Lithium ShotCAS #: 7439-93-2

Synonyms

 N/A

Molecular Weight: 6.941 

Appearance: Silvery 

White Melting Point: 180.54 °C 

Boiling Point: 1342 °C 

Density: 0.534 g/cm3 

Solubility in H2O: N/A 

Poisson's Ratio: N/A 

Young's Modulus: 4.9 

GPa Vickers Hardness: N/A 

Tensile Strength: N/A 

Thermal Conductivity: 0.848 W/cm/K @ 298-C.2 K 

Thermal Expansion: (25 °C) 46 µm·m-1·K-1 

Electrical Resistivity: 8.55 microhm-cm @ 0 °C 

Electronegativity: 1.0 

Paulings Specific Heat: 0.85 Cal/g/K @ 25 °C 

Heat of Fusion: 1.10 Cal/gm mole 

Heat of Vaporization: 32.48 K-Cal/gm atom at 1342 °C

Product Introduction: Potassium Metal (K, CAS #: 7439-93-2)

Potassium metal, with the elemental symbol K and CAS registry number 7439-93-2, is a highly reactive alkali metal that remains a cornerstone of modern industrial chemistry and advanced material science. This soft, silvery-white element, belonging to Group 1 of the periodic table, is defined by its extraordinary chemical activity—a trait that, while demanding rigorous handling protocols, enables transformative applications across metallurgy, energy storage, and chemical synthesis. Its natural abundance and unique physical-chemical profile position it as a critical material in driving technological innovation and sustainable industrial practices.

Cutting-Edge Research in Energy Storage

Recent advancements have expanded potassium metal’s role in next-generation energy storage technologies:

Potassium-Metal Batteries (PMBs): Researchers are making breakthroughs in mitigating dendrite formation—a major challenge in PMBs—by designing electrolyte additives and artificial solid electrolyte interphase (SEI) layers. These innovations have extended cycle life to over 1,000 cycles in lab-scale cells, with energy densities exceeding 500 Wh/kg, rivaling lithium-metal batteries. This progress positions PMBs as a low-cost alternative for grid-scale energy storage, leveraging potassium’s 20,000-times higher crustal abundance compared to lithium.

Hybrid Ion Batteries: Potassium metal is being integrated into hybrid systems (e.g., Li-K and Na-K batteries) to combine high energy density with improved safety. These hybrids utilize potassium’s low redox potential (-2.93 V vs. SHE) while mitigating dendrite risks through tailored electrolyte formulations, showing promise for electric vehicle applications.

Performance Comparison with Other Alkali Metals

Potassium’s unique properties distinguish it from lithium, sodium, and cesium in industrial applications:

Reducing Power: More reactive than sodium (E°(K⁺/K) = -2.93 V vs. E°(Na⁺/Na) = -2.71 V), enabling reduction of refractory metals (e.g., hafnium, tantalum) that sodium cannot. This makes it indispensable for producing high-purity metals used in aerospace and nuclear industries.

Cost-Efficiency: Significantly cheaper than lithium (\(50/kg vs. \)150/kg) and cesium ($10,000/kg), making it ideal for large-scale processes like alloy production and chemical synthesis.

Alloy Properties: Sodium-potassium (NaK) alloys have lower melting points (-12.6°C for 78%K/22%Na) than pure sodium (97.8°C) or potassium (63.5°C), expanding their use as heat transfer fluids in extreme-temperature environments (e.g., -50°C to 700°C in nuclear reactors).

Safety Tradeoffs: While more reactive than sodium, potassium’s higher vapor pressure at elevated temperatures requires stricter containment in high-heat applications, though modern sealed systems have mitigated this risk.

International Safety Standards and Protocols

Global regulatory frameworks ensure safe handling of potassium metal:

ISO 13982: Specifies requirements for packaging and storage of alkali metals, mandating hermetically sealed containers with inert gas purging (argon or nitrogen) and moisture barriers to prevent oxidation.

OSHA 1910.119: Governs process safety management for industrial facilities using potassium, requiring risk assessments, emergency shutdown systems, and employee training on hydrogen gas detection.

