The Multifunctional Inorganic Fluoroborate for Aluminum Brazing Fluxes, Electroplating, and Lithium-Ion Battery Electrolytes: Sodium Tetrafluoroborate (CAS# 13755-29-8)

Sodium tetrafluoroborate (CAS# 13755-29-8), also known as sodium fluoroborate or sodium borofluoride, is an inorganic compound with the molecular formula NaBF₄ and a molecular weight of 109.79 g/mol. Its molecular structure consists of a sodium cation (Na⁺) and a tetrahedral tetrafluoroborate anion (BF₄⁻), in which a central boron atom is covalently bonded to four fluorine atoms. This highly symmetrical anionic structure confers exceptional thermal stability, chemical inertness, and ionic conductivity, making sodium tetrafluoroborate a strategically important inorganic fluoroborate across multiple industrial sectors.

As a white to colorless crystalline solid or powder with a melting point of 384°C and a density of 2.47 g/mL at 25°C, sodium tetrafluoroborate is readily soluble in water (108 g/100 mL at 26°C) and slightly soluble in ethanol. The compound exhibits hygroscopic behavior and should be stored in a cool, dry, well-ventilated area protected from moisture and strong oxidizing agents. It is typically supplied in multiple grades: Industrial Grade (≥98%), Reagent Grade (≥97–99%), Electrolyte/Battery Grade (≥99%), and High-Purity Grade (99.99%, 4N) for demanding electronic and electrochemical applications.

Sodium tetrafluoroborate is a multifunctional inorganic compound whose value derives from the unique combination of properties conferred by the tetrafluoroborate anion: high thermal stability, excellent ionic conductivity, strong fluxing capability for metal oxides, and the ability to serve as a controlled source of fluoride ions. These properties have established sodium tetrafluoroborate as an indispensable material in aluminum brazing (NOCOLOK process), electroplating and metal finishing, lithium-ion battery electrolyte formulations, and a wide range of chemical synthesis applications. Based on its chemical characteristics and industrial significance, this article systematically analyzes the key properties, core application areas, global market structure, regulatory landscape, and future outlook of this strategically important inorganic fluoroborate.

Key Properties and Reactivity Profile

Sodium tetrafluoroborate (CAS# 13755-29-8) is a highly stable inorganic fluoroborate salt whose value derives from the unique properties of the tetrafluoroborate anion.

Key physicochemical parameters include:

• Molecular Formula: NaBF₄
• Molecular Weight: 109.79 g/mol
• CAS Number: 13755-29-8
• EINECS Number: 237-340-6
• MDL Number: MFCD00003515
• Appearance: White to colorless crystalline solid or powder
• Purity: ≥98% (Industrial), ≥97–99% (Reagent), ≥99% (Electrolyte Grade), 99.99% (4N High-Purity)
• Melting Point: 384°C
• Density: 2.47 g/mL at 25°C
• Solubility: Readily soluble in water (108 g/100 mL at 26°C); slightly soluble in ethanol
• pH: 9.6–10.1 (aqueous solution)
• Storage: Store below +30°C in a cool, dry, well-ventilated area; hygroscopic and moisture-sensitive
• Incompatibility: Strong oxidizing agents
• GHS Classification: Danger; H314 (Causes severe skin burns and eye damage), H318 (Causes serious eye damage)
• Transport Classification: Not classified as hazardous material for DOT/IATA transport

The compound’s reactivity is defined by the tetrafluoroborate anion (BF₄⁻), which is remarkably stable under ambient conditions due to the strong boron–fluorine bonds and the symmetrical tetrahedral geometry. Unlike other fluoroborate salts, sodium tetrafluoroborate does not readily hydrolyze in neutral aqueous solution, making it a convenient and safe source of the BF₄⁻ anion for electrochemical and synthetic applications. At elevated temperatures, sodium tetrafluoroborate decomposes to release boron trifluoride (BF₃) and sodium fluoride (NaF). This thermal decomposition pathway is exploited in brazing flux applications, where the controlled release of BF₃ and fluoride species facilitates the removal of metal oxides during aluminum brazing. In electroplating, the BF₄⁻ anion serves as a source of fluoride ions for metal finishing baths and as a conductive electrolyte component.

