Preparation and performance of natural rubber/styrene-butadiene rubber based separators

The natural rubber (NR)/stytene-butadiene rubber (SBR) based porous polymer membranes were prepared by means of phase-inversion, and the processing parameters and mechanism of membrane-forming were studied systematically. Microstructure of the porous membranes was observed using scanning electronic microscope (SEM) and atomic force microscope (AFM) Abilities of solution uptake and reservation, thermal stability and electrochemical performance were studied as well. Results show that the prepared polymer membranes are porous honeycombing with excellent solution uptake and reservation abilities, the solution uptake ratio is up to 320% and the mass loss is only 31% after heated at 50 degrees C for 5 h. With that solution uptake ratio, the conductivities arrive 3.93 X 10(-4) S/cm at ambinet temperature. Electrochemical stability window (4.8 V) and thermal decomposition temperature( 157 degrees C)are suitable implying they can be used below 4.8 V and 157 degrees C safety. The interfacial impedance between membranes and lithium electrodes increase quickly after being kept for 10 days or scanned 20 cycles using cyclic voltammetry, and then, stabilized gradually, showing good interfacial stability which can surpress effectively further growth of solid electrolyte interface (SEI).