A Novel Approach for Development of Stable Quasi-Solid Lithium-O₂ Batteries: Assembly and Performances of Double Layer Gel Polymer Electrolytes

Gel-polymer electrolytes (GPEs) offer a suitable alternative to flammable organic liquid electrolytes in lithium-oxygen batteries (LOBs) to address safety concerns. However, a major challenge with GPEs is their low ionic conductivity. To enhance the ionic conductivity of GPEs, active inorganic particles have been incorporated. To increase the ionic conductivity of GPE, active inorganic particles have been reinforced in GPE. While this increases the ionic conductivity, it also leads to blockage of the cathode porous structure and reduces the actual surface area of the cathode materials, resulting in poor battery performance. This study proposes a novel double-layer polymer gel electrolyte (d-GPE) that exhibits both high ionic conductivity and stability for quasi solid-state LOBs. The double-layer GPE consists of a bare GPE layer integrated in the cathode, and a composite GPE (c-GPE, containing 5wt.% lithium aluminum titanium phosphate (LATP)), which is in contact with Li anode and bare-GPE. The produced double-layer gel polymer electrolyte displays high reaction kinetic and better stability due to the excellent electrode/electrolyte interface and rapid oxygen diffusion in the air-cathode. Furthermore, the d-GPE electrolyte is resistant to fire and protects Li from dendrite growth and water molecules attack, indicating tremendous promise for the development of practical LOBs.