Fast Ag-Ion-Conducting GeS2-Sb2S3-Agl Glassy Electrolytes with Exceptionally Low Activation Energy

摘要

Silver-ion-sconducting solid electrolytes with low activation energy are important because of their distinctive application potential in solid-state batteries operated within a broad temperature range, especially below room temperature. Achieving glassy solid electrolytes with high ionic conductivity, low activation energy, and good thermal stability is a continuous challenge for the design and synthesis of novel fast ion-conducting glasses. Here, we report markedly low activation energy and high room-temperature ionic conductivity in melt-quenched GeS2-Sb2S3-AgI chalcogenide glasses. Homogeneous 2.5GeS(2)-27.5Sb(2)S(3)-70AgI glass presenting high glass transition temperature of 135 degrees C shows high ionic conductivity of 9.18 X 10(-3) S/cm at 25 degrees C and low activation energy of 0.07 eV, which is the lowest among those of Ag-ion glassy electrolytes. Structural characterization by using Raman spectra suggests that, in the disordered network structure of GeS2-Sb2S3-AgI glasses, the formation of chain fragments composed by [SbS3-xIx](n), which is similar to the double chain of [(SbSI)(infinity)](2) in the SbSI crystal structure, provides possible diffusion pathways to facilitate low-barrier concerted migration of silver ions.