First-principles density functional theory (DFT) simulation has become a powerful tool to explore the material properties and reaction mechanisms in electrochemical energy conversion and storage devices. In this study, DFT simulations were applied in understanding the electrolyte decomposition mechanisms in lithium-ion batteries (LIBs) on both LiCoO₂ (LCO) and LiNi_1/3Co_1/3Mn_1/3O₂ (NCM) layered cathode materials. It was found that the decomposition of ethylene carbonate (EC) was initiated by the ring-opening reaction and followed by the H-abstraction reaction on metal oxide surfaces. In another study, Li plating mechanism in Li metal-based batteries was elucidated by DFT simulations for the first time. The extreme reactivity of the Li metal surface induced a strongly inhomogeneous e...[ Read more ]

First-principles density functional theory (DFT) simulation has become a powerful tool to explore the material properties and reaction mechanisms in electrochemical energy conversion and storage devices. In this study, DFT simulations were applied in understanding the electrolyte decomposition mechanisms in lithium-ion batteries (LIBs) on both LiCoO₂ (LCO) and LiNi_1/3Co_1/3Mn_1/3O₂ (NCM) layered cathode materials. It was found that the decomposition of ethylene carbonate (EC) was initiated by the ring-opening reaction and followed by the H-abstraction reaction on metal oxide surfaces. In another study, Li plating mechanism in Li metal-based batteries was elucidated by DFT simulations for the first time. The extreme reactivity of the Li metal surface induced a strongly inhomogeneous electron distribution upon deposition of a cation on the surface. This strong charge inhomogeneity favored further attraction of cations and their reduction, thus promoting uneven Li growth.

DFT calculations were also used to explore electrocatalytic reactions including hydrogen evolution reaction (HER) and CO₂ reduction reaction (CO₂RR) on various advanced electrocatalysts. Pd₃Ru with Ru clusters on catalyst surfaces showed excellent activity toward HER in alkaline solutions. Theoretical simulations demonstrated that the existence of Ru clusters could weaken the H binding energy, enhance the OH adsorption, consequently reducing the reaction barrier of the rate-determining step (RDS). Fe, N co-doped carbon materials (Fe-N-C) showed excellent selectivity on CO during the CO₂RR. DFT simulations revealed that the Fe sites were poisoned by strongly adsorbed *CO, which was consistent with the in situ infrared absorption spectroscopic results. The excellent CO₂RR performance originated from the Fe-N₄moieties embedded in defective nanoporous graphitic layers with balanced binding energies of adsorbed *COOH and *CO intermediates.