High Purity Alumina

HPA is a very pure form of aluminium oxide (Al2O3)

99.99% (4N), <100 ppm of impurities Currently the most widely used grade
99.999% (5N), <10 ppm of impurities The fastest growing grade
99.9999% (6N), <1 ppm of impurities  

HPA is chemically inert in most environments, has a very high melting point, doesn't conduct electricity and is very abrasive. These unique characteristics make HPA ideal for many high-tech applications.

The current markets for HPA include:

The production of synthetic sapphire for use in:

  • LED light substrates and lenses
  • Semiconductor substrates
  • Lasers
  • Phosphors
  • Optical lenses
  • Bio-medical devices

Lithium ion batteries:

  • Coating of the battery separator to improve safety and performance, particularly in larger batteries such those for Electric Vehicles and Energy Storage

Figure 5: Global HPA demand by application 2016 (total 24.7kt)


Source: Roskill

Lithium Batteries

The fastest growing market for HPA is in Lithium Ion batteries. HPA is coated onto the separator between the anode and the cathode. Coating separators with HPA has been found to significantly improve safety and efficiency:

  • provides greater thermal stability to the battery, reducing the risk of batteries catching fire
  • significantly improves impedance (Macmullan number <3) allowing for high power capability,
  • improves battery life cycle and lowers self-discharge


HPA Coating Terminal Case

The larger the battery, the greater the thermal management becomes important. This is very important when used in Electric Vehicles (EV's) as battery safety is vital in ensuring vehicle safety.

Electric Vehicles (EV's)

Forecasts for the growth in the sale of EV's is extremely positive. In a report published by Bloomberg New Energy Finance ( https://about.bnef.com/electric-vehicle-outlook/#toc-download), they are forecasting that up to 55% of total new car sales in 2040 will be EV's, meaning that in excess of 50 million EV's will be produced

Annual Global Light Duty Vehicle Sales


Synthetic Sapphire

Synthetic sapphire is becoming more widely used in many developing technologies. It is well established in LED and semiconductor markets and is increasingly used in optical and medical devices require the unique properties offered by sapphire.