PET/PEGDMA改性PAN电池隔膜

本文通过在聚丙烯腈隔膜中植入PET无纺布提高了隔膜的热稳定性和力学性能,通过添加PEGDMA进行热交联提高了PAN的耐化学腐蚀性和降低PAN的结晶度,PEGDMA同时有利于提高PAN多孔膜的孔隙率,PAN通过倒相法成孔,制备出了孔隙率高达43.38%、离子电导率高达1.56m S cm-1的锂电池隔膜,经150℃高温测试隔膜的热收缩率均低于5%,经过2h以及12h离子电导率对比发现经过热交联的锂电池隔膜的耐腐蚀性增强。     

扫描喷射电沉积制备多孔金属镍

采用扫描喷射电沉积制备具有一定厚度、孔隙率较高、组织较均匀的多孔金属镍;并研究了在不同扫描速率、喷嘴高度等实验条件下,多孔金属镍电沉积生长的行为特性;最后应用图形处理软件Image J对多孔金属镍的孔隙率和相对密度进行分析,得到了最佳实验参数.结果表明:采用扫描速率为4 mm/s时,孔隙结构相当完善;当喷嘴高度为6 mm时,孔隙率和相对密度比较适中.     

溶剂型多层复合隔膜的制备及其性能研究

将聚偏氟乙烯(PVDF)粉末和陶瓷氧化铝(Al₂O₃)加入到二甲基乙酰胺(DMAC),进行高速分散,得到陶瓷/PVDF涂布液。采用陶瓷膜为基材,在其双面均匀涂覆陶瓷/PVDF涂布液,通过浸渍相反转的方法得到陶瓷混胶隔膜。与传统的商用陶瓷涂胶膜相比,PVDF凝胶层中加入无机陶瓷颗粒和丙烯酸酯类黏合剂,既能提高复合隔膜的正极黏结性能、热稳定性及离子传导性,降低复合隔膜的热收缩率,又能有效提高复合隔膜层间的剥离强度,降低复合隔膜的材料成本,复合隔膜具有综合性能表现,进而可提升锂电池的使用性能。复合隔膜剥离强度为125 N/m,是同等类型陶瓷涂胶膜的5倍。黏接强度由陶瓷膜的0.1 N/m提升至11.3 N/m,吸液率由85%提升至108%,提高了27%。溶剂型多层复合隔膜均通过全面的试验验证,并成功侧应用到锂电池产品中。     

锂离子电池聚烯烃隔膜改性及功能化研究

综述了近年来国内外锂电池聚烯烃隔膜的改性及功能化研究进展,分类介绍了锂电池聚烯烃隔膜的制造方法和性能的表征指标,及孔径分布、孔隙率、润湿性、耐热性、安全性、机械强度等方面的改性状况.     

锂电池用非织造布隔膜研究进展

隔膜是锂电池结构中的核心组成部分之一。非织造布隔膜具有高孔隙率、良好的保液性、高热稳定性而受到广泛关注。文章综述了湿法非织造布隔膜、静电纺丝非织造布隔膜、熔喷/纺黏非织造布隔膜等制备原理、特点及应用进展。对每种非织造布隔膜性能和改进方法进行评价。研究表明：未来锂电池隔膜的研究将聚焦保证非织造布隔膜力学强度的前提下解决隔膜厚度、孔径等方面的技术难题，以及探索新的隔膜用原材料，研究可产业化制备理化性能满足锂电池需求的非织造布隔膜工艺，从而开发具有自主知识产权的高端隔膜。     

不同温度下隔膜厚度对电池自放电的影响

自放电性能是锂电池一项重要指标,而隔膜对锂电池自放电性能起到关键作用.以镍钴锰酸锂(LiNi0.5 Co0.2 Mn0.3 O2)为正极、石墨为负极制备了不同隔膜厚度的软包锂电池.研究了隔膜厚度对锂电池厚度、保液量、容量、内阻的影响,并测试了不同温度下搁置后不同隔膜厚度锂电池的荷电保持率、容量恢复率、压降与内阻,探讨了...     

