Vacancy graphite as the cathode materials of Al-Ion batteries using first principle calculation

Abstract

The defect graphite will change the electrochemical properties of the aluminium-ion batteries. However, the theoretical research on the defect-free graphite as cathode material for aluminium-ion batteries remain uncertain. Therefore, the objective of this paper is to develop the theoretical prediction of defect graphite to be used in the aluminium-ion batteries analysis. The structural properties of graphite and vacancy point defect of graphite were calculated using the first principle calculation. The generalized gradient approximation and van der Waals correction (vdW-D3) implemented to the calculation. The validation of the methodology on the defect-free graphite is evaluated with the experiment and other theoretical prediction. After that, the lattice constants of the defect graphite were evaluated and calculate the formation energy. The results show that the lattice constant of defect-free graphite was closer to the experimental values compared to other theoretical prediction. However, the atomic distances near to the vacancy point observed slightly lower than other theoretical prediction using different exchange correlation approximation. The formation energy calculated for monovacancy and divacancy was 7. 92 eV and 7.34 eV, respectively. As a conclusion, the structural properties obtained in this calculation could be references in the development of the defect cathode analysis in the aluminium ion batteries.