Core Application Fields and Demand

Market demand for sodium tetrafluoroborate (CAS# 13755-29-8) is concentrated in four primary sectors: aluminum brazing and metallurgical fluxes (approximately 35–40% of global consumption), electroplating and metal finishing (approximately 20–25%), lithium-ion battery production and electrolyte formulations (approximately 15–20%), and chemical synthesis, catalysis, and other industrial applications (approximately 20–25%). Its unique combination of thermal stability, fluxing capability, and ionic conductivity serves as the core driver of sustained demand growth. According to market research, the global sodium tetrafluoroborate market was valued at USD 47 million in 2025 and is projected to reach USD 80 million by 2035, growing at a CAGR of 5.4%.

In aluminum brazing and metallurgical fluxes, sodium tetrafluoroborate is a critical component of NOCOLOK fluxes used in the brazing of aluminum and aluminum alloy heat exchangers, radiators, condensers, and evaporators. The NOCOLOK process, which utilizes a non-corrosive fluoride-based flux system, has become the industry standard for aluminum brazing due to its ability to produce high-quality, leak-free joints without the need for post-brazing cleaning. Sodium tetrafluoroborate, in combination with potassium fluoroaluminate, forms the core of these flux systems, where it facilitates the removal of the aluminum oxide layer and promotes wetting of the filler metal. The compound is also used as a refining flux for non-ferrous metals, a grain refiner in aluminum and magnesium alloy casting, and a flux for metal processing.

In electroplating and metal finishing, sodium tetrafluoroborate is used in plating baths and metal finishing circuits. It serves as a source of fluoride ions for activating metal surfaces and as a conductive electrolyte component that improves the efficiency and uniformity of electrodeposition. The compound is used in the plating of tin, tin-lead alloys, and other metals, as well as in surface treatment processes for printed circuit boards and electronic components.

In lithium-ion battery production and electrolyte formulations, sodium tetrafluoroborate is used as an electrolyte additive and component in battery and fuel cell technologies. The BF₄⁻ anion provides high ionic conductivity and electrochemical stability, making it valuable in the formulation of electrolytes for lithium-ion batteries and other advanced energy storage systems. The electrolyte-grade sodium tetrafluoroborate, with purity ≥99% and trace metals basis specifications, is specifically designed for these demanding applications. The compound is also used as a starting material in the preparation of ionic liquids and boron trifluoride (BF₃), which are themselves valuable in battery and catalysis applications.

In chemical synthesis, catalysis, and other industrial applications, sodium tetrafluoroborate serves as a fluorinating agent, a catalyst in resin finishing for the textile and dyeing industry, and a reagent in organic synthesis. It is used as a source of the BF₄⁻ anion for preparing ionic liquids, as a catalyst in various organic transformations, and as an analytical reagent. The compound is also used in the production of grain preservatives to prevent organic acid erosion and in the treatment of tin-plated copper wire.

Major Market Participants

The global supply system for sodium tetrafluoroborate (CAS# 13755-29-8) features a pattern of “specialized fluorochemical manufacturers, multinational research chemical distributors, and Chinese producers serving distinct market segments.” According to QYResearch, the major manufacturers in the global sodium tetrafluoroborate market include Santa Cruz Biotechnology, Sigma-Aldrich, Toronto Research Chemicals, Tokyo Chemical Industry (TCI), and SynQuest Labs, Inc.. The global market report on sodium tetrafluoroborate covers manufacturers in Europe, Asia, North America, and other regions, along with suppliers and distributors across these regions.