锂电池电源新型复合隔膜的研制

重要赛事场馆备用电源是保障赛事顺利进行的重要设备，锂电池作为当前电力储备的关键模块，在重大赛事场馆备用电源系统建筑中应用十分广泛。隔膜材料是锂电池的关键部件，关系到电池性能的发挥。因此，本文制备一种锂电池应用的新型复合隔膜，并检测隔膜性能。结果表明：E-Li与有机蒙脱土之间形成了新的化学键，构成了交联结构，相比其他两种隔膜，新型复合隔膜的力学性能有大幅度提升；孔隙率和吸液率得到提升。电化学测试可知，新型复合隔膜能够有效降低的界面阻抗和内阻，0.1C倍率100次循环后仍有较高的容量保留率，且倍率性能优异。     

PVA/APP改性锂电隔膜的制备与性能

以高聚合度的聚磷酸铵(APP)作为阻燃剂,聚乙烯醇(PVA)为成膜骨架材料,通过相转化的方法制备PVA/APP改性隔膜,使用在锂电池中。对改性隔膜的机械强度、湿润性、热稳定性、微观形貌以及电化学性能进行表征。探究不同APP添加量对隔膜性能的影响,对其组装电池的循环倍率性能进行评价。结果表明,当PVA质量分数为10%、APP添加量为8%时,改性隔膜具有优异的电解液湿润性以及热稳定性,吸液率达到215%,在200 ℃下几乎不收缩;拉伸强度达到47.4 MPa。使用改性隔膜组装电池,在0.1 C放电条件下循环50次,放电比容量为143.2 mAh/g,库伦效率均大于97%,容量保持率达到95.1%,而商用锂电池隔膜所组装电池的容量保持率只有82.8%。改性隔膜在具有阻燃性能的同时所组装电池能保持良好的电化学性能。     

PVDF/类石墨相氮化碳电纺锂电池隔膜制备及性能

设计机械强度高、电化学性能好和绝缘性优良的锂电池隔膜具有重要意义。采用热缩聚法将类石墨相氮化碳(g-C_3N_4)与聚偏氟乙烯(PVDF)混纺制备了PVDF/g-C_3N_4复合纤维隔膜,通过扫描电子显微镜、万能拉伸试验仪、热重分析仪、电化学工作站、电池测试系统对PVDF/g-C_3N_4复合纤维隔膜的微观形貌和性能进行测试与表征。考察了g-C_3N_4纳米片添加量对复合纤维隔膜的形貌、热稳定性、力学性能以及电化学性能等的影响。研究表明,当g-C_3N_4纳米片添加量为PVDF质量的5%时,纤维直径最小,力学性能最好且孔隙率最大为74.08%;提高其含量至15%时,吸液率达到最大为443.48%;当g-C_3N_4纳米片添加量为PVDF质量的10%时,复合纤维隔膜的离子电导率及电化学稳定窗口分别达到了1.15×10~(–3) S/cm和5.1 V。与商用隔膜相比,PVDF/g-C_3N_4复合纤维隔膜表现出良好的电化学性能。     

锂离子电池用隔膜孔隙率对电池性能的影响

考察了锂离子电池用隔膜孔隙率对锂离子电池内阻、倍率放电、高温储存、常温0.5 C/0.5 C循环等性能的影响。随着锂离子电池隔膜孔隙率的增加,电池内阻有所降低,高温储存性能有所下降;电池小电流(0.5 C、1 C)倍率放电性能影响不大,大电流(2 C、3 C)倍率放电性能有所提升;常温0.5 C/0.5 C循环性能有所提高。综合考虑,当锂离子电池隔膜孔隙率为42%时,电池性能较优。     

动力电池用聚四氟乙烯复合隔膜研究

以聚乙烯为基膜,制备动力电池用聚四氟乙烯复合隔膜。用冷场发射扫描电子显微镜表征了聚四氟乙烯/聚乙烯复合薄膜的表面形态,并测试了复合隔膜的孔隙率和力学性能。结果表明,复合聚四氟乙烯微孔膜后,复合膜的孔隙率仍可以达到37.8%,耐刺穿强度提高了近25%。     

