Preparation And Modification Of Lignin / PAN Electrostatic Spinning Composite Membrane For Lithium Ion Batteries

The lignin/polyacrylonitrile(PAN) composite fiber-based nonwoven membranes (L-PANs) were prepared by electrospinning and hot pressed with different weight ratio of lignin/PAN. The physical properties and electrochemical properties of L-PANs were characterized and compared with the commercialized PP separator. Subsequently, by changing the temperature of hot pressed, we discussed that how the temperature of hot pressed influenced on lignin/PAN composite fiber-based nonwoven membranes. Eventually, in order to further improve the thermal stability of the lignin/PAN composite fiber-based nonwoven membranes, some (3-aminopropyl)triethoxysilane(APTES) was added to the spinning solution of lignin/PAN composite fiber-based nonwoven membranes, preparing the lignin/PAN/APTES composite fiber-based nonwoven membranes, the physical properties and electrochemical properties of lignin/PAN/APTES membranes were characterized.The results showed that the L-PAN (3:7 by weight) had better performance than the other weight ratio of L-PANs (0:10,1:9 and 5:5) and the commercialized PP separator. The discharge capacity of the Li/LiFePO4 cell containing the L-PAN (3:7 by weight) could retain 148.9 mAh·g-1 after 50 cycles at 0.2C and the discharge capacity retention was 95%.The L-PAN (3:7 by weight), which was hot pressed at 100℃ (L/P-100), has the best performance. The SEM showed that some fibers were bonded together and the L/P-100 had a three dimensional network structure. The Li/LiFePO4 cell containing the L/P-100 had better C-rate performance and cycling performance.After 50 cycles at 0.2C, the discharge capacity retention of the Li/LiFePO4 cell containing the L/P/S-100 was 95.7%, indicating the L/P/S-100 had better electrochemical properties. Compared to the L/P-100, the mechanical properties and thermal stability of the L/P/S-100 were both improved.