Fire-resistant, high-performance gel polymer electrolytes derived from poly(ionic liquid)/P(VDF-HFP) composite membranes for lithium ion batteries
Fire-resistant, high-performance gel polymer electrolytes derived from poly(ionic liquid)/P(VDF-HFP) composite membranes for lithium ion batteries
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DOI：
10.1016/j.memsci.2020.117827
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发表时间：
2020-04
影响因子：
9.5
通讯作者：
Zhenyuan Hu;Junjie Chen;Yue Guo;Jingjing Zhu;Xinxin Qu;Wenwen Niu;Xiaokong Liu
中科院分区：
文献类型：
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作者：
Zhenyuan Hu;Junjie Chen;Yue Guo;Jingjing Zhu;Xinxin Qu;Wenwen Niu;Xiaokong Liu
具有耐火性能的高性能凝胶聚合物电解质（gpe）是锂离子电池（lib）提高安全性的迫切需要。本文报道了一种新型GPE，该GPE由多孔聚离子液体/P(VDF-HFP) （PIL/P(VDF-HFP)）复合膜通过简单且可扩展的相转化方法制备而成。PIL与P（VDF-HFP）之间的离子偶极子相互作用使PIL/P（VDF-HFP）膜的力学性能和热稳定性显著提高。液体电解质被PIL/P（VDF-HFP）膜吸收后，可以得到柔性gpe。与商用Celgard 2325分离器（3.5 × 10−4S cm−1）吸收的液体电解质相比，PIL/P(VDF-HFP) GPE表现出更高的离子电导率（1.78 × 10−3S cm−1）。用GPE组装的锂/ lifepo4电池在1C和4C条件下，经过200次充放电循环后，其可逆容量分别为99.2 mAh g - 1C和138.4 mAh g - 1C，放电容量为125.4 mAh。这些性能都优于使用饱和液态电解质的商用Celgard 2325隔膜的锂/ lifepo4电池。重要的是，PIL/P(VDF-HFP) GPE具有优异的耐火性，这得益于PIL的不可燃特性。制备的GPE具有优异的电化学性能和较高的安全性，在锂离子电池中具有广阔的应用前景。
High-performance gel polymer electrolytes (GPEs) with fire-resistant properties are highly desirable for lithium ion batteries (LIBs) with enhanced safety. Herein, we report a novel GPE derived from a porous poly(ionic liquid)/P(VDF-HFP) (PIL/P(VDF-HFP)) composite membrane prepared via a simple and scalable phase inversion method. The ion-dipole interactions between the PIL and P(VDF-HFP) endow the PIL/P(VDF-HFP) membrane with significantly enhanced mechanical performances and thermal stability. Flexible GPEs can be obtained after absorption of the liquid electrolytes into the PIL/P(VDF-HFP) membrane. The PIL/P(VDF-HFP) GPE exhibits a much higher ionic conductivity (1.78 × 10−3S cm−1) compared to the liquid electrolytes absorbed in the commercial Celgard 2325 separator (3.5 × 10−4S cm−1). The Li/LiFePO4battery assembled with the GPE exhibits a high reversible capacity of 99.2 mAh g−1at 12C and high discharge capacities of 138.4 and 125.4 mAh g−1after 200 charge-discharge cycles at 1C and 4C, respectively. These performances are all superior to the Li/LiFePO4battery using the commercial Celgard 2325 separator saturated with liquid electrolytes. Importantly, the PIL/P(VDF-HFP) GPE exhibits excellent fire-resistance, benefiting from the non-flammable property of the PIL. The as-developed GPE shows great potential for the practical application in LIBs with superior electrochemical performances and high safety.