There are hybrid vehicles with a base internal combustion engine and a battery pack to extend the mileage obtained from the engine. Then there are range extenders that employ just the opposite, a small fossil fuel engine that provides backup to an otherwise all electric car. Tesla, has now come up with a third way to extend the mileage on its cars.
The breakthrough comes through a research by Tesla¡¯s Canada centre. Titled ¡®Hybrid Lithium-Ion/Lithium Metal Cells,¡¯ the research has now been published in science magazine Joule and as per it, Tesla cars will be able to have an extended range, in an all electric manner.
The new battery technology has been developed by battery technology veteran Jeff Dahn and his team at the University of Dalhousie in Canada under Tesla¡¯s ¡®Advanced Battery Research¡¯ division. It takes advantage of the longevity of lithium ion cells as well as the high energy density of lithium metal cells.
For this, the scientists replaced the graphite anode in conventional lithium-ion cells with lithium metal. The recorded results indicated a significant increase in energy density of the new battery system.
There was, however, a significant challenge with this. Lithium metal anodes face rapid capacity loss and hence result in a short cell lifetime. To avoid that, the team of scientists proposed a hybrid lithium-ion/lithium metal cell achieved by ¡°purposefully plating lithium metal on graphite,¡± as per the study.
So what is the use case we can expect out of this? As per the research, ¡°If an electric vehicle with a conventional lithium-ion battery can deliver a range of 400 km, then hybrid cells could enable a range of 480 km.¡±
The research also mentions that operating the hybrid cell in lithium-ion mode delivers an energy density about 25% less than a conventional lithium-ion cell.
It should be noted that the research is still in early stages. Though the improvements indicated in it are significant over the prevailing battery technology, it could be some time before the batteries are commercialised.
The efforts towards such a power pack for Tesla cars is not new. Tesla first filed for such hybrid Li-Ion/Li Metal battery patents back in 2013.
The development, however, does mark an important milestone for Tesla¡¯s endeavour to further increase the range in its cars. Tesla CEO Elon Musk recently got in a to and fro blame game with the EPA over the claimed range of Tesla Model S. While Musk maintains them to be over 400 miles on a single go, EPA tested it for a maximum of 391 km. You can read all about it here.