Date of Graduation

Summer 2023


Master of Science in Materials Science


Physics, Astronomy, and Materials Science

Committee Chair

Kartik Ghosh


The proliferation of renewable energy sources and the promising market for net-scale battery applications immediately increases the need for electrochemical energy storage technology. Sodium (Na) components are more accessible and less expensive than lithium. Being a sodium-based material with a high-power density provided by Na-ion diffusion, NaxMnO2- δ is a strong contender for large-scale Sodium-ion-battery (SIB) applications. In the current study, NaxMnO2- δ is created using a solid-state reaction technique, and investigated structural, electrical, and electrochemical properties of materials were investigated using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), UV-VIS spectroscopy, and X-ray photoelectron spectroscopy (XPS). The Rietveld refinement on the respective XRD pattern led to a hexagonal structure with space group P63/mmc. Raman spectroscopy provides information about the structural fingerprint of the prepared powders by identifying the vibrational modes. XPS analysis was carried out to investigate the Mn valence of NaxMnO2- δ. Electrochemical charge-discharge cycling was performed from 2.0- 4.2 V vs Na+/Na for C/10 where the initial discharge capacity 102 mA h/g-1 and 90% capacity retention after 20 cycles for NaxMnO2- δ. An ideal layered P2-type NaxMnO2-δ cathode calcined at 400°C has the highest specific discharge capacity of 130 mAh/g at 0.1C with capacity retention of approximately 99% and average coulombic efficiency of 98% after 20 cycles compared to 300°C in between 2.0-4.2V range (Na+/Na). These findings will encourage more investigation into SIB.


SIB, solid-state technique, Rietveld refinement, capacity retention, coulombic efficiency

Subject Categories

Other Materials Science and Engineering


© Zia Uddin Mahmud

Available for download on Sunday, May 31, 2026

Open Access