Final Report Summary - NECOBAUT (New Concept of Metal-Air Battery for Automotive Application based on Advanced Nanomaterials)
Executive Summary:
NECOBAUT project started with the study of the requirements that are demanded for batteries employed in different types of electric vehicles. The purpose is to identify the specifications that the Fe-air battery developed in the project should have for this application. Then, the technical work of the project was structured in several workpackages that follow the value chain from the development of new nanomaterials for the electrodes up to the final testing and validation of the complete iron-air battery.
Both the iron and the air electrode employ nanostructured carbon-based materials as active components. Carbon samples with different properties for both electrodes have been prepared, being the corrosion resistance and the electronic conductivity the most important parameters. For the iron electrode, different FeC nanostructured materials supported in high surface carbons have been developed using different synthesis routes.. Discharge capacities about ~600mA•h/gFe have been obtained with low-loading FeC electrodes. For the air electrode, also specific Pd and LSFCO electro-catalysts formulations dispersed on carbons have been developed.
Novel air and iron electrodes were manufacturing starting from these nanomaterials. The iron electrode has been produced by the hot-pressing method. This electrode works properly in durability test, obtaining a maximum discharge capacity of 750 mAh/gFe at 25 mA/cm2. The air electrode has also achieved good stability over several days cycling at up to 150 mA cm-2, with good corrosion resistance.
The cell design, assisted with modelling and simulation tools, has been improved along the project, achieving a lightweight, durable and low-cost iron-air cell, which can be easily manufactured using 3D printing techniques. The extensive testing of the final cell of 25 cm2 has offered values of capacity very promising. Several configurations of this cell have been tested, using one iron electrode y one or two air electrodes. In the energy density range up to 20 mA cm-2, the capacity was > 700 mAh.g-1Fe. The energy efficiency is as expected for the iron air cell, in the range of 40 to 45 %. Nevertheless the testing results lead to the conclusion that it is best to run the cell at 5-10 mA cm-2.
The upscaling of the cell from 25 to 400 cm2 has suffered problems with the mechanical stability of the electrodes, leading to a poor performance of the cell. The design and manufacturing of the five-cells stack, following ecodesign principles, have been quite successful. The performance of the stack was characterised and it was found to be capable of running a small 12 V motor at a high rotational speed. Nevertheless it is limited to run at current density above 10 mA cm-2 (250 mA) to avoid quick degradation of the cell components.
On the other hand, the LCA and risk analysis has been evaluated in detail for the iron-air battery. Recommendations about these items for a potential use of this battery have been given.
Project Context and Objectives:
The main hurdles that are slowing down the mass-market adoption of electric vehicles are their low autonomy and high price. Both are aspects directly related to the battery, which nowadays can sum up to the half of the cost of the EV.
The aim of the NECOBAUT project is to develop a novel Iron-Air Battery capable of overcoming the lithium-ion batteries currently used in electric vehicles in terms of energy density and cost.
Iron-air batteries belong to the category of metal-air batteries; a type of batteries that employ a metal as the negative electrode and ambient air as positive electrode. Having only one reactant contained inside the cell, metal-air batteries permit much more compact and lighter designs and therefore, have very high theoretical energy densities. However, currently they are only commercially available as primary (non-rechargeable) batteries, and making them electrically rechargeable involves many technical difficulties, and new materials and components (electrodes, electrolytes, current collectors, bipolar plates,…) need to be developed to achieve this objective.
NECOBAUT project is developing a new Fe-air battery based on low cost nanostructured electrode materials with a final energy density target of 400Wh/kg, a cost lower than 100$/kWh and a durability of more than 3000 cycles. NECOBAUT’s well-balanced consortium allows encompassing every aspect of the battery development, from nanomaterial synthesis to battery manufacturing, including electrode development, modelling and simulation, electrochemical engineering and battery safety analysis.
Project Results:
NECOBAUT project started with the study of the requirements that are demanded for batteries employed in different types of electric vehicles. The purpose is to identify the specifications that the Fe-air battery developed in the project should have for this application.
