title: Nanoscale Nucleation and Growth of Electrodeposited Lithium Metal.
abstract: Lithium metal has re-emerged as an exciting anode for high energy lithium-ion batteries due to its high specific capacity of 3860 mAh g-1and lowest electrochemical potential of all known materials. However, lithium has been plagued by the issues of dendrite formation, high chemical reactivity with electrolyte, and infinite relative volume expansion during plating and stripping, which present safety hazards and low cycling efficiency in batteries with lithium metal electrodes. There have been a lot of recent studies on Li metal although little work has focused on the initial nucleation and growth behavior of Li metal, neglecting a critical fundamental scientific foundation of Li plating. Here, we study experimentally the morphology of lithium in the early stages of nucleation and growth on planar copper electrodes in liquid organic electrolyte. We elucidate the dependence of lithium nuclei size, shape, and areal density on current rate, consistent with classical nucleation and growth theory. We found that the nuclei size is proportional to the inverse of overpotential and the number density of nuclei is proportional to the cubic power of overpotential. Based on this understanding, we propose a strategy to increase the uniformity of electrodeposited lithium on the electrode surface.
authors.affiliation: Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States.
authors.forename: Allen
authors.identifier: 0000-0001-8930-2125
authors.initials: A
authors.lastname: Pei
authors.affiliation: Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States.
authors.forename: Guangyuan
authors.initials: G
authors.lastname: Zheng
authors.affiliation: Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States.
authors.forename: Feifei
authors.initials: F
authors.lastname: Shi
authors.affiliation: Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States.
authors.forename: Yuzhang
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States.|Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, California 94025, United States.
authors.forename: Yi
authors.initials: Y
authors.lastname: Cui
keywords: Lithium metal anode; anode-free; anode-less; copper; electrodeposition; nucleation and growth