Chemists have always looked for ways to move beyond the boundaries of water and organic solvents. In that search, ionic liquids showed up and shifted how laboratories handle chemical reactions and separations. As researchers dug for answers to energy storage and electrochemistry, the world of imidazolium-based ionic liquids started growing. The story of 1-(2-Ethoxyethyl)-3-Methylimidazolium Bis(Fluorosulfonyl)Imide, often dubbed [EMIM][FSI], has its roots in the 2000s, during a boom in lithium battery research and the chase for new electrolytes. Back then, scientists noticed imidazolium salts could take the heat, keep a low vapor pressure, and solve the problem of flammable solvents in batteries. The [FSI] anion took off as a game-changer, unlocking new paths around solubility and ionic conductivity. University and industry teams pushed the molecule, testing how it behaved under high voltage, intense cycles, and a mix of temperatures. This molecule began as a laboratory curiosity, and now you find it under the microscope of energy researchers around the globe.
1-(2-Ethoxyethyl)-3-Methylimidazolium Bis(Fluorosulfonyl)Imide sits as a clear to pale yellow liquid at room temperature. Its make-up combines a bulky imidazolium head with a flexible ethoxyethyl tail, paired with the highly delocalized bis(fluorosulfonyl)imide counterion. Chemists reference it under several names, such as EMIM-FSI, or sometimes simply by its molecular formula. The molecule attracted attention because of its electrochemical stability and the way it can transfer charge in a battery cell without letting solvents boil away or catch fire.
Looking at physical traits, EMIM-FSI tells its story through clear numbers. Its viscosity falls below most classic ionic liquids, making it easier to handle and pour. Around 1.9 g/cm³, its density stands out in a flask as heavier than water. A melting point near -30°C means you aren’t fighting with a solid at room temperature, and its decomposition temperature floats above 280°C. On the chemical side, this liquid shrugs off most organic acids and bases, giving it long-term staying power in tough electrolyte mixes. The anion’s electron-withdrawing sulfonyl groups tame unwanted side reactions, letting sensitive compounds survive during battery cycling or catalysis work.
Currently, commercial suppliers and research labs rely on detailed technical guidelines for labeling and shipping this compound. Typical sample labels point out a purity greater than 99%, and they carefully mention possible water content, since humidity pokes holes in performance, especially inside battery cells. Technical sheets highlight handling needs, storage between 10-30°C out of direct sun, and the need for dry, inert gas blanketing. You see labeling compliant with GHS standards, where the specifics of chemical hazards appear in pictograms and signal words, usually connected to skin, eye, and respiratory precautions. Most research-grade bottles check off batch reference, production dates, and supplier certifications to make sure data lines up from one experiment to the next.
Getting from raw chemicals to EMIM-FSI means following a deliberate route in the lab. The most direct way starts by alkylating 1-methylimidazole with 2-ethoxyethyl chloride to give the intermediate imidazolium chloride salt. Then, a metathesis step brings in lithium bis(fluorosulfonyl)imide. This step swaps the chloride for FSI through an aqueous or biphasic reaction. After thoroughly washing away lithium chloride byproduct, the chemist dries the organic phase under vacuum, then runs extra purifications like charcoal filtration to polish off impurities. Each extra step costs resources, but every shortcut costs the final purity, affecting performance in the field. In-house labs sometimes tweak the preparation to tailor properties, like modifying the alkyl group for viscosity, but every detour comes with trade-offs on stability or reactivity.
EMIM-FSI doesn’t just stand on its own; chemists have pushed it into blends and co-salts to meet new research needs. Mixing with small percentages of lithium bis(fluorosulfonyl)imide forms dual-ion electrolytes, pushing electrochemical windows beyond tradition. Researchers have also grafted functional groups onto the imidazolium ring, changing how the salt interacts with electrodes. Under high voltages, FSI sometimes breaks down to yield fluorinated fragments, which can help build protective layers on metal anodes. Scientists keep an eye on these reactions, since too much breakdown leads to battery failure, but the right amount improves device lifespan. Modifiers and additives, from organic esters to siloxanes, mix into the EMIM-FSI base to tune viscosity, ionic mobility, and compatibility with new electrode materials.
Depending on who you talk to, this compound shows up under a handful of product names. Chemical catalogs list 1-(2-ethoxyethyl)-3-methylimidazolium bis(fluorosulfonyl)imide, EMIM-FSI, or even C7H15F2N3O5S2 for the truly detail-minded. Patent literature sometimes veers into trade names, especially in battery-focused filings, adding another layer for researchers to track. Sometimes chemistry is a language of translations, and missing a synonym or trade name can mean missing out on breakthroughs published under a different label.
