A team of Japanese scientists have developed a new type of lithium-air battery cell with an ultra-large capacity, and say that it holds great potential for the next-generation of electric cars.
Researchers at the country’s National Institute of Advanced Industrial Science and Technology (AIST) predict that at a filling station, the driver of a vehicle equipped with the new battery could make use of a revolutionary new cassette refill system, and then continue driving without waiting for batteries to be recharged.
Although Lithium-air batteries have been singled out as having great potential as future large-capacity batteries they have been plagued by a persistent problem. A solid reaction product (Li2O or Li2O2), which is not soluble in organic electrolyte, clogs on the air electrode (cathode) during the discharge process. If the air electrode becomes fully clogged, oxygen from the atmosphere can no longer be introduced to the system.
To remedy this, the team used an organic electrolyte on the anode (metallic lithium) side and an aqueous electrolyte on the cathode (air) side. The two electrolytes are separated by a solid state electrolyte (lithium super-ion conductor glass film – LISICON) so that the two electrolytic solutions do not mix. As a result, only lithium ions pass through the solid electrolyte, and the battery reactions proceed smoothly. At the cathode, the reaction product in the discharge process is water-soluble and no solid substances are produced. Continuous discharging of 50,000 mAh/g (per unit mass of the carbon, catalyst and binder) has been experimentally confirmed.
Image Credit – AIST