Cobalt-free cathode for high voltage lithium-ion batteries

The constant growth in the demand of clean energy is driving the world towards an electrification of many sectors, such as transportation and building, and towards renewable technologies for a sustainable energy production and use. For this reason, the energy storage systems will become always more important to cover the fluctuations of the energetic demand, going to compensate the non-linearity of the renewable sources. Among the types of energy storage systems, batteries, thanks to their versatility, are the most considered. In particular, the lithium-ion batteries are the most promising, both for grid-energy storage and distribution and for the utilization in electric vehicles. However, more research and technological development is needed, not only for increasing their energy density and safety, but also for decreasing the production cost and environmental impact, and for their end-of-life management, since critical materials and components with high environmental hazard are also used. This work has been carried out under a collaborative project set between MIDAC S.p.A., partner of the IPCEI/012/00B2 program and GISEL – INSTM (Research unit: University of Bologna), and within the PNRR Project CNMS-Spoke 13-MOST. The purpose of this thesis is the formulation of Cobalt-free, high voltage cathodes (LiNi0.5Mn1.5O4, LMNO) for lithium-ion batteries. The electrodes featured a commercial LMNO powder and were formulated by blending this active material with carbon conductive additive and different binders, and by modifying the mass ratios of the components. The electrochemical characterization was performed by using the benchmark electrolyte used in today lithium-ion batteries, i.e., a solution of Lithium hexafluorophosphate dissolved in mixture of ethylene carbonate – dimethyl carbonate. This study provided a benchmark to MIDAC to compare the performance of the electrodes that they are developing by a recycling approach from spent batteries.