纳米SiO2/LiClO4/PVDF-HFP复合凝胶聚合物电解质的制备及其电化学性能

Electrochemical performances and preparation of nano-SiO2/LiClO4/PVDF-HFP composite gel polymer electrolyte

  • 摘要: 为了解决液态电解质锂离子电池存在的安全性问题,以偏氟乙烯和六氟丙烯的共聚物(PVDF-HFP)为基体,通过加入高氯酸锂(LiClO4) 、增塑剂(碳酸丙烯酯和碳酸二甲酯) 、纳米二氧化硅等,制备出了具有高电导率的复合凝胶聚合物电解质。用 X射线衍射仪测试聚合物电解质的结构,用交流阻抗法测定其电导率,用线性伏安扫描法研究了该聚合物电解质体系的电化学稳定性,并以其为电解质制备成锂离子电池进行充放电测试。结果表明,在20℃ 时复合凝胶聚合物电解质的电导率最高可达7. 56×10-3 S/ cm , 该电解质在4.6 V 以下电化学窗口稳定,以其为电解质的锂离子电池具有良好的电化学性能,说明纳米SiO2/LiClO4/PVDF-HFP复合凝胶聚合物电解质能满足锂离子电池的应用。

     

    Abstract: In order to solve the security problems of the lithium-ion batteries,a nano-SiO2/poly(vinylidene fluoride-co-hexafluoro-propylene) (PVDF-HFP) gel polymer electrolyte with high ionic conductivity was prepared,using nano-SiO2 as an additive,LiClO4 as the salt,and propylene carbonate (PC) and dimethyl carbonate (DMC) as the plasticizer. The structure and microstructure were characterized using XRD,the ionic conductivity was determined by AC impedance method,the electrochemical stability was measured by linear scan voltammetry experiment,and the charge-discharge of the polymer lithium batteries based on this composite gel polymer electrolyte was investigated. The results indicate that the highest conductivity of the gel polymer electrolyte is 7. 56 ×10-3 S/ cm at 20℃,and the electrochemical character of the gel polymer electrolyte is stable under 4. 6 V,and the polymer lithium batteries have excellent electrochemical performances. The SiO2/LiClO4/PVDF-HFP composite gel polymer electrolyte shows the potential application in lithium ion batteries.

     

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