That means that as the electrode moves toward the separator, if the pore sizes are small, there are fewer places the metal ions can penetrate. Instead of evenly spreading out, much of the current ends up in some naturally selected spots, which can lead to a battery short circuiting.
Bai and Ma have devised a mathematical model, called the Young-Laplace overpotential, that captures the dynamics of the physics inside an actual battery, which is now guiding Bai’s lab to develop more stable and safer anode-free metal batteries.
“We had already found a physical threshold for the ideal cases,” Bai said. “But the practical threshold is much lower. And it depends on the microstructure of the separator precisely following the mathematical model we developed.”
This work was supported by a National Science Foundation grant (Award No. 1934122). The materials characterization experiments were partially supported by IMSE (Institute of Materials Science and 56 Engineering) and by a grant from InCEES (International Center for Energy, Environment and Sustainability) at Washington University in Saint Louis. P.B. acknowledges the startup support from Washington University in St. Louis.