Lithium Selenide Sputtering TargetCAS #: 12136-60-6

Synonyms

 Dilithium selenide; lithium selenidolithium

Compound Formula: Li2Se 

Molecular Weight: 92.842 

Appearance: solid 

Melting Point: N/A 

Boiling Point: N/A 

Density: N/A 

Solubility in H2O: Reacts violently 

Exact Mass: 93.94853 

Monoisotopic Mass: 93.948532 

Da Sensitivity: Moisture sensitive

Product Introduction: Sodium Hexafluorophosphate (NaPF₆, CAS #: 12136-60-6)

Sodium hexafluorophosphate, with the chemical formula NaPF₆ and CAS number 12136-60-6, is an inorganic salt composed of sodium cations (Na⁺) and hexafluorophosphate anions (PF₆⁻). This white, crystalline compound is valued for its high solubility in polar organic solvents, electrochemical stability, and versatility in energy storage and chemical applications. While overshadowed by its lithium analog (LiPF₆) in lithium-ion batteries, NaPF₆ plays a critical role in sodium-ion batteries (SIBs) and specialty chemical processes, leveraging sodium’s abundance and cost-effectiveness.

Chemical & Physical Properties

NaPF₆ exhibits properties that make it suitable for diverse industrial uses:

Solubility: Highly soluble in polar organic solvents such as propylene carbonate (PC), dimethyl carbonate (DMC), and acetonitrile, forming electrolytes with concentrations up to 1.5 M. It is moderately soluble in water (approximately 107 g/100 mL at 25°C), though hydrolysis occurs slowly in moist conditions.

Thermal Stability: Decomposes above 200°C, releasing phosphorus pentafluoride (PF₅) and sodium fluoride (NaF)—a higher stability threshold than LiPF₆, making it more resilient in high-temperature applications.

Hygroscopicity: Moderately hygroscopic, reacting with moisture to form hydrofluoric acid (HF), sodium phosphate (Na₃PO₄), and other byproducts. This requires storage in dry environments, with moisture levels controlled below 50 ppm in electrolyte formulations.

Density & Structure: Has a density of 2.36 g/cm³ and a molar mass of 167.95 g/mol, with a cubic crystal structure that ensures stability in anhydrous conditions.

Electrochemical Window: Exhibits a stable electrochemical window up to 4.2 V vs. Na⁺/Na, compatible with common SIB cathodes such as Prussian blue analogs and layered oxides (e.g., NaNi₀.₃Co₀.₃Mn₀.₃O₂).

Key Applications

Sodium hexafluorophosphate (CAS 12136-60-6) is primarily used in energy storage and specialty chemistry:

Sodium-Ion Batteries (SIBs): Serves as a primary electrolyte salt in SIBs, a promising alternative to lithium-ion batteries for grid storage and low-cost applications. Its high solubility in organic solvents enables ionic conductivities of 8–12 mS/cm, supporting efficient sodium-ion transport. In SIBs, NaPF₆ contributes to forming a stable solid electrolyte interphase (SEI) on hard carbon anodes, reducing capacity fade and extending cycle life (often exceeding 2,000 cycles in laboratory tests).

Electrolyte Additives: Used as an additive in lithium-ion batteries to improve safety and performance. Small concentrations (0.1–0.5%) of NaPF₆ enhance SEI stability on graphite anodes, reducing gas evolution and improving thermal runaway resistance.

Chemical Synthesis: Acts as a fluorinating agent in organic chemistry, facilitating the introduction of fluoride groups into pharmaceutical intermediates and agrochemicals. It also serves as a source of PF₆⁻ ions in the preparation of ionic liquids, which are used as green solvents and electrolytes.

Ion Exchange and Analysis: Employed in ion chromatography as an eluent for separating and detecting anions in environmental and industrial samples. Its ability to form stable complexes with metal ions makes it useful in solvent extraction processes for metal recovery.

Advantages & Limitations

NaPF₆ offers distinct benefits in specific applications, alongside notable limitations:

Cost-Effectiveness: Sodium’s abundance (2.3% of Earth’s crust) makes NaPF₆ significantly cheaper than LiPF₆, supporting large-scale applications like grid storage where material costs are critical.

