New Material Routes to Polymeric Solid Electrolytes

Tuesday, 30 May 2017
Grand Ballroom (Hilton New Orleans Riverside)
S. Janietz, W. Meyer (Fraunhofer-IAP), and S. Asaftei (Hochschule Osnabrück)
In our work photocurable liquid ionic compounds (PLICs) [1] and oxygen rich crosslinkers (ORCs) with carboxy- and ethoxygroups build the base of a monomer blend system [2] to obtain thin films on electrode surfaces of new polyionic polyacrylates as polymeric solid electrolytes (PESs) in a battery buildup [3].

The aim of our study is to show that the low ionic forces in an ionic liquid is preserved when the cation of the PLIC is fixed covalently bonded into a polymer network and turns into a PES after curing process. With similar intention ORC are designed to achieve a fixation of carboxy groups as an ideal chelator for lithium ions within a polymeric solid electrolyte.

The synthesis of PLICs and ORCs is described and characterized by NMR, IR and melting points. Formulation of PLICs, ORCs and lithium salts has been bladed and UV cured direct on Li foils as electrode material and the ionic conductivity in a half cell setup were determined by impedance spectroscopy. The free foils of PES show high temperature stability and the absents of crystallinity in DSC measurements.

Secondly a polymer design concept is presented that combine ion conductivity and mechanical stability in a block-co-polymer consisting of a PEG unit and a rigid rod aromatic unit aiming as a new material basis for battery separators.