**6. Conclusions**

Aerosol Spray pyrolysis is a sustainable and promising route for the synthesis of anode and cathode nanostructured materials, which is exploited by research laboratories and is employed for industrial production. In the current work, LiNi0.5Mn1.5O4 spinel was synthesized at a production rate of 100 gr hrs−1 and was studied for three different doping compositions of Mg, Fe and Al; LiNi0.4Mg0.1Mn1.5O4, LiNi0.42Fe0.08Mn1.5O4 and LiNi0.4 Al0.1Mn1.5O4 by substituting Ni molar ratio in the spinel lattice. The aqueous precursor solutions were sprayed at a heated tubular reactor at 800°C, while further calcination of the collected powder was carried out at 850°C for 16 hrs [11]. The Raman spectra and XRD diagrams depict successful synthesis of the mixed structure, while SEM showed spherical particles with partially hollow morphology. The electrochemical evaluation was performed for different electrode formulations and loading/densities in half coin cells at different C-rates. Fe- and Al-doped materials for the electrode formulation

AM/C/PVdF = 90/5/5 exhibited high specific capacity values (~120 mAh. g−1) at low C-rates, while at higher discharge C-rates of 2C, 5C, 8C and 10C the specific capacity demonstrated values of ~110, ~90, ~50 and ~ 20 mAh. g−1 respectively, showing interesting activity for further study, while pristine and Mg- doped material showed very low capacity at rates exceeding 1C. Fe- and Al- LNMO were further studied at lower active material ratios; namely 80/10/10 ratio using a density of 1.5 g. cm−3, where Fe-doped LNMO demonstrated higher values of specific discharge capacity compared to Al-doped LNMO at low C-rates of C/5 to 1C (~138 and 118 mAh. g−1 respectively), while similar performance in the range 80–100 mAh. g−1 was observed for the higher C-rate of 5C. Increasing the amount of active material to 84/8/8 to increase electrode energy density for practical battery application, improved the capacity for the Al-doped case, while a capacity reduction was observed for the Fe-doped LNMO. The current work shows the potential of Fe and Al doped LNMO synthesized by ASP as promising materials for cobalt free cathodes for the development of high voltage next generation Li-ion batteries.
