Improved Single-Ion Conductivity of Polymer Electrolyte via Accelerated Segmental Dynamics
Improved Single-Ion Conductivity of Polymer Electrolyte via Accelerated Segmental Dynamics
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DOI：
10.1021/acsaem.0c02079
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发表时间：
2020-12
期刊：
影响因子：
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通讯作者：
Sheng Zhao;Yiman Zhang;H. Pham;J. Carrillo;B. Sumpter;J. Nanda;N. Dudney;Tomonori Saito;A. Sokolov;P. Cao
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文献类型：
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作者：
Sheng Zhao;Yiman Zhang;H. Pham;J. Carrillo;B. Sumpter;J. Nanda;N. Dudney;Tomonori Saito;A. Sokolov;P. Cao
单离子导电聚合物电解质（SICPE）对于固态电池应用具有许多优势，但低电导率仍然是其实际应用的瓶颈。在此，通过热性能、流变行为、形态分析、分子动力学模拟和电导性能的评估，论证了一种基于加速链段动力学概念的可显着提高SICPE离子电导率的策略。具有“软”聚二甲基硅氧烷（PDMS）主链和聚乙二醇（PEG）侧链，所得SICPE具有更快的链段弛豫和更高的锂离子电导率。由于锂“转移”数接近1，所获得的SICPE还对锂金属电极表现出优异的电化学稳定性。聚合物电解质的链段动力学与其离子电导率之间建立的明确关系应该有助于实现具有改进的离子电导率的固体电解质，用于下一代固态电池。
Single-ion conducting polymer electrolytes (SICPEs) have many advantages for solid-state battery applications, while low conductivities remain the bottleneck for their practical applications. Herein, a strategy that can significantly improve the ionic conductivity of SICPEs based on the concept of accelerated segmental dynamics was demonstrated by the evaluation of the thermal property, rheological behavior, morphology analysis, molecular dynamics simulation, and conductivity performance. With both “soft” poly(dimethylsiloxane) (PDMS) backbone and poly(ethylene glycol) (PEG) side chains, the obtained SICPE possesses faster segmental relaxation and higher lithium-ion conductivity. With lithium “transference” number close to unity, the obtained SICPE also shows excellent electrochemical stability against lithium metal electrodes. The clear relationship established between the segmental dynamics of polymer electrolyte and its ionic conductivity should contribute to achieve a solid electrolyte with improved ionic conductivity toward the next-generation solid-state battery.