Then, the technical work of the project is structured in several workpackages that follow the value chain from the development of new namonaterials for the electrodes up to the final testing and validation of the complete iron-air battery:
Both the iron and the air electrode employ nanostructured carbon-based materials as active components. IMERYS has prepared and characterized carbon samples with different properties for both electrodes, being the corrosion resistance and the electronic conductivity the most important parameters of the carbon materials. For the iron electrode, CNR-ITAE has prepared different FeC nanostructured materials supported in high surface IMERYS carbon using different synthesis routes. Various carbons to iron ratios have been tested and additives have also been added in order to minimize the parasitic hydrogen evolution and therefore enhancing the charging efficiency. The small particle size of the iron precursors and the interaction with the carbon improves the iron usability. Discharge capacities about ~600mA•h/gFe have been obtained with low-loading FeC electrodes. For the air electrode, CNR/ITAE developed specific Pd and LSFCO electro-catalysts formulations dispersed on carbons provided by IMERYS.
TECNALIA and SOUTHAMPTON were in charge of developing the iron and air electrodes respectively. TECNALIA has produced iron electrodes from the hot-pressing method. This electrode works properly in durability test, obtaining a maximum discharge capacity of 750 mAh/gFe at 25 mA/cm2. The air electrode developed by SOUTHAMPTON is composed of three main parts: a carbon cloth + C/PTFE powder gas diffusion layer, a Pd/C catalyst layer, and a nickel current collector, which were bound together in a single step by hot-pressing. This electrode has achieved good stability over several days cycling at up to 150 mA cm-2, with good corrosion resistance.
The cell design, assisted with modelling and simulation tools, has been improved along the project, achieving a lightweight, durable and low-cost iron-air cell, which can be easily manufactured using 3D printing techniques. The extensive testing of the final cell of 25 cm2 has offered values of capacity very promising. Several configurations of this cell have been tested, using one iron electrode y one or two air electrodes. In the energy density range up to 20 mA cm-2, the capacity was > 700 mAh.g-1Fe. The energy efficiency is as expected for the iron air cell, in the range of 40 to 45 %. Nevertheless the testing results lead to the conclusion that it is best to run the cell at 5-10 mA cm-2.
The upscaling of the cell from 25 to 400 cm2 was achieved maintaining the initial design of the smallest cell, but problems with the mechanical stability of the electrodes were found, leading to a poor performance of the cell.
The design and manufacturing of the 5-cells stack, following ecodesign principles, have been quite successful. The performance of the stack was characterised and it was found to be capable of running a small 12 V motor at a high rotational speed. Nevertheless it is limited to run at current density above 10 mA cm-2 (250 mA) to avoid quick degradation of the cell components.
On the other hand, the LCA and risk analysis has been evaluated in detail for the iron-air battery. Recommendations about these items for a potential use of this battery have been given.
Potential Impact:
NECOBAUT project has conducted an extensive research in several lines, and although the final result achieved for the iron-air battery is not directly exploitable for the industry, a very good scientific background has been generated. This background will be very useful for further developments in the battery field. Some of important research lines of interest explored in this project were:
- Development of new nanomaterials, mainly nanocatalysts and carbon supports, that haven been proved to show interesting properties for the iron-air battery, but also for other type of applications (e.g. in other type of batteries or fuel cells).
- Design and testing of the iron-air cell. A compact and lightweight design has been developed using the 3D printing technology. This method has been very useful and versatile to improve the cell design along the project and can be extrapolated to other battery designs.
- Extensive testing of the iron-air cell has been conducted, getting very useful information about the behaviour of the cell under different testing conditions.
- Study of LCA and Evaluation of Risks for the iron-air battery, that could be useful for further similar studies in metal-air (or even redox flow) batteries.
The dissemination of the project has been very extensive, including several scientific (per reviewed) papers and many presentations in congresses and conferences related to the electrochemistry and the battery field. Also, A specific Workshop have been organised in Universidad Autónoma of Madrid, Spain, on the 28th of September 2015, to disseminate the results of NECOBAUT project.
There is not a clear direct exploitation of the results of the project by the involved industrial partners, but the particular results achieved in the different workpackages could be of interest for them in future development.
