Nowadays, Batteries performance and efficiency is a main stake for electrical energy storage. The huge amount of different usages like energy, transport, communications, etc make them strategic for research and development topics.
Their performances depends mainly on their power density and their charge/discharge rate speed. The porosity of the electrodes plays a key role on these two parameters. However, its effects is antagonist: a lower porosity gives a better power density but leads to a lower ionic conductivity inside the porosities and thus a lower charge/discharge rate speed. The manufacturers constantly search and want to make the best compromise between power density and charge/discharge rate speed. This porosity is obtained during their manufacturing process.
During its manufacturing process, the electrode is calendered. This step consist in reducing its porosity by applying a stress between two cylinders. The link between the calendering parameters and the final characteristics of the electrodes needs improvements. During a previous PhD, we developed and set up a simulation tool for this manufacturing step. We employed the Discrete Element Method to simulate the granular behaviour of the active material, its binder and the electrode. We studied the effect of the mechanical properties of the binder on the mechanical behaviour of the electrode during the calendering process and compared the results of the simulation to experimental data.
This PhD aims to go further in the simulation to integrate more physics inside the model and take into account the deformation of the current collector, central part of the electrode. This new feature will allow us to improve the simulations and study the influence of the deformation of the current collector on the final properties of the electrodes like its microstructure.
This PhD work will be carried out within the IRESNE Institut (CEA Cadarache centre), in the Nuclear Fuels Department (DEC) in close collaboration with academia(LMGC, Montpellier University) and the CEA/LITEN from Grenoble. The student will have access to both advanced Discrete Element Codes and to unique developing and simulation facilities.