Ceria based catalyst for cathode in non-aqueous electrolyte based Li/O2 batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-oxygen (Li/O2) batteries offer high theoretical energy density.
• Development of efficient cathode catalysts is crucial for Li/O2 battery performance.
• Non-aqueous electrolytes present unique challenges for Li/O2 battery operation.

Purpose of the Study:

• To investigate combustion synthesized cerium zirconate (Ce(1-x)ZrxO2, CZO) as a novel cathode catalyst for non-aqueous Li/O2 cells.
• To evaluate the effect of zirconium doping on CZO's catalytic activity and electrochemical properties.
• To explore composite CZO-based materials for enhanced Li/O2 battery performance.

Main Methods:

• Combustion synthesis of CZO catalysts with varying Zr content (x = 0.1-0.5).
• Characterization of CZO catalysts including structure (fluorite) and morphology (spherical, 5-17 nm diameter).
• Electrochemical testing of CZO as a cathode catalyst in Li/O2 cells to determine discharge capacity and reaction pathways.

Main Results:

• CZO catalysts exhibit a fluorite structure with tunable properties.
• Zr doping reduces Ce4+ to Ce3+, enhancing catalytic activity.
• Ce0.8Zr0.2O2 achieved a maximum discharge capacity of 1620 mAh g(-1) due to high surface area and porosity.
• CZO demonstrated a two-electron oxygen reduction pathway.

Conclusions:

• Combustion synthesized CZO is a promising cathode catalyst for non-aqueous Li/O2 batteries.
• Optimized Zr doping and high surface area contribute to superior electrochemical performance.
• CZO/MnO2 composites show potential for further improvements in Li/O2 cell efficiency.