Rechargeable Lithium Polymer Batteries Assembled with Electrospun Poly(ethylene oxide) Membranes

Solid polymer electrolytes have been paid much attention in rechargeable lithium batteries, due to absence of electrolyte leakage, enhanced safety and design flexibility [1,2]. Solid polymer electrolytes studied to date are mainly based on poly(ethylene oxide)(PEO) containing lithium salts.  However, these materials have a major drawback that the ionic conductivity for practical application can only be reached at high temperature, due to the high degree of crystallinity inherent in these complexes at ambient temperature.  Because of the inherent drawback, various attempts such as grafting, block copolymerization, interpenetration polymer network have been tried to incorporate PEO into a macromolecular sequence, which inhibits crystallization, while maintaining a low value of the glass transition temperature.  In our study, with the aim of developing highly conductive polymer electrolytes with high mechanical strength, we prepared the cross-linked polymer electrolytes using low-molecular weight PEO, which are supported by electrospun nanoporous membrane based on high-molecular weight PEO.  In this system, mechanically robust porous membrane with chemical cross-linking can protect against electric short to assure safety reliability and make a flexible thin film.  By using these solid polymer electrolytes, the lithium polymer cells are assembled and their cycling performances are evaluated at room temperature.

References

[1] F.M.Gray, Polymer Electrolytes, The Royal Society of Chemistry, Cambridge, 1997.

[2] W.A.Van Schalkwijk, B.Scrosati, Eds., Advances in Lithium-Ion Batteries, Kluwer Academic/Plenum Publishers, New York, 2003.