High-rate oxygen evolution reaction on Al-doped LiNiO2

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The oxygen evolution reaction (OER) is crucial for energy conversion technologies.
• Developing efficient and cost-effective OER catalysts is a significant challenge.
• Iridium dioxide (IrO2) is a benchmark OER catalyst but is expensive.

Purpose of the Study:

• To investigate the OER activity of LiNi0.8 Al0.2 O2 synthesized by solution-combustion.
• To explore the role of nickel's redox states in OER catalysis.
• To compare the performance of LiNi0.8 Al0.2 O2 with IrO2.

Main Methods:

• Synthesis of LiNi0.8 Al0.2 O2 using the solution-combustion method.
• Electrochemical characterization of the synthesized material for OER activity in alkaline solution.
• Analysis of nickel redox states and their correlation with OER performance.

Main Results:

• LiNi0.8 Al0.2 O2 demonstrated OER activity comparable to IrO2.
• A higher degree of Ni(3+)/Li(+) ordering was observed in the synthesized material.
• The octahedral-site Ni(IV)/Ni(III) couple was identified as an active redox center for OER.

Conclusions:

• Solution-combustion synthesis yields LiNi0.8 Al0.2 O2 with high OER performance.
• Nickel-based oxides with specific Ni redox states can be effective OER catalysts.
• The findings suggest a promising alternative to precious metal catalysts like IrO2 for OER.