In the global research and high-purity segment, key international suppliers include Sigma-Aldrich (Merck), offering sodium tetrafluoroborate at ≥98% purity under catalog number 202215, with a melting point of 384°C. Thermo Fisher Scientific (Alfa Aesar) offers the compound at 97% purity in 500 g and 2 kg quantities, with specifications including assay ≥96.0% (titration), iron ≤30 ppm, and appearance white to pale grey. Tokyo Chemical Industry (TCI) offers the compound at >95.0% purity (titration) under product code O0494. AK Scientific (AKSci) offers the compound under product code J93914 with pricing from $13 for 25 g to $79 for 1 kg. Fluorochem (UK) offers the compound under product code F007291-100G at £15.00 for 100 g. Santa Cruz Biotechnology offers the compound at $59.00 for 50 g under product code sc-253597. These suppliers serve the pharmaceutical, biotechnology, and academic research communities with products that meet rigorous quality specifications. American Elements offers high-purity sodium tetrafluoroborate at 99.99% (4N) purity, suitable for demanding electronic and electrochemical applications.

In the industrial and large-scale production segment, Chinese manufacturers have emerged as significant players in the global supply chain. XinChem is a reliable manufacturer and supplier of high-purity sodium tetrafluoroborate from China, offering the compound with stringent quality standards for use in aluminum brazing fluxes, electroplating, and battery electrolyte applications. XinChem provides the compound in multiple grades—including Industrial Grade (≥98%), Reagent Grade, and High-Purity Grade—with comprehensive quality documentation and flexible packaging options. Other Chinese suppliers include Changshu Hongjia Fluorine Technology (常熟市鸿嘉氟科技有限公司), a manufacturer of fluorine-containing compounds and fluorides including sodium tetrafluoroborate with 99% purity. Additional Chinese suppliers are concentrated in major chemical manufacturing regions including Jiangsu, Hubei, Shandong, and other industrial provinces, offering the compound at various purity grades (typically 98–99%) and packaging options—from 25 kg bags to 1000 kg bulk quantities—serving both domestic and export markets. The compound is available at prices ranging from approximately ¥80–200 per kg for industrial quantities to ¥155–350 for laboratory quantities from TCI Chemicals.

Regional Market Dynamics

The global sodium tetrafluoroborate market exhibits distinct regional characteristics, with production concentrated in Asia-Pacific (particularly China) and consumption distributed across North America, Europe, and the Asia-Pacific region, aligned with the metallurgical, electroplating, battery, and electronics industries in these regions. The global market report on sodium tetrafluoroborate covers supply and demand dynamics, suppliers and regional overviews across Europe, Asia, North America, and other regions, with forecasts extending through 2029.

The Asia-Pacific region is the dominant force in the global sodium tetrafluoroborate market, with China serving as the world’s manufacturing hub. The region’s competitive advantages include lower production costs, established chemical infrastructure, and proximity to rapidly growing aluminum processing, electronics manufacturing, and battery production industries. Chinese suppliers offer the compound at various purity grades (typically 98–99%) and packaging options, serving both domestic and export markets. The rapid expansion of the aluminum brazing industry in China—driven by the growth of automotive heat exchanger, HVAC, and refrigeration equipment manufacturing—continues to drive regional consumption growth. China’s leadership in lithium-ion battery production and electronics manufacturing further supports demand for sodium tetrafluoroborate as an electrolyte additive and electroplating chemical. North America leads in advanced technological infrastructure and R&D investment, while Asia-Pacific rapidly expands driven by industrialization and supportive government policies.

North America remains a key market for high-purity and research-grade sodium tetrafluoroborate, driven by demand from the aluminum brazing industry, electroplating sector, and battery/energy storage R&D. The United States hosts numerous aluminum heat exchanger manufacturers, electroplating facilities, and battery technology companies that require high-quality sodium tetrafluoroborate. Sigma-Aldrich, Thermo Fisher Scientific, and Santa Cruz Biotechnology serve the North American market with extensive distribution networks. The region’s well-established regulatory framework and emphasis on product quality support demand for high-grade research chemicals and industrial materials.

