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The NaMnO system is an important class of materials with potential applications in rechargeable batteries, supercapacitors, catalysts, and gas sensors. This work reports the synthesis of NaMnO ( = 0.39, 0.44, 0.48, 0.66, and 0.70) compounds and their characterization by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and impedance spectroscopy (IS) techniques. The compounds in this series exhibit a significant variation in their structures with the extent of Na-content. The change in the nature of bonding with increasing Na content was investigated, and its effect on material stability as well as electrotransport properties was investigated. A detailed thermodynamic evaluation of these materials was carried out employing calorimetric techniques, and the data were correlated with changes in the chemical environment around the Na ion. This analysis is crucial for predicting the thermodynamic stability of NaMnO compounds under different environments for their applications in Na-ion batteries.
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http://dx.doi.org/10.1021/acs.inorgchem.4c01539 | DOI Listing |
ACS Omega
July 2025
ICMUV, Instituto de Ciencia de Materiales, Universidad de Valencia, Valencia 46071, Spain.
In this study, we present a biphasic (orthorhombic/monoclinic) NaMnO material synthesized by using cheap and low-temperature sol-gel methods, which presents potential applications as an advanced cathode material for aqueous sodium-ion energy storage. By leveraging its unique structural and morphological properties, our approach optimizes the balance between diffusion-controlled and surface-controlled pseudocapacitive charge storage, significantly enhancing electrochemical performance with capacity values over 100 mAh/g. Electrochemical investigations reveal that the tailored morphology of NaMnO allows for a high pseudocapacitive contribution, with the NaSO electrolyte exhibiting the most stable cycling behavior and the highest capacity retention.
View Article and Find Full Text PDFNat Commun
March 2025
School of Physical Science and Technology, ShanghaiTech University, Shanghai, China.
The pursuit of advanced battery chemistries with enhanced energy density necessitates the exploration of new materials, a process intricately tied to synthesis science. Despite the promise of O3-type sodium oxygen anionic redox cathodes as high-capacity materials, their development has been severely hindered by a lack of understanding regarding synthetic mechanisms. Here, we elucidate the pivotal role of atmospheric conditions, particularly oxygen content, in the synthesis of such materials by synchronizing multiple operando characterization techniques to monitor changes in both solid and gaseous components.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Department of Chemical Engineering, Imperial College London, London, SW7 2AZ, UK.
ChemSusChem
November 2024
TERIN-DEC-ACEL Technical Unit, ENEA, Via Anguillarese 301, 00123, Rome, Italy.
The behaviour and compatibility of monoclinic sodium manganite, α-NaMnO, cathodes at the interface with electrolytes based on the 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMIFSI) and N-trimethyl-N-butylammonium bis(fluorosulfonyl)imide (NFSI) ionic liquids is presented and discussed. The Na insertion process was analysed through cyclic voltammetry tests combined with impedance spectroscopy measurements and the cell performance was tested by charge-discharge cycles. XPS and FIB-SEM measurements allowed analysis of the surface composition and the morphology of post-mortem cathodes.
View Article and Find Full Text PDFChem Asian J
October 2023
School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin, 150080, P. R. China.