Advanced semi-interpenetrating polymer network gel electrolyte for rechargeable lithium batteries

• Published in: Electrochimica acta Vol. 152; pp. 489 - 495
• Main Authors: Lu, Qingwen, Yang, Jun, Lu, Wei, Wang, Jiulin, Nuli, Yanna
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 10-01-2015
• Subjects: Crosslinking; Electrodes; Electrolytes; Electrolytic cells; Gel polymer electrolyte; Liquids; Lithium; Mechanical properties; Membranes; Networks; Rechargeable lithium battery; Semi-interpenetrating polymer network; Stability; UV-cured; Mechanical properties; Gel polymer electrolyte; UV-cured; Semi-interpenetrating polymer network; Rechargeable lithium battery
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2014.11.176

A semi-interpenetrating polymer network (Semi-IPN) gel polymer electrolyte (GPE) membrane based on the cross-linked PEGDA-co-PVC and linear PVDF-HFP has been prepared by UV-cured technology. It exhibits excellent interface stability to lithium metal electrode, superior thermal stability and mechanical properties. Its use in Li/LiFePO4 cell shows superior cycling stability and rate performance.
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•A new type of Semi-IPN GPE was prepared via UV-cured technology.•This electrolyte shows superior thermal stability and good mechanical properties.•The GPE membrane has excellent interface stability toward Li electrode.•Li/LiFePO4 cell using GPE membrane displays excellent electrochemical behavior.
A new type of semi-interpenetrating polymer network (Semi-IPN) gel polymer electrolyte (GPE) membrane based on the cross-linked poly(ethylene glycol) diacrylate-co-poly(vinylene carbonate) P(EGDA-co-VC) and PVDF-HFP linear polymer is successfully synthesized by UV-cured technology. The cross-linked P(EGDA-co-VC) can accommodate a large amount of liquid electrolyte inside the non-porous membrane via its strong interaction with Li+ and solvents, which avoids the liquid electrolyte leakage. The ionic conductivity of the Semi-IPN GPE reaches 1.49×10−3Scm−1 at 25°C and the electrochemical stability window up to 4.2V (versus Li/Li+). It demonstrates excellent interface stability to lithium metal electrode, superior thermal stability and good mechanical properties. A symmetric Li/Li cell with the above electrolyte displays a lower voltage polarization and longer valid cycle life than that based on conventional liquid electrolyte. Moreover, the Li/LiFePO4 cells using the Semi-IPN GPE show superior cycling stability and rate performance comparable to the cell based on conventional liquid electrolyte. This Semi-IPN GPE is promising for rechargeable lithium batteries with high safety and energy density.