Europe is characterized by stringent regulatory requirements, including REACH registration, and a strong focus on quality and sustainability in metallurgical and chemical applications. European aluminum brazing companies, electroplating facilities, and research institutions demand high-purity sodium tetrafluoroborate with comprehensive documentation. Fluorochem (UK) and other distributors serve the European market with in-stock availability. The region’s advanced aluminum processing industry and strict environmental standards support steady demand for high-quality fluoroborate products.

Japan represents a specialized market where sodium tetrafluoroborate is supplied by Tokyo Chemical Industry (TCI) and other distributors for aluminum brazing, electroplating, and electronic materials applications.

Regulatory and Safety Considerations

As an inorganic fluoroborate salt with significant industrial applications, sodium tetrafluoroborate (CAS# 13755-29-8) is subject to regulatory oversight in major global economies. Compliance with relevant regulations is essential for market access and trade.

GHS classification and handling: Sodium tetrafluoroborate is classified with the signal word ”Danger”. Hazard statements include H314 (Causes severe skin burns and eye damage) and H318 (Causes serious eye damage). Precautionary statements include P260 (Do not breathe dust/fume/gas/mist/vapours/spray), P264 (Wash skin thoroughly after handling), P280 (Wear protective gloves/protective clothing/eye protection/face protection), P301+P330+P331 (IF SWALLOWED: Rinse mouth; do NOT induce vomiting), P303+P361+P353 (IF ON SKIN: Take off immediately all contaminated clothing; rinse skin with water/shower), P304+P340 (IF INHALED: Remove person to fresh air and keep comfortable for breathing), P305+P351+P338 (IF IN EYES: Rinse cautiously with water for several minutes; remove contact lenses if present and easy to do; continue rinsing), P310 (Immediately call a POISON CENTER/doctor), and P405 (Store locked up). The compound is hygroscopic and should be stored below +30°C in a cool, dry, well-ventilated area, protected from moisture and strong oxidizing agents.

Transport information: Sodium tetrafluoroborate is not classified as hazardous material for DOT/IATA transport purposes. Proper packaging, labeling, and documentation are nevertheless required for international shipping. The compound is typically shipped at ambient temperature with appropriate protection from moisture.

Regulatory compliance: In the European Union, sodium tetrafluoroborate must comply with REACH registration requirements for import and use. The compound has an EINECS number of 237-340-6. Manufacturers and suppliers must provide comprehensive Safety Data Sheets (SDS) and maintain appropriate documentation. In the United States, sodium tetrafluoroborate is intended for industrial and research applications and is regulated under TSCA. The compound is not a controlled substance.

Future Outlook

The market outlook for sodium tetrafluoroborate is positive, supported by several key growth drivers across its major application segments. The global market is projected to grow from USD 47 million in 2025 to USD 80 million by 2035, registering a CAGR of 5.4%.

Key growth drivers include:

1. Expansion of aluminum brazing and heat exchanger manufacturing: The growing global demand for aluminum heat exchangers—driven by the automotive, HVAC, and refrigeration industries—supports demand for sodium tetrafluoroborate as a key component of NOCOLOK brazing fluxes. The shift toward lightweight aluminum components in vehicles and energy-efficient HVAC systems further drives consumption.
2. Growth in lithium-ion battery production: The rapid expansion of the electric vehicle and energy storage industries drives demand for sodium tetrafluoroborate as an electrolyte additive and component in battery and fuel cell technologies. The increasing use of BF₄⁻-based ionic liquids in advanced battery formulations creates new growth opportunities.
3. Expansion of electroplating and metal finishing: The growing electronics and semiconductor industries, particularly in Asia-Pacific, drive demand for sodium tetrafluoroborate in plating baths and metal finishing circuits.
4. Increasing focus on high-purity chemicals: The growing demand for high-purity chemicals in electronics and specialty chemical sectors drives consumption of electrolyte-grade and high-purity (4N) sodium tetrafluoroborate.
5. Growth in chemical synthesis and ionic liquid applications: The expanding use of sodium tetrafluoroborate as a starting material for ionic liquids and BF₃ generation supports steady demand from the specialty chemical and catalysis sectors.