List of Websites:
http://www.necobaut.eu
NECOBAUT project started with the study of the requirements that are demanded for batteries employed in different types of electric vehicles. The purpose is to identify the specifications that the Fe-air battery developed in the project should have for this application. Then, the technical work of the project was structured in several workpackages that follow the value chain from the development of new nanomaterials for the electrodes up to the final testing and validation of the complete iron-air battery.
Both the iron and the air electrode employ nanostructured carbon-based materials as active components. Carbon samples with different properties for both electrodes have been prepared, being the corrosion resistance and the electronic conductivity the most important parameters. For the iron electrode, different FeC nanostructured materials supported in high surface carbons have been developed using different synthesis routes.. Discharge capacities about ~600mA•h/gFe have been obtained with low-loading FeC electrodes. For the air electrode, also specific Pd and LSFCO electro-catalysts formulations dispersed on carbons have been developed.
Novel air and iron electrodes were manufacturing starting from these nanomaterials. The iron electrode has been produced by the hot-pressing method. This electrode works properly in durability test, obtaining a maximum discharge capacity of 750 mAh/gFe at 25 mA/cm2. The air electrode has also achieved good stability over several days cycling at up to 150 mA cm-2, with good corrosion resistance.
The cell design, assisted with modelling and simulation tools, has been improved along the project, achieving a lightweight, durable and low-cost iron-air cell, which can be easily manufactured using 3D printing techniques. The extensive testing of the final cell of 25 cm2 has offered values of capacity very promising. Several configurations of this cell have been tested, using one iron electrode y one or two air electrodes. In the energy density range up to 20 mA cm-2, the capacity was > 700 mAh.g-1Fe. The energy efficiency is as expected for the iron air cell, in the range of 40 to 45 %. Nevertheless the testing results lead to the conclusion that it is best to run the cell at 5-10 mA cm-2.
The upscaling of the cell from 25 to 400 cm2 has suffered problems with the mechanical stability of the electrodes, leading to a poor performance of the cell. The design and manufacturing of the five-cells stack, following ecodesign principles, have been quite successful. The performance of the stack was characterised and it was found to be capable of running a small 12 V motor at a high rotational speed. Nevertheless it is limited to run at current density above 10 mA cm-2 (250 mA) to avoid quick degradation of the cell components.
On the other hand, the LCA and risk analysis has been evaluated in detail for the iron-air battery. Recommendations about these items for a potential use of this battery have been given.
Project Context and Objectives:
The main hurdles that are slowing down the mass-market adoption of electric vehicles are their low autonomy and high price. Both are aspects directly related to the battery, which nowadays can sum up to the half of the cost of the EV.
The aim of the NECOBAUT project is to develop a novel Iron-Air Battery capable of overcoming the lithium-ion batteries currently used in electric vehicles in terms of energy density and cost.
Iron-air batteries belong to the category of metal-air batteries; a type of batteries that employ a metal as the negative electrode and ambient air as positive electrode. Having only one reactant contained inside the cell, metal-air batteries permit much more compact and lighter designs and therefore, have very high theoretical energy densities. However, currently they are only commercially available as primary (non-rechargeable) batteries, and making them electrically rechargeable involves many technical difficulties, and new materials and components (electrodes, electrolytes, current collectors, bipolar plates,…) need to be developed to achieve this objective.
NECOBAUT project is developing a new Fe-air battery based on low cost nanostructured electrode materials with a final energy density target of 400Wh/kg, a cost lower than 100$/kWh and a durability of more than 3000 cycles. NECOBAUT’s well-balanced consortium allows encompassing every aspect of the battery development, from nanomaterial synthesis to battery manufacturing, including electrode development, modelling and simulation, electrochemical engineering and battery safety analysis.
Project Results:
NECOBAUT project started with the study of the requirements that are demanded for batteries employed in different types of electric vehicles. The purpose is to identify the specifications that the Fe-air battery developed in the project should have for this application.
