电池首圈放电比容量为934 mAh·g^-1,循环16圈后放电比容量为917 mAh·g^-1以上. 而基于PEO-LiTFSI ([EO]/[Li⁺]=8)电解质的锂硫电池,由于与锂负极较低的界面稳定性不能够正常循环,首圈就出现了严重过充现象.     

Enhanced ionic conductivity of poly(ethylene oxide) (PEO) electrolyte by adding mesoporous molecular sieve LiAlSBA

Mesoporous molecular sieve LiAlSBA was prepared via an ion exchange process with mesoporous AlSBA directly, which has a regular 2D hexagonal structure with pore size about 7 nm. It was added into poly(ethylene oxide) (PEO) solid electrolyte as filler. The characteristics of the composite polymer electrolyte were determined by XRD, DSC, TGA, FTIR, PLM and electrochemical methods. Compared with bare PEO electrolyte, the adding of dispersed LiAlSBA powder improved the ionic conductivity of PEO polymer electrolyte more than three orders. The reason for it is that mesoporous LiAlSBA powder acts as crystal cores in PEO composite electrolyte and fines the crystallites, decreases the crystallinity, which provides much more continuous amorphous domain for Li⁺ moving easily in PEO electrolyte. Besides, lithium ions of the mesoporous molecular sieves can hop from one site to another along the surface of the mesoporous channels, this mechanism is absent in the case of common nano-ceramic fillers in PEO electrolyte.