Sensing and self-healing of batteries
Apart from offering larger energy density at lower costs, the increasing social demand is also calling for improvements to enhance present batteries lifespan, reliability, durability, and sustainability. It implies introducing smartness in batteries and monitoring their state of health in order to extend their lifetime. Thus, batteries could be given a second life by switching them from an application to another (e.g. EVs to smart grid technologies) as a function of their real-time-monitored performances. The research activities on smart batteries at CSE are inspired by medicine and mainly focus on embedding batteries with intelligent sensing and curing chemical functionalities.
The sensing of batteries is carried out using non-invasive operando techniques where a fibre Bragg grating (FBG) sensor(s) is injected into the batteries that sense battery functionalities such as local temperature (T), pressure (P) and strain (ε), with high temporal and spatial resolution. The obtained information together with the knowledge about the cell chemistry is used to understand parasitic reactions and interfacial growth dynamics. Additionally, by wisely combining multiple optical fibres, calorimetry measurements are performed to access heat flow information, which will help to improve cooling and battery management systems of electrical vehicles. The methodology developed so far could be used in both Li- as well as Na-ion batteries irrespective of the cell geometries (18650, pouch type and coin type cells).
As a next step, such a diagnosis must be followed by a healing strategy to resorb electrodes cracks, restore electrode conductivity or regulate species migration through smart membrane, hence improving batteries cycling life. Towards this application, a team of our group has been focusing on the development of new materials, based on bio-molecules or polymers with auto-repairing properties relying on dynamic supramolecular self-assembly, to be integrated inside electrochemical cells.
Our innovative research strategy coupling both sensing and self-healing functionalities are part of the large-scale European research initiative BATTERY 2030+.