News | New technologies
Researchers at Liten, a CEA Tech institute, recently produced thermoelectric materials that meet the specifications of the automotive industry from a cheap, abundant, and non-toxic raw material. The highly-reproducible process was rolled out with success at an almost-industrial scale.
The combustion engines that power most
motor vehicles offer maximum yields of just 35% to 40%. Researchers at Liten
set out to improve those figures by using thermoelectricity to harvest and
recycle some of the waste heat that normally escapes out of a car’s tailpipe.
The technique involves using thermoelectric semiconductors—which respond to
fluctuations in temperature—to convert heat to electricity.
In research conducted in partnership with
automotive component manufacturer Valeo and startup HotBlock OnBoard, Liten’s
scientists began by designing and making the terminals that would form the core
of the future thermogenerator from a silicon-based material that is both cheap
and environmentally-friendly. The material was first sprayed, and then sintered
to achieve the desired shape.
Liten’s thermoelement lab played a pivotal
role, providing the equipment and know-how needed to successfully manufacture
the thermoelements using a process that proved to be reproducible at a large
scale (2,000 units).
In research conducted under the Renoter2
project, financed by the French Single Interministerial Fund, a prototype with
a 400-watt electrical capacity will be developed. If successful, the prototype
will generate fuel savings of 3% and bring the CO2/km rate down by
2 g to 4 g in NEDC emissions testing.
The results of both
projects should pave the way for industrial-scale manufacturing of the
thermogenerator, positioning Liten on the extremely-demanding and potentially
vast automotive market.
CEA is a French government-funded technological research organisation in four main areas: low-carbon energies, defense and security, information technologies and health technologies. A prominent player in the European Research Area, it is involved in setting up collaborative projects with many partners around the world.