New graphene device could make fossil-fuel cars ultra-efficient

2 Jun 2016

Another week, and another graphene breakthrough has been made, with the creation of a new graphene-based device that could be placed in fossil-fuel-powered cars to make their engines ultra-efficient.

This new graphene device, built by a team at the University of Manchester led by Prof Aimin Song and Dr Ernie Hill, is being dubbed a ‘ballistic rectifier’, with the intention being to cut down on the wasted energy produced by a vehicle.

Based on the team’s concept, the ballistic rectifier would use electrical nanotechnology to convert waste heat from a car’s exhaust and engine and turn it into a useable electrical current for the car.

Future Human

Based on the knowledge that parts of car exhausts can reach temperatures of 600ºC, the graphene device could turn this wasted energy into electricity to run other components in the car that typically drain energy, such as air conditioning and power steering.

As explained by the University of Manchester, this same idea would be incredibly beneficial to hybrid cars, which contain a fossil fuel engine and secondary battery, with this recouped energy being capable of being stored for later use.

Ballistic rectifier

A concept image of the graphene ballistic rectifier. Image via University of Manchester

Could be upscaled to power plants

The new device utilises graphene’s phenomenally-high electron mobility, a property h determines how fast an electron can travel in a material and how fast electronic devices can operate.

Compared with current-generation rectifier technologies, which require cryogenically low temperatures, this graphene device has now become the most sensitive room-temperature rectifier ever made.

The team will now be looking to expand upon this research by scaling up the ballistic rectifier by using large wafer-sized graphene to perform high-frequency experiments.

By increasing the size of this graphene device, it opens up the possibility of it being used as a means of converting waste heat from electricity-generation plants into additional electricity for a power grid.

Car exhaust image via Shutterstock

Colm Gorey was a senior journalist with Silicon Republic