Abstract
While current commercial lithium-ion batteries consist of stacked leaflets (2D planar design), innovative approaches, such as additive manufacturing, are now required to enable the development of 3D complex architectures reported to significantly improve the electrochemical performances in terms of power. In this context, the aim of this PhD thesis was to demonstrate the printability of lithium-ion battery components by means of the Fused Deposition Modeling (FDM) 3D-printing process. First stage was thus dedicated to the development and optimization of polylactic acid (PLA)-based composite filaments, corresponding to each part (electrodes, separator and current collector) of a liquid electrolyte lithium-ion battery (LIB) configuration. The active material within the electrode filaments was increased as high as possible to maximize the electrochemical performances while still maintaining just enough mechanical strength for handling and printing. The incorporation of such a high amount of charges was made possible thanks to the incorporation of an optimized amount of poly(ethylene glycol) dimethyl ether average Mn ~ 500 (PEGDME500), acting as plasticizer. In parallel, PLA/Ag-Cu current collector, and PLA/SiO2 separator filaments were developed. From the optimized filament compositions, assembly from independent 3D-printed components (stacking), and direct printing of the complete LIB in a single step (one-shot), have been demonstrated. On the other hand, as a safer alternative to the classical volatile and flammable organic solvent-based liquid electrolyte configuration, the elaboration and optimization of a solid polymerelectrolyte filament composed of poly(ethylene oxide) (PEO) as polymer matrix and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) as lithium salt, for an all-solid-state LIB, was achieved. Finally, acting as a perspective study, the last part of this PhD thesis was focused on the development of polypropylene (PP)-based composite electrodes via FDM and selective laser sintering (SLS)