ULtra-ThIck Multi-mAterial baTtery Electrodes

ended

Over the past decades, significant advances have been achieved in the performance of Li-ion batteries by the development of new active materials and better understanding of energy storage and degradation mechanisms. One aspect of batteries that has received little attention so far, is the form factor of the electrodes. However, simple changes in the battery architecture, such as increasing the coating thickness, allows to drastically decrease the relative fraction of dead volume in the battery (e.g. separators and current collectors). Theoretically, it is possible to replace a stack of ten standard 50 µm thick electrode coatings by one 500 µm thick coating. This would result in up to 30% savings in weight as well as volume of the battery, and would be transformative for both portable electronics and electrical vehicles. However, this is fundamentally challenging because of 1) slow ion diffusion through thick electrodes, 2) high electric resistance through the thickness of the electrode, and 3) cracking and flaking challenges during the fabrication of thick electrodes. This MSCA Fellowship is building on novel gel electrodes developed by the applicant, which can be moulded into 3D geometries that allow to move away from the current flat battery morphology and to address the above challenges with thick battery electrodes. During this Fellowship, the dynamics of ion and electron transport in thick 3D interdigitated electrodes will first be simulated. Then, the electrochemical performance of the gels will be optimised, in particular, a phase separation method to improve Li-diffusion will be optimised. Next, the thermal moulding process will be optimised to create interdigitated electrodes which will be tested in half and full cells. Finally, the proposed fabrication process will be demonstrated on a roll-to-roll coater, which is important to prove its scalability to industrial stakeholders.