Automakers test graphene to reduce vehicles’ weight

By Davide Ghilotti
Published: Thursday, 27 April 2017

Car manufacturer FIAT-FCA has experimented with graphene-based polymer materials for wiring substitution in parts of its vehicles, aiming to reduce weight and emissions, Chief Reporter, Davide Ghilotti, writes.

The need to reduce the weight of vehicles while enhancing performance is at the heart of automakers interest in graphene, IM heard at the Graphene 2017 conference in Barcelona, Spain in April.

Addressing delegates, Vito Lambertini, head of materials innovation at Centro Ricerche at automotive manufacturer FIAT-FCA (Fiat Chrysler Automobiles), said that the need to comply with emission regulations and to reduce the carbon footprint of vehicles on the road means that producers have to look to alternative materials to improve the weight-to-performance profile.

"Cost is one of the main drivers that affect production [for FIAT and other automakers] […] and weight is one major focus," Lambertini said in Barcelona.

The weight of cars has increased significantly in recent years as new components were added to improve safety and expand functionality, he said.

A FIAT Tipo built in 2016 carries 20% more weight – equivalent to 300kg – in its engine system compared with a FIAT Ritmo of 1978. Its weight is also 30% higher as regards body and chassis (+380kg), while it doubled against the older model in electronic components (+100kg) and interior components (+310kg).

"So you have much heavier cars today, while emissions have decreased," he said.

A FIAT Bravo from 2009, he showed, consumes 29% less fuel than the same model build in 1999.

The environmental-related concerns at an international level regarding vehicle emissions are behind much of the work done by producers to cut the carbon impact of their products.

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A 1978 FIAT Ritmo and a 2016 Tipo. While the weight of vehicles has increased over time, emission levels have declined. Netcarshow; Flickr\smoothgroove22 

In the case of Europe, EU-wide regulations setting emission thresholds and long-term targets are forcing companies to plan ahead to stay within the targets. Current emission thresholds are set to be reduced further by 2020, and again by 2025, which means producers have to work today to have their vehicles ready by the time the regulations change.

"This is a key driver. Now you have to contain weight so you can cut fuel consumption and, thus, emissions," said Lambertini. "The other [driver] is customer demand, in terms of style of the vehicle and personalisation." 

FIAT is investigating how it can use graphene in its materials as a way to help reduce the weight of vehicles.

Graphene-based polymers are one such area that is being looked at. Considering that about 14% of cars is made of polymeric materials (some 200kg), the company believes there is scope to reduce that with alternative materials.

FIAT has tested smart electrically conductive polymer-based components in wirings, electrical circuits, sensors and switches, as well as parts of the car’s dashboard. By using graphene polymers, due to graphene’s high conductivity, such parts could be assembled without copper cables.

"We can achieve metal wiring substitution in this way. This leads to weight reduction as well as cost reduction, if you think that there are about 2.5km of copper cables in your average car," he said.

Other testing has been carried out in anti-corrosive graphene coatings, and under-hood plastic components.

The challenges that the company sees at this stage in the potential use of graphene as a material component are down to the costs related with using the material – sourcing as well as further processing costs required – and manufacturing optimisation, he added.

Aerospace

The aviation industry is also looking to replace conventional, metal-based material, with lighter and more performing options, according to Maria Rodriguez Gude from Spanish nanomaterials and composites producer FIDAMC.

In the case of aerospace, the core of the interest is in the use of fibre-reinforced composites (CFRP), due to their stiffness and strength and lower weight compared with metallic structures.

"The aim is to obtain CFRP that not only are lightweight but also improve mechanical performance, functionality, health monitoring and surface technology," Rodriguez Gude said.