COBRA creates a lighter and safer automotive battery system

  • Energy storage
  • Smart energy management

A European consortium of nineteen partners from the automotive industry, research and technology specialists, has managed to develop a complete system based on cobalt-free lithium batteries for electric vehicles, which integrates a series of innovations in safety, control and efficiency to be incorporated into the next generation of batteries.

With a budget of twelve million euros, the COBRA project, co-financed by the European Commission, has completed four years of this “ambitious plan” with a complete demonstration of the system. The ‘battery pack’ has a lighter weight in its design, and also incorporates innovative sensors, algorithms and communications developed by the initiative itself.

For the senior researcher at the Catalonia Institute for Energy Research (IREC) and coordinator of the project, Lluis Trilla, the most complex challenge has been “the integration of all the innovations” in a “single demonstrator” made with materials such as treated wood and recycled aluminium, which have reduced its external weight by 30% compared to other batteries.

“The most interesting novelty is the innovative design of the BMS -Battery Management System- that incorporates internal wireless communications in the system, executing a series of algorithms and advanced models within the battery”. “A lot of sensors” have been added to obtain “greater control” of the system, the researcher explained.

Made up of 96 individual cobalt-free lithium-ion cells, the complete battery system contains temperature, deformation and impedance sensors that inform the user about its status. In addition, a pressure sensor and a gas detector are capable of detecting any internal reaction, information useful for monitoring its operation at all times.

The engineer from the Applus+ IDIADA Battery Systems Department, Iván Viáfara, considers that this 400 volt demonstrator -the standard for batteries- is “functional and relevant” since the tests on the prototypes at the voltage and capacity level, although slightly lower than the standard, are applicable to the industry.

This Spanish company specialised in design, engineering and certification services for the automotive industry has been responsible, in collaboration with other members of the consortium, for the planning and execution of the set of tests for the validation of the prototype. To carry out this task, they had to adapt their internal system for carrying out electrical safety, performance and durability tests.

“Wood, one of the components that make up the battery casing in addition to recycled aluminium, worked very well in the ‘Thermal propagation’ test, which consists of overheating a battery cell at extreme temperatures to check how it responds, and the results were quite positive,” said Viáfara regarding the tests for based on Regulation No. 100 of the United Nations Economic Commission for Europe.

Currently, the entire system is at TRL 6 on the scale that measures the degree of maturity of a technology, although both experts expect that in the coming years it will be possible to reach TRL 9 – a system successfully tested in a real environment – and that by 2030 some of these innovations can be applied to achieve more sustainable, efficient batteries with optimal performance.

“Now that everything has been developed, we are going to try to ensure that the project has continuity and that this really does not remain in a drawer,” said Trilla.

COBRA is a project within the BATTECH initiative, the R+D+i reference center for batteries in Southern Europe. More information about the COBRA project:

You can find the press release in Spanish (ES) and Catalan (CAT) in the following links:

Details of the battery system

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement nº 875568.