ORMOCERs as inorganic-organic electrolytes for new solid state lithium batteries and supercapacitors

ORMOCERs (ORganically MOdified CERamics) are inorganic-organic copolymers which are synthesized as matrix for Li-ion conduction. The inorganic oxidic backbone of these materials results from polycondensation of alkoxy compounds whereas the organic network is formed from reactive functional groups R' of alkoxysilanes of the type R'Si(OR)(3), or by co-polymerising reactive organic monomers with reactive functionalized alkoxysilanes. Depending on the reactive organic functionalities and their thermal and uv-initiated organic crosslinking reactions the materials were adapted to the needs of battery and supercapacitor manufacturing. For ionic conductivity polyethers with different chainlengths and functionalized (eg epoxy) termination sites were synthesized and attached to organically functionalized oxidic oligomers. Conductivities of up to 10(-4) Omega(-1) cm(-1) at room temperature (RT) were achieved without plasticizer. The electrolytes form an amorphous network with configuration temperatures T-o. (according to Vogel-Tammann-Fulcher) close to -80 degrees C, several degrees below the transformation temperature T, (measured by DSC) in agreement with conventional configuration theory. The activation energies correlate favourably with results for good polymer electrolytes. (C) 1998 Elsevier Science Ltd. All rights reserved.