Controlling Li Ion Flux through Materials Innovation for Dendrite-Free Lithium Metal Anodes

Lithium (Li) metal with high theoretical capacity and the lowest electrochemical potential has been proposed as the ideal anode for high-energy-density rechargeable battery systems. However, the practical commercialization of Li metal anodes is precluded by a short lifespan and safety problems caused by their intrinsically high reductivity, infinite volume change, and uncontrollable dendrite growth during deposition and dissolution processes. Plenty of strategies have been introduced to solve the above-mentioned problems. Among these, controlling Li+ flux plays a vital role to directly influence the plating and stripping process. In this work, the fundamental effect of Li+ flux distribution on Li nucleation and early dendrite growth is discussed. Then, recent strategies of controlling Li+ flux to suppress dendrite formation and growth through materials design are summarized, including homogenizing Li+ flux, localizing Li+ flux, and guiding gradient Li+ distribution. Finally, underexplored materials are proposed and explored to control Li+ flux and further directions for dendrite-free Li anodes. It is expected that this progress report will help to deepen the understanding of Li+ flow tuning and morphology control of Li anodes and eventually facilitate the practical application of Li metal batteries.