Lithium Bis(oxalato)borate (LiBOB) Storage & Tank Compatibility

Storing Lithium Bis(oxalato)borate (LiBOB)? Start Here

Lithium bis(oxalato)borate, abbreviated LiBOB, is a white crystalline lithium salt (C₄BLiO₈) used as a conducting salt and additive in lithium-ion battery electrolytes. The borate anion is chelated by two oxalate groups, forming a stable spiro structure that helps build a protective film on electrode surfaces. Unlike volatile organic solvents, LiBOB is a non-flammable, non-volatile solid, so the primary storage challenge is its strong tendency to absorb atmospheric moisture, which can hydrolyze the salt and ruin battery-grade purity. It is supplied and stored dry or dissolved in anhydrous carbonate solvents. Because it behaves as a dissolved salt rather than a corrosive liquid, polyethylene and polypropylene containers are well suited to bulk handling, provided the system stays sealed against humidity and free of reactive metals.

Polyethylene (HDPE / XLPE) Compatibility With LiBOB

LiBOB is a lithium salt, and dissolved salts plus aqueous salt solutions are squarely within the favorable range for polyethylene, so both HDPE and crosslinked polyethylene (XLPE) are rated suitable (S) for the dry salt and for its water-based solutions at ambient temperature. There is no oxidizing, aromatic, chlorinated, or ketone character to attack the polymer backbone. The real limitation is operational rather than chemical: LiBOB is markedly hygroscopic, and polyethylene is mildly permeable to water vapor over long periods. For battery-grade material that demands very low water content, store the salt in sealed, moisture-barrier packaging or under dry inert gas, and treat polyethylene as the bulk shell rather than the sole moisture barrier. If the salt is dissolved in organic carbonate solvents such as ethylene or propylene carbonate, confirm the polymer rating against that carrier solvent, since the solvent - not the salt - then governs compatibility.

Material compatibility at a glance

Lithium bis(oxalato)borate is a soluble, hygroscopic lithium salt rather than an aggressive solvent, so polyethylene (HDPE and crosslinked XLPE), polypropylene, and fluoropolymers are all rated suitable for the dry salt and its aqueous solutions. The dominant engineering concern is not chemical attack on the plastic but moisture exclusion and contamination control: the salt readily absorbs water, and metallic surfaces such as carbon steel must be avoided to prevent corrosion and metal-ion pickup that would degrade battery-grade purity. Reserve fluoropolymer-lined or 316L surfaces for high-purity electrolyte contact.

Ratings: S suitable · C conditional / limited · U unsuitable. Verify against the cited resistance charts and your concentration/temperature before specifying.

The safety that actually matters

• Signal word DANGER: toxic if swallowed (H301) and causes serious eye damage (H318); wear chemical splash goggles and gloves and avoid ingestion.
• May cause an allergic skin reaction (H317) and skin and respiratory irritation (H315, H335); handle the powder with dust control and respiratory protection where airborne dust can form.
• Strongly hygroscopic: keep containers tightly closed and store under dry conditions to prevent caking, hydrolysis, and loss of battery-grade purity.
• Keep away from acids and strong oxidizers and avoid contact with reactive metals such as bare carbon steel to prevent contamination and corrosion.
• Use sealed transfer and dry inert-gas blanketing for high-purity work; ground and bond equipment when transferring dry powder to control static.
• Always consult the specific supplier Safety Data Sheet for the exact grade before selecting tank, gasket, and fitting materials.

Common questions

Is LiBOB safe to store in an HDPE or XLPE tank?

Yes. As a soluble lithium salt, LiBOB and its aqueous solutions are rated suitable (S) for both HDPE and XLPE. The salt does not chemically attack polyethylene. The key precaution is keeping the system sealed against humidity, because LiBOB is hygroscopic and water uptake degrades battery-grade purity.

Is LiBOB flammable?

No. LiBOB is a non-volatile crystalline solid with no flash point and negligible vapor pressure, so it does not present a flammable-liquid hazard. It can decompose on strong heating above roughly 300 C, so keep it away from high heat and ignition-prone conditions.

Why does moisture matter so much with LiBOB?

LiBOB is strongly hygroscopic and absorbs atmospheric water readily. Absorbed water can hydrolyze the salt and introduce impurities that are unacceptable in lithium-ion electrolyte applications. Sealed, moisture-barrier storage or a dry inert-gas blanket is essential for battery-grade material.

Can LiBOB be stored in steel containers?

Stainless steel such as passivated 316L is conditionally acceptable when the system is kept dry, but bare carbon steel is not recommended. Trace moisture and the oxalate ligand can corrode steel and contaminate the salt with metal ions, so polyethylene, polypropylene, or fluoropolymer surfaces are preferred.