Understanding the Decomposition Mechanism of Li2O2 in the Cathode of Li-O2 Battery with First Principles Molecular Dynamics
نویسندگان
1 Department of Physics, University of Barishal, Kornokathi, Barishal-8200, Bangladesh
2 Department of Physics, University of Barishal, Kornokathi, Barishal-8200, Bangladesh
3 Department of Environmental Chemistry and Chemical Engineering, School of Advanced Engineering, Kogakuin University, 2665-1 Nakano Hachioji, Tokyo 192-0015, Japan
doi
10.22036/pcr.2025.512159.2655چکیده
First-principles molecular dynamics (FPMD) regarding electron removal was used to investigate the decomposition of lithium peroxide (Li2O2) as a model of the cathode reaction in a lithium–air (Li–O2) battery. The decomposition of Li2O2 was demonstrated in a vacuum and the Li2O2 cluster at the surface of the carbon cathode as a function of the number of electrons that was removed from the system. Further, the Li2O2 cluster was decomposed into Li+ and LiO2, after which it almost formed Li+ and molecular oxygen (O2). The formation of O2 after delithiation was confirmed from the measured bond length, frequency, and atomic charge analysis. The estimated voltage that was required for the decomposition reaction was calculated from the free energy changes (~4.0 V); it agreed well with the experimental value. Moreover, the carbon layer increased the voltage, indicating that the interaction of Li2O2 with the cathode surface also contributed to the charging voltage.
