Section 1 — General Ionic Liquid Questions
What are ionic liquids?
TL;DR: Ionic liquids are salts that remain liquid at or below 100°C, combining negligible vapor pressure with tunable physicochemical properties.
Ionic liquids (ILs) are salts composed of bulky, asymmetric organic cations paired with organic or inorganic anions. Unlike conventional salts such as NaCl (melting point > 800°C), these ion combinations disrupt crystal packing and produce melting points at or below 100°C — many are liquid at room temperature. Key properties include negligible vapor pressure, high thermal stability (typically 200–400°C), wide electrochemical windows, and tunable viscosity, conductivity, and hydrophobicity. Ionic liquids are used across energy storage, catalysis, separations, lubrication, electroplating, polymer processing, and carbon capture.
Related: Browse the RoCo® ionic liquid catalog
What are ionic liquids used for?
TL;DR: Ionic liquids are used in batteries, carbon capture, catalysis, lubrication, electroplating, polymer processing, and pharmaceutical extraction and delivery.
Major application areas include energy storage (battery electrolytes, supercapacitor media), catalysis (reaction solvents and catalysts), carbon capture (CO₂ absorption from flue gas and direct air capture), lubrication (high-temperature and vacuum-compatible lubricants), electroplating (metal deposition baths), polymer processing (cellulose dissolution, polymer modification), and pharmaceutical applications (drug delivery, extraction, and purification). The ability to independently select cation and anion structures gives researchers access to a vast design space — properties like viscosity, conductivity, hydrophobicity, and thermal stability can be tuned for specific applications.
How are ionic liquids made?
TL;DR: Ionic liquids are synthesized in two steps: forming the organic cation by quaternization, then exchanging the anion to tune properties.
Synthesis follows a two-step process. First, a quaternization reaction creates the cation — for example, reacting 1-methylimidazole with an alkyl halide to form an imidazolium halide salt. Second, an anion exchange (metathesis) replaces the halide with the target anion, such as bis(trifluoromethylsulfonyl)imide (TFSI) or tetrafluoroborate (BF4). The product is then purified to remove residual solvents, water, and halide impurities. RoCo synthesizes custom ionic liquids in-house under controlled conditions with full analytical verification (¹H NMR, FTIR, TGA/DSC, and elemental analysis).
Related: Learn more about Custom Ionic Liquid Synthesis
Are ionic liquids safe?
TL;DR: Ionic liquids are generally safer than organic solvents — negligible vapor pressure and very low flammability reduce inhalation and fire risk.
Ionic liquids have negligible vapor pressure under normal conditions, which significantly reduces inhalation exposure and flammability compared to conventional organic solvents. However, safety varies by structure. Some ionic liquids with fluorinated anions (e.g., PF6, BF4) can release HF or other decomposition products above their thermal stability limits. As with any laboratory chemical, proper handling with gloves, eye protection, and adequate ventilation is recommended. RoCo provides a Safety Data Sheet (SDS) with every product shipment.
Are ionic liquids environmentally friendly?
TL;DR: Many ionic liquids are recyclable, non-volatile, and biodegradable — but environmental performance depends on the specific cation-anion combination.
Ionic liquids offer environmental advantages over traditional organic solvents: near-zero volatile organic compound (VOC) emissions, recyclability in many processes, and, for some structures, biodegradability. However, not all ionic liquids are inherently low-impact — aquatic toxicity and biodegradability vary widely depending on the cation and anion. Amino acid ionic liquids are non-toxic. Acetate and choline-based ionic liquids are also non-toxic. Sulfonates are considered low-toxicity ionic liquids. RoCo offers bio-based and low-toxicity options for applications where environmental performance is a priority.
What is the difference between ionic liquids and molten salts?
TL;DR: Ionic liquids melt at or below 100°C; molten salts require heating to 400–800°C or higher.
The defining difference is melting point. Molten salts are conventional inorganic salts (NaCl, KCl, LiF-BeF2 mixtures) heated above their melting points, typically 400–800°C or higher. Ionic liquids, by contrast, are liquid at or below 100°C by definition, and many are liquid at room temperature. This low melting point results from bulky, asymmetric organic cations and charge-delocalized anions that prevent efficient crystal packing. The practical consequence: ionic liquids can be handled, pumped, and processed at ambient temperature, avoiding the energy cost and materials challenges of high-temperature molten salt systems.
