Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, India.
Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA.
Nat Mater. 2022 Sep;21(9):1050-1056. doi: 10.1038/s41563-022-01264-8. Epub 2022 Jun 2.
Solid-state Li-ion batteries with lithium anodes offer higher energy densities and are safer than conventional liquid electrolyte-based Li-ion batteries. However, the growth of lithium dendrites across the solid-state electrolyte layer leads to the premature shorting of cells and limits their practical viability. Here, using solid-state Li half-cells with metallic interlayers between a garnet-based lithium-ion conductor and lithium, we show that interfacial void growth precedes dendrite nucleation and growth. Specifically, void growth was observed at a current density of around two-thirds of the critical current density for dendrite growth. Computational calculations reveal that interlayer materials with higher critical current densities for dendrite growth also have the largest thermodynamic and kinetic barriers for lithium vacancy accumulation at their interfaces with lithium. Our results suggest that interfacial modification with suitable metallic interlayers decreases the tendency for void growth and improves dendrite growth tolerance in solid-state electrolytes, even in the absence of high stack pressures.
具有锂金属阳极的固态锂离子电池比传统的基于液态电解质的锂离子电池具有更高的能量密度和更高的安全性。然而，锂枝晶在固态电解质层中的生长会导致电池过早短路，限制了它们的实际可行性。在这里，我们使用具有金属中间层的固态 Li 半电池，在石榴石基锂离子导体和锂之间，我们表明界面空隙生长先于枝晶成核和生长。具体来说，在大约为枝晶生长临界电流密度的三分之二的电流密度下观察到空隙生长。计算计算表明，对于枝晶生长具有更高临界电流密度的中间层材料在其与锂的界面处具有最大的热力学和动力学锂空位积累障碍。我们的结果表明，用合适的金属中间层进行界面改性可以降低空隙生长的趋势，并提高固态电解质中枝晶生长的耐受性，即使在没有高压堆的情况下也是如此。
