Li Metal

13 MPa

Researchers from Columbia University investigated the role of stack pressure on the interface Li//LLZO*//Li interfaces using a synchronized operando setup that can probe both the microstructure and mechanics of a buried interface during cycling. They found that a stack pressure of 2 MPa or less is unable to maintain interfacial homogeneity over cycling. At a high stack pressure of 13 MPa, interfacial homogeneity is maintained, but high pressure also accelerates dendrite growth. This happens because of the increase in local hydrostatic stress which leads to solid electrolyte fracture and Li metal penetration. Such high pressures are likely impractical for commercial battery development. High stack pressures are neither beneficial nor practical for solid state battery development. Strategies are needed to homogenize the interface at lower stack pressure. 169

Research: Li metal Source: Chang, May, Wang, Thorsteinsson, Sakamoto, Marbella, and Steingart

*lithium lanthanum zirconium oxide

Volta Foundation

Extracted from the PDF; charts and images may read imperfectly.