Single Crystal Cathode (SCC) is a cathode material made of micron sized particles that resemble single crystals. The benefits are:
Unlike conventional polycrystalline NMC, where each secondary particle is an agglomerate of many smaller crystallites bound together, a single crystal particle is effectively one grain. That difference in microstructure drives most of the benefits and trade-offs below: polycrystalline particles are prone to intergranular cracking under cycling and calendering stress, opening fresh unpassivated surface to the electrolyte, while single crystal particles have no internal grain boundaries to crack and instead concentrate degradation at the particle surface.
- Safety
- Thermal stability
- Cycling stability
- Particle integrity
- High-voltage stability
Challenges
- Structural stability – can become structurally unstable after being cycled at high voltages
- Capacity fade – after being cycled at high voltages
- Irreversible structure degradation
- Longer ionic transport pathway
The absence of grain boundaries also means single crystal cathodes can be calendered to lower porosity without cracking, which turns out to matter for more than density. A 2026 WMG/Faraday Institution study found that heavier calendering of single-crystal NMC811 delayed the point where extended-voltage cycling starts losing to conventional-voltage cycling from around 40 cycles to around 300, by reducing contact resistance at the aluminium foil interface (Cathode Contact Resistance: The Overlooked Lever Behind Single-Crystal NMC811 Longevity).
References
Ogley, M. J. W. et al. “Understanding Degradation in Single-Crystalline Ni-Rich Li-Ion Battery Cathodes.” Chemical Reviews 125, 9774–9806 (2025). doi.org/10.1021/acs.chemrev.5c00330
See also: NMC Composition, Cathode