There is a lot of attention being paid to the issue of energy storage, driven by the need for extended operational lifetimes in products from smartphones to sports cars. Although significant advances in the efficiency, power density, and performance of embedded electronic systems has and will continue to increase, better batteries (betteries?) wouldn’t hurt either. In the electric vehicle (EV) space, denser and more powerful battery packs will not only directly impact cruising range, they will also speed adoption by removing range anxiety.
There are other important factors to consider as well, such as battery life span, safety or charging times, among others. Waste, pollution and sustainability are other issues that need to be addressed, as no real battery solution can be considered such if it brings problems with materials or processes that cause an ecological impact.
Ensuring that Europe is a player in the burgeoning market for advanced batteries, 10 partners from industry and research organizations will cooperate in an EU-funded project called ECO COM'BAT, with the goal of creating a sustainable high-voltage lithium-ion battery. EIT RawMaterials, an initiative of the EU’s EIT (European Institute of Innovation and Technology), has a mission to ensure the competitiveness of European minerals, metals and materials companies.
The objective of ECO COM'BAT is to research and develop green and high-performance materials as well as their production methods, in order to create the next generation of high-voltage lithium-ion batteries. Coordinated by the Fraunhofer Institute for Silicate Research ISC, the project took place from April 2016 to December 2018. Participant companies included materials producers Arkema and Umicore, battery cell manufacturers SAFT and Customcells, the research and technology organizations Fraunhofer, CEA, CSIC, ENEA, VITO, and the Technical University Darmstadt.
“The main task of the ECO COM’BAT project was to substitute conventional, often expensive, rare or even critical materials as cobalt in the electrodes and of fluorine in the electrolyte,” explained project coordinator Dr. Andreas Bittner from Fraunhofer ISC. The team worked with ORMOCER-coated, low-cobalt NMC 622 and a special high-voltage electrolyte based on the conductive salt lithium-bis (fluorosulfonyl) imide (LiFSI). This combination can reduce cobalt content by 20 percent and reduce electrolyte fluorine content by two-thirds.
To further improve performance without causing additional materials issues, the sustainable structured carbon additives Porocarb and Graphistrength were used to increase energy and power density. Integrated in pouch cells on a pilot level, the materials increased performance, with up to 50 percent better cycle stability at 4.3 V, compared to legacy solutions.
In addition to working on production methods, the ECO COM'BAT project also developed an efficient recycling concept to recover precious materials like nickel, cobalt, graphite and lithium. The results of the project show a roadmap for a new generation of sustainable high-voltage batteries, addressing both performance and materials issues.
Too often, people evaluate the success of a technology by the momentary snapshot of existing art. By developing an improved sustainable battery, the ECO COM’BAT project is an excellent example of the solutions available to address the problems we face with current solutions. Better and more sustainable batteries will solve many of the criticisms being leveled today at EVs, speeding adoption and acceptance in society.
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