The EU-funded research project Composite Structural Power Storage for Hybrid Vehicles (STORAGE) was set up to develop new concepts for lightweight energy storage to radically improve the efficiency of hybrid vehicles by using parts of a car’s structure as power sources.
With an award of €3.37 million under the 'Transport' theme of the EU's Seventh Framework Programme (FP7), the project is focusing on research into materials that simultaneously carry mechanical loads whilst storing electrical energy. These materials are resilient, strong and lightweight, making them well suited to the manufacture of car parts, while at the same time having crossover applications for information and communications technology.
Essentially, the heavier a vehicle is the more energy it requires to move. Consequently, the weight of existing batteries is a factor that reduces the environmental benefits of hybrid vehicles. This is the main problem that the STORAGE project seeks to address and, by focusing on innovative composite materials that lower the weight of the vehicles by integrating the energy storage systems into the structure of the vehicle itself, the aim is to improve the efficiency of the hybrid cars and make them a more viable alternative to conventional vehicles.
Materials used in the construction of a vehicle that do not contribute to its load-carrying capacity are structurally parasitic in that they contribute to the power drain on the vehicle. While the standard approach to maximizing the efficiency of hybrid vehicles has been to examine the efficiency of individual subcomponents, this project differs in that it aims to create new materials that simultaneously perform more than one function, thereby offering significant savings in mass and volume, in addition to performance benefits.
The project’s novel concepts include composite structural capacitors and batteries, which reduce the need for traditional batteries, allowing for an associated reduction in the total weight of the vehicle. According to the researchers working on the project, using the composite material to replace the wheel well for the spare wheel alone could reduce a car's overall weight by 15% and significantly improve its driving range. Furthermore, the composite material will be able to store and discharge large amounts of energy, and can simply be recharged by plugging a hybrid car into the driver's home power supply.
One of the priorities of Horizon 2020 will be to promote research leading to the market rollout and consumer uptake of technologies that achieve the twin goals of helping Europe reach its SET-Plan targets, while at the same time ensuring Europe’s place at the cutting edge of innovation. The STORAGE project addresses the ‘competitive industrial processes’ research area identified in the FP7 call for proposals, and involves work on innovative product concepts that will strengthen the competitiveness of European industry in emerging green technologies, while at the same time providing a means to significantly reduce CO2 emissions from surface transport.
The STORAGE consortium, which sees the UK's Imperial College London (ICL) collaborating with teams from Belgium, Germany, Greece and Sweden, will provide innovative products and concepts which will strengthen the competitiveness of European industry. ICL’s Dr Emile Greenhalgh said: “We think the car of the future could be drawing power from its roof, its bonnet or even the door, thanks to our new composite material. Even the Sat Nav could be powered by its own casing.”
The versatility of the polymer composites being examined means they provide an ideal opportunity to develop novel multifunctional materials which can store the electrical energy required to power systems, while simultaneously meeting structural demands. Carbon fibre composites are attractive as they are commonly used as both electrodes and high performance reinforcements. Previous work has demonstrated that these multifunctional materials can be synthesised in a laboratory, and the technology is ready to be taken up by industry.
Initial work for the project focused on two techniques for developing the innovative materials: 'reinforcing and grafting' and 'multifunctional resin'. Cost-benefit analyses helped to identify the most promising constituents, which were then combined into composites. Samples of these innovative materials were then manufactured and tested for their mechanical and electrical performance, with a view to showing that they provide an efficiency improvement of at least 15% compared to conventional materials.
The researchers have identified several novel technologies which improved performance. These include carbon aerogel reinforcement, matrix development based on a mixture of existing epoxy resins and liquid electrolyte, and improved composition of multifunctional resins for super-capacitors. The STORAGE researchers also looked at system issues associated with structural power sources such as power management, packaging and connectivity. Demonstrators using the new composites were built and tested on a small scale.
The STORAGE project has laid the groundwork for revolutionary developments in efficient vehicles for the future. These technologies will help implement more sustainable transport solutions and, by developing revolutionary lightweight energy storage concepts for future vehicles, they will not only make a significant contribution to the meeting of greenhouse gas reduction goals for 2020 and beyond, they will also serve to keep the EU at the cutting edge of high-tech research and development.
For more information: