Lithium-Ion Cells Assembled with Flexible Hybrid Membrane Containing Li+-Conducting Lithium Aluminum Germanium Phosphate

Abstract

Hybrid membranes composed of 90 wt% Li+-conducting inorganic electrolyte (lithium aluminum germanium phosphate, LAGP) and 10 wt% poly(vinylidene fluoride-co-hexafluoropropylene) (P(VdF-co-HFP)) polymer were prepared in the form of a flexible thin film and directly formed on the as-prepared negative electrode. The lithium-ion cells assembled with the hybrid membrane exhibited superior cycling performance in terms of discharge capacity, capacity retention, rate capability and high temperature cycling stability, as compared to the cell with polypropylene separator and liquid electrolyte. The use of hybrid membranes allowed improve thermal properties compared to conventional polyolefin separator and use less amount of flammable liquid electrolyte, resulting in enhancement of thermal safety of the cell.