Design and characterization of flexible lithium-ion batteries

The inherent link between human development and energy management is unquestionable. Among energy sources, electrical energy and more precisely lithium-ion battery has emerged as a critical technology to power everyday life equipment. Recently, development of intelligent clothes and flexible displays or electronics has created the need for new off-grid energy solutions to be seamlessly integrated with equipment. To meet this requirement, we have considered in this thesis the creation of flexible lithium- ion batteries using a new process. To achieve this objective, we created electrodes through a filtration process. Dispersions of active materials such and multi-walled carbon nanotubes were filtered to produce performing self-standing electrodes with excellent electrochemical properties. Morphology and electrochemical properties of carbon nanotubes allowed the production of conducting network supporting the active materials. A second part of this work was devoted to the creation of separators. Cellulose nanofibers were individualized from soft wood pulp and filtered to produce robust separators that can be included in electrochemical cells. Poly(ethylene oxide)-based electrolyte were later designed. Modified silica nanoparticles were incorporated to improve mechanical properties while preserving ionic conductivity. Last part of this work was dedicated to the design of full cells by sequential filtration of all the components. It was proved that this method can be envisioned to produce performing lithium-ion batteries in a single step.