Suspended Lithium Nitrate‐Based Electrolytes: Electrostatic Interactions for Mutually Rewarding Interface Optimization Strategies

Abstract Designing a stable electrode‐electrolyte interface (EEI) is critical for developing lithium metal batteries with high energy density, enhanced safety, and broad applicability. Lithium nitrate (LiNO 3 ) is an attractive sacrificial additive for lithium metal anode, while its poor solubility in high‐voltage‐resistant ester/nitrile electrolytes severely limits its utility. To solve it, a novel suspension electrolyte strategy is proposed that uniformly disperses LiNO 3 particles in an ester/nitrile mixed electrolyte to stabilize the electrode interface. The suspended LiNO 3 particles exhibit dual functionality: LiNO 3 enhances the compatibility between the electrode and the electrolyte by affecting the Li + solvation environment and preferentially adsorb on the electrode surface; moreover, the in situ formed LiN x O y ‐rich EEI by LiNO 3 decomposition with accelerated Li⁺ transport kinetics, effectively suppresses parasitic reactions and improves rate performance. The optimized electrolyte makes Li||NCM523 battery run stably for 100 cycles with a high capacity retention of 90.05% at 60 °C and stably operated at low temperature (‐10 °C). Moreover, the electrolyte shows excellent electrochemical stability at a high‐voltage of 4.5 V. This work presents a dual‐strategy advancement featuring wide‐temperature electrolyte formulation and precision interface engineering, synergistically achieving high‐specific‐energy lithium metal batteries.