Lithium Atom Surface Diffusion and Delocalized Deposition Propelled by Atomic Metal Catalyst toward Ultrahigh-Capacity Dendrite-Free Lithium Anode

Abstract

Lithium metal anode possesses overwhelming capacity and low potential but suffers from dendrite growth and pulverization, causing short lifespan and low utilization. Here, a fundamental novel insight of using single-atomic catalyst (SAC) activators to boost lithium atom diffusion is proposed to realize delocalized deposition. By combining electronic microscopies, time-of-flight secondary ion mass spectrometry, theoretical simulations, and electrochemical analyses, we have unambiguously depicted that the SACs serve as kinetic activators in propelling the surface spreading and lateral redistribution of the lithium atoms for achieving dendrite-free plating morphology. Under the impressive capacity of 20 mA h cm–2, the Li modified with SAC-activator exhibits a low overpotential of ∼50 mV at 5 mA cm–2, a long lifespan of 900 h, and high Coulombic efficiencies during 150 cycles, much better than most literature reports. The so-coupled lithium–sulfur full battery delivers high cycling and rate performances, showing great promise toward the next-generation lithium metal batteries.

Toward Dendrite-Free Metallic Lithium Anodes: From Structural Design to Optimal Electrochemical Diffusion Kinetics

“…Regulating the surface activation helps to increase diffusion kinetics to realize homogeneous deposition (Figure 15A). 83 As reported in our previous finding, the SAC is available to modulate the Li nucleation by decreasing the barrier. Furthermore, in comparison with the pristine Li metal with high diffusion barriers (Figure 15B,C), a significant decrease of lithium atom diffusion barrier was realized down to 0.09 eV by introducing SAC activators into the system, suggesting the enhanced lateral diffusion for evenly distributed Li plating.…”

“…The rapid vertical deposition of Li atom will result in dendrite formation. Regulating the surface activation helps to increase diffusion kinetics to realize homogeneous deposition (Figure A) . As reported in our previous finding, the SAC is available to modulate the Li nucleation by decreasing the barrier.…”

“…Morphology of Li atom plating on (F) bare SAFeNi@LNCP and (G) LNCP to verify lateral deposition modulated by SACs. Reproduced with permission from ref . Copyright 2022, American Chemical Society.…”

“…89,90 The solvation, desolvation, transfer, and migration of lithium ions/atoms can be regarded as a sequence of "reactions" involving the formation and breaking of different types of lithium bonds. 83,91 Therefore, the catalyst design principles can be readily implemented for modulating the lithium diffusion kinetics. This offers an alternative method for covering the pristine lithium metal surface with catalysis/ modulation layer to regulate the lithium plating behaviors.…”

“…From the dynamical viewpoint, enhancing the surface affinity of the conductive matrix to lithium ions/atoms can create a thermodynamically favorable environment for smooth lithium deposition: Increasing the Li-ion/atom diffusion rates, especially those along the electrode surface, can kinetically ensure the rapid and uniform distribution of the lithium flux to the nucleation sites, even at large current densities. , Therefore, a combination of these two strategies would be the most effective solution for achieving dendrite-free Li plating. To decrease the diffusion energy barriers, one can apply the fundamentals of conventional catalysis for reducing the energy barriers of chemical reactions. ,− Actually, the concept of lithium bonding, as an analogue to hydrogen bonding, has been well established and widely applied to the understanding of lithium ionic/atomic behaviors in lithium batteries. , The solvation, desolvation, transfer, and migration of lithium ions/atoms can be regarded as a sequence of “reactions” involving the formation and breaking of different types of lithium bonds. , Therefore, the catalyst design principles can be readily implemented for modulating the lithium diffusion kinetics. This offers an alternative method for covering the pristine lithium metal surface with catalysis/modulation layer to regulate the lithium plating behaviors.…”