Preparation and characterization of poly(vinylidene fluoride)-13X zeolite mixed matrix membranes for lithium ion batteries' separator with enhanced performance

13X zeolite was hydrothermally synthesized and poly(vinylidene fluoride) (PVDF)/13X zeolite particles mixed matrix membranes were prepared using phase inversion method as the lithium-ion battery separator. Hydrophilic and porous 13X zeolite loading impacts on the critical separator properties of morphology, wettability, electrolyte uptake, and high temperatures dimensional stability were investigated using scanning electron microscopy, contact angle, and thermal shrinkage analysis. Electrolyte uptake of the 13X zeolite particles loaded PVDF separators increased and also the incorporation facilitated the lithium ions migration (ion conductivity) due to the Lewis acidity of their structure. The 8 wt% 13X zeolite loaded separator (S2) revealed higher porosity (~+20%), electrolyte uptake (+80%), ion conductivity (+80%), and thermal shrinkage (~−47% at 165°C). C-rate capability and cycle performance of a cell battery assembled using the S2 separator considerably improved compared with those of the assembled by the neat PVDF and commercial polypropylene separators.     

紊流循环法合成超细磷酸锂及表征

采用共沉淀法在紊流循环方式下制备超细磷酸锂的一种新工艺,探索了氢氧化锂和磷酸在紊流循环釜中制备超细磷酸锂的反应条件,用X射线粉末衍射、激光粒度仪、扫描电镜、比表面及孔隙分析仪及热分析仪对产物的晶体结构、粒度分布、外观形貌、比表面积以及热稳定性进行了表征。结果表明该方法制得的磷酸锂热稳定性好,粒度分布窄（D₅₀=3.25 mm）,比表面积（BET）为13.38 m²·g^-1,为一种分散均匀的超细粉体材料,可望成为一种高活性的锂离子电池正极材料原材料或电解质添加剂。     

固体电解质的制备及其在锂氧电池性能研究

本文提出了将高离子电导率的全固态电解质Li1.4Al0.4Ti1.6(PO3)4(LATP)用于锂氧电池。用Pechini法成功的合成了全固态电解质，采用X射线荧光衍射(XRD)、场发射扫描电子显微镜(SEM)和电化学性能分析其性能。结果显示，LATP不仅具有较高的离子导电性，而且LATP作为固体电解质，具有更高的放电平台。同时，LATP固体电解质能降低电解质的分解，从而能够减少放电产物的生成。因此，LATP玻璃陶瓷固体用于锂氧电池提高了锂氧电池的热稳定性并且降低了锂氧电池热膨胀。LATP固体电解质利用在可再充电锂氧电池中具有良好的前景。     

Polyethylene battery separator with auto‐shutdown ability,thermal stability of 220°C,and hydrophilic surface via solid‐state ultraviolet irradiation

To assure the safety of the lithium‐ion battery, the separator is required to have good thermal stability. Because the single‐layer polyethylene (PE) separator can only tolerate a temperature of 130°C, it is seldom employed currently by lithium‐ion battery manufacturers although its cost is low. In this article, we modified PE separator chain structure through solid‐state ultraviolet (UV) irradiation method to achieve a separator with composite structure of ～40% crystallized PE and ～70% gel content. Approximately 40% crystallized PE chains fulfill the task of auto‐shutdown at 130°C through melting and filling the pores. At the same time, the PE separator can maintain integrity till 220°C because of its highly cross‐linked chain structure. Besides, the modified PE separator is hydrophilic with a water contact angle of 33° after UV treatment and is able to absorb more electrolyte. However, the tensile strength and elongation at the break decreased because the cross‐linking network increased the rigidity. Nevertheless, these values still meet the requirements as the separator for lithium‐ion battery. Considering the low cost and easy preparation, current cross‐linked PE separator has potential to be used in lithium‐ion batteries for various applications, including electric vehicles and energy storage purpose. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42169.     

