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. No substance-specific limit is published for LiOH, but the aerosol is controlled to the far lower level used for lithium hydride — orders of magnitude below ordinary nuisance dust. 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. We deliberately do not publish occupational exposure limits or other regulatory thresholds: those values are revised over time and differ between jurisdictions, so the only correct source is the current SDS and the regulations that apply where you work.