Novel polymer/salt hybrid composed of comblike organoboron polymer electrolyte and boron-stabilized imido anion
Novel polymer/salt hybrid composed of comblike organoboron polymer electrolyte and boron-stabilized imido anion
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DOI：
10.1021/ma047469p
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发表时间：
2005-03-22
期刊：
影响因子：
5.5
通讯作者：
Ohno, H
中科院分区：
文献类型：
--
作者：
Matsumi, N;Nakashiba, M;Ohno, H
醚氧对锂离子的强配位通常阻止PEO衍生物表现出对阳离子传输的高选择性。考虑到不仅实现高能量密度而且实现系统的可靠性能，PEO衍生物的这种特征是不期望的，因为这种双离子系统在电解质基质内产生电势梯度，使得装置的内部电压被抵消。由于聚醚衍生物的阳离子导电性不足，单离子导电聚合物的分子设计已被广泛研究。1这种材料通常通过将阴离子固定到聚合物电解质基质上来获得。迄今为止，已经开发了许多称为“聚合物-盐杂化物”的材料。虽然阴离子的固定化降低了载体离子数并导致较低的离子电导率，但通过采用高度可解离的盐结构已经获得了改善的离子电导率。2作为基于稳定的亚氨基阴离子的高度可解离的锂盐，LiTFSI和LiBETI已被广泛用作聚合物电解质中的盐添加剂作为盐。3在这些盐中，亚氨基阴离子通过对磺酰基的共振效应而高度稳定。因此，磺酰胺和磺酰亚胺结构已成为高导电聚合物/盐杂化物的一个有吸引力的组分。2作为稳定亚氨基阴离子的另一种途径，本文提出了通过亚氨基硼烷的中和反应来设计硼稳定亚氨基阴离子的分子。通常，硼原子能够稳定其相邻的阴离子，类似于羰基。[4]利用这种化学性质，我们最近报道了硼稳定碳负离子的体离子电导率。[5]更常见的是，氮原子的孤对电子强烈地流入相邻硼原子的空p轨道（pπ-pπ相互作用;图1）。6因此，在亚氨基阴离子附近引入硼原子似乎是一种很有前途的方法，可以产生一类具有高度解离性的新型非卤化盐。近年来，我们一直在研究有机硼主链聚合物电解质的合成及其离子导电性能。利用硼氢化聚合8制备了硼酸酯型聚合物、烷基硼烷型聚合物、梳状聚合物、硼烷-咪唑配合物、有机硼聚合物熔盐等多种离子导电基体。我们还报道了一些硼酸锂
Strong coordination of ether oxygen toward lithium ion generally prevents PEO derivatives from exhibiting high selectivity for cation transport. Such features of PEO derivatives are undesirable in view of achieving not only high energy density but also reliable performance of systems, since such biionic systems generate potential gradients within the electrolyte matrix so that the inner voltage of devices is offset. Because of such inadequate cationic conductivity of polyether derivatives, molecular design of single ion conductive polymers has been widely examined. 1 Such materials are typically obtained by immobilizing the anion onto the polymer electrolyte matrix. A number of materials called “polymer-salt hybrids” have been thus developed so far. Although immobilization of the anion decreases the carrier ion number and leads to lower ionic conductivity, improved ionic conductivity has been attained by employing highly dissociable salt structure. 2 As highly dissociable lithium salts based on a stabilized imido anion, LiTFSI and LiBETI have been widely used as salt additives in polymer electrolytes. 3 In these salts, imido anions are highly stabilized via the resonance effect on sulfonyl groups. Therefore, sulfonamide and sulfonimide structure had been an attractive component for highly conductive polymer/salt hybrids. 2 As a different approach for the stabilization of imido anion, herein is proposed the molecular design of boronstabilized imido anion via the neutralization reaction of iminoborane. Generally, boron atom is capable of stabilizing its adjacent anion similar to a carbonyl group. 4 Making use of this chemistry, we have recently reported bulk ionic conductivity of boron-stabilized carbanions. 5 It is more commonly known that a lone pair electron of the nitrogen atom strongly flows into the vacant p-orbital of the adjacent boron atom (pπ-pπ interaction; Figure 1). 6 Therefore, incorporation of the boron atom adjacent to imido anion appears to be a promising method to create a novel class of nonhalogenated salts showing a high degree of dissociation.In recent years, we have been studying synthesis of organoboron main-chain polymer electrolytes7 and their ion conductive properties. Taking advantage of hydroboration polymerization, 8 a variety of ion conductive matrixes such as boric ester type polymer, alkylborane type polymer, comblike polymer, borane-imidazole complex, and organoboron polymer molten salts were prepared. We have also reported some lithium borate