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Composite Gel Polymer Electrolyte for Improved Cyclability in Lithium–Oxygen Batteries
ACS Applied Materials & Interfaces ( IF 9.5 ) Pub Date : 2017-09-19 00:00:00 , DOI: 10.1021/acsami.7b08448
Amir Chamaani 1 , Meer Safa 1 , Neha Chawla 1 , Bilal El-Zahab 1
Affiliation  

Gel polymer electrolytes (GPE) and composite GPE (cGPE) using one-dimensional glass microfillers have been developed for their use in lithium–oxygen batteries. Using glass microfillers, tetraglyme solvent, UV-curable polymer, and lithium salt at various concentrations, the preparation of cGPE yielded free-standing films. These cGPEs, with 1 wt % of microfillers, demonstrated increased ionic conductivity and lithium transference number over GPEs at various concentrations of lithium salt. Improvements as high as 50% and 28% in lithium transference number were observed for 0.1 and 1.0 mol kg–1 salt concentrations, respectively. Lithium–oxygen batteries containing cGPE similarly showed superior charge/discharge cycling for 500 mAh g–1 cycle capacity with as high as 86% and 400% increase in cycles for cGPE with 1.0 and 0.1 mol kg–1 over GPE. Results using electrochemical impedance spectroscopy, Raman spectroscopy, and scanning electron microscopy revealed that the source of the improvement was the reduction of the rate of lithium carbonates formation on the surface of the cathode. This reduction in formation rate afforded by cGPE-containing batteries was possible due to the reduction of the rate of electrolyte decomposition. The increase in solvated to paired Li+ ratio at the cathode, afforded by increased lithium transference number, helped reduce the probability of superoxide radicals reacting with the tetraglyme solvent. This stabilization during cycling helped prolong the cycling life of the batteries.

中文翻译:

复合凝胶聚合物电解质可改善锂氧电池的循环性

使用一维玻璃微填充剂的凝胶聚合物电解质(GPE)和复合GPE(cGPE)已开发用于锂氧电池。使用玻璃微填料,四甘醇二甲醚溶剂,可紫外线固化的聚合物和各种浓度的锂盐,制备cGPE可获得独立的薄膜。与各种浓度的锂盐相比,具有1 wt%的微填料的这些cGPE表现出比GPE更高的离子电导率和锂转移数。在0.1和1.0 mol kg –1的盐浓度下,锂的迁移率分别提高了50%和28%。同样,含有cGPE的锂氧电池在500 mAh g –1的情况下也表现出出色的充电/放电循环与1.0和0.1 mol kg –1相比,cGPE的循环容量可高达86%和400%,比GPE高。使用电化学阻抗光谱法,拉曼光谱法和扫描电子显微镜的结果表明,改进的来源是降低了阴极表面上碳酸锂形成速率。由于电解质分解速率的降低,含cGPE的电池可降低这种形成速率。锂的转移数增加,导致阴极上Li +的成对溶剂化比率增加,有助于降低超氧化物自由基与四甘醇二甲醚溶剂反应的可能性。循环过程中的这种稳定有助于延长电池的循环寿命。
更新日期:2017-09-20
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