Effects of the Cross-Linking Agent on Electrochemical Performances of the Lithium Metal Polymer Batteries Prepared by In-Situ Thermal Polymerization with Trimethylolpropane Treiacrylate

All-solid lithium metal polymer batteries (LMPBs) consisting of lithium transition metal cathodes, polymer electrolytes and lithium (Li) metal anodes have long been investigated for over two decades to achieve higher level of energy density compared to those of lithium-ion batteries (LIBs) [1-2]. Unfortunately, however, LMPBs have failed to come to the market because of their low level of standard to use; relatively poor ion conductivity level (<10^-3 Scm^-1) and high interfacial resistance. In order to improve these bottlenecks, gel polymer electrolytes (GPEs) were developed by adding solvents into pure solid polymer electrolytes (SPEs).

In this study, we developed the novel GPE systems based on in-situ thermal polymerization process, which play as polymer electrolytes within pores of microporous polyethylene separators and polymeric binders for cathode at the same time. GPEs were synthesized via in-situ thermal polymerization process, and thus it is remarkably economical and easy to handle. We found optimum ratio of cross-linking agent for GPEs, and evaluated cell performance of LMPBs employing the same. Furthermore, we evaluated the effects of GPEs upon surfaces of Li metal anodes and cathodes by monitoring the morphological changes of them by electron scanning microscopy (SEM) as a function of cross-linking agent concentration.

Acknowledgements

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (2010-0025738).

References

[1] J.Y. Lee et al., Journal Solid State Electrochem 14 (2010) 1445–1449

[2] J.Y. Lee et al., Journal of Power Sources 174 (2007) 603–606