Truly solid polymer electrolyte membranes are designed by thermally induced free radical polymerisation. The overall membrane architecture is built on a semi-interpenetrating polymer network (s-IPN) structure, where a di-methacrylate oligomer is cross-linked (in situ) in the presence of a long thermoplastic linear PEO chain and a supporting lithium salt to obtain a freestanding, flexible and non-tacky film. In the envisaged systems, the di-methacrylate functions as a soft cross-linker, thus avoiding physico-mechanical deformation of the s-IPNs at elevated temperature, without hampering the ionic conductivity. s-IPNs exhibit remarkable stability towards lithium metal and no traces of impurity are detected while testing their oxidation stability (4.7 V vs. Li/Li+) towards anodic potential. The newly elaborated system is also successfully tested at moderately high temperature in Li metal cells in which LiFePO4/C is used as the cathode active material, showing excellent indications of safe and highly durable electrolyte separator (i.e.; 2000 cycles at reasonably high 1C rate).
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Energy Engineering and Power Technology
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering
Nair, J. R., Destro, M., Bella, F., Appetecchi, G. B., & Gerbaldi, C. (2016). Thermally cured semi-interpenetrating electrolyte networks (s-IPN) for safe and aging-resistant secondary lithium polymer batteries. Journal of Power Sources, 306, 258 - 267. https://doi.org/10.1016/j.jpowsour.2015.12.001