Details

Autor(en) / Beteiligte

• Sudayama, Takaaki
• Uehara, Kazuki
• Mukai, Takahiro
• Asakura, Daisuke
• Shi, Xiang-Mei
• Tsuchimoto, Akihisa
• Mortemard de Boisse, Benoit
• Shimada, Tatau
• Watanabe, Eriko
• Harada, Yoshihisa
• Nakayama, Masanobu
• Okubo, Masashi
• Yamada, Atsuo

Titel

Multiorbital bond formation for stable oxygen-redox reaction in battery electrodes

Ist Teil von

• Energy & environmental science, 2020, Vol.13 (5), p.1492-15

Ort / Verlag

Cambridge: Royal Society of Chemistry

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• High-energy-density batteries have been a long-standing target toward sustainability, but the energy density of state-of-the-art lithium-ion batteries is limited in part by the small capacity of the positive electrode materials. Although employing the additional oxygen-redox reaction of Li-excess transition-metal oxides is an attractive approach to increase the capacity, an atomic-level understanding of the reaction mechanism has not been established so far. Here, using bulk-sensitive resonant inelastic X-ray scattering spectroscopy combined with ab initio computations, we demonstrate the presence of a localized oxygen 2p orbital weakly hybridized with transition metal t 2g orbitals that was theoretically predicted to play a key role in oxygen-redox reactions. After oxygen oxidation, the hole in the oxygen 2p orbital is stabilized by the generation of either a (σ + π) multiorbital bond through strong π back-donation or peroxide O 2 2− through oxygen dimerization. The multiorbital bond formation with σ-accepting and π-donating transition metals can thus lead to reversible oxygen-redox reaction. Nonbonding oxygen 2p orbitals during oxygen-redox reaction are monitored using resonant inelastic X-ray scattering (RIXS).