Lithium Tetra(2-methyl-8-hydroxyquinolinato)boronCAS #: 338949-42-1

Synonyms

 Lithium tetrakis(2-methyl-8-quinolinolato-κO)borate(1-)

Compound Formula: C40H32BLiN4O4 

Molecular Weight: 650.46 

Appearance: White to off-white powder, crystals, or chunks 

Melting Point: 250-258 ° °C 

Boiling Point: N/A 

Density: N/A 

Solubility in H2O: N/A 

Exact Mass: 650-C.267665 

Monoisotopic Mass: 650-C.267665

Product Introduction: Lithium Difluoro(oxalato)borate (LiDFOB, CAS #: 338949-42-1)

Lithium difluoro(oxalato)borate, with the chemical formula LiBF₂(C₂O₄) and CAS number 338949-42-1, is an advanced lithium salt gaining prominence as a high-performance electrolyte additive and co-salt in lithium-ion batteries (LIBs). This white crystalline solid combines the benefits of fluorinated borate anions and oxalate ligands, delivering exceptional thermal stability, superior SEI (solid electrolyte interphase) formation, and compatibility with electrode materials. Its unique structure enhances battery safety, cycle life, and high-temperature performance, making it a key material in next-generation energy storage systems.

Chemical & Physical Properties

LiDFOB exhibits a set of properties that distinguish it as a premium electrolyte component:

Solubility: Highly soluble in common organic carbonate solvents (e.g., ethylene carbonate, dimethyl carbonate) and their mixtures, enabling flexible formulation of electrolytes with concentrations up to 1.0 M.

Ionic Conductivity: Delivers moderate to high ionic conductivity (typically 6–9 mS/cm in optimized solvent blends), supporting efficient lithium-ion transport in battery cells.

Thermal Stability: Maintains stability up to approximately 240°C, significantly higher than conventional LiPF₆, reducing the risk of thermal runaway in batteries operating at elevated temperatures.

Electrochemical Window: Boasts a wide electrochemical stability window (up to 5.0 V vs. Li⁺/Li), compatible with high-voltage cathodes such as LiNi₀.₅Mn₁.₅O₄ and LiCoO₂.

Hydrolytic Stability: Exhibits better resistance to hydrolysis than LiPF₆, generating fewer corrosive byproducts (e.g., HF) when exposed to moisture, thus protecting electrode materials and extending battery lifespan.

Key Applications in Lithium-Ion Batteries

Lithium difluoro(oxalato)borate (CAS 338949-42-1) is revolutionizing battery performance through its targeted applications:

Electrolyte Additive: Used in small concentrations (1–3% by weight) to improve SEI formation on graphite anodes. The oxalate moiety promotes the formation of a dense, stable SEI layer, reducing irreversible capacity loss and enhancing cycle life (often by 20–30% in long-term cycling).

Co-Salt in High-Temperature Batteries: Blended with LiPF₆ or LiFSI in electrolytes for batteries operating at 40–60°C (e.g., automotive and industrial applications), where its thermal stability minimizes electrolyte decomposition and gas generation.

Silicon Anode Compatibility: Enables the use of high-capacity silicon anodes by forming a protective SEI that accommodates the large volume changes of silicon during lithiation/delithiation, a critical challenge in silicon-based battery development.

Safety-Enhanced Batteries: Reduces the risk of thermal runaway in consumer electronics and electric vehicle batteries by suppressing flammable electrolyte decomposition at high temperatures.

Advantages Over Conventional Electrolyte Salts

LiDFOB offers significant benefits compared to traditional lithium salts and additives:

SEI Optimization: Outperforms additives like vinylene carbonate (VC) in forming a robust SEI, particularly on graphitic and silicon anodes, due to the synergistic effects of fluorine and oxalate groups.

Thermal and Chemical Stability: Combines the thermal resilience of borate salts with the passivating properties of oxalate, making it more stable than LiPF₆ and less corrosive than LiTFSI.

