to be satisfied. The range of Li, Mn, Ni and O chemical potential values where LMNO is thermodynamically stable can therefore be determined in this way using CPLAP. The atomic chemical potential diagrams for the host was constructed by exploring the stable competing Li-Mn-Ni-O phases in Materials Project (accessed date: 22 Nov 2020). Magnetic compounds were relaxed with the ground state magnetic ordering, according to previous literature studies. Elemental reference energies were obtained from the constituent elements in their standard states e.g. O 2 (g). In a solid, defects typically occur in multiple charge states with positive/negative charge states involving removal/addition of electrons. The actual position of Fermi level (µ e ) is determined by minimising the system energy under self-consistent charge neutrality condition using py-sc-fermi: 49,77,78