Lithium Hydroxide
Properties
| State | Solid at room temperature |
| Color | White |
| Solubility | Soluble in water (12.8 g/100 mL at 25°C) |
| Melting Point | 462°C |
| Boiling Point | 924°C (decomposes) |
About Lithium Hydroxide
Lithium hydroxide is the lightest alkali hydroxide, and that low molar mass turns out to matter in two completely separate billion-dollar applications. First, CO2 scrubbing in closed atmospheres: 2 LiOH + CO2 -> Li2CO3 + H2O removes 0.92 g of CO2 per gram of LiOH, the highest mass-specific CO2 absorption capacity of any alkali hydroxide. NASA and the US Navy both rely on it — Apollo missions carried LiOH canisters in the lunar module's environmental control system (the famous 'square peg in a round hole' improvisation on Apollo 13 was a LiOH canister adapter), and submarines on patrol use LiOH to scrub crew-exhaled CO2 between snorkel cycles. Second, high-nickel cathode synthesis for EV batteries: NMC811, NCA, and LiNiO2-based cathodes prefer LiOH over Li2CO3 as the lithium source because LiOH reacts at lower temperatures (~700 °C versus ~900 °C), producing fewer cation-mixing defects in the layered structure and higher capacity, which is why Tesla and several Chinese cell makers now buy LiOH-monohydrate by the kiloton. The reaction LiOH + NiO + CoO + ... in oxygen at 700 °C builds the layered Li(Ni0.8Mn0.1Co0.1)O2 structure with the Ni in the +3 state. LiOH also thickens the lithium 12-hydroxystearate greases that lubricate everything from wheel bearings to spacecraft mechanisms over the -50 to +150 °C range that conventional grease can't handle.
Where you'll encounter it
If you've ever followed an Apollo mission, watched a Tesla cell assembly video, or pulled apart a wheel bearing packed with the smooth amber lithium grease that's been the automotive industry standard for 70 years, you've seen LiOH doing the load-bearing chemistry. NMC811 cathode plants now buy LiOH-monohydrate by the kiloton because the lower 700-degree-C calcination temperature versus 900 °C for Li2CO3 gives fewer Ni-Li cation-mixing defects in the layered structure, which is exactly what stretches an EV pack's cycle life past 1500 full cycles. Service techs repacking a wheel bearing scoop the amber lithium 12-hydroxystearate grease that LiOH saponifies — the same product holds up from -50 to +150 °C without the slumping or oxidation that takes down sodium-soap greases by 100 °C.
Common Uses
- CO2 scrubber in spacecraft environmental control (Apollo, ISS) and submarine atmospheres
- Lithium source for high-nickel layered cathode synthesis (NMC811, NCA, LiNiO2)
- Thickener (saponification with 12-hydroxystearic acid) for lithium-soap greases
- pH adjuster and electrolyte additive in Ni-Cd and Ni-MH alkaline batteries
- Glaze flux in ceramic and porcelain manufacturing
- Catalyst and intermediate in stearate, palmitate, and oleate lithium-soap synthesis
- Photographic developer alkalinity adjuster (legacy)
- Air-revitalization chemical in hyperbaric and rebreather systems
Safety Information
GHS: Acute Tox. 4 oral (H302), Skin Corr. 1B (H314 — causes severe skin burns and eye damage), STOT SE 3 (H335 — respiratory irritation). Strong base, pH 14 in concentrated solution. OSHA does not have a specific PEL for LiOH but lithium-hydroxide aerosols are typically controlled to <0.025 mg/m3 (TLV-TWA per ACGIH for lithium hydride). The corrosivity hazard exceeds the lithium-systemic-toxicity hazard for short-term contact — full face shield, butyl rubber gloves, and a base-resistant apron are standard PPE. Reacts vigorously with strong acids and CO2.
This safety summary is for educational reference only and may not be complete. It is not a substitute for Safety Data Sheets (SDS), medical advice, or professional chemical safety guidance. Always consult appropriate SDS and qualified professionals before handling chemicals.