Effect of Postannealing on the Properties of a Ta-Doped Li7La3Zr2O12 Solid Electrolyte Degraded by Li Dendrite Penetration
Effect of Postannealing on the Properties of a Ta-Doped Li7La3Zr2O12 Solid Electrolyte Degraded by Li Dendrite Penetration
复制标题
DOI：
10.1021/acsaem.0c02474
复制
发表时间：
2020-12-28
影响因子：
6.4
通讯作者：
Thangadurai, Venkataraman
中科院分区：
文献类型：
--
作者：
Inada, Ryoji;Takeda, Atsuto;Thangadurai, Venkataraman
在本研究中，我们研究了后退火对石榴石型钽掺杂的Li₆.₅₅La₃Zr₁.₅₅Ta₀.₄₅O₁₂（Ta - LLZO）陶瓷固体电解质性能的影响，该电解质在Li/Ta - LLZO/Li对称电池的电化学锂镀/脱测试过程中因锂枝晶穿透而性能下降。在对称电池中进行电化学测试后，将Ta - LLZO片从电池中取出，然后在空气中于800℃或900℃退火4小时。经证实，锂枝晶穿透的Ta - LLZO表面局部变色斑点在后退火后消失。退火后的Ta - LLZO片的总电导率低于初始电导率，但在室温下仍保持在10⁻⁴ S cm⁻¹以上。当因锂枝晶穿透导致的软短路或性能下降区域的尺寸是局部的且小于Ta - LLZO的面积尺寸时，预计退火后的Ta - LLZO电导率的下降幅度会更小。所获得的电化学结果表明，在另一个全固态锂电池中重新使用因锂枝晶穿透而性能下降的石榴石型固体电解质是有可能的。
In this study, we investigated the effect of postannealing on the properties of a garnet-type Ta-doped Li6.55La3Zr1.55Ta0.45O12 (Ta-LLZO) ceramic solid electrolyte degraded by lithium (Li) dendrite penetration during electrochemical Li plating and stripping testing in a Li/Ta-LLZO/Li symmetric cell. After the electrochemical testing in the symmetric cell, the Ta-LLZO pellet was taken out of the cell and then annealed at 800 or 900 degrees C for 4 h in air. It was confirmed that locally discolored spots on the Ta-LLZO surface at which Li dendrite penetrated disappeared after postannealing. The total conductivity of the annealed Ta-LLZO pellet was lower than the initial one but was retained above 10(-4) S cm(-1) at room temperature. When the soft-shorted or degraded area size by Li dendrite penetration is localized and smaller than the area size for Ta-LLZO, it is expected that the degradation of the conductivity of annealed Ta-LLZO becomes smaller. Obtained electrochemical results indicate the possibility of reusing the degraded garnet-type solid electrolyte by Li dendrite penetration in another all-solid-state Li battery.