High-Modulus Single-Ion-Conducting Electrolytes Based on a Rigid-Rod Polyanion
High-Modulus Single-Ion-Conducting Electrolytes Based on a Rigid-Rod Polyanion
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DOI：
10.1021/acsaem.3c00243
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发表时间：
2023-06
影响因子：
6.4
通讯作者：
J. Bostwick;Deyang Yu;Curt J. Zanelotti;T. Dingemans;L. Madsen;R. Colby
中科院分区：
文献类型：
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作者：
J. Bostwick;Deyang Yu;Curt J. Zanelotti;T. Dingemans;L. Madsen;R. Colby
单离子导电电解液易于加工，可以阻止Li树枝晶的生长，显示出在固态电池中的应用潜力。报道了将刚性棒状聚阴离子聚(2，2‘-二磺酰基-4，4’-联苯二甲酰胺)(PBDT)与Na+或Li+反离子和聚乙二醇(PEG400 gmol-1)结合的固体电解质。PBDT-PEG膜的杨氏模数在90~2110兆帕之间，随PBDT含量的增加而增大，锂基膜的杨氏模数是钠基膜的4倍。我们将LiPBDT-PEG的高模数归因于Li+和PBDT磺酸盐基团之间较差的离子离解以及LiPBDT和聚乙二醇之间较强的相互作用。这些膜的离子电导率随着聚乙二醇浓度的增加而增加(30°C时为0.1-7μS cm-1)，在120°C时达到0.13ms cm-1。这些材料使用高刚性和带电的PBDT双螺旋将低分子聚乙二醇“固化”成机械强度高、单离子导电性高、热稳定性高的固体聚合物电解质。它们的高阳离子电导率和高模数的组合超过了30°C时竞争对手的单离子导体。
Single-ion-conducting electrolytes enable easy processing and can block Li dendritic growth, showing potential for use in solid-state batteries. We report solid electrolytes that combine a rigid-rod polyanion, poly(2,2′-disulfonyl-4,4′-benzidine terephthalamide) (PBDT), with Na+or Li+counterions, and poly(ethylene glycol) (PEG,Mn= 400 g mol–1). PBDT-PEG membranes show Young’s modulus from 90 to 2110 MPa that increases with the PBDT content and is >4× higher for Li-based vs Na-based electrolytes. We attribute this dramatically higher modulus in LiPBDT–PEG to poorer ion dissociation between Li+and PBDT sulfonate groups and stronger interactions between LiPBDT and PEG. These membranes show an increase in ionic conductivity with increasing PEG concentration (0.1–7 μS cm–1at 30 °C), reaching 0.13 mS cm–1at 120 °C. These materials use highly rigid and charged PBDT double helices to “solidify” low-molecular-weight PEG into mechanically strong and highly single-ion-conductive solid polymer electrolytes with high thermal stability. Their combination of high cation conductivity and high modulus exceeds those of competing single-ion conductors at 30 °C.