纳米 SiO 2/ LiClO 4/ PVDF2 HFP复合凝胶聚合物电解质的制备及其电化学性能

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( PVDF2 HFP)为基体 , 通过加入高氯酸锂(LiClO 4) 、 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- 3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 S/ cm , 该电解质在 41 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 SiO 2/ LiClO 4/ PVDF2 HFP复合凝胶聚合物电解质能满足锂离子电池的应用。

Electrochemical performances and preparation of nano2SiO 2/ LiClO 4/ PVDF2 HFP composite gel polymer electrolyte

In order to solve the security problems of the lithium2ion batteries , a nano2SiO 2/ poly(vinylidene fluoride2co2 hexafluoro2propylene) ( PVDF2 HFP) gel polymer elect rolyte with high ionic conductivity was prepared , using nano2SiO 2 as an additive , LiClO 4 as the salt , and propylene carbonate ( PC) and dimethyl carbonate (DMC) as the plasticizer. The st ructure and microst ructure were characterized using XRD , the ionic conductivity was determined by AC impedance method , the elect rochemical stability was measured by linear scan voltammet ry experiment , and the charge2discharge of the polymer lithium bat teries based on this composite gel polymer elect rolyte was investiga2 - 3ted. The result s indicate that the highest conductivity of the gel polymer elect rolyte is 7. 56 ×10 S/ cm at 20℃,and the elect rochemical character of the gel polymer elect rolyte is stable under 4. 6 V , and the polymer lithium bat-teries have excellent elect rochemical performances. The SiO 2/ LiClO 4/ PVDF2HFP composite gel polymer elect rolyte shows the potential application in lithium ion bat teries.