When should I use ionic liquids instead of organic solvents?
TL;DR: Choose ionic liquids when you need thermal stability, non-flammability, wide electrochemical windows, recyclability, or zero VOC emissions.
Ionic liquids outperform traditional organic solvents in applications requiring high thermal stability (200–400°C), non-flammability, wide electrochemical windows (up to 5–6 V), or zero VOC emissions. They can also be recycled in many processes, reducing solvent waste. Traditional organic solvents remain more practical when cost is the primary constraint, when low viscosity is essential, or for routine bench-scale chemistry. As a rule of thumb: if your application involves elevated temperatures, electrochemistry, or emissions restrictions, ionic liquids are worth evaluating.
Related: Book a consultation to discuss your application
How do I store ionic liquids, and what is their shelf life?
TL;DR: Store ionic liquids in tightly sealed containers in a cool, dry, dark environment. Most have a shelf life of 2+ years.
Store ionic liquids in tightly sealed containers, away from moisture and direct sunlight, ideally in a cool, dry environment. Many ionic liquids are hygroscopic (they absorb water from the air), which can affect purity and performance. When stored properly, most ionic liquids have a shelf life of 2+ years without significant degradation. RoCo® ships all products in sealed containers with Certificates of Analysis (COAs) documenting purity at the time of shipment.
How do I choose the right ionic liquid for my application?
TL;DR: Match your ionic liquid to the application’s electrochemical window, viscosity, thermal stability, hydrophobicity, and conductivity requirements.
Selection depends on your application requirements. Key parameters to consider: electrochemical window (for battery or electrochemistry work), viscosity (for processing, flow, and mass transport), thermal stability (for high-temperature applications), hydrophobicity (for extraction, separation, and biphasic systems), and conductivity (for electrolyte applications). As starting guidance: imidazolium-based ILs offer wide property ranges; pyrrolidinium-based ILs are preferred for battery electrolytes; phosphonium-based ILs excel in high-temperature lubrication and catalysis. RoCo scientists offer complimentary 15-minute initial consultations to help you identify the right ionic liquid for your project.
Related: Book a consultation
Section 2 — Ionic Liquids in Batteries & Energy Storage
Why use ionic liquids in batteries?
TL;DR: Ionic liquids improve battery safety by replacing flammable organic electrolytes with non-flammable, thermally stable alternatives with wide voltage windows.
Ionic liquids eliminate the fire risk of conventional organic carbonate electrolytes. They are non-flammable, thermally stable to 200–400°C, and have electrochemical windows up to 5–6 V, which can enable higher-voltage cathode chemistries. They are being evaluated in lithium-ion, sodium-ion, magnesium-ion, and solid-state battery systems. Pyrrolidinium and piperidinium cations paired with TFSI or bis(fluorosulfonyl)imide (FSI) anions are the most widely studied ionic liquid electrolyte candidates, offering favorable cathodic stability against lithium metal.
Related: Browse the Battery Materials catalog
Ionic liquid electrolyte vs. conventional liquid electrolyte — what’s the difference?
TL;DR: Ionic liquid electrolytes replace volatile, flammable organic solvents with non-flammable ionic liquids, dramatically improving thermal stability at the cost of higher viscosity.
Conventional lithium-ion electrolytes use volatile organic solvents (ethylene carbonate, dimethyl carbonate) that are flammable and degrade at elevated temperatures. Ionic liquid electrolytes replace those solvents with non-flammable ionic liquids, substantially improving thermal stability and safety. The tradeoff is higher viscosity (typically 50–100 cP vs. 1–5 cP for carbonates at 25°C), which reduces ion transport rates at room temperature. However, FSI-based ionic liquid systems, co-solvent strategies, and optimized salt concentrations are closing this gap while preserving the intrinsic safety advantage.
Can ionic liquids be used in solid-state batteries?
TL;DR: Yes — ionic liquids are widely used as plasticizers in polymer and composite electrolytes and as the liquid phase in semi-solid systems.
Ionic liquids are used in solid-state and semi-solid battery formats in two main ways: as plasticizers in polymer or composite electrolytes (improving ionic conductivity at the polymer-salt interface), and as the liquid phase in quasi-solid gel electrolytes. Pyrrolidinium-FSI and piperidinium-TFSI families are the most common, often paired with LiTFSI or LiFSI lithium salts. RoCo® supplies pyrrolidinium and piperidinium ionic liquids in research and pre-pilot quantities for solid-state development.
