A translucent Al-containing garnet type electrolyte (Al-LLZTO) with high lithium-ion conductivity was made by pressure filtration followed by sintering to study in-situ lithium dendrite growth. A transparent tube furnace was built for in-situ dendrite growth studies above room temperature. In-situ lithium dendrite growth in a garnet-type electrolyte under an applied DC voltage was investigated at three different temperatures (room temperature, 100 °C, and 200 °C (above the melting point of lithium)). Critical current density (CCD) was estimated based on a previous model developed for sodium dendrites (which are actually filaments) in Na-β”-alumina. The CCD defined here is different than most of the reported work in lithium and lithium-ion batteries. When the temperature is higher than room temperature but lower than the melting point of lithium, lithium dendrites grow rapidly. However, when the temperature is above the melting point of lithium, no lithium dendrites were observed under similar testing conditions. This is because the CCD for liquid lithium dendrites to form is much higher than that for solid lithium dendrites to form. Approximate estimates of the CCD below and above the melting point of lithium are also given. This investigation provides significant insights into dendrite (filament) growth above room temperature, and possible prevention of lithium dendrites in working solid-state lithium-ion batteries, and the efficiency improvement of solid-state batteries.

通过压滤和烧结制备了具有高锂离子电导率的半透明含铝石榴石型电解质（Al-LLZTO），并研究了锂枝晶的原位生长。建造了透明管式炉，用于在室温以上进行原位枝晶生长研究。在三种不同温度（室温、100°C 和 200°C（高于锂熔点））下研究了施加直流电压下石榴石型电解质中锂枝晶的原位生长。临界电流密度 (CCD) 是根据先前为 Na-β”-氧化铝中的钠枝晶（实际上是细丝）开发的模型估算的。这里定义的 CCD 与大多数报道的锂和锂离子电池工作不同。当温度高于室温但低于锂熔点时，锂枝晶迅速生长。然而，当温度高于锂的熔点时，在类似的测试条件下没有观察到锂枝晶。这是因为液态锂枝晶形成的CCD远高于固态锂枝晶形成的CCD。还给出了低于和高于锂熔点的 CCD 的近似估计值。这项研究为室温以上枝晶（丝）的生长、固态锂离子电池工作中锂枝晶的可能预防以及固态电池效率的提高提供了重要见解。