Periodic Reporting for period 2 - MIGHTY (Roll-to-Roll Manufacturing of Hierarchical Li-Ion Battery Electrodes)
Période du rapport: 2021-08-01 au 2023-01-31
Li-Ion batteries are playing an increasingly important role in de-carbonising our society, examples of this includes the transition to electrical vehicles and storage of renewable energy sources. However, to achieve a wider adoption of electric vehicles, the cost and the performance of these batteries needs to be further improved. This is a huge research challenge, which is being addressed by many different research angles. Most research in this area is focussing on the development of new and better active battery materials, and much less attention is given to manufacturing processes and in particular how new manufacturing processes may lead to better battery performance. This ERC Consolidator Grant seeks to redefine how battery electrodes will be manufactured in the future with a view to increase the energy and power density and reduce cost.
A first overarching objective is to develop manufacturing processes that allow to structure the battery electrode such that we can increase the energy and power that can be stored per unit mass and volume of battery.
A second overarching objective of the project is that from the start, it aims to take into account the scalability of the manufacturing processes that are developed. More specifically, Roll-to-Roll (R2R) coating us currently the only manufacturing process that is able to create battery electrodes at a suitable throughput and cost. All processes developed in this project are designed from early development phases to be compatible with R2R to ensure that the outcomes of our research are relevant to the EU’s industrial stakeholders.
A first overarching objective is to develop manufacturing processes that allow to structure the battery electrode such that we can increase the energy and power that can be stored per unit mass and volume of battery.
A second overarching objective of the project is that from the start, it aims to take into account the scalability of the manufacturing processes that are developed. More specifically, Roll-to-Roll (R2R) coating us currently the only manufacturing process that is able to create battery electrodes at a suitable throughput and cost. All processes developed in this project are designed from early development phases to be compatible with R2R to ensure that the outcomes of our research are relevant to the EU’s industrial stakeholders.
Increasing the thickness of battery electrodes is an attractive approach to reduce the fraction of battery parts that do not store energy, such as current collectors and separators. However, the fabrication of thick electrodes holds challenges of its own such as cracking or flaking during the electrode production and limitations in ion and electron transport. One important contribution from this project is that we developed a scalable roll-to-roll compatible method for fabricating ultrathick electrodes using a phase segregation process. This manufacturing method creates a bi-continuous electrolyte and electrode network with excellent ion and electron transport reducing the charge-transport challenges in thick electrodes. Using this process, electrodes with areal capacities of more than 30mAh/cm2 are demonstrated. Capacity retentions of 87% are attained over 500 charge-discharge cycles. Finally, we verified the scalability of the TIPS process by coating thick electrodes continuously on a pilot-scale roll-to-roll coating tool.
Other advances include the discovery that energy can be stored reliably in anodes using a combination of three different energy storage mechanisms: Intercallation, alloying and plating. By balancing these three mechanisms, stable high energy density anodes were achieved. Finally, an unexpected discovery during this project was the observation that certain material formulations which allow for both storing energy (as in a battery) and harvesting light energy (as in a photo-voltaic cells). Finally, part of our work has been focusing on how to crease better structured active materials, which is being evaluated for patenting and could lead to a new spin out company being created.
Other advances include the discovery that energy can be stored reliably in anodes using a combination of three different energy storage mechanisms: Intercallation, alloying and plating. By balancing these three mechanisms, stable high energy density anodes were achieved. Finally, an unexpected discovery during this project was the observation that certain material formulations which allow for both storing energy (as in a battery) and harvesting light energy (as in a photo-voltaic cells). Finally, part of our work has been focusing on how to crease better structured active materials, which is being evaluated for patenting and could lead to a new spin out company being created.
A total of 17 journal papers have been published, which each represent an important contribution to the state of the art. We have achieved substantial breakthroughs beyond the state of the art in increasing the areal loading of batteries using scalable manufacturing processes. Further, we developed a new approach to balance energy storage in batteries using a combination of intercalation, alloying and plating. We have also made important new contributions to multi-functional battery materials to combine energy harvesting and storage in a combined device. In the next phase of the project, we seek to further advance our insights into methods to structure battery electrodes using continuous roll-to-roll coating processes. Ultimately, this will lead to increases in energy and power densities of batteries relying on manufacturing methods that are relevant to European industrial stakeholders.