black Silicon Carbide Grade Selection for EV Battery Aerogel Sheets
Purpose: Used as high-temperature reinforcing filler for silica aerogel. It improves high-temperature strength and suppresses thermal runaway, applied in thermal insulation sheets for power battery PACK modules.
Top recommended grade: #3000 (D50≈4.0 μm), the most widely used in industry. For ultra-thin aerogel, choose #4000 (W2.5, D50≈3.0 μm)
black silicon carbide physical index
| Mesh Grade | W Micron Grade | D50 Median Particle Size | Applicable Aerogel Products | Features |
|---|---|---|---|---|
| #3000 | W3.5 | 4.0 μm | Conventional 1~3mm aerogel thermal insulation sheets (customer’s first choice) | Good powder dispersibility without agglomeration. Balanced high-temperature skeleton reinforcement effect, moderate cost, mainstream grade for mass production |
| #4000 | W2.5 | 2.7~3.0 μm | Ultra-thin 0.5~1mm aerogel sheets | Ultra-fine powder, will not puncture fiberglass substrate. Higher specific surface area and better high-temperature shrinkage resistance |
| #2000 | W5 | 6.7 μm | Thick aerogel composite boards, molded fire insulation boards | Slightly coarser particles, improves flexural strength of boards and reduces formulation cost |
Key Physical & Chemical Specifications for Aerogel Grade
| Item | Typical Value | Remarks |
|---|---|---|
| SiC Content | ≥98.0% (≥98.5% for high-end customers) | Higher purity brings better high-temperature stability |
| Fe₂O₃ | ≤0.20% | Strict control of iron impurities to reduce minor conductivity risk and avoid battery safety hazards |
| Free Carbon (F.C) | ≤0.20% | Free carbon is the source of conductivity and must be kept low |
| True Density | 3.20 g/cm³ | — |
| Crystal Form | α-SiC | Stable at high temperature, no phase transition |
Selection Guidelines
- Mass-produced standard power battery aerogel sheets: Recommend #3000 W3.5, D50=4μm, adopted by most aerogel manufacturers.
- Ultra-thin aerogel (0.5/1mm thin type): Recommend #4000 W2.5, D50=3μm, less likely to damage felt and achieves finer slurry dispersion.
- Thick boards & low-cost formulations: #2000 W5
