论文标题
锂溶解度较低的层间层增强固态电解质中对树突生长的耐受性
An interlayer with low solubility for lithium enhances tolerance to dendrite growth in solid state electrolytes
论文作者
论文摘要
使用金属锂作为阳极的所有固态锂离子电池都具有更高的能量密度，同时也比常规的液体电解质锂离子电池更安全。然而，锂（树突）在固态电解质层上的微小细丝的生长导致细胞过早短路，并限制了其实际生存力。导致固态细胞中锂树突生长的微观机制尚不清楚。使用基于石榴石的锂离子导体作为模型固态电解质，我们表明锂溶解过程中的界面空隙生长先于树突成核和生长。使用简单的静电模型，我们表明，空隙边缘处的电流密度可以通过多达四个数量级扩增，从而使细胞在空隙形成后高度容易受到树突生长的影响。我们提出使用具有低溶解度和高核的金属层中锂的金属层中层，以延迟空隙生长。这些中间层增加了固态电解质中的树突生长耐受性，而无需高堆积压力。
All solid state Li-ion batteries employing metallic lithium as an anode offer higher energy densities while also being safer than conventional liquid electrolyte based Li-ion batteries. However, the growth of tiny filaments of lithium (dendrites) across the solid state electrolyte layer leads to premature shorting of cells and limits their practical viability. The microscopic mechanisms that lead to lithium dendrite growth in solid state cells are still unclear. Using garnet based lithium ion conductor as a model solid state electrolyte, we show that interfacial void growth during lithium dissolution precedes dendrite nucleation and growth. Using a simple electrostatic model, we show that current density at the edges of the voids could be amplified by as much as four orders of magnitude making the cells highly susceptible to dendrite growth after void formation. We propose the use of metallic interlayers with low solubility and high nucleation overpotential for lithium to delay void growth. These interlayers increase dendrite growth tolerance in solid state electrolytes without the undue necessity for high stack pressures.
