锂过量对钙钛矿型Li3/8Sr7/16Ta3/4Hf1/4O3固体电解质性能的影响

锂过量对钙钛矿型Li_3/8Sr_7/16Ta_3/4Hf_1/4O₃固体电解质性能的影响

摘要: 固相烧结法合成钙钛矿型Li_3/8Sr_7/16Ta_3/4Hf_1/4O₃(LSTH) 固体电解质材料，制备过程中分别加入过量的碳酸锂，质量分数分别为(0~30 %).通过XRD、SEM、ICP-OES以及EIS测试，表征不同锂过量LSTH固体电解质材料成相、显微形貌以及室温电导率的影响.实验结果表明，配料时，过量一定质量百分数的碳酸锂，能够有效减少烧结过程中因锂挥发而生成的SrTa₂O₆杂相，提高样品密度和室温电导率.样品最佳锂过量质量百分数为20 %，20 %锂过量样品1 300 ℃烧结10 h为钙钛矿纯相，密度6.5 g/cm³，室温电导率达到3.12×10^-4 S/cm.

Abstract: A new perovskite-type electrolyte "Li_3/8Sr_7/16Ta_3/4Hf_1/4O₃" (LSTH) was prepared by conventional solid-state reaction with different excess lithium carbonate (from 0 to 30 %). XRD, SEM, ICP-OES and AC impedance were used to determine the phase formation, microstructure, and room tempertature Li-ion conductivity. The results indicate that the impurity phase SrTa₂O₆ is significantly reduced, the density and room-temperature ionic conductivity of the LSTH pellet were improved with excess lithium salt. The LSTH pellets with 20 % excess lithium salt sintered at 1 300 ℃ for 10 h has a density of 6.56 g/cm³ and a room-temperature ionic conductivity to 3.12×10^-4 S/cm.