Related: Battery Materials catalog
What are the viscosity and conductivity tradeoffs of ionic liquid electrolytes?
TL;DR: Ionic liquids are more viscous and slightly less conductive than carbonate solvents, but FSI-based formulations and co-solvent strategies close the gap.
Most ionic liquid electrolytes have viscosities of 50–100 cP at 25°C, compared to 1–5 cP for typical carbonate solvents. Ionic conductivity at 25°C is generally 1–10 mS/cm for IL electrolytes vs. 8–12 mS/cm for carbonates. Ionic liquids can be mixed and formulated to change viscosities and conductivities. The performance gap narrows significantly with FSI-based ionic liquids, optimized lithium salt concentrations, and co-solvent or additive strategies, bringing transport properties into the target window for many cell designs while preserving safety advantages.
What ionic liquid electrolytes does RoCo® offer?
TL;DR: RoCo® offers LiTFSI, LiFSI, pyrrolidinium TFSI/FSI, and piperidinium-based electrolytes, plus custom formulations.
RoCo supplies pyrrolidinium TFSI and FSI systems, piperidinium-based electrolytes, lithium bis(trifluoromethylsulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium battery solvents (propylene carbonate, vinylene carbonate, LiPF6), and Zn-air battery materials. Custom electrolyte formulations tailored to specific cell chemistries are available through our synthesis services.
Related: Browse the Battery Materials catalog or contact us for custom electrolyte formulations.
Section 3 — Ionic Liquids in Carbon Capture
How do ionic liquids capture CO₂?
TL;DR: Ionic liquids capture CO₂ through physical or chemical absorption, and can be regenerated by heating or reducing pressure.
Ionic liquids capture CO₂ through physical absorption (dissolving CO₂ into the liquid) or chemical absorption (reacting with CO₂ through amine-functionalized or carboxylate groups). Their negligible vapor pressure means they don’t evaporate during the capture process, compared to amine scrubbing where solvent losses are a known operational challenge. Ionic liquids can be regenerated by heating or reducing pressure, releasing the captured CO₂ for storage or utilization.
Related: Contact RoCo to discuss ionic liquid selection for your capture system
When should I consider ionic liquids for CO₂ capture instead of amine scrubbing?
TL;DR: Use ionic liquids when solvent stability, low vapor losses, and tunable selectivity matter — especially in modular, distributed, or high-purity capture systems.
Amine scrubbing remains cost-effective at very large industrial scale and at low CO₂ partial pressures, and has decades of operational data behind it. Ionic liquids are a strong fit when solvent stability, near-zero vapor loss, tunable CO₂ selectivity, or lower-temperature regeneration matter — particularly in modular, distributed, or high-purity capture systems where solvent makeup and emissions are significant cost drivers. Many next-generation systems also explore ionic liquid–amine hybrid formulations to combine the strengths of both approaches.
Section 4 — Products & Ordering
What products does RoCo® sell?
TL;DR: RoCo® supplies 350+ ionic liquids, battery-grade metal salts, electrolytes, chemical precursors, and functional polyurethane powder.
RoCo® supplies ionic liquids (350+ catalog products across imidazolium, pyrrolidinium, piperidinium, ammonium, phosphonium, sulfonium, and triazolium families), metal salts (lithium, zinc, magnesium, potassium, and sodium salts), ionic liquid electrolytes and battery materials, chemical precursors, and functional polyurethane powder. We also offer custom synthesis for ionic liquids not in our catalog.
Related: Browse the full product catalog
What purity grades are available?
TL;DR: RoCo® offers standard (≥95%), high-purity (≥98–99%), and ultra-high-purity (≥99.5–99.9%) grades, with custom specifications on request.
RoCo® offers standard grade (≥95%), high-purity grade (≥98–99%), and ultra-high-purity / optical purity grade (≥99.5–99.9%). Every order includes a Certificate of Analysis (COA) and Safety Data Sheet (SDS). Custom purity specifications are available through our synthesis services.
What is the minimum order quantity?
TL;DR: RoCo® ships research-scale quantities from 5–25 g through bulk industrial volumes.
RoCo® offers flexible ordering from research-scale quantities (as low as 5 g or 25 g) through bulk industrial volumes. Most catalog products are available in 25 g, 100 g, 500 g, and 1 kg packaging. Contact us for custom volume pricing.
Where does RoCo® ship?
