Ab-initioStudy of the Strain Tuning Method for Improving Li Diffusion Performance of the LiCoO2Cathode Material in Lithium-ion Batteries

The charging speed of lithium-ion batteries can be enhanced by improving the diffusion performance of Li ions inside and at the interface of their cathodes. In this study, we applied strain to LiCoO2(LCO) cathode materials to elongate their lattices, and the relationship between the lattice strain and energy required for Li deintercalation, referred to as “Li vacancy formation energy,” was estimated by ab-initiocalculations to determine the optimal strain. The results suggest that the charging speed can be improved by adding a strain of less than 5% while retaining its high mechanical properties and equilibrium potential. Furthermore, we found that applying approximately 10% strain in the c-axis direction significantly reduces the Li vacancy formation energy of the LCO cathode.We applied strain to LiCoO2cathodes to elongate their lattices, and the relationship between the lattice strain and energy required for Li deintercalation was estimated by ab-initiocalculations. We found that the charging speed can be improved by adding a strain of less than 5% while retaining its high mechanical properties and equilibrium potential.