Final Report Summary - LI-AIR CATHODES (Engineering and Design of Novel Tailored Li-Air Battery Cathodes)
Continuing research into renewable sources of energy is essential in order to overcome the issues arising from man’s insatiable demand for energy and our current dependence on fossil fuel sources. Highly efficient energy storage devices are required to enable a smooth transition to energy sources with reduced environmental impact. Batteries have long been researched as devices with the potential to affect a significant change in global energy generation, storage and use, especially for applications in the transport sector, which currently represents the largest user of fossil fuels. Lithium (Li-ion) batteries possess high energy density compared to other secondary (rechargeable) batteries and have transformed portable electronic devices. However, the maximum energy density of current Li-ion batteries is limited due to the electrode materials which rely on chemical intercalation. This limit is too low to meet the demands of key markets, such as transport, in the long term. Metal-air batteries present a promising form of energy storage with a theoretical specific energy approaching that of petrol and an order of magnitude higher than the current ubiquitous Li-ion battery.
This project utilizes a methodical approach to the development of novel cathode materials. Investigation of metal-air cell behaviour by electrochemical impedance spectroscopy (EIS), a technique with little application in the field, has enable establishment of a quantitative model of the relationship between cathode chemistry, morphology and cell performance. This project also encompasses the study of the chemistry and morphology of reaction products, an understanding of which is central to achieving cells with long cycle lifespans. In addition, Na air batteries have been investigated for valuable comparison with Li air.
The specific objectives of the proposed project are summarized as follows:
1. Study the mechanisms of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) using Electrochemical Impedance Spectroscopy with the aim of developing a model and utilizing this to monitor charge and discharge reactions of Li-air cells.
2. Design and characterize optimal, nanostructured materials which are electrocatalytically active for application in Li-air batteries
3. To utilize surface chemistry analysis techniques to investigate cathode reaction products after successive charge/discharge cycles.
4. To develop a prototype device capitalizing on the knowledge attained during this project to ensure the materials selected are suitable for production on a commercial scale
The main results achieved since the beginning of the project include:
1. The development of an impedance model based on an equivalent circuit which has been validated for discharge and charge processes for both lithium and sodium air cells.
2. The investigation of promising catalysts by studying the effect of chemistry and morphology on the charge/discharge voltages of rechargeable Li-O2 batteries.
3. Reversibility studies have been performed in both metal-air batteries with higher reversibility and cycle life found for Na-air. In-situ formation of discharge products have been monitored by microscopy techniques which provides a great understanding of this technology for prototype development.
4. During the course of the project several Li-air prototypes have been developed by other researchers which do not solve the actual energy problem. Because of the promising results of the Na-air battery, this battery is being investigated in order to develop a prototype. The material chosen is graphene because is light and cheap and presents great properties (porous, high conductivity, large specific surface area, excellent electrocatalytic activity for the ORR) which make an excellent candidate for the air cathode.
The multidisciplinary approach which forms the basis of this project (both theoretical and experimental) has provided results relevant for the scientific community and affects a large number of scientific disciplines such as chemistry, physics, materials science, electrochemistry. This knowledge and experience has been disseminated to the Spanish research community and industry during the return phase of the project through seminars at CIC Energigune and talks to general public. The expertise in the battery field of the outgoing host organisation has enhanced the scientific capabilities of the fellow in this vital area and makes a substantial contribution to European competitiveness. The materials discovered are under development in the cell test facilities at CIC Energigune. These systems require the engagement of an industrial partner (automotive industry) which is under study. Finally, the primary contribution to European competitiveness is the resultant flow of skilled manpower and knowledge arising from this project and the applicant’s future work. As the transition to a global economy dominated by low carbon technologies accelerates, it is likely that there will be a substantial shortfall of skilled manpower trained in materials science and solid state electrochemistry. One potential way of filling this skills gap is by establishing new research groups and strengthening the collaboration between different countries in the relevant technology areas. In this sense, the researcher has been awarded an Ikerbasque Resarch Fellow to start developing her research in metal-air batteries at CIC EnergiGUNE.
