Detailed Mechanical Characterization of LiCoO2 and LiNi0.33Co0.33Mn0.33O2 Cathode Materials Using DFT Calculations

We investigated and compared various mechanical properties of two major cathode materials (LiCoO2 (LCO) and LiNi0.33Co0.33Mn0.33O2 (NCM)), which are particularly susceptible to degradation among components of lithium-ion batteries. In this analysis, ab initio calculations using density functional theory (DFT) are adopted. The plotting of stress-strain curves and mechanical characterization of Li-deintercalated structures are conducted in addition to conventional elastic tensor calculations. In this study, the elastic moduli (stiffness) of LCO and NCM are similar, however, the strength and durability of the NCM cathode in the c-axis direction are clearly lower than those of LCO. These approaches can be applied to the mechanical characterization of new promising cathodes in the future. We conducted various mechanical chcaracterization of two major cathode materials: LiCoO2 (LCO) and LiNi0.33Co0.33Mn0.33O2 (NCM) using ab-initio calculations, including the plotting of stress-strain curves and mechanical characterization of Li-deintercalated structures. Our main results are that the stiffness of LCO and NCM are similar whereas the strength and durability of the NCM cathode are clearly lower than those of LCO.