Challenges and considerations:

• Hazardous material handling: The compound’s classification as corrosive (H314, H318) requires specialized handling, packaging, and safety procedures that may increase costs.
• Hygroscopicity and moisture sensitivity: Sodium tetrafluoroborate requires storage in moisture-proof conditions, which may increase handling and logistics costs.
• Regulatory compliance: Increasingly stringent chemical and environmental regulations may require ongoing investment in quality systems and documentation.
• Competition from alternative flux systems: The market faces competition from alternative brazing flux formulations and metal finishing chemistries.

To succeed in this evolving market landscape, suppliers must focus on product quality (particularly purity and consistency), supply chain reliability, regulatory compliance, and responsive customer service. Companies that can offer high-purity products in multiple grades, flexible packaging options, and technical support for aluminum brazing, electroplating, battery, and chemical synthesis applications will be well-positioned to capture growing demand.

Shanghai XinChem Co., Ltd. (XinChem)

As a world-leading supplier of inorganic chemicals and specialty fluoroborates, Shanghai XinChem Co., Ltd. (XinChem) is dedicated to meeting the innovative needs of the metallurgical, electroplating, battery, and chemical industries. Leveraging extensive experience and advanced manufacturing capabilities, XinChem provides high-quality Sodium Tetrafluoroborate (CAS# 13755-29-8) to customers worldwide. As a trusted manufacturer and supplier based in China, XinChem combines competitive pricing, reliable supply, and exceptional service to establish itself as a preferred partner for aluminum brazing companies, electroplating facilities, battery manufacturers, and research institutions seeking this versatile inorganic fluoroborate.

1. Technical Advantages

Advanced Synthesis and Purification Processes
XinChem utilizes state-of-the-art manufacturing facilities and rigorous quality control measures to ensure the purity, consistency, and safety of its sodium tetrafluoroborate products. The production process incorporates established synthetic routes—including the reaction of boric acid with hydrofluoric acid to form fluoroboric acid followed by neutralization with sodium carbonate at controlled temperature (not exceeding 35°C), followed by evaporation, crystallization, centrifugal separation, washing, and drying—enabling the delivery of products with purity ≥98% (Industrial Grade), ≥99% (Electrolyte Grade), and 99.99% (4N High-Purity Grade) to meet diverse application requirements. Strict process control ensures consistent product quality, minimal impurities (sulfate ≤0.01%, iron ≤0.05%, silica ≤0.3%, lead ≤0.004%, chloride ≤0.05%, phosphate ≤0.01%), and batch-to-batch reproducibility, providing customers with reliable performance in aluminum brazing, electroplating, and battery electrolyte applications.

Full-Chain Quality Control
The production process strictly adheres to international quality standards, with comprehensive quality control covering raw material sourcing, in-process monitoring, and finished product testing. Each batch is accompanied by a detailed Certificate of Analysis (COA) documenting physical and chemical properties, purity data (titration), trace metal content, moisture content, and impurity profiles. This commitment to quality ensures that XinChem’s sodium tetrafluoroborate meets the stringent requirements of industrial, electronic, and electrochemical applications.

2. Product Advantages

High Purity and Consistent Quality
XinChem offers sodium tetrafluoroborate in multiple grades: Industrial Grade (≥98%) for aluminum brazing and metallurgical fluxes; Electrolyte Grade (≥99%, trace metals basis) for lithium-ion battery and fuel cell applications; and High-Purity Grade (99.99%, 4N) for demanding electronic and specialty chemical applications. The product’s high purity and consistent quality minimize the risk of unwanted side reactions and impurities, making it suitable for demanding applications in brazing, plating, and battery manufacturing.

