Fabrication of Li-β' alumina + Yttria-Stabilized Zirconia Composites and Their Application in Lithium Battery

摘要

Samples of Na-β"-alumina + yttria-stabilized (YSZ) were made by vapor phase conversion of sintered a-alumina + YSZ. The samples were then treated in molten LiNO_3 to convert Na-β"-alumina into Li-β"-alumina by ion exchange. The resulting two phase material is a Li~+-ion conductor with room temperature ionic conductivity of ~2 x 10~(-4) to 7.5 x 10~(-4) Scm~(-1). The corresponding activation energy is 0.18 eV. Two lithium batteries of LMO+C||Li~+/Na~+- β"-alumina + YSZ ||Li structure were constructed using the same ion exchanged disc of 1 mm thickness over a period two months apart. Both batteries displayed a stable OCV of around 3.2 V at room temperature. No chemical and mechanical degradation of the solid electrolyte disc was observed over the testing period, indicating a high stability of the reported solid electrolyte against lithium metal. Thermodynamic activity of lithium is estimated to be {formula} in LMO, and {formula} in Li_2O.