以聚酰亚胺(PI)作为粘结剂,利用纳米二氧化硅(Si02)颗粒对锂离子电池用聚丙烯(PP)隔膜进行陶瓷改性,得到PP/Si02复合隔膜。通过场发射扫描电镜、热收缩、交流阻抗及充放电实验等方法,对复合隔膜的热性能及电化学性能进行分析。制备的复合隔膜具有良好的耐热收缩性能,纳米颗粒间形成了高度发达的孔隙结构,150oC时的热收缩率仅为1.8%,可提高锂离子电池的安全性。30min涂层复合隔膜组装的LiC002/Li电池,以0.2C充电、0.5C放电,在2.75~4.20V循环,首次放电比容量为140mAh/g,高于PP隔膜组装电池的138mAh/g。
Nano silicon dioxide ( SiO2 ) particle was coated on polypropylene (PP) separator with polyimide (PI) as binder to get modified composite separator. The composite separator was characterized by SEM, thermal shrinkage,A. C. impendance and charge- discharge experiments. The thermal performance of ceramic modified composite separator was fine,the thermal shrinkage at 150 ~C was only 1.8% and the safety of Li-ion battery could be improved. Due to the highly developed porous structure formed by nanopar- ticle, when cycled in 2. 75 - 4. 20 V with 0. 2 C charging,0. 5 C discharging, the initial specific discharge capacity of LiCoOJLi cell assembled with 30 nm coating composite separator was 140 mAh/g,higher than PP separator( 138 mAh/g).