Then, the technical work of the project is structured in several workpackages that follow the value chain from the development of new namonaterials for the electrodes up to the final testing and validation of the complete iron-air battery:
Both the iron and the air electrode employ nanostructured carbon-based materials as active components. IMERYS has prepared and characterized carbon samples with different properties for both electrodes, being the corrosion resistance and the electronic conductivity the most important parameters of the carbon materials. For the iron electrode, CNR-ITAE has prepared different FeC nanostructured materials supported in high surface IMERYS carbon using different synthesis routes. Various carbons to iron ratios have been tested and additives have also been added in order to minimize the parasitic hydrogen evolution and therefore enhancing the charging efficiency. The small particle size of the iron precursors and the interaction with the carbon improves the iron usability. Discharge capacities about ~600mA•h/gFe have been obtained with low-loading FeC electrodes. For the air electrode, CNR/ITAE developed specific Pd and LSFCO electro-catalysts formulations dispersed on carbons provided by IMERYS.
TECNALIA and SOUTHAMPTON were in charge of developing the iron and air electrodes respectively. TECNALIA has produced iron electrodes from the hot-pressing method. This electrode works properly in durability test, obtaining a maximum discharge capacity of 750 mAh/gFe at 25 mA/cm2. The air electrode developed by SOUTHAMPTON is composed of three main parts: a carbon cloth + C/PTFE powder gas diffusion layer, a Pd/C catalyst layer, and a nickel current collector, which were bound together in a single step by hot-pressing. This electrode has achieved good stability over several days cycling at up to 150 mA cm-2, with good corrosion resistance.
The cell design, assisted with modelling and simulation tools, has been improved along the project, achieving a lightweight, durable and low-cost iron-air cell, which can be easily manufactured using 3D printing techniques. The extensive testing of the final cell of 25 cm2 has offered values of capacity very promising. Several configurations of this cell have been tested, using one iron electrode y one or two air electrodes. In the energy density range up to 20 mA cm-2, the capacity was > 700 mAh.g-1Fe. The energy efficiency is as expected for the iron air cell, in the range of 40 to 45 %. Nevertheless the testing results lead to the conclusion that it is best to run the cell at 5-10 mA cm-2.
The upscaling of the cell from 25 to 400 cm2 was achieved maintaining the initial design of the smallest cell, but problems with the mechanical stability of the electrodes were found, leading to a poor performance of the cell.
The design and manufacturing of the 5-cells stack, following ecodesign principles, have been quite successful. The performance of the stack was characterised and it was found to be capable of running a small 12 V motor at a high rotational speed. Nevertheless it is limited to run at current density above 10 mA cm-2 (250 mA) to avoid quick degradation of the cell components.
On the other hand, the LCA and risk analysis has been evaluated in detail for the iron-air battery. Recommendations about these items for a potential use of this battery have been given.
Potential Impact:
NECOBAUT project has conducted an extensive research in several lines, and although the final result achieved for the iron-air battery is not directly exploitable for the industry, a very good scientific background has been generated. This background will be very useful for further developments in the battery field. Some of important research lines of interest explored in this project were:
- Development of new nanomaterials, mainly nanocatalysts and carbon supports, that haven been proved to show interesting properties for the iron-air battery, but also for other type of applications (e.g. in other type of batteries or fuel cells).
- Design and testing of the iron-air cell. A compact and lightweight design has been developed using the 3D printing technology. This method has been very useful and versatile to improve the cell design along the project and can be extrapolated to other battery designs.
- Extensive testing of the iron-air cell has been conducted, getting very useful information about the behaviour of the cell under different testing conditions.
- Study of LCA and Evaluation of Risks for the iron-air battery, that could be useful for further similar studies in metal-air (or even redox flow) batteries.
The dissemination of the project has been very extensive, including several scientific (per reviewed) papers and many presentations in congresses and conferences related to the electrochemistry and the battery field. Also, A specific Workshop have been organised in Universidad Autónoma of Madrid, Spain, on the 28th of September 2015, to disseminate the results of NECOBAUT project.
There is not a clear direct exploitation of the results of the project by the involved industrial partners, but the particular results achieved in the different workpackages could be of interest for them in future development.
List of Websites:
http://www.necobaut.eu