Growth mechanism for dendrite-free lithium regulated deposition

Abstract

The unhealthy electrodeposition leads to uncontrolled growth and random fracture of Li, causing safety problems. Here we elaborate on the growth mechanism of Li on different substrates by integrating overpotential testing and Gibbs free energy calculating. Induced nucleation sites are brought into the substrate to trap Li preferentially, reducing the primary deposition barrier and contributing to the uniform nucleation of Li. The Li grows along the sites where the pits grow on the carbon substrate. The secure connection between the metal and the substrate can be used to stabilize the bulk metal. In addition, the external magnetic field during electrodeposition homogenizes the direction of ion movement and promotes uniform deposition. At the same time, the 3D frame distributes the ion flux homogenization, providing enough space to mitigate the volume change. The design of the substrate provides a unique inside-out growth path for metal, which guides the uniform deposition of Li and effectively inhibits the growth of dendrites. The electrochemical performance using CC/Co3O4/Li electrode is significantly improved in the full battery with sulfur as the cathode. This work explores the growth mechanism of Li metal and guides stable dendrite-free Li electrode fabrication.