Construction of Moisture‐Stable Lithium Diffusion‐Controlling Layer toward High Performance Dendrite‐Free Lithium Anode

Abstract

Spatially random lithium nucleation and sluggish lithium diffusion across the electrode/electrolyte interface lead to uncontrollable lithium deposition and the growth of lithium dendrite on metallic lithium surface, causing severe safety problems. Herein, a functional rapid-ion-diffusion alloy layer on the metallic lithium surface (RIDAL-Li) is designed through a simple chemical reduction reaction. Such a layer efficiently reduces energy barriers for lithium transport and thus significantly homogenizes the lithium atom flux for lateral deposition, which are confirmed by electrochemical tests, theoretical simulations, and spectroscopic analysis. Furthermore, the as-prepared RIDAL layer also displays a much higher corrosion resistance to moisture and oxygen. As a result, in ether-based and carbonate-based electrolytes, the pretreated RIDAL-Li anode can achieve a long stripping/plating lifespan of 900 h and a high Coulombic efficiency of 99% without dendrite growth. Even after being exposed to the ambient environment with relative humidity of 51% for 60 min, the RIDAL-Li can survive for stripping/plating 400 h and exhibit a low overpotential of 18 mV, displaying the superiority for ambient atmosphere battery assembly. Matched with LiFePO 4 or sulfur cathode, the full cells exhibit remarkably improved stability and capacity retention, showing its suitability for applications in lithium metal batteries.

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

“…The massive demands in smart portable devices, electromobility and stationary storage systems push the developments of high-energy-density battery systems. − Lithium metal anode exhibits high theoretical capacity and the low potential (−3.04 V vs SHE). , However, the dendrite resulted from random lithium plating behaviors and sluggish surface atom diffusion, and uneven solid electrolyte interphase (SEI) prevent its wide applications. − Moreover, large volumetric changes during cycling will break down the fragile SEI so that fresh SEI will be continuously formed at the Li/electrolyte interface, exhausting the limited electrolyte . These cross-linked issues would lead to severe safety problems and significantly degraded performances .…”

Tuning 4f‐Center Electron Structure by Schottky Defects for Catalyzing Li Diffusion to Achieve Long‐Term Dendrite‐Free Lithium Metal Battery

“…[ 2 ] However, the practical application of metallic lithium anode still faces rigorous challenges such as uncontrollable dendrites growth due to random dispersions of lithium ion/atom flux within the solvation surroundings, and cracking of the fragile solid electrolyte interphase (SEI) as a result of large volumetric changes. [ 3 ] More severely, the repeated formation of fresh SEI continuously consumes and eventually exhausts the little finite electrolyte, [ 4 ] resulting in low Coulombic efficiency (CE), limited lifespan, and even safety hazards by short circuiting. [ 5 ]…”

“…[ 12 ] Based on the classical Arrhenius formula , decreasing these barriers can help improve the lithium plating kinetics toward dendrite‐free morphologies. [ 4 , 7 , 9 ] Therefore, the core challenge is concentrated on looking for proper catalysts/activators to speed up the desired lithium kinetics.…”

Regulation of Dendrite-Free Li Plating via Lithiophilic Sites on Lithium-Alloy Surface

“…Besides, Li diffusion on the substrate is another dominant factor for dendrite-free Li plating. Li diffuses faster in Li alloys, such as Li 13 In 3 , LiZn, Li 3 Bi, and Li 3 As, compared to Li metal, where the Li dendrite formation and growth can be suppressed significantly. − , The fast Li diffusion can avoid tip effect-induced Li nucleation and thus achieve a uniform Li deposition, whereas a slow Li diffusivity and random Li nucleation process cause a large overpotential. A higher Li diffusion could allow a higher probability for Li to deposit in the vicinity of the substrate instead of being reduced directly on a local protuberant site of the substrate. − Furthermore, the 3D scaffold structure can adjust the volume change and increase the Li diffusion, resulting in high capacity and good cycling stability. ,, For example, the innovative 3D Li/Li 22 Sn 5 nanostructure forming a 3D Li 22 Sn 5 interconnected network provides an easy pathway for Li-ion and electron diffusion, which accelerates the Li diffusion and subsequently suppresses the Li dendrite formation and increases the Coulombic efficiency of LMBs.…”