Cross-Linked lonomer Gel Separators for Polysulfide Shuttle Mitigation in Magnesium-Sulfur Batteries: Elucidation of Structure-Property Relationships
Cross-Linked lonomer Gel Separators for Polysulfide Shuttle Mitigation in Magnesium-Sulfur Batteries: Elucidation of Structure-Property Relationships
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DOI：
10.1021/acs.macromol.8b01717
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发表时间：
2018-11-13
期刊：
影响因子：
5.5
通讯作者：
Schaefer, Jennifer L.
中科院分区：
文献类型：
--
作者：
Ford, Hunter O.;Merrill, Laura C.;Schaefer, Jennifer L.
已经研究了不同聚（乙二醇）二丙烯酸酯交联剂链长、离子共聚单体化学和共聚单体比率的交联离聚物网络作为镁-硫（Mg-S）电池中的多硫化物穿梭抑制隔板的用途。通过使用X射线散射、多硫化物扩散实验、电导率测量和Mg-S电池循环，确定在聚合物网络中包含束缚阴离子减轻了多硫化物穿梭效应。通过网络进入本体电解质的多硫化物交叉可以通过吸收到聚合物凝胶中、空间排斥和静电排斥来减少，这些机制的优势由聚合物组成和结构决定。与使用文献标准玻璃纤维隔板的365 mAh/g的放电容量相比，最佳网络组成允许522 mAh/g的初始Mg-S电池放电容量。离聚物电池在三次循环后看到67%的容量保持率，而玻璃纤维隔板由于多硫化物穿梭而不能完成第一次充电循环。
Cross-linked ionomer networks of varying poly (ethylene glycol) diacrylate cross-linker chain length, ionic comonomer chemistry, and comonomer ratio have been studied for their use as polysulfide shuttle inhibiting separators in magnesium-sulfur (Mg-S) batteries. Through the use of X-ray scattering, polysulfide diffusion experiments, conductivity measurements, and Mg-S cell cycling, it was determined that inclusion of tethered anions in polymer networks mitigates the polysulfide shuttle effect. Polysulfide crossover through networks into a bulk electrolyte can be reduced by absorption into the polymer gel, steric rejection, and electrostatic rejection, with the predominance of these mechanisms dictated by polymer composition and structure. The best network composition allowed an initial Mg-S cell discharge capacity of 522 mAh/g compared to a discharge capacity of 365 mAh/g using a literature standard glass fiber separator. The ionomer cell saw 67% capacity retention after three cycles, whereas the glass fiber separator could not complete the first charging cycle due to the polysulfide shuttle.