Lithium-Metal Foil Surface Modification: An Effective Method to Improve the Cycling Performance of Lithium-Metal Batteries

Lithium metal as an electrode material possesses a native surface film, which leads to a rough surface and this has a negative impact on the cycling behavior. A simple, fast, and reproducible technique is shown, which makes it possible to flatten and thin the native surface film of the lithium-metal anode. Atomic force microscopy and scanning electron microscopy images are presented to verify the success of the method and X-ray photoelectron spectroscopy measurements reveal that the chemical composition of the lithium surface is also changed. Furthermore, galvanostatic measurements indicate superior cycling behavior of the surface modified electrodes compared to the as-received ones. These results demonstrate that the native surface film plays a key role in the application of lithium metal as an anode material for lithium-metal batteries and that the shown surface modification method is an excellent tool to obtain better performing Li metal electrodes.