Direct Growth of CuO Particles on Carbon Papers for High-Performance Rechargeable Li-O₂ Batteries.

Lithium-oxygen (Li-O₂) batteries are considered as a promising high-energy storage system. However, they suffer from overpotential and low energy efficiency. This study showed that CuO growth on carbon using facile synthesis (simple dipping and heating process) reduces overpotential, thus increasing the energy efficiency. We confirmed the structure of CuO on carbon using X-ray diffraction pattern, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, and field-emission transmission electron microscopy. The cathode of CuO on carbon shows an average overpotential reduction of ˜6% charge/discharge during 10 cycles in nonaqueous Li-O₂ batteries. The possible reason for the reduced charge overpotential of the cathode of CuO on carbon is attributed to the formed Li₂O₂ of smaller particle size during discharging compared to pristine carbon.