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 α-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 × 10~(-4) to 7.5 × 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 α_(Li)~(LMO) ≈ 7.6 × 10~(-58) in LMO, and α_(Li)~(Li_2O) ≈ 8.8 × 10~(-50) in Li_2O.