Preparation and characterization of novel “polyMOB” polyanionic solid electrolytes with weak coulomb traps

We describe the synthesis of new chain polymers that contain weakly basic anionic mono-oxalato orthoborate (MOB) moieties in a polyether backbone at controllable anionic separations. The conductivities of these lithium-conducting polymers are found to be high relative to those of most conventional dry salt-in-polymer electrolytes. An ambient conductivity of about 10−5 S cm−1 has been obtained for a solid polymer with 14 ethyleneoxy repeating units. The electrochemical window for these materials is in excess of 4.5 V. These inexpensive benign materials should be very suitable as electrolytes for rechargeable lithium batteries.