Accelerated and cost-effective synthesis of NaFe0.5Mn0.5O2 layered oxide cathode material and performance evaluation in sodium-ion batteries

Abstract

Iron and manganese-containing O3-type layered oxides cathode materials are well known for their high specific capacity and operating voltages in sodium-ion batteries (SIBs). The layered oxides with multiple transition metal combinations are aimed to utilize the synergistic relation of the transition metals and bring out enhanced electrochemical performance. However, the popular methods of synthesis most often involve very long heat treatment periods. In this work, O3-type layered oxide material NaFe_0.5Mn_0.5O₂ is developed using a facile sol-gel followed by microwave sintering, significantly shortening the synthesis duration. The structural characterization using X-ray diffraction confirms the structural phase purity of the synthesized material, while infrared spectroscopy confirms the various metallic bonds in the material. The microwave sintering has resulted in denser and finer microstructures of the material, as confirmed by the microscopy images. The electrochemical performance of the synthesized material has also been investigated in detail. The specific discharge capacity of the synthesized material is ∼120 mAh/g, comparable to the conventional sintered layered oxide material. This work provides insights into using the microwave-assisted synthesis technique for Sodium layered oxide battery material.