Relevant contact details:
Dr. Nagore Ortiz Vitoriano
Ikerbasque Research Fellow
CIC EnergiGUNE
Parque Tecnológico
C/Albert Einstein, 48
01510 Miñano (Alava) Spain
Tlf.: +34 945 297 108
nortiz@cicenergigune.com
www.cicenergigune.com
Prof. Teófilo Rojo Aparicio
Principal Scientific Director
Power Storage, Batteries and Supercaps
CIC EnergiGUNE
Parque Tecnológico
C/Albert Einstein, 48
01510 Miñano (Alava) Spain
Tlf.: +34 945 297 108
trojo@cicenergigune.com
www.cicenergigune.com
This project utilizes a methodical approach to the development of novel cathode materials. Investigation of metal-air cell behaviour by electrochemical impedance spectroscopy (EIS), a technique with little application in the field, has enable establishment of a quantitative model of the relationship between cathode chemistry, morphology and cell performance. This project also encompasses the study of the chemistry and morphology of reaction products, an understanding of which is central to achieving cells with long cycle lifespans. In addition, Na air batteries have been investigated for valuable comparison with Li air.
The specific objectives of the proposed project are summarized as follows:
1. Study the mechanisms of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) using Electrochemical Impedance Spectroscopy with the aim of developing a model and utilizing this to monitor charge and discharge reactions of Li-air cells.
2. Design and characterize optimal, nanostructured materials which are electrocatalytically active for application in Li-air batteries
3. To utilize surface chemistry analysis techniques to investigate cathode reaction products after successive charge/discharge cycles.
4. To develop a prototype device capitalizing on the knowledge attained during this project to ensure the materials selected are suitable for production on a commercial scale
The main results achieved since the beginning of the project include:
1. The development of an impedance model based on an equivalent circuit which has been validated for discharge and charge processes for both lithium and sodium air cells.
2. The investigation of promising catalysts by studying the effect of chemistry and morphology on the charge/discharge voltages of rechargeable Li-O2 batteries.
3. Reversibility studies have been performed in both metal-air batteries with higher reversibility and cycle life found for Na-air. In-situ formation of discharge products have been monitored by microscopy techniques which provides a great understanding of this technology for prototype development.
4. During the course of the project several Li-air prototypes have been developed by other researchers which do not solve the actual energy problem. Because of the promising results of the Na-air battery, this battery is being investigated in order to develop a prototype. The material chosen is graphene because is light and cheap and presents great properties (porous, high conductivity, large specific surface area, excellent electrocatalytic activity for the ORR) which make an excellent candidate for the air cathode.
The multidisciplinary approach which forms the basis of this project (both theoretical and experimental) has provided results relevant for the scientific community and affects a large number of scientific disciplines such as chemistry, physics, materials science, electrochemistry. This knowledge and experience has been disseminated to the Spanish research community and industry during the return phase of the project through seminars at CIC Energigune and talks to general public. The expertise in the battery field of the outgoing host organisation has enhanced the scientific capabilities of the fellow in this vital area and makes a substantial contribution to European competitiveness. The materials discovered are under development in the cell test facilities at CIC Energigune. These systems require the engagement of an industrial partner (automotive industry) which is under study. Finally, the primary contribution to European competitiveness is the resultant flow of skilled manpower and knowledge arising from this project and the applicant’s future work. As the transition to a global economy dominated by low carbon technologies accelerates, it is likely that there will be a substantial shortfall of skilled manpower trained in materials science and solid state electrochemistry. One potential way of filling this skills gap is by establishing new research groups and strengthening the collaboration between different countries in the relevant technology areas. In this sense, the researcher has been awarded an Ikerbasque Resarch Fellow to start developing her research in metal-air batteries at CIC EnergiGUNE.
Relevant contact details:
Dr. Nagore Ortiz Vitoriano
Ikerbasque Research Fellow
CIC EnergiGUNE
Parque Tecnológico
C/Albert Einstein, 48
01510 Miñano (Alava) Spain
Tlf.: +34 945 297 108
nortiz@cicenergigune.com
www.cicenergigune.com
Prof. Teófilo Rojo Aparicio
Principal Scientific Director
Power Storage, Batteries and Supercaps
CIC EnergiGUNE
Parque Tecnológico
C/Albert Einstein, 48
01510 Miñano (Alava) Spain
Tlf.: +34 945 297 108
trojo@cicenergigune.com
www.cicenergigune.com