Energy storage devices: graphite/LiFePO4 batteries and supercapacitors

Lithium-ion batteries are the leading rechargeable systems on the market today and they are considered as promising candidates for application in high-rate devices. However, the safety of lithium-ion battery is still a technical hurdle for same interesting applications, such as in hybrid electric vehicles and electric vehicles. Up to now, literature research is focused on studying batteries under extreme conditions in order to improve their safety. In this work, post-mortem experimental studies have been performed on graphite/LiFePO4 cells designed for power-type applications, investigating a fresh and an abused cell under normal/regular conditions. Still in the field of energy storage, a highly interesting alternative to batteries are supercapacitors that have gained a lot of attention for their high specific capacitance, long life cycle, high power density and safety. In particular, literature studies focus on the development of new materials, such as biomass-derived graphene-like carbon ones, to be used in novel energy storage applications. In detail, porous activated carbons represent promising candidates for electric double layer capacitors. On this basis, in this work, two activated carbons materials were prepared starting from the waste biomass hazelnut shells, using KOH as activated agent. The preliminary cyclic voltammetry and electrochemical impedance spectroscopy measurements have shown promising results.