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 and 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.

Magnetic Field–Suppressed Lithium Dendrite Growth for Stable Lithium‐Metal Batteries

“…In the first cycle, the Li deposit is uneven and there are numerous Li islands distributed on the surface, shown in Figure 3e. [37,55,59] Besides the CE, the cycling stability and rate capability are largely improved under magnetic field based on 3D Cu/NiCo current collector for Li metal anode, shown in Figure 5. When the cycle number reaches 120, the surface is covered with abundant of uneven and loose Li deposits implying the formation of dead Li and dendrites (Figure 3g).…”

Reliable seawater battery anode: controlled sodium nucleationviadeactivation of the current collector surface

“…[41][42] In particular, applying a low current density is one of the crucial factors for both (i) retardation of the onset time of dendrite The latter, which is expressed as r* = 2γVm/F|η|, where γ is the interfacial energy between solid Na metal and electrolyte, η is the overpotential, Vm is the molar volume, and F is Faraday's constant, suggests an inversely proportional relationship between current density and critical radius; the critical radius of nucleation decreases due to the high overpotential during the metal plating at a high current density. 40,[43][44] Thus, the abundant nuclei (high nucleation rate) on the current collector surface give rise to smaller grain size of plated Na metal, and subsequently the formation of a rough and inhomogeneous surface.…”

A bidirectional growth mechanism for a stable lithium anode by a platinum nanolayer sputtered on a polypropylene separator

“…[4][5][6] Generally, Li-ions rstly form mushroom-/sphere-like roots on the Li surface, and these nuclei give the Li anodes rough surfaces, which leads to inhomogeneous current distributions and high local current densities, especially on the tips of the Li nuclei. 7 In the stage of Li growth, Li tends to form unstable dendrites on the nuclei. Eventually, the Li dendrites penetrate through the separator leading to short-circuit that may end in cell failure by either voltage or thermal run-away.…”