Urea-Assisted Sol-Gel Synthesis of LaMnO3 Perovskite with Accelerated Catalytic Activity for Application in Zn-Air Battery

Abstract

Precious metal-based materials such as commercial Pt/C are available electrocatalysts for redox reactions in Zn-air batteries. However, their commercial use is still limited by slow kinetics and restricted stability. In this work, we highlight a facial urea-assisted sol-gel method to synthesize A-site vacancy in LaMnO3+δ oxide for boosting its catalytic activity and further explore the effect of the amount of urea on the A-site LaMnO3. The A-site vacancy in LMO was confirmed by XRD, TEM, and XPS, which revealed that the urea-assisted sol-gel method mitigated the A-site vacancy in LaMnO3+δ and increased its surface area, thus ultimately accelerating its redox reaction kinetics. The half-wave potential and current density of the resultant 3.0U-LMO electrocatalyst were 0.74 V and 5.74 mA cm−2, respectively. It is worth noting that the assembled Zn-air battery with the 3.0U-LMO catalyst presented a power output of 130.04 mW cm−2 at 0.51 V and a promising energy efficiency of 58.4% after 150 cycles. This protocol might offer an efficient approach for developing new defect-regulated perovskites for electrocatalysis.