Working with EMIM-FSI, chemists learn to respect both its promise and risk factors. Regulatory files highlight the risk from eye and skin contact, with company safety data sheets warning about irritation or burns with repeated exposure. Labs set up designated zones for ionic liquid handling, using gloves, splash goggles, and chemical-resistant aprons. Local exhaust ventilation or glovebox setups help cut down vapor and aerosol formation. Storage rules keep bottles away from moisture and acids. Handling spills calls for absorbent pads and plenty of soap and water, never just a paper towel. Disposal gets special treatment, since some regions restrict ionic liquid waste to control environmental build-up. Fire safety focuses on secondary risks, since the compound resists ignition far better than acetonitrile or ether, but the fluorinated anions still call for a healthy respect in high-temperature experiments.
EMIM-FSI has carved out a home in battery research, especially in next-generation lithium-ion systems. Its low volatility and high breakdown voltage lets researchers stretch the upper limits of energy storage, pulling out more capacity without roasting the cell internals. In supercapacitors and dual-ion batteries, this molecule extends cycle life and fights thermal runaway. Parts of the world chase after safer transport and longer device runtimes, and EMIM-FSI rides shotgun in that journey. I’ve watched research teams test it in combination with new cathode materials and separators, learning how electrolyte chemistry tweaks ripple through the entire energy storage system. Beyond batteries, labs have tapped it for catalysis, CO₂ capture, and sometimes as a solvent for organic synthesis where water or polar solvents can’t deliver results. Some groups probe its use in electroplating, polymers, and advanced sensors, hoping to find an edge over classic salt and solvent systems.
Innovation with EMIM-FSI often comes from cross-pollination between academic institutes, battery startups, and materials companies. R&D teams set up high-speed screening platforms, testing tweaks in anion and cation structure to see which combinations deliver the best conductivity with the lowest toxicity. Collaboration with universities fuels much of the breakthrough, as they track crystal structure, viscosity curves, and battery cycling data. Tech transfer offices patent new blends as soon as numbers hint at a leap in performance. Industry partners, with their eyes on cost and scale, pull apart published recipes and try to adapt them for continuous-flow synthesis. The most successful outfits meet in the middle, blending the intricate structure–property relationships seen in basic research with cost-effective prep methods. Benchmarking against legacy electrolytes drives the pace, and failures often teach more than successes.
Safety studies chase ionic liquids at every stage. Since EMIM-FSI isn’t as old as other industrial solvents, the body of toxicity work continues to grow. Early data from aquatic toxicity studies warns about moderate risk for fish and invertebrates in case of uncontrolled release. Some groups test how it breaks down in soil and water, measuring trace organics and fluoride ions. Human cell-line studies measure cytotoxicity, flagging some caution, though less often than with pyrrolidinium-based solvents. I’ve followed regulatory updates and seen companies fund extended research to fill in data gaps, often spurred by calls from European and Asian authorities for comprehensive ecological screening. Waste management stays top-of-mind for labs, with restricted drain disposal and growing interest in closed-loop recycling for spent batteries and electrolytes. Toxicity studies push users to handle EMIM-FSI with diligence, not with fear, since information clears the hazy line between risk and benefit.
Looking at current trends, demand for efficient, thermally stable, and safe electrolytes will only increase as the world shifts to renewable energy and electric transportation. Research teams keep dialing in cation–anion combinations, and EMIM-FSI’s strong track record for conductivity and safety points toward a broader use beyond energy storage. Just as the electronics industry phased out dangerous solvents, advances with EMIM-FSI could help entire sectors cut environmental harm and workplace hazards. The pressure to boost battery lifespan, support fast charging, and drop manufacturing costs will keep product lines and synthetic routes evolving. If future regulations keep sustainability at the core, the challenge will turn to recycling spent ionic liquids and ensuring every stage—production, use, disposal—meets stricter guidelines. Improvements in green chemistry and process intensification may soon make EMIM-FSI more accessible, affordable, and suitable for the next wave of industrial innovation.
For most people, 1-(2-ethoxyethyl)-3-methylimidazolium bis(fluorosulfonyl)imide sounds like something cooked up in a laboratory far away from everyday life. Chemists usually call it by the abbreviation [EEMIM][FSI]. Even if the name doesn't roll off the tongue, this compound’s story traces back to a fast-changing world where new materials shape cleaner, safer, and more powerful batteries.
