Si-Drive European Project: Developing Crosslinked Polymer and Composite Membrane Electrolytes for Lithium-Based Batteries

Currently the main application of lithium ion batteries is in portable electronics, but new emerging applications such as electric cars require lower cost, improved cycle life, sustainability, safety and energy density. The ambition of Si-DRIVE European project is proposing next-generation batteries for electric cars built in Europe, designed to ensure recycling above 50%. Si-Drive battery will contain a Silicon anode, which has a high specific capacity, and a high voltage cathode without cobalt to reduce the cost and improve sustainability. As an alternative to conventional organic solvents, ionic liquids have been widely investigated over the years, due to their excellent properties in terms of safety and stability. The 1 st generation of electrolytes for Si-Drive includes selected ionic liquids with high ionic conductivity and wide electrochemical stability. The 2 nd generation of electrolytes combines the ionic liquids and the precursors of the polymer matrix in the formulation, in order to obtain crosslinked self-standing flexible films. The addition of ceramic super lithium ion conductors to obtain composite polymer electrolytes is also envisaged to improve the electrochemical stability window of the electrolyte. Here we present several different polymer electrolytes and semi interpenetrating polymer networks encompassing ionic liquids and ceramic materials having ionic conductivity > 10 mS/cm at 20 °C, which can be in situ-deposited and crosslinked on top of the electrodes, and combined to form bi-layered electrolyte membranes to tune the compatibility with the electrode materials. The cycling performance with different positive and negative electrodes at ambient temperature is also demonstrated. Acknowledgements: The Si-DRIVE project has received funding from the European Union’s Horizon 2020 Research&Innovation programme, under Grant Agreement 814464. References J.-Y. Hwang, S.-T. Myung, Y.-K. Sun, Chem. Soc. Rev. 46 , 3529-3614 (2017) M. Falco, C. Simari, C. Ferrara, J.R. Nair, G. Meligrana, F. Bella, I. Nicotera, P. Mustarelli, M. Winter, C. Gerbaldi, Langmuir 35 , 8210-8219 (2019) M. Falco, L. Castro, J.R. Nair, F. Bella, F. Bardé, G. Meligrana, C. Gerbaldi, ACS Appl. Energy Mater. 2 , 1600-1607 (2019) M. Falco et al., Electrochem. Commun. 118 106807 (2020) S. Saffirio, M. Falco, G.B. Appetecchi, F. Smeacetto, C. Gerbaldi, Journal of the European Ceramic Society , 42 (3), 1023-1032 (2022).