Preparation, Structure Characterization And Properties Research Of P(MMA-PEGDMA) Polymer Electrolyte

Rechargeable lithium-ion batteries are an excellent choice as power sources for consumers and portable electronic devices, e.g., laptop computers, cellular phones, walkie-lookie, due to their high specific energy and specific power. These batteries use liquid electrolytes with organic solvents, which are flammable and easy to ignite on exposure to high temperatures. To solve safety problem, the gel polymer electrolytes are thus the most promising candidates. The gel polymer electrolytes have several advantages over their liquid counter parts. The advantages of these electrolytes include such as no internal shorting, leakage of electrolytes and non-combustible reaction products at the electrode surface existing in the liquid electrolytes. Moreover, the use of gel polymer electrolytes allows lithium secondary batteries to be thin and flexible in addition to having high safety.However, the mechanical strength and thermodynamic stability of the gel polymer electrolytes （GPE） were found to be poor.The gel polymer electrolyte which apply in national defence must have good electrochemical performance in wide temperature and much work need further study.Focusing on the chioce of polymer as matrix of polymer electrolyte, the fabrication of the gel polymer electrolyte and optimizing the performance of the GPEs, this paper prepare the GPEs with good performance, which satisfy the demand of national defence. The main contents were as follows:P（MMA-PEGDMA） gel polymer electrolyte was prepared by chemical cross-linking reaction. In order to form the network structure, PFGDMA was used as cross-linkers. The results showed that the mechanical property of the gel electrolyte was apparently improved. Infrared spectra （IR） and thermogravimetric analyzer （TG） were employed to investigate the characteristics of the gel polymer membranes. It is found that the membrane has good structural and thermal stability.A novel composite gel polymer electrolyte using mesoporous silica SBA-15 as the filler has been developed. The structure, morphology and conductivity of composite gel polymer electrolyte were studied by atomic force microscopy （AFM） and thermogravimetric analyzer （TG）. The experiment results show that SBA-15 can increase the thermal stability of gel polymer electrolyte.Finally, the electrochemical performance of the gel polymer electrolyte was studied by the electrochenmical analyzer systems. The experiment results show that the gel polymer electrolyte with the 70 wt.% of liquid electrolyte possessed the maximum ionic conductivity of 3.16×10^-3 S/cm at room temperature. And SBA-15 can improve ionic conductivity, electrochemical and interface stabilities of the gel polymer electrolyte.The excellent ionic conductivity and broad electrochemical stability window （4.9 V vs. Li⁺/Li） suggesting that the composite polymer electrolyte can be used as candidate electrolyte materials for lithium-ionic batteries.