The push toward cleaner energy depends on batteries that last longer, work harder, and don’t catch fire. Lithium-ion batteries need a liquid medium inside that lets electrons flow. Dangerous, flammable organic liquids used to fill that role have brought safety concerns. [EEMIM][FSI] steps into this scene as an “ionic liquid”—basically, a salt that stays liquid even at room temperature. Its unusual structure means it doesn’t burn easily and remains stable during extreme charging cycles.
Safety is not its only advantage. Ionic liquids like [EEMIM][FSI] can dissolve high concentrations of lithium salts, which improves how much energy a battery can store. Larger electric vehicles ask their power supplies to put out more energy for longer. My own interest rose after seeing news stories about electric cars that ran for hundreds of miles without recharging, thanks in part to better electrolyte solutions. Battery researchers at the Argonne National Laboratory in the United States showed that using ionic liquids similar to [EEMIM][FSI] helped keep batteries stable during thousands of cycles—something that lets batteries last for years.
Everyone hears stories about cell phones overheating or batteries bursting into flames. Regular electrolytes use solvents like ethylene carbonate or dimethyl carbonate, which catch fire at high temperatures. [EEMIM][FSI] stands out because it doesn’t catch fire under conditions that would ignite standard electrolytes. The big question then becomes: What about environmental impact? Ionic liquids don't evaporate into smog-forming clouds, so they help lower the risks found in battery factories and recycling plants.
Companies sweat the details when designing next-generation batteries, especially for electric vehicles and grid storage. The hunt for materials focuses on performance, safety, and resource use. [EEMIM][FSI] ticks several boxes. Its high ionic conductivity improves energy movement inside a battery. It holds up under temperature swings, so batteries charge in cold or hot places. At a factory scale, these properties can cut maintenance costs and lower the risk of costly recalls.
Of course, nothing in chemistry comes entirely risk free. Researchers evaluate every compound for long-term health and environmental impact—nothing gets a blank check. As someone who once worked with battery safety standards, I know regulatory hurdles slow down new electrolytes until their life-cycle impacts are mapped out.
Modern life leans harder on reliable, safe batteries—from electric buses to power grids to watches and smartphones. Materials like [EEMIM][FSI] blend innovation with real-world needs. Research continues, but each new compound brings us closer to safer, cleaner, and better batteries for everyone.
1-(2-Ethoxyethyl)-3-Methylimidazolium Bis(Fluorosulfonyl)Imide stands apart from common table salt or household chemicals. At room temperature, this compound usually presents as a clear, slightly yellowish liquid. It’s got an oily feel, and it doesn’t evaporate easily. Most liquids leave droplets or stains behind, but this stuff barely budges until you clean the surface with a proper solvent. That tells you it resists drying out—a blessing and a curse, depending on the usage.
Thanks to its imidazolium core and bulky anion, it doesn’t freeze until the temperature drops below zero—sometimes way below. I’ve handled similar ionic liquids in the lab and appreciated how their low melting points make them much easier to work with than brittle crystals. The viscosity can be high—think corn syrup, not vodka—which does slow down stirring and blending, especially in colder rooms or drafty warehouses.
If you’re wondering about chemical stability, 1-(2-Ethoxyethyl)-3-Methylimidazolium Bis(Fluorosulfonyl)Imide handles heat decently well. Many ionic liquids break down quickly at high temperatures, but this one holds out up to about 200°C before decomposition starts becoming an issue. The bis(fluorosulfonyl)imide group helps here; its structure sits firmly in the chemical world, making the whole compound much less flammable than classic organic solvents. That doesn’t mean toss out your regular safety rules, though—it still reacts badly around open flames or powerful oxidizers.
Moisture in the air doesn’t wreck it outright, but water will eventually break down the neat organization of the ions. That can cause trouble with electrical properties. As a result, I’ve always stored this chemical in well-sealed bottles with desiccant packs, especially if the goal was to run a fancy organic reaction or test its conductivity.
You can find this imidazolium salt doing the heavy lifting in next-generation batteries, supercapacitors, and as an eco-friendlier solvent for tricky chemical processes. Traditional solvents evaporate, pollute, and catch fire. Ionic liquids like this one barely evaporate, allowing labs to cut down on fumes and environmental impact. Plus, their ability to transfer ions quickly is a big win for batteries or fuel cells needing high conductivity and thermal stability.
Yet, working with 1-(2-Ethoxyethyl)-3-Methylimidazolium Bis(Fluorosulfonyl)Imide isn’t risk-free. The fluorosulfonyl part packs a punch—it’s not something to spill down the drain or splash on skin. Even without obvious smoke or scent, lingering contamination can harm wastewater systems or corrode equipment over time. Employees in chemical plants and research outfits need real-world training, not just manuals, and labs should practice careful waste collection paired with regular checks for leaks or corrosion.
