ScSZ (scandia-stabilized zirconia), used as the electrolyte in solid oxide fuel cells (SOFCs), has become substantially harder to source since scandium came under export control. This article summarizes the specification of 10Sc1CeSZ — the standard SOFC electrolyte material — and the supplier landscape across China, Japan, the US, and Korea, using public information, then offers selection criteria that weigh quality, price, regulatory risk, and lead time together. The bottom line up front: rather than depending on a single region, it is more realistic to dual-source along the axes of regulatory risk and price.
What Is ScSZ?
One of the standard SOFC electrolyte materials is 10Sc1CeSZ — zirconia stabilized with 10 mol% scandium oxide (Sc₂O₃) and 1 mol% cerium oxide (CeO₂). Scandia raises oxygen-ion conductivity for a geometric reason: Sc³⁺ is a much closer size match to Zr⁴⁺ than Y³⁺ is, so the substituted lattice carries less internal strain, oxygen vacancies are trapped less strongly, and the migration barrier is lower.
The 1 mol% ceria is doing a narrower job than "reinforcing phase stability." Plain scandia-stabilized zirconia has a cubic-to-rhombohedral transition near 650 °C that reduces conductivity, and suppressing that transition is what the ceria is for. The 10Sc1Ce composition itself is assessed as slightly under-doped and not fully stabilized — surface transformation from cubic through tetragonal to monoclinic has been reported within 100 hours of operation at 900 °C — so phase stability on this material is something to qualify on aged samples rather than something the formulation guarantees. The full property comparison, including aging against 8YSZ, is in our YSZ vs ScSZ electrolyte comparison.
A representative, publicly cited specification looks like this. The basis matters as much as the number:
| Item | Representative spec | Basis |
|---|---|---|
| Composition | ZrO₂ stabilized with 10 mol% Sc₂O₃ + 1 mol% CeO₂ | Nominal formulation, mole percent |
| Particle size (D50) | 0.4–0.6 µm | Laser diffraction on a dispersed sample — sees agglomerates |
| Specific surface area | 8–12 m²/g | BET nitrogen adsorption — sees primary-particle surface |
Those last two rows look mutually inconsistent and are not. At zirconia's density of about 5.9 g/cm³, 0.5 µm spheres would give roughly 2 m²/g, while 8–12 m²/g corresponds to primary particles nearer 0.1 µm. The two figures describe different length scales — laser diffraction measures the agglomerates, BET measures the surface of the crystallites inside them — which is exactly why both belong on a COA and why neither substitutes for the other. Confirm the stated method for each on the certificate rather than reading them as one coherent spec.
Because this fine powder must sinter into a thin, dense electrolyte membrane, lot-to-lot variation in particle size and surface area directly affects performance. Rather than publish those two figures as a fixed band, our 8YSZ & ScSZ electrolyte powders page agrees the surface area per order and reads it against the COA lot by lot, which is where that variation is caught. Why scandium is so scarce and expensive is covered in Scandium: A Rare Metal Produced at Only ~40 Tonnes a Year.
Supplier Landscape by Region (Public Information)
The following is a landscape summary based on each company's published general profile; it does not indicate any specific trading relationship or terms.
China
- Large vertically integrated ceramics producers: broad ceramic-materials portfolios with the zirconia chain held in-house. Price competitiveness is the strength.
- Zirconia-specialist powder suppliers: narrower lines focused on the zirconia family. Whether a given producer can actually supply ScSZ — as opposed to YSZ and other zirconia grades — has to be confirmed case by case; it is not safe to assume it from a zirconia portfolio.
Chinese suppliers offer clear price competitiveness, but because 10 mol% Sc₂O₃ works out to about 11 wt% scandia (roughly 7 wt% scandium as metal), ScSZ falls under the export controls of the April 2025 Announcement No. 18 — meaning each export requires a case-by-case MOFCOM license. For the structure of the controls and how to respond, see Scandium Export Controls and the SOFC Supply Chain.
Japan
- Daiichi Kigenso (DKKK): A supplier holding foundational zirconia technology, widely cited for low lot-to-lot variation. Pricing tends to be high; a level above $1,000/kg was reported before the April 2025 controls. Sc₂O₃ feedstock has roughly tripled since then — about $1,200/kg to $3,500–4,370/kg — which at 11 wt% scandia puts the scandium content alone near $385–480/kg, so that pre-control figure should be read as a historical floor rather than a current quote.
United States
- Nexceris / FuelCellMaterials: A fuel-cell materials specialist; ScSZ pricing is reported in roughly the $1,200–3,000/kg range.
Korea
- Domestic suppliers such as Kceracell: Using a domestically producing supplier minimizes customs and foreign-exchange risk, with additional advantages in lead time and communication.