Browsing by Author "K. Jayanthi"

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Role of Sodium-Ion Dynamics and Characteristic Length Scales in Ion Conductivity in Aluminophosphate Glasses Containing Na2SO4
(American Chemical Society, 2022) Indrajeet Mandal; Saswata Chakraborty; K. Jayanthi; Manasi Ghosh; Krishna K. Dey; K. Annapurna; Jayanta Mukhopadhyay; Abhijit Das Sharma; Amarnath R. Allu
Achieving high ion conductivity in glass-based Na-ion conducting materials for their applications as solid electrolytes in batteries is still challenging owing to the vague knowledge on the factors governing Na-ion dynamics. In the present study, an attempt has been made to identify the factors affecting the sodium-ion dynamics through structure and conductivity property correlation for the 37.5Na2O-37.5P2O5-15Al2O3-10NaF (FS-0; mol %) glass system with varied concentrations of Na2SO431P, 27Al, and 23Na MAS NMR (magic-angle spinning nuclear magnetic resonance) and Raman spectroscopy are employed to assess the structural modifications, and impedance spectroscopy is used to measure the variations in ionic conductivity on the addition of Na2SO4 in the FS-0 glass. Raman spectra and MAS NMR analysis indicate that the quantity of P-O-Na bonds and sulfate (SO42-) units surrounded by sodium increase with increasing Na2SO4 concentration. Impedance analysis reveals that the conductivity of FS-0 glass enhances by 1 order with the addition of 6 mol % Na2SO4. We identify from the ac-conductivity spectral analysis that the concentration of charge carriers and the critical hopping length of mobile cations increase with the addition of 6 mol % Na2SO4. Overall, we reveal that the structural modifications, Na-ion concentration, and the shallower potential well that is created for sodium due to its interaction with the nearest neighboring cations affect the Na-ion dynamics. The information obtained from the present study certainly helps to optimize the chemical composition of glasses demonstrating high ionic conductivity. © 2022 American Chemical Society
Water-In-Glass: A Self-Supporting Inorganic Aqueous Electrolyte
(American Chemical Society, 2025) Sinorul Haque; Indrajeet Mandal; K. Jayanthi; Prabir S. Pal; Prince Sen; Bijay Laxmi Pradhan; Krishna Kishor Dey; Manasi Ghosh; Nitya Nand Nand Gosvami; N. M.Anoop Krishnan; Mir Wasim Raja; Amarnath R. Allu
Aqueous rechargeable sodium-ion batteries (ARNIBs) are emerging as cost-effective and safe candidates for large-scale energy storage applications. However, their advancement has been constrained by the narrow electrochemical stability window (ESW) of conventional aqueous electrolytes (1.23 V). Here, we present a transformative approach using an inexpensive and rapidly dissolvable inorganic glass material, water glass (W-glass), to significantly enhance the ESW and enable the development of solid-state, self-supporting aqueous film (SSA film) electrolytes. These SSA film electrolytes exhibit an extended ESW of up to 3.5 V and a conductivity of ∼10–4S/cm at room temperature. Structural analysis using magic-angle spinning nuclear magnetic resonance (NMR) and solution-state NMR reveals that the dissolution of W-glass in water is driven by the interdependent hydrolysis of P–O–P linkages and Na+–H+ion exchange. This work offers a cost-effective and scalable solution for advancing high-performance ARNIB technology, addressing critical barriers to commercial adoption. © 2025 American Chemical Society