Investigating miscibility and lithium ion transport in blends of poly(ethylene oxide) with a polyanion containing precisely-spaced delocalized charges
Investigating miscibility and lithium ion transport in blends of poly(ethylene oxide) with a polyanion containing precisely-spaced delocalized charges
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研究聚环氧乙烷与含有精确间隔的离域电荷的聚阴离子的混合物中的混溶性和锂离子传输
DOI：
10.1039/d2py00605g
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发表时间：
2022
影响因子：
4.6
通讯作者：
Kennemur, Justin G.
中科院分区：
文献类型：
--
作者：
Nguyen, Nam;Blatt, Michael Patrick;Kim, Kyoungmin;Hallinan, Daniel T.;Kennemur, Justin G.
通过开环易位聚合（ROMP）和后聚合改性，合成了一种新型的聚乙烯主链上每5个碳原子共价键合有苯磺酰（三氟甲基磺酰）亚胺锂盐的精密单离子导体p5 PhTFSI-Li。通过19 F NMR分析测定并通过其它光谱方法证实，带有94%磺酸根阴离子的聚（4-苯基环戊烯）向三氟甲磺酰亚胺（TFSI）阴离子的转化是高效的（约90%）。柔性烃主链与大体积TFSI阴离子结合导致即使在这些高电离水平下也可观察到199 °C的玻璃化转变温度。还观察到高达375 °C的高热稳定性。将p5 PhTFSI-Li与聚（环氧乙烷）以各种组成共混，以使用阻抗和极化方法的组合来研究相对于锂电极的电化学性能和迁移数。在90 °C和50：50重量%的共混物组成下，该系统显示出最高的电导率（2.00 × 10−4 S cm−1），并且证明锂离子迁移数接近1。 这样的性能也是通过后聚合改性生产的单离子导体的典型，我们将其归因于TFSI转化的高产率。这些共混物在各种组合物的复杂的可溶解性和相行为的调查也探讨了显微镜和差示扫描量热法的组合，这是讨论参考计算预测的电荷相关性如何影响聚合物共混物的相行为。
A novel precision single-ion conductor with phenylsulfonyl(trifluoromethylsulfonyl)imide lithium salt covalently bound to every fifth carbon of a polyethylene backbone, p5PhTFSI-Li, was synthesized via ring opening metathesis polymerization (ROMP) followed by post polymerization modification. The conversion of poly(4-phenylcyclopentene), bearing 94% sulfonate anions, to trifluoromethanesulfonimide (TFSI) anions was highly efficient (∼90%) as determined by 19F NMR analysis and corroborated through other spectroscopic methods. The flexible hydrocarbon backbone combined with a bulky TFSI anion led to an observable glass transition temperature of 199 °C even at these high levels of ionization. A high thermal stability up to 375 °C was also observed. Blending of p5PhTFSI-Li with poly(ethylene oxide) at various compositions was performed to investigate electrochemical performance and transference numbers with respect to the lithium electrode using a combination of impedance and polarization methods. At 90 °C and a 50 : 50 wt% blend composition, this system displayed the highest reported conductivity (2.00 × 10−4 S cm−1) of a system with a demonstrated lithium-ion transference number near unity. Such performance is also atypical of single ion conductors produced through post-polymerization modification, which we attribute to the high yield of TFSI conversion. Investigations into the complex miscibility and phase behavior of these blends at various compositions was also probed by a combination of microscopy and differential scanning calorimetry, which is discussed with reference to computational predictions of how charge correlations affect polymer blend phase behavior.