Room-temperature, one-step synthesis of Mn3O4 nanoparticles using morpholine as a complexing and precipitating agent: toward a cathode material for zinc-ion batteries†

The quest for sustainable energy storage has spotlighted zinc-ion batteries (ZIBs) for their safety, cost-effectiveness, and eco-friendliness. Manganese oxides, particularly Mn₃O₄, stand out as promising cathode materials due to their electrochemical virtues and affordability. However, traditional synthesis methods like solid-state reactions, hydrothermal processes, and sol–gel techniques often entail complex procedures, high temperatures, and environmentally harmful chemicals, which impede their practical applications. This study introduces a novel, eco-friendly synthesis route for Mn₃O₄ nanoparticles via the room-temperature reaction of morpholine with manganese nitrate for 24 h, reducing both the environmental impact and the complexity of production. This method yields Mn₃O₄ nanoparticles with enhanced crystallinity and surface area, which is crucial for improved electrochemical performance in ZIBs by offering increased active sites for zinc intercalation. The resultant high-performance Mn₃O₄ nanoparticles align with sustainable practices and hold the potential for advancing next-generation energy storage technologies. The detailed structure and electrochemical performance were investigated in detail in this study. The produced Zn//Mn₃O₄ nanoparticles cell exhibited a remarkable electrochemical performance, which displayed a high reversible capacity of 209.7 mAh g⁻¹ after 300 cycles at 0.6 A g⁻¹.