Tougher regulations and community education go hand in hand with improved product stewardship. Tighter controls around disposal and recycling could keep more ionic liquids out of water and soil. Manufacturers designing these compounds might also look for ways to tweak the chemical backbone, making a molecule that performs well but breaks down faster in the environment. At the end of the day, these choices shape not just how we power tomorrow’s gadgets, but the kind of world we leave behind.
1-(2-Ethoxyethyl)-3-methylimidazolium bis(fluorosulfonyl)imide is finding use in laboratories researching advanced batteries and electrolytes. Chemists view this family of ionic liquids as promising for safe energy storage, since many claim they are thermally stable and unlikely to burn. Still, “safe” describes a spectrum, and safety depends on both chemical properties and human habits in the lab.
People often assume ionic liquids are safer than volatile organics, but experience shows they are not without risks. Skin contact can cause irritation, and studies on similar compounds warn of long-term toxicity in aquatic organisms and potential slow-release routes through spills or leaks. Inhalation during accidental aerosolization or splashes reaching the eyes call for quick action. Research from the Journal of Hazardous Materials points to the fluorosulfonyl imide anion as potentially reactive under acid or high heat. Fumes may not always announce themselves with a strong odor, so one cannot trust nose alone as a warning.
In my own lab, we respect any chemical that contains fluorinated sulfonyl groups. Team members use gloves—nitrile holds up well unless grossly contaminated. Long sleeves and goggles go on as second nature, not as afterthoughts. A chemical fume hood provides the only safe environment for opening new bottles or making transfers. Spills always prompt work stoppage, because cleaning up even small puddles with dry absorbent and bagging the waste properly keeps everyone safer. I’ve seen fingers develop rashes after ignoring glove protocols. The lesson sticks: nobody wants to become the reason for a safety review.
Sometimes eagerness to try a new material makes people jump past reading the full Safety Data Sheet. This shortcut can turn minor incidents into big problems. The SDS for 1-(2-ethoxyethyl)-3-methylimidazolium bis(fluorosulfonyl)imide points out that heating or mixing with acids brings out fumes that need careful ventilation. Proper labeling and secondary containment reduce mix-ups and spills, which I learned the hard way during a frantic instrument calibration. Quick access to eyewash stations and a buddy system prove invaluable if something goes wrong.
Disposal offers another challenge. Local regulations treat these compounds as hazardous, especially considering their persistence in water and potential harm to aquatic organisms. My experience shows that working with the institution’s hazardous waste program makes things smoother—pouring remnants down the drain or tossing them in regular trash ends up as a costly mistake for both the facility and the community. Training sessions make sure everyone in the group knows the proper steps, reducing risky shortcuts.
Building a culture of safety matters more than any single piece of protective equipment. Labs that discuss incidents, maintain up-to-date training records, and keep clear signage around chemical storage handle emergencies better and avoid many close calls. Even when chasing ambitious research goals, patience and care pay off. Electronic logs, spill kits within arm’s reach, and clear lines of communication all chip away at the risks. Sharing lessons from one mishap often prevents ten more. For those who want to work with new electrolytes, learning from old mistakes helps keep everyone healthy, productive, and able to celebrate the next breakthrough together.
1-(2-Ethoxyethyl)-3-Methylimidazolium Bis(Fluorosulfonyl)Imide holds a role in advanced battery research, particularly for high-performance electrolytes. Its chemical properties push innovation, but safety never takes the backseat. Nobody wants to open a shipping crate and find leakage, caustic fumes, or an unexpected mess that sets research timelines back months. Time in chemical labs taught me that trust in materials depends on careful handling every step of the way.
This liquid ionic compound, like many imidazolium salts, shows sensitivity to moisture and can react with water if conditions get sloppy. Spills bring risk not just to people but to the environment. Breathing in vapors or getting splashed might land someone in the emergency room or trigger a costly cleanup. Reading the safety data sheets and watching experienced coworkers handle sensitive materials taught me the value of closing containers the right way and not cutting corners on procedures.
Keep this compound in sealed, chemically resistant containers—think glass or dedicated plastics, not materials that soften or react under stress. Polyethylene or PTFE often stand up to its demands. Don’t store it anywhere near acidic or basic chemicals. Experienced labs separate chemicals not only by hazard class but also by reactivity—mistakes happen most where someone rushes.
Cool and dry storage does more than prolong shelf life. It shields this salt from humidity sneaking in and starting unwanted side reactions. In my old workplace, even minor humidity shifts messed with sensitive samples. Silica gel packs or nitrogen blankets often take up residence in storage cabinets.
