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

Abstract 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, preventing partial NO 3 − from participating in the Li + solvent sheath to reduce the solvation binding energy. Moreover, MgAl LDHs absorb the anions due to electrostatic attraction, accounting for more dissociated Li + and active Li + migration in carbonate electrolytes. NO 3 − stored in MgAl LDHs is also preferentially reduced to form Li 3 N‐rich solid electrolyte interphase (SEI), decreasing the activation energy barrier for Li + transport and striving to form a uniform Li deposition. The cells assembled with MgAl LDHs and LiNO 3 additives deliver high Coulombic efficiency, excellent rate capability, and high capacity retention. This strategy provides new insights into LiNO 3 ‐promotor design and excavates the potential of LDHs materials for Li metal batteries.