Phase Behavior and Ionic Conductivity of Blended, Ion-Condensed Electrolytes with Ordered Morphologies
Phase Behavior and Ionic Conductivity of Blended, Ion-Condensed Electrolytes with Ordered Morphologies
复制标题
DOI：
10.3390/app12136529
复制
发表时间：
2022-06
期刊：
影响因子：
--
通讯作者：
Hannah Collins;Jiacheng Liu;Lingyu Yang;J. Schaefer
中科院分区：
文献类型：
--
作者：
Hannah Collins;Jiacheng Liu;Lingyu Yang;J. Schaefer
在这项研究中，两亲性盐锂三氟甲磺酰亚胺十八烷（C18 LiTFSI）被用作基础，研究的阴离子密度和阳离子配位点的影响，在混合电解质与强离子聚集。C18LiTFSI先前被报道为具有宽层状液晶相区的单组分离子凝聚电解质。合成了三种具有不同大小的极性磺酰基的添加剂分子，并将其与C18LiTFSI混合。对共混电解质的热性能、形貌和离子电导率进行了表征。结果发现，混合电解质在比纯盐更窄的温度范围内表现出层状液晶形态，并且混合液晶电解质的离子电导率普遍低于纯盐的离子电导率。令人惊讶的是，发现添加剂对电解质的半结晶相的体离子电导率具有最大的影响。甲磺酰基十八烷的小部分的C18锂TFSI导致在室温下的电导率的增加超过两个数量级，而乙基磺酰基十八烷或异丙基磺酰基十八烷与较大的头部基团导致在整个组合物的空间和温度范围内的离子电导率降低调查。
In this study, the amphiphilic salt lithium trifluoromethanesulfonylimide octadecane (C18LiTFSI) was used as a basis to investigate the effects of anion density and cation coordination sites within blended electrolytes with strong ionic aggregation. C18LiTFSI was previously reported as a single-component, ion-condensed electrolyte with a wide layered liquid crystalline phase regime. Three additive molecules with varyingly sized polar sulfonyl groups attached to an octodecane-tail were synthesized and mixed with C18LiTFSI. The thermal properties, morphology, and ionic conductivity of the blended electrolytes were characterized. It was found that the blended electrolytes exhibited layered liquid crystalline morphology over a narrower temperature range than the pure salt, and the ionic conductivity of the blended liquid crystalline electrolytes were generally lower than that of the pure salt. Surprising, the additives were found to have the greatest effect on the bulk ionic conductivity of the semicrystalline phase of the electrolytes. Addition of minor fractions of methylsulfonyloctadecane to C18LiTFSI resulted in increases in conductivity of over two orders of magnitude at room temperature, while addition of ethylsulfonyloctadecane or isopropylsulfonyloctadecane with the larger head group resulted in decreased ionic conductivity over the entire composition space and temperature range investigated.