+86 531 68657995
What is lithium hydroxide? How does it work? What are its industrial applications?
Ⅰ.What is Lithium hydroxide? How does it work?
Lithium hydroxide (LiOH) is the most important industrial alkali for lithium and one of the core raw materials in the lithium battery new energy industry chain. It exists in two commercial forms: anhydrous and monohydrate (LiOH·H₂O), both white crystalline powders. It is the only lithium source that can be used on a large scale in high-nickel ternary cathode materials. Lithium hydroxide is a strong alkali (pKa 14.4), but it is the weakest of the alkali metal hydroxides (NaOH, KOH, RbOH, CsOH). This “strong alkali but mildest” characteristic makes it irreplaceable in many high-temperature, high-activity processes.
Basic identification information: Molecular formula LiOH (LiOH·H2O monohydrate), molecular weight 23.95 (41.96 for monohydrate), CAS number 1310-65-2 (anhydrous)/1310-66-3 (monohydrate), EC number 215-183-4, UN 2680.
Physically, lithium hydroxide is a white, hygroscopic solid with no odor; its density is 1.46 g/cm³ (anhydrous) / 1.51 g/cm³ (monohydrate); its melting point is 462℃, and its boiling point is 924℃ (decomposes); it is readily soluble in water (solubility 12.8 g/100 mL at 20℃), slightly soluble in ethanol, and insoluble in isopropanol; its aqueous solution is strongly alkaline and releases heat (strong alkali dissolution is exothermic).
Chemically, lithium hydroxide is a typical strong base: it can neutralize various acids (reacting with HF to form lithium fluoride, saponifying with fatty acids to form lithium soap, and reacting with CO2 to form lithium carbonate), and is corrosive. The small radius and high charge density of lithium ions give it a unique “lithium effect” in ceramic fluxing and inhibiting alkali-aggregate reaction in concrete. Lithium hydroxide enriched with 7Li also exhibits good neutron absorption and shielding properties. Storage must be airtight and moisture-proof, avoiding contact with acids and carbon dioxide.
From the perspective of its mechanism of action, lithium hydroxide plays an irreplaceable role in many industrial fields due to its “strong alkalinity + lithium-ion properties”. The mechanisms of action in different applications are as follows:
1.Cathode material synthesis mechanism (lithium source + low melting point and high activity)
Lithium hydroxide has a low melting point (462℃), low decomposition temperature, and higher reactivity than lithium carbonate. When mixed with nickel-cobalt-manganese/nickel-cobalt-aluminum precursors, it can be solid-state sintered at a lower temperature, avoiding structural damage and residual alkali problems in high-nickel cathodes caused by the high-temperature decomposition of lithium carbonate (CO2 escape). Therefore, high-nickel NCM/NCA cathodes must use lithium hydroxide as the lithium source. Lithium cobalt oxide, lithium iron phosphate, etc., also commonly use lithium hydroxide to provide alkaline lithium sources.
2.Saponification thickening mechanism (lithium soap fibre network)
In the saponification reaction, lithium hydroxide reacts with fatty acids such as 12-hydroxystearic acid to form lithium 12-hydroxystearate soap. Lithium soap molecules self-assemble into a fibrous network structure within base oil, trapping lubricating oil to form semi-solid grease. This endows lithium-based grease with a high dropping point, excellent water resistance and wide-temperature-range performance.
3.CO2 chemical absorption mechanism (strong base to salt formation)
Lithium hydroxide is a strong base that can undergo an irreversible chemical absorption reaction with CO2: 2LiOH + CO2 → Li2CO3 + H2O (monohydrate 2LiOH·H2O + CO2 → Li2CO3 + 3H2O). One gram of anhydrous lithium hydroxide can absorb approximately 450 cm³ of carbon dioxide, and there are no corrosive liquid byproducts after absorption, making it suitable for air purification in enclosed spaces.
4.Strong base neutralisation and saponification mechanism
Lithium hydroxide is a strong base capable of neutralising acids (for example, forming LiF upon reaction with HF), saponifying fats and oils to produce lithium soap, and adjusting pH. Meanwhile, its lithium ions integrate into the product structure, achieving the dual function of “neutralizing and introducing lithium”, which cannot be replaced by other bases such as NaOH/KOH.
5.Lithium-ion inhibition mechanism (Concrete ASR control)
Reactive silica aggregates trigger ASR, known as “concrete cancer”, in concrete. They react with alkali metals to form expansive gels that lead to cracking. Lithium ions can react with alkali-silica gels to generate stable, low-solubility and low-expansivity lithium silicate products, suppressing ASR expansion at the source. Thus, lithium hydroxide has become the primary raw material for lithium-based concrete admixtures.
In summary, lithium hydroxide is the “core alkali of the lithium battery new energy era.” With its dual characteristics of strong alkalinity and lithium ions, it is used in many key links of modern industry, from lithium battery cathodes to lubricants to air purification.
Ⅱ.What are the applications of industrial-grade Lithium hydroxide?
