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

Abstract

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 Li1.5Al0.5­Ge1.5­(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.

Ionic liquids for high performance lithium metal batteries

“…Fig. 4 summarizes the room temperature ion conductivity and Li + ion transference number of ionic liquid electrolytes [25,26,[65][66][67]69,[82][83][84][85][86][87][88][89][90][91][92][93][94][95]. It can be observed that the room temperature ionic conductivities of both liquid electrolytes and composite electrolytes are above 10 -4 S/cm due to the high ionic conductivity and plasticizing effect of ionic liquids.…”

Recent Advances in Non-Flammable Electrolytes for Safer Lithium-Ion Batteries

“…The electrolyte displayed high ionic conductivity and low crystallinity. Flexible composite ionic liquid gel polymer electrolytes (ILGPEs) supported by Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 (LAGP) were fabricated and investigated by Guo et al for improving the electrochemical performance and thermal safety of the batteries [48]. They optimized 10% LAGP for the electrolyte.…”

Reducing interfacial resistance of a Li1.5Al0.5Ge1.5(PO4)3 solid electrolyte/electrode interface by polymer interlayer protection

“…[18][19][20][21][22][23][24][25] Moreover, gel electrolyte interlayers were introduced in ceramic-based solid state batteries, which displayed a remarkable wettability toward the Li surface, with high ionic conductivity at room temperature thanks to the composition of the polymer and liquid. 26,27 However, a detailed analysis of the interfacial resistance of the multilayer LAGPbased composite electrolyte has been rarely reported, and the interaction between the ceramic layer and the polymer layer has yet to be understood.…”