Dendrite Growth Suppression and In-Situ Surface Observation of Lithium Battery Under an Optical Microscope

Abstract

Dendrite growth is a major obstacle to the commercialization of Li metal batteries. A dendrite formed on a Li anode can cause thermal run-aways and permanent capacity loss. An in-situ optical techniques is considered as one of the major methods to study the dendrites growth behaviors and morphologies real-time. A home-designed in-situ optical cell with a digital optical microscope was used to investigate the behavior of Li deposition on a metallic Li electrode under different electrochemical operation conditions. The impacts of electrolytes, additives and cycling conditions on the dendrite formation were investigated. Guiding by the in-situ optical observation results, polycyclic aromatic hydrocarbons (PAHs) were introduced as additives to suppress the dendrite growth by forming a dynamic elastic protection layer and reacting with newly deposited dendrites. The in-situ observation method of solid-state electrolyte is also introduced.