Lattice strains in the layered Mn, Ni and Co oxides as cathode materials in Li and Na batteries

• The lattice strains in the layered Mn–Ni–Co oxides were described in detail.
• Effect of different cation substitutions on the lattice strains was discussed.
• The strains result in disintegration and cation ordering in solid solutions.
• Changes in the lattice strains agree with those of formation energy.

This work proposes for the first time a detailed description of the lattice strains in the layered Mn-Ni-Co oxides and their derivatives based on the available structural data. It relates the strains to material instability upon synthesis and electrochemical functioning. In particular, it was shown that exsolution (separation on two phases) or cation ordering in two-component solid solutions, LiCo1-yMyO2 and LiNi1-yMyO2 (M - different cations), can be predicted in accordance with the introduced tolerance factor. Bond valence model was used for the strain calculations. The results agree with the first principle calculations.

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