Reliability of lithium batteries with crosslinked polymer electrolytes

Polymer electrolyte films were prepared by chemical crosslinking of polyethylene glycol 2000 (PEG) containing LiSO3CF3 or Li[(SO2CF3)(2)N]; polyethylene glycol dimethylether 500 (PEGDME) was also added to a PEG-LiSO3CF3 electrolyte. The electrochemical properties of these three electrolytes were investigated for ionic conductivity, electrochemical stability window, steady state current fraction, interface resistance and lithium/electrolyte interface stability. Furthermore, we tested prototype Li cells with a LiMn2O4 composite cathode to ascertain the effective viability of these electrolytes in solid-state Li batteries. The Li[(SO2CF3)(2)N] salt in the crosslinked electrolyte presents a steady-state current fraction too low for battery application, while the addition of PEGDME improves conductivity, interface resistance and battery performance.