Thermal Stability: Its higher decomposition temperature compared to LiPF₆ reduces safety risks in high-temperature environments, a key advantage in stationary energy storage systems.

Compatibility: Well-suited for sodium-based chemistries, with good compatibility with SIB electrodes and electrolytes, unlike some alternative salts (e.g., NaBF₄) which exhibit lower conductivity.

Limitations: Lower ionic conductivity in organic solvents compared to LiPF₆ limits its use in high-power applications. Its hygroscopicity requires strict moisture control during manufacturing, increasing production costs. Additionally, hydrolysis produces HF, necessitating corrosion-resistant equipment.

Synthesis & Quality Control

NaPF₆ is produced via metathesis reactions to ensure high purity:

Reaction of Sodium Fluoride with Phosphorus Pentafluoride: Sodium fluoride (NaF) reacts with PF₅ in anhydrous hydrogen fluoride (HF) solvent: NaF + PF₅ → NaPF₆. The product is isolated by crystallization and dried under vacuum to remove residual HF.

Neutralization Route: In aqueous systems, phosphoric acid (H₃PO₄) reacts with hydrofluoric acid (HF) and sodium hydroxide (NaOH), followed by precipitation: H₃PO₄ + 6HF + 3NaOH → NaPF₆ + 6H₂O + 2Na₂HPO₄.

Quality control includes:

Ion chromatography to verify PF₆⁻ content (typically 99.0–99.5% purity for industrial grades).

Inductively coupled plasma mass spectrometry (ICP-MS) to detect trace metals (Fe, Ca, K <10 ppm).

Karl Fischer titration to ensure moisture content <50 ppm, critical for preventing hydrolysis in electrolyte applications.

Safety & Handling

Proper handling of NaPF₆ is essential due to its reactivity with moisture and toxicity:

Toxicity: Inhalation of dust or contact with moisture releases HF, causing severe burns to skin, eyes, and respiratory tracts. Chronic exposure to fluoride ions may damage bones and teeth.

Handling: Use in well-ventilated fume hoods with moisture levels <1% RH. Wear PTFE gloves, splash goggles, and a respirator rated for HF exposure.

Storage: Keep in airtight, moisture-proof containers (e.g., HDPE or stainless steel) in a cool, dry area, separated from water, acids, and bases.

Spill Response: Neutralize spills with calcium carbonate (CaCO₃) to form insoluble CaF₂, avoiding water which accelerates HF release. Dispose of waste as hazardous material per local regulations.

Refer to the product’s Safety Data Sheet (SDS) for detailed emergency protocols, including first aid for HF exposure.

Packaging & Availability

NaPF₆ is available in forms tailored to industrial and research needs:

Industrial Grade: 25kg–50kg sealed drums with moisture barriers, suitable for large-scale battery production and chemical manufacturing.

Research Grade: 100g–5kg bottles in argon-purged aluminum bags, ensuring ultra-low moisture content (<10 ppm) for laboratory use.

Electrolyte Solutions: Pre-dissolved in solvent blends (e.g., 1.0 M in PC/DMC) in 1L–20L containers, used in small-batch battery assembly.

Global production is concentrated in China, Europe, and the United States, with annual capacity growing to meet demand for sodium-ion batteries. High-purity grades (99.9%) with ultra-low metal impurities are available for advanced research and electronics applications.

For technical specifications, pricing, or custom formulations, contact our team specializing in fluorinated salts for energy storage and chemical applications.

Health & Safety Information

 Signal Word: Danger 

Hazard Statements: H261-H301+H331-H373-H410 

Hazard Codes: F, T, N 

Precautionary Statements: P223-P231+P232-P260-P264-P270-P271-P273-P280-P301+P310-P304+P340-P314 

Risk Codes: N/A 

Safety Statements: N/A 

Transport Information: UN 3134 4.3(6.1)/ PG II 

GHS Pictogram: Image,Image,Image,Image

Chemical Identifiers 

Linear Formula: Li2Se 

Pubchem CID: 82935 

MDL Number: N/A 

EC No.: 235-230-2 

IUPAC Name: lithium selenidolithium 

Beilstein/Reaxys No.: N/A 

SMILES: [Li][Se][Li] 

InchI Identifier: InChI=1S/2Li.Se 

InchI Key: PEXNRZDEKZDXPZ-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.