论文标题
了解浓缩的块聚合物电解质中的锂离子转运在微观水平上
Understanding the Lithium Ion Transport in Concentrated Block-Copolymer Electrolytes on a Microscopic Level
论文作者
论文摘要
带有层状微结构的块聚合物电解质对实验中离子传输显示出令人鼓舞的结果。由这些观察结果激励，我们研究了由聚苯乙烯（PS）块和聚集在层状结构中组装的聚（PS）块和聚（PEO）块组成的块状聚合物。将Lamella与各种量的锂双（三氟甲烷）磺胺酰亚胺（LITFSI）掺杂，直到达到具有EO单体与阳离子比1：1的高负载。我们从广泛的分子动力学模拟中介绍了对结构和离子传输的见解。对于高盐浓度，大多数阳离子不是由PEO协调的，而是由TFSI和THF协调。更具体地说，LITFSI部分与PEO结构域分离，并在Lamella的中间形成类似网络的结构。这个富含盐的中央层起着决定性的作用，可以使阳离子迁移率显着，并且与实验结果一致。
Block-copolymer electrolytes with lamellar microstructure show promising results regarding the ion transport in experiments. Motivated by these observations we study block-copolymers consisting of a polystyrene (PS) block and a poly(ethylene oxide) (PEO) block which were assembled in a lamellar structure. The lamella was doped with various amounts of lithium-bis(trifluoromethane)sulfonimide (LiTFSI) until very high loadings with ratios of EO monomers to cations up to 1:1 were reached. We present insights into the structure and ion transport from extensive Molecular Dynamics simulations. For high salt concentrations most cations are not coordinated by PEO but rather by TFSI and THF. More specifically, LiTFSI partially separates from the PEO domain and forms a network-like structure in the middle of the lamella. This central salt-rich layer plays a decisive role to enable remarkably good cationic mobilities as well as high transport numbers in agreement with the experimental results.
