Lithium Bis(Fluorosulfonyl)Imide, commonly called LiFSI, comes up frequently in technical discussions about advanced battery chemistries. As the world asks for cleaner vehicles and better energy storage, LiFSI doesn't just fill a gap—it has shifted expectations for battery performance. The formula, LiN(SO2F)2, points toward its precise chemical nature. It takes the form of a salt, usually found as off-white to white solid flakes, granules, or crystalline powders. Sometimes, suppliers offer it as prilled crystals, pellets, or dissolved in solvents to form clear, stable solutions. These are standard working forms for researchers and engineers aiming to achieve tight control over chemical processes.
This compound shows a density between 1.6 and 1.7 g/cm³ in its most common, crystalline form. Most batches come highly pure, often exceeding 99.9%, thanks to the tight quality controls demanded by battery manufacturers and high-tech labs. Melting points tend to fall near 124°C. The white crystals stay stable under standard atmospheric conditions, but exposure to air and moisture will begin to degrade material quality over time. Its solubility shines, with LiFSI easily dissolving in organic solvents such as carbonates, acetonitrile, and various ethers. This open solubility profile makes the salt stand out against other lithium salts. When you aim for fast ion transport and low impedance across a range of temperatures, very few options can match LiFSI’s reliability.
The molecule features a central lithium ion surrounded by two bis(fluorosulfonyl)imide anions. This arrangement results in high ionic dissociation even in low-polarity solvents. The correct molecular formula is LiN(SO2F)2, and it weighs in at about 187 g/mol. The molecular structure is not only significant for the electrochemical applications it offers but also for how the ion pairs interact at the microscopic level. Good researchers and engineers dig deep into these properties, tweaking other materials and additives to take advantage of the strong dissociation and high mobility LiFSI brings to any electrolyte formulation. Consistency in raw material sourcing means end results aren’t left up to chance—a necessity in high-performance chemical applications.
Suppliers package LiFSI as solid flakes, white powder, crystals, or, less often, transparent solution for easy dosing and mixing. Some advanced lines can convert between these forms without introducing impurities, allowing manufacturers to switch between bulk deliveries and specialty pack sizes as next-generation projects scale up. Lithium Bis(Fluorosulfonyl)Imide carries the HS Code 2825.20 for international trade purposes—critical knowledge for anyone navigating import/export logistics or regulatory filings. Consistently accurate packing and documentation matter to prevent accidental exposure and ensure every shipment arrives as intended.
This salt does not belong in the average laboratory or storeroom that lacks proper ventilation and controls. Direct contact with solids or concentrated solutions can pose health risks: While no single exposure symptom shows up universally, breathing in fine dust or prolonged skin exposure leads to irritation and discomfort. Lithium and fluorinated raw materials bring a risk of toxic byproducts if not handled with trained precautions, so respirators and gloves are non-negotiable for staff. Dust control, spill containment, and sealed handling systems stand out as the best line of defense. Combustion can give rise to hazardous gases such as hydrogen fluoride and sulfur oxides, so storing LiFSI away from incompatible substances such as strong acids, moisture, or flame sources reduces risk. Disposal means consulting proper hazardous waste regulations and not sending anything down the drain or regular landfill streams.
Research and industry appreciate LiFSI for what it makes possible: New lithium-ion battery chemistries that survive extreme temperatures, last longer, and offer faster charging. This salt offers high conductivity and improved electrochemical stability, attracting developers working on everything from electric vehicles to grid-scale storage. Some companies push LiFSI to replace older salts in commercial cells, removing weak links that limit charging rates or battery life. By having a higher resistance to hydrolysis compared to LiPF6 and not releasing PF5, developers see fewer corrosive failures over time. The demand for reliable, high-purity raw materials drives suppliers to improve synthesis routes and invest in cleaner, scalable production. When energy demand soars, and reliability can't wait, materials like LiFSI ensure new projects don’t get derailed by underperforming chemistry.
Handling challenges remain an ever-present concern. Facilities can upgrade air handling systems and enforce strict personal protective equipment policies to keep staff healthy and prevent leaks. Ongoing research and open data sharing between suppliers and battery startups help drive further safety improvements and recycling methods, bringing such advanced chemicals into the larger sustainability conversation. Supply chain transparency matters—clear labeling, data sheets, and full safety documentation empower everyone touching this material to do so confidently. With predictable pricing and oversight, the market can keep up with rapid growth and set new standards for handling hazardous but essential materials.