Preparation of 4A zeolite coated polypropylene membrane for lithium-ion batteries separator

This study aims to improve wettability and thermal resistance of lithium-ion batteries separators. For this purpose, a commercial polypropylene (PP) separator was coated by 4A zeolite using poly(vinylidene fluoride) as binder and effects of the separators' zeolite content was investigated. All the coated separators showed lower contact angles, higher electrolyte uptakes, and less thermal shrinkages compared to the neat commercial separator. The coated PPA8 separator (zeolite to binder ratio of 8) showed the lowest wettability (contact angle of 0°) and electrolyte uptake (270%) due to its surface porosity resulting from the zeolite particles interstitial cavities as well as their internal cavities. Also, the PPA8 separator ion conductivity was found as 2.25 mS cm⁻¹ and C-rate and cycling performance of its assembled battery were higher compared to those of the commercial PP separator assembled battery. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47841.     

锂离子电池隔膜研究与发展现状

介绍了锂离子电池隔膜的特性和类型。重点介绍了国内外聚烯烃隔膜的发展现状,通过专利和文献的检索了解到以聚烯烃为原料生产锂离子电池隔膜的发展历史和目前国外对锂离子电池隔膜开展研究较活跃的国家,最后介绍了锂离子电池隔膜的生产技术和国内市场情况,并提出了发展建议。     

Preparation and performance of aramid nanofiber membrane for separator of lithium ion battery

Stable and uniform dispersions of para‐aramid nanofibers have been prepared by adding methoxypolyethylene glycol (mPEG) in the polymerization process, followed by strong shear and dispersion. Aramid membranes are fabricated by vacuum‐assisted filtration of the nanofiber dispersion and assembled into batteries as separator. The membrane properties and battery performances are characterized in detail and the effect of mPEG content on these properties is explored. It is demonstrated that aramid membranes possess good electrolyte wettability, excellent mechanical properties, and superior thermal stability, which improve the safety of lithium ion batteries. The mPEG is critical to the formation of aramid nanofibers and improves the porosity and ionic conductivity of the membranes. These fascinating characteristics and facile papermaking method endow aramid membrane potential application as separator in lithium ion batteries with superior safety. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43623.     

The Effect of Sodium Dodecyl Sulfate (SDS) and Cetyltrimethylammonium Bromide (CTAB) on the Properties of ZnO Synthesized by Hydrothermal Method

ZnO nanostructures were synthesized by hydrothermal method using different molar ratios of cetyltrimethylammonium bromide (CTAB) and Sodium dodecyl sulfate (SDS) as structure directing agents. The effect of surfactants on the morphology of the ZnO crystals was investigated by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) techniques. The results indicate that the mixture of cationic-anionic surfactants can significantly modify the shape and size of ZnO particles. Various structures such as flakes, sheets, rods, spheres, flowers and triangular-like particles sized from micro to nano were obtained. In order to examine the possible changes in other properties of ZnO, characterizations like powder X-ray diffraction (PXRD), thermogravimetric and differential thermogravimetric analysis (TGA-DTG), FTIR, surface area and porosity and UV-visible spectroscopy analysis were also studied and discussed.     

Understanding the influence of conductive carbon additives surface area on the rate performance of LiFePO4 cathodes for lithium ion batteries

Conductive carbon additives with different surface area and particle size, alone or in different combinations, were tested as conductive additives for LiFePO₄ cathode materials in lithium ion batteries. Their influence on the conductivity, rate capability as well as the structure of the resulting electrodes was investigated. Mercury porosimetry was carried out to define the porosity and pore size distribution of electrodes, and scanning electron microscopy was used to image their morphology. By comparing the discharge capacity, especially at higher rates, it can be concluded that the electrochemical performance of LiFePO₄ cathode material is significantly affected by the surface area, particle size and morphology of the used carbon additives. The best rate performance is achieved with the electrode containing a carbon additive with a specific surface area of 180 m² g⁻¹. This work reveals that the choice of conductive additive influences discharge capacity of LiFePO₄ Li-ion battery cells by as much as 20–30%. This is due to conductive additive’s influence on both electronic conductivity and porosity (which determines ionic conductivity) of LiFePO₄ electrodes. A system approach to lithium ion battery material research should always consider inactive materials, such as conductive additives and binders, in addition to active materials.