Recent Advances in Understanding the Formation and Mitigation of Dendrites in Lithium Metal Batteries

Lithium (Li) metal battery systems are currently gaining significant attention as the most energy-intensive architectures among the various battery architectures being actively examined at present for multiple emergent applications. Although the cathode chemistries in Li metal systems are fairly simple and far less challenging in liquid electrolytes, the metallic chemistry of the anode poses many challenging problems. The dendrite formation and consequent dead Li formation and short circuiting have rendered the practical realization of these promising battery systems extremely hard. Therefore, the issue of dendrite mitigation has recently triggered hectic research efforts by battery scientists around the globe. The major research thrust of this activity has primarily been on gaining deep insights into the dendrite formation using advanced characterization methods. In this review, we seek to understand the Li dendrite formation as an interplay between the solid electrolyte interphase and surface features. We try to understand the dendrite formation as a consequence of the above two parameters via advanced imaging techniques, like X-ray imaging techniques, X-ray computed tomography, atomic force microscopy, and cryo-electron microscopy. Finally, an outlook is presented suggesting the emergent research directions.