A large effort is performed in order to enable 2nd life of batteries. This effort is often concentrated around extrapolating cycle life data. Some also take calendar life into account but this is not sufficient. All Li-ion battery cells are sealed to prevent electrolyte leakage. This sealing is, however, not perfect and volatile components from the electrolyte can escape. Moreover, if battery cells are charged too hard, hydrogen can be generated and hydrogen will be even more prone to escaping the battery cells than the volatile organic electrolyte components. Knowing that the electrolyte volume and composition influences performance, lifetime and safety, investigating the battery cell seal quality is important for all cell formats; pouch, prismatic & cylindrical. In this project the partners will be focusing on the cell seal quality with the aim to understand the life time of the seal under different conditions. Moreover, quantifying the effect on the cell properties in the event of leakage of the volatile electrolyte components will be an important part of the project. This will help building a very solid foundation for assessing the boundaries of 2bd life applications.
This project focuses on analyzing and assessing the seal integrity of Li-ion battery cells for use in second life applications. The battery cell seal is a very important part in ensuring the extended life of used Li-ion batteries. If the cell container cannot withstand and ensure a leak-free operation for >20 years, use in 2nd life applications cannot be warranted. Any leak in the battery container could impose a safety hazard and thus be critical to further battery operation.
The project will develop a novel methodology for opening Li-ion cells without damaging the seal of the cells. All different common Li-ion geometries will be evaluated. However, the main focus will be on Li-ion pouch cells. With the use of X-ray tomography (CT scan) Li-ion cells will be scanned prior to any disassembly to guide the exact placement for incisions to open these batteries. Furthermore, a methodology to characterize the seal quality and gas and electrolyte leakage from the cells will be developed. By combining these activities with modelling tools, the understanding of cell performance and seal degradation will be established. This will enable Corvus Energy to decide whether the life of their Li-ion cells can warranted after first application use, and hence be a business case of second-life reuse of maritime Li-ion cells.