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以某进口均聚聚丙烯(PP)(PP1)为原料,通过挤出流延工艺制备了PP1硬弹性膜并在130℃下对其进行热处理,研究了挤出温度、流延辊转速及温度、热处理温度和时间等工艺参数对PP1硬弹性膜弹性回复率的影响,得到了最佳工艺条件,即挤出温度为195℃、流延辊温度及转速分别为90℃,26 r/min,热处理温度和时间分别为145℃,30 min。将该工艺应用于分子量及其分布与PP1基本相似的国产PP(PP2),发现由此工艺制备的PP2硬弹性膜的弹性回复率可达94.6%,与PP1硬弹性膜相差不大。通过冷热单向拉伸将PP1和PP2硬弹性膜制备成微孔膜,发现两者具有相似且优异的微孔结构。在此基础上,通过扫描电子显微镜研究了冷热拉伸工艺参数对PP2微孔膜拉伸成孔性的影响。结果表明,当冷拉伸倍数为15%,热拉伸倍数为100%,冷热拉伸速率均为50 mm/min时,制备的PP2微孔膜形成了完整规则的多孔结构。 相似文献
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翟燕燕 《精细与专用化学品》2020,28(8):9-11
电池隔膜是锂电池的重要部件之一。聚烯烃微孔膜性能优异,被广泛用于制备电池隔膜。以电池隔膜用聚烯烃微孔膜的中国专利申请文献为研究对象,在申请势态、区域分布、主要申请人以及重点专利方面进行分析,对我国锂电池隔膜相关企业的研发生产和专利布局提出了一些建议。 相似文献
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正中国石化上海石油化工股份有限公司(简称上海石化)工业化生产的新产品——低灰分聚丙烯(PP)F300C具有立体规整度高(等规指数98.5%)、电性能优异、绝对不含塑化剂(邻苯二甲酸酯盐)等特点,可应用于双向拉伸PP电容器膜、锂电池隔膜等领域。上海石化自主开发并产业化的PP F780R可用 相似文献
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随着塑料制刷业的兴起,硬弹性PP单丝(φ0,8~1mm)的需求量越来越大.由于用途上特殊的硬弹性需求,其生产技术也不同一般.目前,国内仅有几家企业能够生产,本文根据生产实践,研究讨论了硬弹性单丝的生产技术.1 硬弹性PP单丝的特殊性与通常单丝相比,硬弹性PP单丝直径大且具有较高的弯曲刚性和弯曲变形回弹性.已知PP单丝的硬弹性受分子量大小,结晶度高低,球晶完善程度,单丝内部空穴多少(大小)等因素影响,除此之外在很大程度上还取决于PP分子取向度.经验表明PP拉伸比≥19时,单丝的硬弹性达到理想范围.如此大的拉伸比,要求用较粗的拉伸条(如φ1mm单丝需要用φ4.3~4.5mm粗的拉伸 相似文献
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为解决聚丙烯(PP)隔膜对电解液润湿性能差、耐热性能差的问题,选用氧化铝(Al2O3)为陶瓷填料、聚乙烯醇(PVA)为粘结剂、去离子水为溶剂制备涂覆浆料,采用刮涂法在传统PP隔膜表面涂覆上Al2O3 /PVA层。通过X射线衍射图谱(XRD)、扫描电镜(SEM)、接触角测试、润湿性能测试和耐热性能测试对改性前后隔膜进行表征,并将改性前后隔膜组装成纽扣电池进行电化学性能表征。结果表明:在PP隔膜表面成功引入Al2O3 /PVA涂层后,润湿性能和耐热性能得到明显改善,吸液率由98%提高到203%,在170℃下热处理1 h的热收缩率由46.1%减小至24.4%。与原隔膜相比,改性隔膜组装的电池的循环性能和倍率性能更好。 相似文献
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对于锂电池安全性来说,隔膜的使用具有重要意义。首先对锂离子电池隔膜性能要求作出简要阐述,然后对高热稳定性锂电池复合隔膜的制备进行实验,并对其表征情况进行分析,明确复合隔膜可以发挥的重要作用,希望对业内可以起到一定参考作用。 相似文献
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Majid Badini Pourazar Toraj Mohammadi Mohamad Reza Jafari Nasr Omid Bakhtiari Mehran Javanbakht 《应用聚合物科学杂志》2020,137(44):49367
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. 相似文献
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The mechanical integrity of battery separators is critical for battery safety and durability. A comprehensive study of strain‐rate‐dependent tensile and puncture properties of a polypropylene lithium‐ion battery separator is presented here with a new model. Due to anisotropy of the polymeric membrane, tensile testing was conducted for different directions. Results showed that tensile strength and elastic modulus were increased 1000% and 500%, respectively, for different directions. It was also demonstrated that tensile strength changed 10 to 25% with strain rate (1.67 × 10?4 to 1.67 × 10?1 s?1) for different directions. An equation was obtained for the first time for flow stress versus strain rate at varied tensile directions with respect to machine direction. Moreover, puncture testing was performed and it was shown that puncture strength was increased 140% with increasing strain rate from 0.25 to 250 mm min?1. Two failure modes were also observed in puncture samples. Finally, Eyring's model was used to calculate activation enthalpy of the porous polypropylene separator. © 2020 Society of Chemical Industry 相似文献
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A biaxial stretched β‐isotactic polypropylene microporous membrane for lithium‐ion batteries
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In this article, microporous polypropylene (PP) membranes were produced with TMB‐5 as β‐crystal nucleating agent by biaxial stretching. Influences of different concentration of TMB‐5 were studied using differential scanning calorimetry and X‐ray diffraction. It was found that the highest crystallinity was reached when the nucleating agent content was 0.5 wt %. The effect of stretching temperature and stretching ratio on pore size distribution and porosity of the membranes were investigated by scanning electron microscopy and mercury porosimeter, respectively. And physical properties, such as tensile strength, permeability, and puncture resistance of the microporous membrane prepared at the optimized conditions, were evaluated. Compared with commercial PP separator membrane, the as‐prepared microporous membrane shows similar uniform pore size distribution and exhibits slightly higher porosity and ionic conductivities. When used as lithium‐ion separator, the experimental film shows more stable cycling performance than the commercial one. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45825. 相似文献
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相对于传统锂离子电池隔膜,有机-无机陶瓷复合隔膜兼具有机材料的柔韧性、无机材料的耐温性和电解液亲和性。本文对锂离子电池用陶瓷复合隔膜进行综述,首先介绍了此类隔膜相对于传统隔膜的优势,其次对目前研究的陶瓷锂离子电池隔膜的结构形式和主要成膜材料进行了讨论,并介绍了国内外主要公司的陶瓷复合隔膜的研究和发展现状,最后对陶瓷复合隔膜的应用前景和面临的挑战进行了简要分析。鉴于该新型隔膜的优势,随着锂离子电池在高端电子产品以及动力、储能等新兴领域的发展,高安全性陶瓷复合锂离子电池隔膜必将代替传统的聚烯烃隔膜,成为主流隔膜满足人们的需要。 相似文献
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