Smalltalks "Lithium metal growth on the nanoscale"

Abstract

The energy density of current battery technology severely limits the driving range of electric trucks, cars and airplanes. To improve the energy density of batteries, new electrode materials need to be developed. In theory, one of the most desirable electrode materials to work with is lithium metal. However, batteries using these electrodes typically have short lifetimes, limiting their commercial viability. The root of this problem is that as the battery is charged and discharged, the lithium electrode tends to evolve branched structures with large surface areas. Over time, this leads to loss of electrode material and sometimes even short-circuiting of the battery. To understand the mechanisms through which these detrimental structures develop, and eventually stop them, we study the 3D-structure of lithium metal electrodes using x-ray nanotomography. By tracking how the structures change as the battery is charged and discharged, we correlate battery cycling conditions and the electrode nanostructure.