Insights Into 1, 2‐Dimethoxypropane Mediated Dissolution of Low‐Solubility LiNO ₃ in Carbonate Electrolytes Toward High‐Voltage Lithium‐Metal Batteries

ABSTRACT In high‐energy‐density lithium‐metal batteries (LMBs), the pronounced solvation effect and strong interfacial reactivity of carbonate‐based electrolytes pose persistent challenges. Although LiNO 3 can effectively optimize electrolyte‐electrode interphases (EEIs), its limited solubility in carbonate‐based electrolytes restricts practical utility. Herein, by leveraging the favorable properties of 1, 2‐dimethoxypropane (DMP), including moderate LiNO 3 ‐solubilizing ability, low polarity, significant steric hindrance, and high fluidity, DMP is introduced into carbonate‐based electrolytes to design a weak‐solvation high‐voltage electrolyte enriched with NO 3 − and PF 6 − . This strategy facilitates the formation of an anion‐rich high‐entropy solvation structure, thereby in situ constructing dense EEIs capable of effectively inhibiting lithium dendrite growth and transition metal dissolution under high‐voltage conditions. Consequently, Li plating/stripping exhibits highly reversibility over 1400 h and a Coulombic efficiency of 95.3%. LMBs assembled with typical cathodes, including LiCoO 2 , LiFePO 4, LiNi 0.9 Co 0.05 Mn 0.05 O 2 (NCM955), and LiNi 0.8 Co 0.1 Mn 0.1 O 2 , demonstrate exceptional long‐cycling stability and wide‐temperature adaptability across the voltage range of 2.0–4.5 V. The assembled Li||NCM955 cell achieves stable cycling over 880 cycles with 75.3% capacity retention. The approach of enhancing LiNO 3 solubility via introducing functional ethers provides a feasible strategy for developing stable high‐voltage LMBs.