High-temperature stability
RHK temperatures can reach up to 1,200°C (2,192°F) during the calcination process for cathodes. Hexoloy® SE material’s single-phase composition allows it to operate up to 1,600°C in air (and even higher in an inert atmosphere) and results in an extremely low coefficient of thermal expansion (4.02 x 10-6/°C), making it very stable in severe-environment applications.
High thermal conductivity
Hexoloy® SE materials’ high thermal conductivity (34.8 W/mK at 1,200°C) makes it very resistant to thermal shock.
Extreme hardness
Hexoloy® SE SiC is one of the hardest high-performance materials available and is 50% harder than tungsten carbide. Its density is over 95% theoretical and it is essentially impervious without the use of any impregnants, which means no contamination in high-purity applications. Minimizing contamination is critical to high-quality battery manufacturing: particles are especially damaging and can produce unwanted reactions and shorts in finished batteries.
High strength
Hexoloy® SE SiC rollers offer higher load-bearing capability than silicon-infiltrated silicon carbide (SiSiC); therefore, these rollers are typically offered with thinner walls. In large RHKs, Hexoloy® SE SiC rollers can measure up to 50 mm in diameter with 7 to 8 mm thick walls in lengths up to 3350 mm. The ability to achieve the same strength with a lighter, thinner roller allows the designer to increase energy efficiency with lower-cost smaller motors that draw less power.
Virtually universal corrosion resistance
High corrosion resistance gives longer product life, lowers maintenance costs, and increases uptime. RHKs in battery manufacturing operate with a variety of gases: air, oxygen, nitrogen, nitrogen plus hydrogen, and CO2. In addition, cathode powders include corrosive chemistries: the RHK must be resistant to all of the various gases and formulations.
The many desirable properties of Hexoloy® SE SiC make it the clear choice for use in RHKs in Li-ion battery manufacturing production lines of cathode active material.
