Parveen Kumar

Understanding the Solvation Structure in Bulk Electrolyte Solutions

Understanding the relationship between the interaction of ions in solution with the solvation structure and its dynamics and the bulk properties like ionic conductivity, viscosity, etc is of considerable importance. Solute-solute, solute-solvent, and solvent-solvent interactions play a crucial role in determining the solvation structure and its dynamics. The selection of suitable electrolyte can greatly impact the performace of electrical energy storage devices.

Structural Transformation During Li/Na Insertion and Theoretical Cyclic Voltammetry of the δ-NH4V4O10 Electrode: A first-principles study

A double layer δ-NH4V4O10, due to its high energy storage capacity and excellent rate capability, is a very promising cathode material for Li-ion and Na-ion batteries for large-scale renewable energy storage in transportation and smart grids. While it possesses better stability, and higher ionic and electronic conductivity than the most widely explored V2O5, the mechanisms of its cyclability are yet to be understood.

Rare Earths Recovery from Secondary Resources: Opportunities, Challenges and Environmental impacts

Rare earths are not as rare as the name suggests, they are relatively abundant in the earth`s crust,
but their concentration is less in ore deposits, in particular heavy rare earths. Commercially,
REEs are extracted from the bastnasite, monazite and xenotime ores. The extraction of REEs
from mineral ore (primary source) is a complicated multi step process with a huge amount of
toxic wa ste released during the processes. The recovery of REEs from secondary sources such

Comparative analysis of electrochemical properties of LiMO2, LiMSiO4 and LiMPO4 (M=Fe, Co and Mn): A first principles study

Polyanion based cathode materials are most promising candidates for lithium ion batteries due to low cost, safety, environmental friendliness, etc. We performed first principles based DFT calculations to understand the stability, charge transfer mechanism and electrochemical performance of olivine phosphates, silicates and its comparison with the transition metal layered oxides based cathode materials. We have computed the changes in oxidation states using Bader method of topological analysis and charge re-distribution by analysis of partial density of electronic states.

A microscopic view of ion solvation in aqueous and non-aqueous electrolyte solutions from molecular dynamics simulations

Molecular dynamics simulations were performed to understand the ionic association and its effect on the structure and dynamics of ion solvation shell in aqueous and non-aqueous electrolyte solutions (water and methanol). The simulation results show that the probability of ion pairing depends on the interplay between ion-solvent interactions on the one hand, and Coulomb forces between ion and its counter-ion on the other hand.

Rechargeable Sodium-Ion Battery: High-Capacity Ammonium Vanadate Cathode with Enhanced Stability at High Rate

A sodium-ion battery (NIB) cathode performance based on ammonium vanadate is demonstrated here as high capacity, long cycle life and good rate capability. The simple preparation process and morphology study enable us to explore this electrode as suitable NIB cathode. Furthermore, density functional theory (DFT) calculation is envisioned for the NH4V4O10 cathode and three possible sodium arrangements in the structure are depicted for the first time. Relevant NIB-related properties have been derived like average voltage, lattice constants and atomic coordinates etc.

Feasibility Analysis for c-Si PV Manufacturing in India

India has set a target of deploying 100 GW solar power by 2022. Solar installations in the country primarily use Photovoltaic (PV) technology. It is estimated that 339-395 GW of solar PV will be deployed by 2040. At present, the domestic cell and module manufacturing capacities stand at approximately 3.2 GW and 8.4 GW, respectively. However, the existing manufacturing capacities are underutilised.

Effect of interionic interactions on the structure and dynamics of ionic solvation shells in aqueous electrolyte solutions

We have performed molecular dynamics (MD) simulations to explore the structure and dynamics of the ionic solvation shells of alkali ions and halide ions in aqueous solution. Several structural and dynamical properties such as radial distribution functions (RDFs), diffusivity, velocity autocorrelation function (VACF), etc. are computed to obtain a microscopic picture of solvation.

Mechanism of Charge Transfer in Olivine-Type LiFeSiO4 and LiFe0.5M0.5SiO4 (M = Mg or Al) Cathode Materials: First-Principles Analysis

Olivine silicates LiMSiO4 (where M = Mn, Fe, Co, and Ni) are promising candidates for the next generation of cathode materials for use in lithium ion batteries (LIB). Among these compounds, LiFeSiO4 is an attractive choice due to its low cost, environmental friendliness, high safety, and stability In this work, we use first-principles density functional theory-based calculations to determine the structural and electrochemical properties of olivine-type LiFeSiO4 and LiFe05M05SiO4 (where M = Mg or Al).