TiO_2改性PVDF锂离子电池隔膜的研究

Study on TiO_2 modified PVDF lithium ion battery separator

静电纺丝制备聚偏氟乙烯(PVDF)锂离子电池隔膜电化学性能一般,可采用混纺增强其电化学性能。采用二氧化钛(TiO_2)与PVDF混纺,制得TiO_2/PVDF锂离子电池隔膜,研究不同TiO_2的添加量对TiO_2/PVDF锂离子电池隔膜性能的影响,考察其力学性质、离子电导率、放电比容量和循环性能。结果表明:在添加1.5%(wt,质量分数)TiO_2条件下,制得的TiO_2/PVDF锂离子电池隔膜的孔隙率高达52.54%,吸液率403.70%,离子电导率4.2×10^(-4)S/cm;在0.5C条件下放电比容量为134.0mAh/g,循环25次条件下,TiO_2/PVDF锂离子电池隔膜的放电比容量仍有130.0mAh/g,放电比容量的波动小,循环稳定性好。

The electrochemical properties of PVDF lithium ion battery separators prepared by electrospinning were general,but it can be enhanced by blending.TiO2/PVDF separator was prepared by blending titanium dioxide (TiO2)with PVDF.The effects of different TiO2 addition on the performance of TiO2/PVDF and its mechanical properties,ionic conductivity,discharge capacity and cycle performance were also investigated.The results showed that when added TiO2 of 1.5wt%(wt,mass fraction),the porosity of TiO2/PVDF reached 52.54%,the electrolyte uptake reached 403.70%,and the ion conductivity reached 4.2×10^-4S/cm.The discharge capacity was 134.0mAh/g at the rate of 0.5C,the discharge still remained 130mAh/g after 25 cycles,the fluctuation of discharge capacity was small,and the cycle stability was good.