Unraveling the Catalytic Mechanism of Co₃O₄ for the Oxygen Evolution Reaction in a Li–O₂ Battery

Abstract

Unraveling the catalytic mechanism of transition-metal oxides (TMOs) for the charging reaction in a Li−O 2 battery and characterizing their surface structures and electronic structure properties of active sites are of great importance for the development of an effective catalyst to improve low round-trip efficiency and power density. In the current study, an interfacial model is first constructed to study the decomposition reaction mechanism of Li 2 O 2 supported on Co 3 O 4 surfaces. The computational results indicate that the O-rich Co 3 O 4 (111)C with a relatively low surface energy in high O 2 concentration has a high catalytic activity in reducing overpotential and O 2 desorption barrier due to the electron transfer from the Li 2 O 2 layer to the underlying surface. Meanwhile, the basic sites of Co 3 O 4 (110)B surface induce Li 2 O 2 decomposition into Li 2 O and a dangling Co− O bond, which further leads to a high charging voltage in the subsequent cycles. The calculations for transition-metal (TM)-doped Co 3 O 4 (111) indicate that P-type doping of Co 3 O 4 (111) exhibits significant catalysis in decreasing both charging overpotential and O 2 desorption barrier. The ionization potential of doped TM is determined as an important parameter to regulate the catalytic activity of metal oxides.

Recent Progress in Electrocatalyst for Li‐O2 Batteries

“…[169,170] The high active catalyst should have an appropriate O adsorption strength close to those of well-established Pt and Pd catalysts. Other kinds of factors which can correlate with the performances, such as the catalyst size, [171,172] the crystal facet, [173,174] and the conductivity are reported. [175] Among these efforts, Zhu…”

Adsorption-energy-based activity descriptors for electrocatalysts in energy storage applications

“…Furthermore, they took surface acidity (defined as the energy change of catalysts with charge transfer) as a descriptor of charge transfer to study the electrocatalytic activity in the charging process [77,80,81]. They elucidated that the O-rich Co 3 O 4 (111) surface with a relatively low surface energy, promoting charge transfer from the Li 2 O 2 particles to the underlying surface, has a high catalytic activity to reduce overpotential and the O 2 evolution barrier [80]. Furthermore, as shown in Fig.…”

Porous nanoarchitectures of spinel-type transition metal oxides for electrochemical energy storage systems

“…To examine the catalytic effect, Zhu et al carried out firstprinciples studies on the Co 3 O 4 surfaces and suggested that the Co 3 O 4 surface with Lewis acid sites is capable of reducing charge voltages due to facilitated electron transfer from Li 2 O 2 to the catalytic surface and a reduced O 2 desorption barrier. 141 Using a carbon-free, oxide-only cathode, moreover, Lee and his co-workers have provided clear evidence that Co 3 O 4 and other spinel-type transition metal oxides have the ability to catalyse O 2 reduction and Li 2 O 2 decomposition in an ether-based electrolyte. 142,143 Given that Li 2 O 2 should be stored within the cathode, three-dimensional (3D) architectures of the cathode would play a significant role in determining the electrochemical performance of non-aqueous Li-air batteries.…”