Compatibility: Works seamlessly with a wide range of cathode materials (NCM, NCA, LFP) and electrolyte solvents, avoiding the cathode dissolution issues seen with some fluorinated salts.

Safety: Reduces flammability of electrolytes and minimizes HF formation, addressing key safety concerns in lithium-ion battery design.

Synthesis & Quality Control

LiDFOB is synthesized through precise processes to ensure high purity and consistency:

Precursor Reaction: Lithium oxalate (Li₂C₂O₄) reacts with boron trifluoride diethyl etherate (BF₃·OEt₂) in an anhydrous organic solvent (e.g., acetonitrile) under inert atmosphere, forming LiDFOB and byproducts.

Purification: The crude product is purified via recrystallization from anhydrous solvents (e.g., ethyl acetate) and dried under vacuum to remove residual moisture and impurities.

Quality control includes ion chromatography (IC) for anion analysis, inductively coupled plasma mass spectrometry (ICP-MS) for trace metal detection, and Karl Fischer titration to ensure moisture content is below 10 ppm. Purity levels of 99.9% or higher are standard for battery-grade LiDFOB.

Safety & Handling

Proper handling of LiDFOB is essential to maintain performance and safety:

Hygroscopicity: Absorbs moisture moderately from the air; store in sealed containers under inert atmosphere (nitrogen or argon) to prevent hydrolysis.

Toxicity: May cause skin and eye irritation; use chemical-resistant gloves, goggles, and a lab coat when handling. Avoid inhalation of dust.

Reactivity: Incompatible with strong acids (which release HF) and reducing agents. Keep away from open flames, as it may enhance combustion of flammable materials.

Storage: Store in a cool, dry, well-ventilated area, separate from oxidizing agents and combustible materials.

Refer to the product’s Safety Data Sheet (SDS) for detailed safety protocols.

Packaging & Availability

LiDFOB is available in forms tailored to battery manufacturing and research needs:

Anhydrous Powder: Packaged in moisture-proof aluminum bags (100g–5kg) with inert gas purging, suitable for laboratory and pilot-scale use.

Bulk Quantities: Available in 25kg–50kg drums for industrial electrolyte production, with strict moisture control during packaging.

Custom purities and particle sizes can be provided for specialized applications. Our battery-grade LiDFOB meets the stringent requirements of automotive and electronics industries for consistency and performance.

For technical specifications, pricing, or sample requests, contact our sales team specializing in advanced electrolyte materials.

Health & Safety Information

 Signal Word: Warning 

Hazard Statements: H315-H319-H335 

Hazard Codes: Xi 

Risk Codes: 36/37/38 

Safety Statements: 26-36 

RTECS Number: N/A 

Transport Information: N/A 

WGK Germany: 3

Chemical Identifiers 

Linear Formula: C40H32BLiN4O4 

Pubchem CID: 23714786 

MDL Number: MFCD03093696 

EC No.: N/A 

IUPAC Name: lithium; tetrakis[(2-methylquinolin-8-yl)oxy] boranuide 

SMILES: [Li+].[B-](OC1=CC=CC2=C1N=C(C=C2)C)(OC3=CC=CC4=C3N=C(C=C4)C)(OC5=CC=CC6=C5N(=CC=C6)C)OC7=CC=CC8=C7N=C(C=C8)C 

InchI Identifier: InChI=1S/C40H32BN4O4.Li/c1-25-17-21-29-9-5-13-33(37(29)42-25)46-41(47-34-14-6-10-30-22-18-26(2)43-38(30)34,48-35-15-7-11-31-23-19-27(3)44-39(31)35)49-36-16-8-12-32-24-20-28(4)45-40(32)36;/h5-24H,1-4H3;/q-1;+1 

InchI Key: AVPRLXSPVRRDIE-UHFFFAOYSA-N

Packing of Standard Packing: 

Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 735 gallon liquid totes Special package is available on request.