Ventilated chemical storage rooms give an added layer of safety. Spills get isolated and the air system sucks away harmful fumes before people notice them. Every week, quick checks of tamper seals and expiry dates keep everyone honest and alert.
Moving sensitive chemicals, whether across the building or to another city, calls for more than just sturdy boxes. Approved shipping containers marked with hazard labels put couriers and handlers on notice. There’s a chain of trust; each hand-off brings a moment where someone can prevent disaster by following a checklist.
The Department of Transportation classifies many ionic liquids, so keeping up with state and federal rules isn’t bureaucracy gone wild—it’s the way to avoid fines and real danger. Proper paperwork, including safety data sheets and emergency contact info, travel with the shipment. No one wants a delivery truck catching fire or leaking unknown liquid on a city street because someone skipped paperwork.
Shippers avoid stacking heavy boxes on top of chemicals like this one. Experience taught me that rushed jobs often end in punctured bottles or jostled containers. Secure packaging with shock absorption—think foam inserts or double containment—keeps the liquid inside where it belongs.
People storing or moving this chemical benefit most from hands-on training. Watching a video or reading a manual won’t compare to walking through the steps with someone who knows the ropes. In the event of a spill, access to spill kits, neutralizers, and PPE saves injuries and clean-up costs. From lab technicians to shipping staff, peer training and quick access to up-to-date information prevent most problems before they start.
Keeping a culture where questions are welcome means newcomers feel comfortable asking if they’re unsure how to secure or transfer this compound. Mistakes shrink when teams take pride in careful work, not just speed.
Pouring 1-(2-Ethoxyethyl)-3-methylimidazolium bis(fluorosulfonyl)imide into water really puts the nature of ionic liquids on display. Water draws in many salts through its polarity, but this one barely gives in. On the bench, it tends to stay in globs or clumps, refusing to blend. Researchers tracking the finer points find solubility to be low, in the range of milligrams per milliliter. This weak mixing traces back to the fluorous tail and the organic cation, both of which shy away from water’s demands. Publications in Green Chemistry and RSC Advances highlight the same struggle with water, citing values well below one gram per liter at room temperature. Someone hoping for a freely-mixing solution in water hits a wall here, unless heating the mix or using a cosolvent.
Switching to organic solvents like acetonitrile, acetone, or dichloromethane tells a different story. The ionic liquid dissolves with much less resistance. During solvent-switching experiments, 1-(2-ethoxyethyl)-3-methylimidazolium bis(fluorosulfonyl)imide tends to flow in without clumping, showing solubilities above ten grams per 100 grams of solvent in many cases. In my experience, acetonitrile takes up this ionic liquid quickly and forms a clear, consistent solution at even moderate stirring. Dimethyl sulfoxide (DMSO) and N-methylpyrrolidone (NMP) give the same behavior, thanks to their high polarity and ability to support both ionic and organic groups.
Low water solubility brings up a practical concern. A researcher aiming to use this ionic liquid for extractions or catalysis in an aqueous setting faces poor results without a workaround. At the same time, strong solubility in organic solvents opens the door for applications in battery electrolytes, organic synthesis, and specialized separations. For battery developers, for example, high solubility in DMSO or acetonitrile avoids clogging and allows for better control of ion concentration, helping push for higher energy density and stability. As an extraction solvent, its low water miscibility pulls out nonpolar compounds from water without getting lost to the aqueous phase. Many large-scale researchers gravitate to ionic liquids for this unique ability—to behave very differently with water compared to organic solvents.
Peer-reviewed papers and safety data sheets from suppliers like Sigma-Aldrich back up these results. One can find solubilities under 0.5 g/100 mL for water, but surging above 10 g/100 mL for solvents like acetone, DMSO, DMF, and acetonitrile. These differences matter for industrial process design, where waste treatment and solvent recovery affect costs and safety. Regulations have begun asking for cleaner, less volatile solvents. Here, substances with high boiling points and low vapor pressures—like this ionic liquid—fit the bill, provided their solubility matches the application. In green chemistry, the drive to use less hazardous substances leads some researchers to push for water-miscible ionic liquids, but this one isn’t likely to join that crowd.
Trouble mixing with water prompts researchers to try additives or blend partners like ethanol or surfactants. Using a small amount of alcohol for pre-dissolving often brings some of the ionic liquid into water, at least for certain reactions. For waste recovery, separating this ionic liquid from water with simple decanting or mild heating avoids the more complex treatments needed for fully water-soluble salts. The overall message from bench work and published studies: picking the right solvent means the difference between success and struggle.