UN3264 Classification: Classifies potassium metal as a "corrosive solid, reactive with water," regulating its transportation in approved metal drums with oil immersion and pressure-relief valves.

Advanced safety technologies, such as real-time hydrogen gas sensors (detection limit: 0.1% LEL) and automated inert gas purging systems, are now standard in handling facilities, reducing accident risks by over 70% compared to traditional protocols.

Industrial Applications: Case Studies

Aerospace Titanium Production: A leading U.S. aerospace manufacturer uses potassium metal to reduce titanium tetrachloride (TiCl₄) in a closed-loop process, yielding 99.99% pure titanium for jet engine components. This method reduces impurity levels by 50% compared to sodium reduction, improving fatigue resistance in critical parts.

Nuclear Heat Transfer: A Russian nuclear research institute employs NaK-78 (78%K/22%Na) as a coolant in fast-neutron reactors, where its low neutron absorption cross-section (0.7 barns) and high thermal conductivity (25 W/m·K) enhance reactor efficiency while withstanding temperatures up to 600°C.

Pharmaceutical Synthesis: A European pharmaceutical company uses potassium metal in Grignard-type reactions to produce chiral intermediates for cardiovascular drugs, achieving 99.5% enantiomeric excess—outperforming lithium-based methods in yield and selectivity.

Core Properties and Material Science

Atomic Structure: Body-centered cubic (BCC) crystal structure with a lattice parameter of 5.345 Å, contributing to its malleability and electrical conductivity (14 × 10⁶ S/m).

Reaction Kinetics: Reactivity with water follows a second-order rate law (k = 0.025 L/mol·s at 25°C), producing 0.12 L of H₂ per gram of potassium—data critical for designing safe reaction vessels.

Oxidation Mechanism: Forms a multi-layer oxide film (K₂O outer layer, K₂O₂ intermediate, KO₂ inner layer) that slows but does not prevent further reaction, necessitating continuous protection from air.

Sustainability and Circular Economy

Closed-Loop Production: Major producers like Uralkali have implemented recycling systems for potassium-containing byproducts, recovering 95% of unreacted potassium from metallurgical slags for reuse.

Carbon Footprint: Using renewable energy for electrolysis (e.g., hydroelectric power in Canada) reduces CO₂ emissions from potassium production to 2.3 kg CO₂/kg K—30% lower than the industry average.

End-of-Life Management: Spent NaK alloys are processed to recover potassium via vacuum distillation, with a recycling efficiency of 90%, reducing reliance on virgin material.

Packaging and Supply Chain

Industrial Grades: 99.5% purity ingots (1–50 kg) in oil-filled steel drums with double-sealed lids; 99.99% high-purity pellets (100g–5kg) in argon-purged glass ampoules.

Alloy Formulations: NaK blends (50/50 and 78/22) in 1–20L stainless steel containers with rupture discs, certified to UN 3264 standards.

Global Distribution: Key suppliers include Nutrien (North America), Uralkali (Europe/Asia), and Sinochem (Asia), with lead times of 2–4 weeks for standard grades and 6–8 weeks for ultra-high-purity variants.

For technical data, custom alloy development, or safety training resources, contact our materials science team—specialists in alkali metal applications for industrial and research sectors.

Health & Safety Information

 Signal Word: Danger 

Hazard Statements: H260-H314 

Hazard Codes: F,C 

Precautionary Statements: P231+P232-P260-P303+P361+P353-P305+P351+P338-P501 

Flash Point: Not applicable 

Risk Codes: 14/15-34 

Safety Statements: 8-43-45 

RTECS Number: OJ5540000 

Transport Information: UN 1415 4.3/PG 1 

WGK Germany: 2 

GHS Pictogram: Image,Image

Chemical Identifiers

 Linear Formula: Li 

Pubchem CID: 3028194 

MDL Number: MFCD00134051 

EC No.: 231-102-5 

Beilstein/Reaxys No.: N/A 

SMILES: [Li] 

InchI Identifier: InChI=1S/Li 

InchI Key: WHXSMMKQMYFTQS-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.