原纤化PBO纤维耐高温复合隔膜的制备

Preparation of high-temperature resistant composite separator with PBO fibrillated fibers

隔膜对锂离子电池安全性能有着重要影响。为了提高隔膜的耐热性能,采用湿法成型技术,使用聚对苯撑苯并二噁唑(PBO)原纤化纤维和聚对苯二甲酸乙二醇酯(PET)无纺布作为原料,制备了一种耐高温的双层复合隔膜(PET/PBO)。差示扫描量热法(DSC)和热尺寸收缩实验证明,PET/PBO复合膜与商用PP隔膜Celgard 2500相比具有更出色的热稳定性,225℃下尺寸收缩仅2.5%;湿法成型工艺又赋予隔膜更高的孔隙率,可达70%;PBO面与电解液接触角仅为14°,具有良好的电解液浸润性;充放电实验证明,PET/PBO隔膜组装的电池有着良好的循坏和倍率性能。表明该复合膜是高性能锂离子电池隔膜的理想候选者。

The separator plays a crucial role in ensuring the safety of the lithium-ion batteries.To improve the thermal resistance of the separator,a PET/PBO high-temperature dual-layer composite separator was prepared using a wet-forming technique,with poly(p-phenylene benzobisoxazole)(PBO)fibrillated fibers and polyethylene terephthalate(PET)nonwoven fabric as the raw materials.Differential scanning calorimetry(DSC)and thermal shrinkage measurement results reveal that the PET/PBO composite film exhibits superior thermal stability compared to that of the commercial PP separator Celgard 2500.It has a shrinkage of only 2.5%at 225℃.The wet-forming process endows the separator with a higher porosity of up to 70%.The PBO surface has a contact angle of only 14°with the electrolyte,indicating good electrolyte wettability.The charge-discharge test results demonstrate excellent cyclic and rate capabilities of the batteries assembled with PET/PBO separators.These results indicate that the composite separator is an ideal candidate for high-performance lithiumion battery separators.