After 20 years of isolation, the research on Li‐ion technology became highly diversified, especially with the arrival of nanomaterials, which opened up many opportunities that are explained in this chapter. Technological breakthroughs still to be made on electrode materials, electrolytes and formulation to improve performances, reliability and safety of nanomaterials are also discussed. The electrodes function over a wide voltage range (0.1 V to 4.6 V) which requires the design of electrolytes that are perfectly resistant to oxidation and reduction. Liquid electrolytes and liquid ionic polymers have been considered, primarily to determine the best formulation by trial and error. The study of electrode/electrolyte interfaces and the impact of their formulation on the electrochemical performance of the negative or positive electrode material or even of the system are currently preferred at RS2E rather than the "design" of new salts or solvents.