Memory Effect of MgAl Layered Double Hydroxides Promotes LiNO₃ Dissolution for Stable Lithium Metal Anode

Abstract

considered the most promising energy storage device to break the energy density bottleneck of conventional graphite-based lithium-ion batteries. [1] However, the stateof-the-art carbonyl-containing carbonate electrolytes are incompatible with Li metal anode due to irrepressible interface side reactions that consequently induce carbonate solvent-derived organic solid electrolyte interphase (SEI), such as alkyl carbonate. [2] The organic-rich SEI possesses strong bonding with the Li anode, resulting in low ionic conductivity, sluggish Li + interfacial transfer, and low Li + transference number (t Li + ). [3] These issues tend to render uncontrollable growth of Li dendrites during electrodeposition, finally leading to low Coulombic efficiency (CE), poor rate capability and lifespan, and even serious safety hazards by puncturing the separator. [4] It is generally accepted that a stable and superior-ionic-conductive SEI are prerequisites for realizing efficient Li + transport and uniform Li deposition. [5] Since the solvent molecules and anions from the Li + solvation sheath spontaneously trigger reactions to form solvents-derived organic SEI or anion-generated chemically inorganic SEI at the electrode-electrolyte interface. [6] Inorganic SEI, a kind of superb Li + conductors such as Li 3 N, LiN x O y , [7] have high interface energy with Li anode, forming weak bonding between SEI and Li anode, keeping Li evenly diffused along the SEI/Li interface to regulate Li plating/stripping behavior and boost stable SEI. Controlling the electrolyte composition has been proven to be a facile and feasible strategy to form a desired inorganic-rich SEI. [8] Thus, functional additives lie at the heart in the field of LMBs' electrolytes. Introducing proper inorganic additives into the electrolyte can effectively generate corresponding inorganic SEI to accelerate the migration of Li + , such as ZrO 2 [9] or LiNO 3 .[10] LiNO 3 , as an efficient ether electrolyte additive in lithiumsulfur batteries, reinforces the interfacial stability of Li metal anode due to the capability of forming a robust SEI to inhibit the shuttle effect of lithium polysulfides. NO 3 − −derived reduction products such as Li 3 N are excellent Li + conductors, which can strengthen Li + migration and restrain dendrites growth. [11] However, LiNO 3 is rarely used in relatively high-electrochemical-window carbonate electrolytes due to its poor solubility. To LiNO 3 is an effective additive for improving the performance of Li metal anodes. However, the practical application of LiNO 3 is limited due to its poor solubility. Here, a novel electrolyte additive of MgAl layered double hydroxides (LDHs) with open interlayered anionic vacancies is proposed. The electropositive MgAl LDHs promote the spontaneous coordination of NO 3 − into anionic vacancies of LDH interlayers via memory effect, rehydrating to original NO 3 − -MgAl LDHs structure and accelerating LiNO 3 dissolution. The reconstructed NO 3 − -MgAl LDHs play a crucial role as sustainable nitrate resources, prev...

Solvation Sheath Engineering by Multivalent Cations Enabling Multifunctional SEI for Fast-Charging Lithium-Metal Batteries

“…As shown in Figure a,b, the SEI components on the lithium metal after cycling in BE and Al/LN-BE electrolytes were characterized by post-mortem analysis using XPS. The C 1s spectra of the BE electrolyte was fitted into four peaks, which correspond to–CO 3 – at 290.0 eV, CO bonds at 288.7 eV, C–O bonds at 286.4 eV, and C–C/C–H at 284.8 eV. − In comparison with the C 1s spectra of the Al/LN-BE electrolyte, more ingredients of solvent decomposition were observed in the BE electrolyte, illustrating the formation of solvent-derived unstable SEI. For the F 1s spectrum, a conspicuous signal of LiF was viewed, and no P–F product was noted in the Al/LN-BE electrolyte, exhibiting that the addition of LiNO 3 and FEC inhibited the decomposition of LiPF 6 and promoted the generation of LiF from FEC.…”

High‐Areal Capacity, High‐Rate Lithium Metal Anodes Enabled by Nitrogen‐Doped Graphene Mesh

“…[19] Lower activation energy suggests that less energy is needed for the Li ions to move through the NGM@Li anode, contributing to faster ion transport. [20] This faster ion transport in NGM@Li is attributed to its highly continuous network of open channels that facilitate easier movement of ions. Exchange current density is a measure of the rate at which an electrode can gain or lose electrons, and it is an indicator of the electrode reaction kinetics.…”

2D semiconductor nanosheets for solar photocatalysis

“…Layered metal hydroxides are widely recognized as 2D materials possessing anion exchange capacity 73 . The presence of hydroxyl groups makes them promising multiphase photocatalysts with potential applications in energy storage and environmental contexts, owing to their amenability to intercalation modification and exfoliation.…”