METAL-AIR BATTERIES FOR ZERO-EMISSION
METAL-AIR BATTERY TECHNOLOGY
Beyond Conventional Batteries
A conventional battery consists of an anode and a cathode, where the cathode takes up to 70% of the battery’s weight. The cathode is used as a container for a reactant (e.g. Oxygen), usually up to 5% of its weight that is required for releasing the energy in a metal anode. The result is that most of a conventional battery’s weight is poorly utilized. A metal-air battery, on the other hand, features an air-electrode that breathes oxygen from ambient air, instead of the conventional cathode. That is, the battery consumes the required oxygen from the air, rather than having heavy materials that bound oxygen inside it. Metal-air batteries therefore have a huge potential for delivering high capacity with low weight.
Aluminum-air Batteries - Already fielded in land applications
The anode in our case is Aluminum. It is the most abundant metal in the earth's crust and widely available. The Aluminum-air battery provides 3-5 times the energy density of a Li-ion battery, at system level. Furthermore, the Aluminum-air battery does not lose capacity when not in use and does not degrade over time. When operated, a water-based, non-flammable electrolyte is circulated through the cells, producing Aluminum Hydroxide Al(OH)3 at the anode and generating electricity. The batteries are inherently safe with no danger of temperature runaway.
Aluminum-air batteries are mechanically recharged by replacing the consumed aluminum. The Aluminum Hydroxide is recyclable.
Containerized Aluminum-air batteries
For marine applications our Aluminum-air batteries are installed in 20 foot ISO shipping containers, complete with the peripherals and the electrolyte for providing up to 4,800 kWh of zero-emission electric power. The containerized concept enables timely replacement, and will be provided as a service to the ship operator.
Extending the applicability of metal-air technology to larger vessels
Zinc-air Electric Power
The Zinc-air technology under development decouples the capacity from the onboard power cell. The energy-carrying Zinc is in semi-liquid form that enables storing large amounts in the integral ship's tanks and replacing "bunker style", to be recharged off-line from sustainable sources or directly from the grid. Case studies show that feeders of circa 1000 TEU powered by this technology could operate fully on electricity alone.