Robust Composite Separator Randomly Interwoven by PI and Pre-oxidized PAN Nanofibers for High Performance Lithium-ion Batteries  

作　　者：Ying Li Chen Pan Feng Gan Zhi-Xun Lin Jin-Chao Yu Zhen-Zhen Wei Yan Zhao 

机构地区：[1]College of Textile and Clothing Engineering,National Engineering Laboratory for Modern Silk,Soochow University,Suzhou,215123,China [2]College of Textile Science and Engineering,Wuyi University,Jiangmen,529020,China

出　　处：《Chinese Journal of Polymer Science》2024年第11期1768-1779,I0012,共13页高分子科学（英文版）

基　　金：financially supported by the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.22KJA480004);the Key Laboratory of Flame Retardancy Finishing of Textile Materials,CNTAC(No.Q811580421)。

摘　　要：Electrospun nanofibrous separators,despite lacking superior mechanical strength,have gained widespread attention with high porosity and facile processing.Herein,utilizing the fact that thermal imidization temperature of poly(amic acid)(PAA)into polyimide(PI)coincides with the pre-oxidation temperature of polyacrylonitrile(PAN)into carbon fiber,we proposed a new cross-electrospinning strategy to obtain a composite nanofibrous separator(PI/oPAN)randomly interwoven by PI and pre-oxidized PAN(oPAN)nanofibers,via synchronously electrospinning the PAA and PAN onto the same collector and then heat-treating for 2 h at 300℃.The resultant PI/oPAN separator was able to preserve high porosity(71.7%),electrolyte wettability and thermal stability of PI nanofibrous membrane,and surprisingly exhibited high mechanical strength,being 3 times of PI,which mainly because of the numerous adhesion points generated by the melting of PAN in the pre-oxidation process.Meanwhile,the polar groups of oPAN and 3D fibrous network enhanced the PI/oPAN separator's ionic conductivity and Li+transference number,rendering the corresponding cell with more stable cycling performance than cells assembled with pure PI,PAN or commercial PP separator.Therefore,this work might provide a new avenue for the ongoing design and further development of LIB separators capable of high safety and high performance.

关 键 词：Lithium-ion battery Nanofibrous separator Cross-electrospinning Polyimide Pre-oxidized polyacrylonitrile 

分 类 号：TM912[电气工程—电力电子与电力传动] TQ340.64[化学工程—化纤工业] TB383.2[一般工业技术—材料科学与工程]