TL;DR: RoCo® ships across North America from a U.S.-based logistics facility.
RoCo® currently ships within North America — the United States, Canada, and Mexico. For hazmat-classified products, packaging and routing follow DOT (49 CFR) requirements, and cross-border shipments to Canada and Mexico include full customs and compliance documentation.
Related: Read the Shipping Policy
What documentation comes with each order?
TL;DR: Every shipment includes a Certificate of Analysis, Safety Data Sheet, lot number with batch traceability, and a technical datasheet on request.
Every RoCo® shipment includes a Certificate of Analysis (COA) documenting purity at the time of shipment, a Safety Data Sheet (SDS) for safe handling, a unique lot number tied to full batch traceability records, and a technical datasheet available on request. Additional analytical reports — such as ¹H NMR, FTIR, TGA/DSC, or elemental analysis — are available for custom-synthesis orders.
How long does custom synthesis take?
TL;DR: Typical custom-synthesis lead time is 4–12 weeks. Initial feasibility and quote within 5–10 business days.
Custom-synthesis lead time is typically 4–12 weeks, depending on cation/anion complexity, purity target, and quantity. Initial feasibility assessment and quote are returned within 10 business days of receiving the request. Rush timelines are available for established customers on a case-by-case basis.
Related: Submit a custom-synthesis request
What is your return and specification-dispute policy?
TL;DR: Products are guaranteed to meet COA specifications. Contact us within 30 days for a spec dispute and we’ll review and resolve.
All RoCo® products are guaranteed to meet the specifications documented in the Certificate of Analysis (COA) at the time of shipment. If you believe a product does not meet COA specifications, contact us within 30 days of receipt. We will review the batch records and analytical data and work with the customer to resolve the issue. Hazmat-classified materials follow specific handling protocols outlined in our Shipping Policy.
Related: Shipping & Returns Policy
What is custom ionic liquid synthesis?
TL;DR: Custom synthesis is a service where RoCo® designs and manufactures an ionic liquid tailored to your specific application, purity, or scale needs.
Custom ionic liquid synthesis is a service where RoCo® scientists design and manufacture an ionic liquid tailored to your specific application requirements — whether that’s a unique cation-anion combination, a specific purity level, or a scale not available in our catalog. The process includes consultation, feasibility assessment, synthesis, purification, and quality testing with full analytical documentation.
Related: Custom Synthesis services
Section 5 — About RoCo®
Who is RoCo®?
TL;DR: RoCo is a Pittsburgh-based ionic liquid technology company serving 400+ R&D customers across energy, aerospace, defense, and specialty chemicals.
RoCo® (Liquid Ion Solutions, LLC) is a Pittsburgh-based ionic liquid technology company specializing in IL synthesis, formulation, and application development. Founded in 2014, RoCo serves 400+ R&D customers across energy storage, aerospace, defense, and specialty chemicals. RoCo is a women-owned small business and North American distributor for IoLiTec GmbH, one of the world’s largest dedicated ionic liquid producers. The team includes PhD chemists and materials scientists with 70+ peer-reviewed publications and 20+ patents in ionic liquid and polymer chemistry.
Where is RoCo® located?
TL;DR: RoCo® is headquartered in Pittsburgh, PA.
RoCo® is located at 1816 Parkway View Drive, Building 18, Pittsburgh, PA 15205, where our laboratory operations are based.
Related: Contact RoCo®
What is RoCo®’s entity registration information and business classifications?
TL;DR: RoCo® is a women-owned small business with CAGE Code 7BGE0, UEI F9LGJ8QLFBF7, and NAICS classifications for chemicals and R&D services.
Liquid Ion Solutions, LLC, doing business as RoCo®, is a women-owned small business incorporated in Delaware in 2014. Our entity registration information includes CAGE Code 7BGE0 and UEI F9LGJ8QLFBF7. Our NAICS classifications include 325199 and 325998 for organic and specialty chemicals, 325211 for polymers, 325510 and 325520 for coatings and adhesives, 325412 for pharmaceuticals, and 541690 and 541713–541715 for scientific and technical services.
Who does RoCo® work with?
TL;DR: RoCo® works with government agencies, universities, and industrial partners across automotive, aerospace, energy storage, and specialty chemicals.
RoCo® partners with three types of organizations: government agencies (including defense, aerospace, and energy programs), universities (across materials science, chemistry, and engineering research), and industrial partners across automotive, aerospace, energy storage, and specialty chemicals.
