偏氟乙烯-六氟丙烯共聚物电解质研究

以偏氟乙烯-六氟丙烯共聚物〔P(VdF-HFP)〕、LiClO4/碳酸二甲酯(DMC)/碳酸乙烯酯(EC)或LiPF6/EC/DMC/碳酸二乙酯(DEC)和纳米SiO2为原料,用自然挥发法和相转移法制成聚合物电解质膜。测试结果表明:对LiClO4/DMC/EC体系,c(LiClO4)=1mol/L,w(SiO2)=7%时,室温(21℃)电导率达最大值2 81mS/cm,72℃时达9 6mS/cm;对LiPF6/EC/DMC/DEC体系,c(LiPF6)=1mol/L,m〔P(VdF-HFP)〕∶m(SiO2)=3∶2时,室温电导率为3 68mS/cm,72℃时达13 8mS/cm。扫描电镜(SEM)和X射线衍射分析(XRD)结果表明,电解质膜为非晶态的多孔结构,纳米SiO2粉末掺入可使微孔的数目明显增多,孔隙率增加,孔分布更均匀;傅里叶红外光谱(FTIR)结果显示,P(VdF-HFP)、增塑剂与LiClO4间存在相互作用。

Study of Vinylidenefluoride-Hexafluoropropylene Copolymer Electrolyte

Polymer electrolyte membranes based on vinylidenefluoride-hexafluoropropylene copolymer,LiClO_4/dimethyl carbonate(DMC)/ethylene carbonate(EC) or LiPF_6/EC/DMC/diethyl carbonate(DEC),and nanoscale SiO_2 were prepared.Measurements on the conductivity of the membranes with different compositions showed that at room temperature conductivities reached maxima(2.81 mS/cm or 3.68 mS/cm) when the concentration of Li~+ was 1 mol/L.It increased monotonically as temperature rises(up to 9.6 mS/cm or 13.8 mS/cm at 72 ℃).Scanning electron microscopy and X-ray diffraction studies of the membranes showed that the membranes are porous and amorphous.Moreover,the porosity increased,pore diameter decreased,and distribution of pores became more uniform,when nanoscale SiO_2 was added.Fourier transform infrared spectroscopy showed that there are chemical interactions among the components.