Interconnected Porous Poly(ether imide) Separator for Thermally Stable Sodium Ion Battery
Interconnected Porous Poly(ether imide) Separator for Thermally Stable Sodium Ion Battery
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DOI：
10.1021/acsaem.1c01949
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发表时间：
2021-10
影响因子：
6.4
通讯作者：
Xuhong Niu;Jing Li;Jianfeng Song;Yueming Li;T. He
中科院分区：
文献类型：
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作者：
Xuhong Niu;Jing Li;Jianfeng Song;Yueming Li;T. He
由于钠资源丰富且成本低廉，钠离子电池越来越受到大规模能源应用的关注。隔膜是决定钠离子电池性能的关键材料之一。本文采用热稳定的聚醚亚胺（PEI）和聚乙烯吡咯烷酮（PVP）共混物通过浸泡相分离制备了钠离子电池分离器。由于PVP和PEI聚合物的二次脱混，PEI/PVP分离器呈现出相互连接的多孔结构。与商用聚丙烯相比，PEI/PVP分离器具有更好的润湿性，更高的离子电导率（1.14 mS cm-1），更高的热稳定性（高达180°C），与玻璃纤维（GF）分离器相比，具有更好的柔韧性和机械强度（39%,6.7 MPa）。采用16/12 PEI/PVP隔板制备的无序介孔碳/钠电池在0.5℃下具有119.4 mAh g - 1的高放电容量，且制备的PEI/PVP隔板大大提高了钠离子电池的循环稳定性和倍率性能。钠离子电池的电化学性能的提高是由于其多孔结构和高电解质吸收率。这些结果表明PEI/PVP分离器是一种安全、高性能的钠离子电池。
Due to the abundance and low costs of sodium resources, sodium ion batteries have attracted increasing attention for large-scale energy applications. The separator is one of the key materials that determines the performance of sodium ion batteries. Here a separator for sodium ion batteries is prepared using a thermally stable poly(ether imide) (PEI) and polyvinylpyrrolidone (PVP) blend via immersion phase separation. The PEI/PVP separators show an interconnected porous structure due to the secondary stage demixing of PVP and PEI polymers. The PEI/PVP separator demonstrated better wettability, higher ionic conductivity (1.14 mS cm–1), and higher thermal stability (up to 180 °C) compared to commercial polypropylene, and better flexibility and mechanical strength (39%, 6.7 MPa) compared to a glass fiber (GF) separator. The disordered mesoporous carbon/Na cell with a 16/12 PEI/PVP separator shows a high discharge capacity of 119.4 mAh g–1at 0.5 C. Moreover, the cycling stability and rate performance of the sodium ion batteries is greatly enhanced using the prepared PEI/PVP as a separator. The enhanced electrochemical performance of the sodium ion batteries is attributed to the interconnected porous structure and high electrolyte uptake. These results suggest that the PEI/PVP separator is promising for safe and high performance sodium ion batteries.