In this project we aim to develop an innovative and safe Li-ion cell that overcomes the state-of-the-art analogues. Our focus will be the exploitation of novel formulations by combining a high potential positive electrode (i.e. the spinel LiMn1.5Ni0.5O4, LMNO), a safe nanostructured negative electrode (i.e. Li4Ti5O12, LTO) and innovative advanced electrolytes (based on sulfone solvents, post-LiPF6 salts and additives, such as ionic liquids) able to safely operate at high cell voltage. To this aim, the optimization of the positive electrode/electrolyte interface at high potential is the major challenge and will be the core-innovation of this project.
In the first part of the project, based on the previous knowledge and experience of the Research Team concerning materials for Li-cells (e.g. high potential cathodes and novel non-aqueous electrolytes based on ionic liquids) and surface investigations, the study of the nature and stability of electrode interface at high potential will be addressed. The final goal is to suppress or mitigate irreversible capacity losses upon cycling, due to the parasitic reactivity of the electrolyte above 4.5 V vs. Li. To this aim, the electrolyte (formed by sulfone-ionic liquid mixtures with boron-salt additives) will be designed and optimized in order to drive the spontaneous formation of an effective solid-electrolyte-interface layer at the positive electrode/electrolyte interface.
In the second part of the project, the innovations developed will be implemented in full Li-ion configurations. The Li-ion cells, adopting the most promising home-made electrolytes and commercial LTO anode and LMNO cathode, will be tested to assess their performance retention upon cycling and stability of the electrode/electrolyte interfaces. The final target of this project is to develop a prototypal coin-cell, at lab-scale demonstrator, able to overcome the state-of-the-art performances in terms of specific energy, cycling life and safety.