Mn-modulated Co–N–C oxygen electrocatalysts for robust and temperature-adaptative zinc-air batteries

Abstract

Flexible zinc-air batteries (FZABs) are featured with safety and high theoretical capacity and become one of the ideal energy supply devices for flexible electronics. However, the lack of cost-effective electrocatalysts remains a major obstacle to their commercialization. Herein, we synthesized a porous dodecahedral nitrogen-doped carbon (NC) material with Co and Mn bimetallic co-embedding (Co_xMn_1−x@NC) as a highly efficient oxygen reduction reaction (ORR) catalyst for ZABs. The incorporation of Mn effectively modulates the electronic structure of Co sites, which may lead to optimized energetics with oxygen-containing intermediates thereby significantly enhancing catalytic performance. Notably, the optimized Co₄Mn₁@NC catalyst exhibits superior E_1/2 (0.86 V) and j_L (limiting current density, 5.96 mA cm⁻²) compared to Pt/C and other recent reports. Moreover, aqueous ZAB using Co₄Mn₁@NC as a cathodic catalyst demonstrates a high peak power density of 163.9 mW cm⁻² and maintains stable charging and discharging for over 650 h. Furthermore, FZAB based on Co₄Mn₁@NC can steadily operate within the temperature range of −10 to 40 °C, demonstrating the potential for practical applications in complex climatic conditions.