Comprehensive Specifications
Key specifications include:

• Molecular Formula: NaBF₄
• Molecular Weight: 109.79 g/mol
• CAS Number: 13755-29-8
• EINECS Number: 237-340-6
• Synonyms: Sodium fluoroborate; Sodium borofluoride
• MDL Number: MFCD00003515
• Appearance: White to colorless crystalline solid or powder
• Purity: ≥98% (Industrial) / ≥99% (Electrolyte Grade) / 99.99% (4N)
• Melting Point: 384°C
• Density: 2.47 g/mL at 25°C
• pH (aqueous solution): 9.6–10.1
• Solubility: Readily soluble in water (108 g/100 mL at 26°C); slightly soluble in ethanol
• Storage: Store below +30°C, cool, dry, well-ventilated area, protected from moisture
• GHS Classification: Danger; H314, H318

Flexible Packaging Solutions
XinChem provides a range of packaging options to accommodate diverse customer needs, from laboratory-scale quantities (25 g, 100 g, 500 g) to industrial-scale packaging (1 kg, 25 kg paper-plastic composite bags, 1000 kg big bags) and bulk shipments. Customized packaging solutions are available upon request, ensuring safe handling, storage, and transportation with appropriate moisture protection.

3. Application Fields

As a multifunctional inorganic fluoroborate, Sodium Tetrafluoroborate (CAS# 13755-29-8) exhibits wide application value across multiple industries:

Aluminum Brazing and Metallurgical Fluxes:

• Key component of NOCOLOK fluxes for aluminum and aluminum alloy brazing
• Heat exchangers, radiators, condensers, and evaporators for automotive and HVAC applications
• Refining flux for non-ferrous metals
• Grain refiner in aluminum and magnesium alloy casting

Electroplating and Metal Finishing:

• Plating baths for tin, tin-lead alloys, and other metals
• Surface treatment of printed circuit boards and electronic components
• Source of fluoride ions for metal surface activation

Lithium-Ion Battery and Energy Storage:

• Electrolyte additive for lithium-ion batteries
• Component in fuel cell technologies
• Starting material for BF₄⁻-based ionic liquids and boron trifluoride (BF₃)

Chemical Synthesis and Catalysis:

• Fluorinating agent in organic synthesis
• Catalyst in resin finishing for textile and dyeing industry
• Analytical reagent
• Grain preservative to prevent organic acid erosion

4. Service Support

Technical Expertise and Customized Solutions
XinChem’s team of experienced chemists and application engineers provides full technical support throughout the customer journey—from product selection and specification development to application guidance and troubleshooting. Whether customers require optimization of brazing flux formulations, guidance on plating bath chemistry, or assistance with regulatory documentation, XinChem’s technical experts are ready to help. Custom synthesis and contract manufacturing with flexible scaling from R&D to commercial quantities are available upon request.

Global Logistics and Reliable Supply
With established supply chains serving markets across Europe, North America, Asia-Pacific, and beyond, XinChem ensures timely delivery and consistent product availability. The company’s logistics team manages all aspects of international shipping, including customs clearance and documentation, with appropriate moisture protection for product stability.

Regulatory Support
XinChem provides comprehensive documentation to support regulatory compliance, including Safety Data Sheets (SDS), Certificates of Analysis (COA), and other required certificates. The company stays current with evolving regulatory requirements in major markets, including REACH, TSCA, and other regional regulations, helping customers navigate the complexities of global trade.

5. Reasons to Choose XinChem

• Professionalism: Extensive experience and deep expertise in inorganic fluoroborate synthesis and supply.
• Quality: Rigorous quality control, high purity (≥98% to 99.99%), and adherence to international standards.
• Reliability: Stable supply, competitive pricing, and timely delivery.
• Flexibility: Customized solutions to meet diverse customer needs, including multiple grades and packaging options.
• Service: Responsive technical support and comprehensive documentation.

Contact us today to start your partnership with XinChem!

Website: www.xinchem.com

Email: sales1@xinchem.com

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