Flame Retardant and Stable Li_1.5Al_0.5Ge_1.5(PO₄)₃‑Supported Ionic Liquid Gel Polymer Electrolytes for High Safety Rechargeable Solid-State Lithium Metal Batteries

Recently, poor security in conventional liquid electrolytes and high interfacial resistance at the electrode/electrolyte interface are the most challenging barriers for the expanded application of lithium batteries. In this regard, easy processing and flexible composite ionic liquid gel polymer electrolytes (ILGPEs) supported by Li_1.5Al_0.5­Ge_1.5­(PO₄)₃ (LAGP) are fabricated and investigated. The electrolyte is effectively combined with good electrochemical performances and thermal safety. Among these, the effects of different types of fillers such as the inert filler-SiO₂ and the active filler-LAGP on the ionic conductivity were studied in detail. LAGP particles can not only effectively reduce the crystallinity of the polymer matrix but also provide lithium ions and act as the lithium-ion conductor leading to higher ionic conductivity and Li⁺ ion transference number. Especially, the electrolyte shows good compatibility and no dendrite with the Li metal anode, significantly improving cyclic stability of LiFe­PO₄/Li batteries. The results indicate that the ILGPE-10%LAGP is a potential alternative electrolyte for high safety rechargeable solid-state lithium metal batteries