Community Research and Development Information Service - CORDIS

Periodic Report Summary 1 - FUNLAB (Fundamental breakthroughs in Lithium-Air Batteries)

Funlab is a project aimed to achieve fundamental breakthroughs in lithium-air batteries. Lithium-air batteries have the potential to deliver a much higher energy than lithium-ion batteries, but major improvements at the level for the fundamentals of the reactions are required in order to improve their practical specific energy and rechargeability. The focus of the project is on the use of redox mediators to facilitate reaction kinetics as well as mitigating the issue of electrode passivation. During the first period of this project, a detailed understanding of action of redox mediators has been developed, which is essential in order to develop a rational screening method to search for mediators that will lead to optimal performance. A new method to avoid degradation reactions in lithium-air batteries by using redox mediators has been demonstrated (Chem. Comm. 51, 1705, 2015). It has been shown that ethyl viologen can be used in order to facilitate the full reduction of oxygen into lithium peroxide, which is the discharge reaction in lithium-oxygen batteries. Ethyl viologen effectively decreases the lifetime of problematic intermediates in the pathways of the reduction of oxygen, such as superoxide, which is a strong nucleophile that attacks most known solvents inducing degradation reactions. Upon reaction with ethyl viologen, superoxide is reduced to lithium peroxide, which is the desired final discharge product. Redox mediators are also very advantageous for the charge reaction in lithium-air batteries, which is the evolution of oxygen from lithium peroxide. It has been found that metal complexes such as cobalt bis(terpyridine) produce a dramatic decrease in the charging potential of lithium-air batteries (J. Phys. Chem. C. 2016 DOI: 101021/acs.jpcc.6b02932), by efficiently oxidizing lithium peroxide to oxygen. Cobalt bis(terpyridine) acts an electron shuttle that carries electrons from the lithium peroxide deposit to the current collectors, thus overcoming the problem of the poor electronic conductivity of lithium peroxide. Other promising redox mediators have been studied within the project, including a systematic study of the effect of the redox potential of mediators on the catalysis of the discharge and charge reactions, as well as the combination of two redox mediators in a single cell, one for the charge and the other for the catalysis of the discharge reaction. In future studies within this project, alternative methods of boosting battery performance will be investigated, such as the in-situ doping of the discharge product Li2O2 in order to enhance its conductivity, and the incorporation of ultrasounds to enhance the activity of the air electrode. These studies will significantly improve our understanding of lithium-air batteries, paving the way for their development as the next generation of rechargeable batteries. The scientific achievements have also made a significant impact in the research career of the researcher Nuria Garcia-Araez, who has now secured her job as assistant professor at the University of Southampton and has consolidated a thriving research team.

Contact

Yan Qiao, (EU Accountant)
Tel.: +4423 80593907
Fax: +4423 80592195
E-mail

Subjects

Life Sciences
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