Purity 99.99% · CAS 7439-93-2 · Li
Lithium 99.99% (4N) — high-purity grade
Thin-film cells, research, optics
Overview
Distilled lithium metal at four-nines, with sodium in the single-digit ppm range. Used for thin-film battery deposition, optical crystal growth precursors and nuclear applications. Small lots, argon-sealed, GDMS certified.
Typical trace impurities
| Impurity | Typical max |
|---|---|
| Na | ≤ 5 ppm |
| K | ≤ 5 ppm |
| Fe | ≤ 2 ppm |
Indicative values. The certificate of analysis for your lot is the binding document.
Where this grade is used
- ▪Thin-film battery deposition
- ▪Optical and scintillator crystal growth
- ▪Nuclear and fusion research
Common forms
Foil, ribbon, granules under argon
Specification at a glance
| Material | Lithium (Li) |
|---|---|
| Purity | 99.99% (4N), metals basis |
| CAS | 7439-93-2 |
| Production route | Molten-salt electrolysis with secondary distillation, handled entirely under argon |
| Available forms | Foil, ribbon, granules under argon |
| Analysis method | ICP-MS trace analysis with LECO combustion for O/C/S |
| Documentation | Certificate of analysis per lot, RoHS and REACH statements, country of origin |
| Typical packaging | Argon pouch · Sealed tin under oil · Drum (DG compliant) |
What 99.99% (4N) actually means
4N is shorthand for 99.99% purity on a metals basis: at most 0.01% of the material, by weight, is something other than Li. The metals-basis convention excludes dissolved gases and, for powders, surface oxygen — which is why oxygen is quoted separately in the trace table below.
Two lots at the same nominal purity are not interchangeable if the residual elements differ. For this grade the limiting element is typically Na at ≤ 5 ppm. What matters is which impurities your process is sensitive to — judge a lot on its full trace analysis, not on the headline number.
Choosing 4N versus the neighbouring grades
Coming from 99.9% (3N): the step up buys you tighter trace control for thin-film cells, research, optics. If your process tolerates the residuals of 3N, the lower grade remains the more economical and more widely available choice.
When in doubt, qualify both adjacent grades on a sample and run your own incoming inspection before committing a process to either.
Quality control and traceability
Lithium at 99.99% is normally released against a lot-specific certificate of analysis stating the assay, the trace elements measured and the method used (ICP-MS trace analysis with LECO combustion for O/C/S). Well-run lots stay traceable from the refinery batch through to the container that reaches the laboratory.
- ▪A retained sample per lot, so a later question can be re-tested against the original material
- ▪Independent third-party verification, used when the assay is contractually critical
- ▪Incoming inspection on the receiving side — the certificate states the method, not the result you will measure
Handling, storage and shipping
- ▪Lithium metal reacts with moisture and nitrogen in air — handle in an argon glovebox below 1 ppm H₂O and O₂.
- ▪Shipments travel as UN1415 (lithium metal) or the applicable UN number for salts, under IATA/ADR dangerous-goods rules with declared packaging.
- ▪Never quench residues with water; use dry sand or a Class D extinguisher and dispose through a licensed reactive-metal route.
Frequently asked questions
Common questions from buyers specifying lithium at 99.99%.
- Is 99.99% lithium the right grade for my application?
- It is the usual choice for thin-film cells, research, optics. Below it, 99.9% (3N) covers less demanding work at lower cost. It is the highest grade we list for this material.
- What does the 4N designation mean?
- The N notation counts the nines in the assay: 4N equals 99.99% Li on a metals basis, with the balance made up of the trace elements listed in the analysis table.
- Which impurities are measured and reported?
- ICP-MS trace analysis with LECO combustion for O/C/S is used, and a certificate of analysis reports each element in the table above, starting with Na at ≤ 5 ppm. The scope of a scan can be widened to further elements when a process is sensitive to one in particular.
- How is this grade normally packed?
- Argon pouch, Sealed tin under oil, Drum (DG compliant). Shipments travel as UN1415 (lithium metal) or the applicable UN number for salts, under IATA/ADR dangerous-goods rules with declared packaging.
- Which forms is 99.99% lithium available in?
- Commonly: foil, ribbon, granules under argon. The form is often a bigger practical constraint than the assay itself, because the last processing step has to preserve the purity already achieved.