© P.Avavian / CEA Pilot production of new battery electrodes. Image file: Fraunhofer ISC
Electromobility places high demands on new high-performance batteries - range, service life, safety and charging times, to name just a few. The real challenge is the resource requirements for a growing number of large lithium-based car batteries. Ten partners from industry and research have therefore come together in the EU-funded ECO COM'BAT project to develop a sustainable next generation of high-voltage lithium-ion batteries - with success.
The aim of the EIT RawMaterials project ECO COM'BAT was to combine environmentally friendly and high-performance materials for the next generation of high-voltage lithium-ion batteries and to improve their production. ECO COM'BAT was coordinated by the Fraunhofer Institute for Silicate Research ISC and carried out from April 2016 to December 2018. With the material manufacturers Arkema and Umicore, the cell manufacturers SAFT and Customcells, the research and technology organizations Fraunhofer, CEA, CSIC, ENEA, VITO and the Technical University of Darmstadt, the project participants covered all essential aspects along the value chain of batteries.
Reduce the use of critical materials
Compared to currently established battery types, the new lithium-ion batteries should be more powerful and more resource-efficient. "The main task of the ECO COM'BAT project was to replace conventional, often expensive, rare or even critical materials such as cobalt in the electrodes and fluorine in the electrolyte," explains project coordinator Dr. Andreas Bittner from Fraunhofer ISC. As part of the project, ORMOCER®-coated, low-cobalt NMC 622 and a special high-voltage electrolyte based on the conductive salt lithium bis (fluorosulfonyl) imide (LiFSI), which can be operated stably even at high voltages, were adapted and optimized to the high battery requirements. This resulted in a decrease in the cobalt content of approximately 20 percent and a decrease in the fluorine content in the electrolyte by two thirds. Energy and power density could be increased significantly through the use of structuring additives such as Porocarb® and Graphistrength®. The sustainable materials were processed in common pouch cells, which showed up to 50 percent higher cycle stability (at 4,3 V) than the industrial reference samples in the comparison test.
Upscaling to pilot scale
Several upscaling steps are usually required to move from the experimental laboratory level to production viability. As part of the ECO COM'BAT project, the partners combined innovative materials with known production properties and were able to achieve a relevant pilot stage for batches of up to 20 kilograms with just a few upscaling steps. In order to optimize the ECO COM'BAT materials and cells, a comprehensive simulation of the battery performance and aging was carried out. In addition, an efficient recycling concept was developed and tested in order to recover valuable materials such as nickel, cobalt, graphite and lithium not only in elemental form, but also in the form of the processed functional materials, thus achieving a high level of sustainability.
The good project results give hope for an economically interesting new generation of sustainable high-voltage batteries. The various battery materials developed and tested in the project have excellent performance and processing characteristics. The materials can be quickly scaled up to a near-production scale, if demand exists.
Information about ECO COM'BAT: www.eco-combat.com
project funding
EIT RawMaterials, initiated and funded by the European Institute of Innovation and Technology (EIT), a European Union body, is the world's largest consortium in the extractive sector. The vision of EIT RawMaterials is to make raw materials a major strength for Europe, its mission to enable the European sector to sustain its competitiveness in minerals, metals and materials along the value chain by driving innovation, education and entrepreneurship.
Source: Fraunhofer ISC
