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.

BANDGAP ENGINEERING OF FUNCTIONALIZED POLYETHYLENE OXIDE (PEO) ELECTROLYTE

Electrolytes enable conduction of ions in a battery across the electrodes. One of the most important properties of an electrolyte material is its electrochemical window, which determines overall safety of the battery. Electrochemical window (also known as HOMO LUMO gap or bandgap) is calculated in the present work for polyethylene oxide (PEO) with different chemistries using a combination of Hartree-Fock and density functional theory (DFT) techniques. The aim is to study how the bandgap can be varied with different functional groups added to the polymer.

Moving from Li to Na ion intercalation battery: electronic charge transfer mechanism in cathodes studied with ab-initio methods

Sodium intercalation batteries might prove to be a viable alternative of lithium ion batteries, which is both expensive and in short supply due to unavailability of lithium .Renewable energy sources being crucial to India's energy future, there is a huge need to develop scalable and cost effective storage technology with earth abundant materials to provide load balancing. Moving from lithium to sodium ion intercalation materials, electrochemical properties change significantly and electrochemical potential of intercalation drops.

Redesigning the National Solar Mission for Rural India

The success of the Jawaharlal Nehru National Solar Mission depends on certain critical features – the subsidy structure, the role of standardised systems and institutional models of delivery As the actual costs of small systems are considerably higher, on a per watt basis, than the benchmark costs assumed for the subsidy, smaller systems that are within the reach of the rural poor receive lower subsidies than larger systems.

Scoping technology options for India’s oil security: Part II – Coal to liquids and bio-diesel

India's diesel consumption is several times that of petrol In this article, we examine two options for meeting India's diesel demand: coal to liquids and bio-diesel Coal gasification, followed by Fischer-Tropsch (FT) synthesis offers an opportunity for large-scale production of diesel as proven by South Africa, and now being attempted by China and Qatar. India could consider this option given its large coal reserves.

Analytical derivation of explicit J–V model of a solar cell from physics based implicit model

Recently a simple explicit model was introduced to represent the J–V characteristics of an illuminated solar cell with parasitic resistances and bias dependent photocurrent as vm + jn = 1. Here the normalized voltage, v and normalized current density j can be represented as v = V/Voc and j = J/Jsc respectively, where Voc is the open circuit voltage and Jsc is the short circuit current density. This model is useful for design, characterization and simple fill factor calculation and its applicability was demonstrated with the measured data of a wide variety of solar cells.