Preparation And Modification Of PVDF And PVDF / PMMA Electrolyte Membrane

Separator plays an important role in the lithium ion battery, can be separated from the positive and negative, and prevent short circuit. The separator main body and the poor wettability of the electrolyte resulted in a large resistance and a lower ionic conductivity of the lithium-ion battery. In order to improve the wettability of the separator for the electrolyte and increase the ionic conductivity, more and more people in the study of the polymer electrolyte. Polyvinylidene fluoride is suitable for production the membrane material due to its good overall performance. This article was prepared PVDF membrane by phase transfer technique, and modified it, because it has the high crystallinity, low aspiration rate and ionic conductivity. Finally, activate the porous membrane in the electrolyte, and then get the electrolyte polymerization electrolyte system.Studied the effect of diethyl carbonate(DEC) on the structure and properties of the porous membrane, found the optimum solution. Experimental results showed that adding DEC can improve the aspiration rate and the ionic conductivity of the porous membrane. And the preparation in the optimal conditions showed a wider electrochemically stable window, and fitting button battery test its ability of cycle charge and discharge, showed its first charge and discharge process is stably, had a good charge and discharge voltage plateau and excellent in cycle performance.In the blend system of PVDF and PMMA, we investigated the effect of the organic solvent PEG400 and the inorganic nanomaterials Ti O2, firstly. And found their optimal experimental program, respectively. Both them can improve the aspiration and conductivity. Adding PEG400 showed more effect than adding nano-Ti O2. On this basis, this paper had a comprehensive study of the impact of adding an organic solvent PEG400 and inorganic nanomaterials Ti O2 on the structure and properties of the film, obtained the excellent properties of the film after comprehensive modified. SEM showed that the pore structure of the membrane integrity of distribution, the porous membrane aspiration rate by 345%, the ionic conductivity was up to 5.2m S/cm, it also showed a stability charge and discharge platform and an excellent cycling performance in the battery tests, and which was assembled by modified membrane material.