| Melting Point | 140 °C |
| Molecular Formula | LiNO₄S₂F₂ (F₂LiNO₄S₂) |
| Molecular Weight | Molecular Weight 187.07 g/mol |
| SMILES String | FS([N-]S(F)(=O)=O)(=O)=O.[Li+] |
| Assay | Powder |
| Potassium (K) | ≤ 10 ppm |
| Sodium (Na) | ≤ 5 ppm |
| Solubility | Soluble in water; also soluble in common organic electrolyte solvents (carbonates, ethers) |
| Chloride (Cl⁻) | ≤ 5 ppm |
| Sulfate (SO₄²⁻) | ≤ 10 ppm |
| NACRES | NA.21 |
| UNSPSC Code | 12352104 |
| MDL Number | MFCD28126786 |
| Quality Segment | 300 |
| InChI | 1S/F2NO4S2.Li/c1-8(4,5)3-9(2,6)7;/q-1;+1 |
| InChI Key | VDVLPSWVDYJFRW-UHFFFAOYSA-N |
| Sustainability | Greener Alternative Product (enhanced for energy efficiency) |
| Applications | Lithium-ion source in liquid electrolyte formulations for Li-ion and Li-metal batteries |
| 86277430 |
Lithium bis(fluorosulfonyl)imide is a lithium-based salt supplied as a white powder, purpose-built for demanding electrolyte applications. In its battery-grade form it is manufactured to a high assay with tightly controlled trace-level impurities — sodium, potassium, chloride, and sulfate are all held to low ppm thresholds, and moisture is minimized — because even small contaminant levels can degrade cell performance and cycle life. The salt dissolves readily in water as well as in the organic carbonate and ether solvents that make up most modern battery electrolyte systems, which gives formulators flexibility when designing new electrolyte chemistries.
What sets LiFSI apart from conventional lithium salts is the balance of properties it brings to a cell. It supports strong ionic conductivity in organic media, resists breakdown from trace moisture better than many alternatives, and remains thermally stable across a wider operating window. These characteristics have made it an increasingly important component in next-generation battery electrolyte design.
LiFSI’s core role is as the lithium-ion carrier in electrolyte solutions for lithium-ion and lithium-metal batteries. Compared with the industry-standard salt LiPF6, it offers several practical advantages: higher ionic conductivity in organic solvent systems, greater resistance to hydrolysis, reduced corrosion of aluminum current collectors even at higher cell voltages, a higher lithium transference number, and improved coulombic efficiency during cycling of lithium-metal anodes. These properties make it valuable in cells that need to operate reliably across a broad voltage range, including systems pushed to cathodic potentials approaching 6 V vs. Li/Li⁺.
Because of this performance profile, LiFSI shows up in several distinct electrolyte strategies. Formulators use it as a stand-alone salt in electrolytes designed for extreme cold-weather performance, since it helps maintain conductivity at temperatures as low as ‑30 °C. It is also frequently blended as a co-salt with LiPF6 to shore up high-temperature stability in electrolyte formulations. In solid and gel polymer electrolyte systems built around lithium-metal anodes, LiFSI contributes to forming a more robust, lithium-fluoride-rich interphase layer on the anode surface, which supports more stable long-term cycling.