1.Lithium source for lithium battery cathode materials (core applications in lithium batteries and the new energy field)
Application Field: New energy vehicles and lithium-ion battery materials
Corresponding Products: Ternary cathode materials (high-nickel NCM811/NCM622/NCA), lithium cobalt oxide cathode (LiCoO₂), lithium iron phosphate cathode (LFP), lithium-ion battery cathode precursor sintering systems
Applicability Principle: High-nickel cathodes are sensitive to sintering temperature. Lithium hydroxide has a low melting point, low decomposition temperature and high reactivity. It enables solid-state sintering with precursors at lower temperatures and prevents crystal structure destruction caused by CO₂ released from lithium carbonate decomposition. It serves as an irreplaceable lithium source for high-nickel ternary cathodes. Lithium cobalt oxide and lithium iron phosphate also rely on its characteristic as a strong alkaline lithium source. Lithium hydroxide is the core raw material for lithium-ion battery cathode materials worldwide.
2.Lithium based grease thickener (the main application of the lubricating grease industry)
Application Field: Lubricating grease industry and machinery equipment sector
Corresponding Products: Lithium grease, lithium 12-hydroxystearic acid grease, automotive wheel bearing grease, industrial motor and precision bearing grease, general-purpose multi-purpose grease
Applicability Principle: Lithium soap is prepared by the saponification of 12-hydroxystearic acid or other fatty acids with lithium hydroxide. Interconnected lithium soap fibres retain base oil to form semi-solid grease. Lithium grease possesses advantages including a high dropping point, good water resistance and wide working temperature range (-20°C to above 120°C). Lithium greases account for roughly three-quarters of global grease consumption and are widely applied in bearings for automobiles, steel, mining, wind power and other equipment.
3.CO₂ scrubber for confined space (key application in special environments)
Application Field: Closed system protection
Corresponding Products: CO₂ absorption tanks, air purification units, CO₂ absorbents, air regeneration units
Applicability Principle: Via strong alkaline chemical absorption, LiOH reacts with CO₂ (CO₂ 2LiOH+CO2→Li2CO3+H2O). One gram of anhydrous lithium hydroxide can absorb about 450 cm³ of carbon dioxide. Its high mass absorption efficiency and solid lithium carbonate byproduct (no corrosive liquid) make it especially suitable for mass-sensitive, space-limited closed-environment protection systems.
4.Lithium chemical feedstock (Lithium Chemical Industry)
Application Field: Lithium chemical industry, fine chemical industry
Corresponding Products: Lithium fluoride (LiF, aluminium electrolysis additive / fluorescent material), lithium bromide (LiBr, absorption refrigerant), high purity lithium carbonate, lithium chloride, lithium soap, and various other lithium salts and compounds
Applicability Principle: Both lithium hydroxide and lithium carbonate are key intermediates for manufacturing lithium compounds. It can react with HF (LiOH + HF → LiF + H2O), HBr, fatty acids and other substances to introduce lithium. Due to its high alkalinity and purity, it is the preferred raw material for preparing various lithium salts.
5.Fluxes for Glass and Ceramics (Glass and Ceramics Industry)
Application Field: Glass and ceramics industry
Corresponding Products: Lithium-aluminium-silicon battery glass, special ceramic glazes and fluxes, heat resistant ceramics, enamel
Applicability Principle: Lithium ions are small with high electric field intensity. In glass and ceramic formulations, lithium hydroxide can greatly reduce melting temperature and thermal expansion coefficient, while improving transparency and thermal shock resistance to boost the performance of glass and ceramic products. It is one of the main fluxing components for lithium-aluminium-silicon glass and special ceramics.
6.Raw materials for alkali-aggregate reaction inhibitors in concrete (field of building materials)
Application Field: Concrete building materials and engineering
Corresponding Products: Lithium-based concrete admixtures, ASR (alkali-aggregate reaction) inhibitors, anti-cracking formulations for hydraulic dams and concrete
Applicability Principle: Lithium ions originating from lithium hydroxide react with alkali-silica gel to form low-expansion, stable lithium silicate, inhibiting alkali-aggregate reaction (ASR, known as “concrete cancer”) and preventing concrete cracking. It is ideal for long-lifespan concrete projects such as dams & bridges.
7.Alkaline batteries electrolyte additives (battery industry field)
Application Field: Battery Industry
Corresponding Products: Nickel-metal hydride (NiMH) battery electrolytes, alkaline zinc-manganese battery electrolytes, coin cell batteries
Applicability Principle: Adding lithium hydroxide to alkaline electrolytes can improve electrolyte conductivity, charge/discharge capacity, high-temperature performance and cycle life. It is a common electrolyte additive in alkaline battery systems.
8.Chemical neutralisers for strong bases and pH control agents (general chemicals)
Application Field: Water treatment and general chemical industry
Corresponding Products: Neutraliser for acid waste / acidic materials, pH adjuster, alkaline source for saponification reactions, alkaline catalyst system for synthesis of organic compounds
Applicability Principle: Lithium hydroxide is a strong base that can neutralise various acids and introduce lithium ions. It can replace NaOH/KOH in scenarios requiring the dual function of “lithium + base” (e.g. lithium saponification and lithium salt synthesis). It costs more than sodium hydroxide, yet it is indispensable for manufacturing lithium-based products.
Summarize
lithium hydroxide (LiOH, CAS 1310-65-2) is an important industrial alkali in the era of lithium-ion batteries. Benefiting from its properties of strong alkali neutralisation, lithium-ion introduction, low melting point and high activity, strong CO₂ absorption, and lithium-effect suppression, it is widely applied in lithium battery cathode materials (the preferred lithium source for high-nickel NCM/NCA), lithium-based greases (the mainstay of global greases), CO₂ absorption in confined spaces, lithium compound production, glass and ceramic fluxing, ASR suppression in concrete, alkaline battery electrolytes, and general chemical neutralisation.
