Electrochemical storage systems: safer and more sustainable batteries

Lithium-ion batteries (LIBs) are the predominant power source for portable electronic devices, and in recent years their use has extended to higher energy and larger devices. However, to satisfy the stringent requirements of safety and energy density, further material advancements are required. Due to the inherent flammability of organic solvent-based liquid electrolytes and their instability against materials utilized in high-energy systems, a transition to alternative io conductive media becomes urgent. In this paper, some possible solutions, shifting from molecular liquids to a class of materials based on ions, such as ionic liquids (ILs), and polymers, such as gel polymer electrolytes (GPEs), will be briefly discussed. Moreover, innovative technologies, the so-called beyond-lithium batteries, will be presented, considering a more sustainable anode material based on calcium.