A dilute nitrate electrolyte for all-climate batteries

Commercial lithium-ion battery electrolytes rely heavily on expensive LiPF 6 , making electrolyte cost a growing concern for battery deployment. Here, machine learning was used to help select dimethylacetamide as the basic solvent for LiNO 3 to yield a low-concentration electrolyte (0.38 M). Remarkably, techno-economic analysis shows that this approach directly reduces the cost of the electrolyte by up to 37.1%. The electrolyte delivered a 4.65-V electrochemical window, an ionic conductivity of 3.34 × 10 −3 S cm −1 , and stable operation from −40°C to 50°C. Its Li 3 N/LiF-rich and inorganic-organic hybrid interphases enabled stable cycling of NMC811, graphite, and lithium-metal electrodes. A 1-Ah NMC811||graphite pouch cell retained 91.3% capacity after 500 cycles. As validated here, dilute electrolytes are expected to present an innovative solution for low-cost batteries.