What is IoLiTec, and what does the partnership mean for customers?
TL;DR: IoLiTec is one of the world’s largest ionic liquid producers; RoCo® is its North American distributor, giving U.S. customers fast catalog access with U.S. logistics and support.
IoLiTec is one of the world’s largest dedicated ionic liquid producers, with one of the deepest catalogs in the industry. RoCo® is IoLiTec’s North American distributor — meaning U.S. and Canadian customers get fast access to a broad ionic liquid catalog with U.S.-based logistics, Certificate of Analysis (COA) and Safety Data Sheet (SDS) documentation, hazmat-compliant shipping, and direct technical support from RoCo’s PhD chemists. This eliminates the lead-time, customs, and hazmat-logistics friction of ordering directly from Europe.
What services does RoCo® offer beyond products?
TL;DR: RoCo® offers expert consultations, custom ionic liquid synthesis, and contract R&D partnerships funded by DOE, NASA, and USAF.
RoCo® offers three core services: expert consultations (complimentary 15-minute initial consultation; 60-minute deep-dive sessions available at $250/hr), custom ionic liquid synthesis (tailored formulations for your application), and contract R&D (full research and development partnerships for advanced materials projects). Our R&D work is supported by funding from DOE, NASA, and USAF, and we collaborate with Carnegie Mellon, Penn State, and the University of Pittsburgh.
Related: Explore RoCo® Services
Section 6 — Custom Synthesis & R&D Services
What does a custom synthesis project look like?
TL;DR: Custom synthesis runs in five stages: consultation, feasibility & quote, synthesis, purification, and analytical verification with COA.
A custom ionic liquid synthesis project at RoCo® follows five stages: (1) consultation — a scoping call with one of our PhD chemists to understand your application and target properties; (2) feasibility and quote — a written assessment covering synthetic route, purity target, scale, timeline, and price; (3) synthesis — execution under our SOP-controlled lab environment; (4) purification — removal of residual solvents, water, and halide impurities to meet target specifications; and (5) analytical verification — including ¹H NMR, FTIR, TGA/DSC, density, and elemental analysis, delivered with a Certificate of Analysis (COA) and Safety Data Sheet (SDS). A mutual NDA is typically in place before disclosure of confidential application data.
Related: Submit a custom-synthesis request
What is the typical timeline for custom synthesis?
TL;DR: Custom-synthesis timelines run 4–12 weeks depending on complexity, purity target, and scale. Quotes returned within 5 business days.
Timelines run 4–12 weeks depending on the complexity of the cation/anion system, purity target, and scale. Factors that extend timelines include multi-step synthetic routes, fluorinated or task-specific anions, high purity targets (99.5%+), and scale-up beyond lab quantities. RoCo returns a detailed quote within 5 business days of receiving a complete request. Expedited timelines are available on a case-by-case basis.
Do I retain IP on a custom synthesis project?
TL;DR: Yes — customers retain rights to their application and resulting data in standard custom-synthesis engagements; RoCo® retains background IP and synthesis know-how.
In standard custom-synthesis engagements, the customer retains rights to their application data and any results generated using the delivered material. RoCo® retains its background intellectual property and synthesis know-how. For deeper R&D collaborations, joint IP, field-of-use restrictions, and exclusive license terms are negotiable in the underlying services agreement.
How does RoCo® protect confidential information?
TL;DR: Mutual NDAs are signed before any disclosure of application or specification data, and internal access is restricted to the project chemist and PI.
Mutual non-disclosure agreements (NDAs) are signed before any disclosure of confidential application or specification data. Internal access to project information is restricted to the assigned project chemist and principal investigator. Customer-supplied samples and proprietary intermediates are stored separately and tracked under our lot-number traceability system.
What contract R&D services does RoCo® offer?
TL;DR: RoCo® offers full R&D partnerships including materials design, scale-up, application validation, and Phase I/II SBIR/STTR collaboration.
RoCo® offers contract R&D services spanning materials design, scale-up, application validation, and Phase I/II SBIR/STTR collaboration. Active and prior funding partners include the Department of Energy (DOE), NASA, and the United States Air Force (USAF, including AFWERX awards). Typical engagements pair RoCo’s synthesis and characterization capabilities with the customer’s application and end-use validation, with milestones structured around real-world performance gates.
Related: Contract R&D engagements