Next generation sodium ion battery: A power dream beyond lithium
Lithium-ion battery (LIB) has been extensively used in all the portable electronic and automobiles (electrical/hybrid electrical vehicles) industry due to its capability to store and release electrochemical energy efficaciously. However, the accessible lithium resources are limited and are not well distributed throughout the world.
The organic way to energy storage
Today, energy is the catalyst for economic growth of any country. Data from the BP statistical review of world energy 2017 as shown in Fig. 1 suggests a decrease of about 10% in consumption of energy from oil (green line) and coal (navy line) have been observed over the last 50 years. This has been gradually replaced by other clean energy sources with a major contribution coming from nuclear (orange) and renewable energy source (dark orange).
Multi-scale computational study of boiling heat transfer
Subcooled flow boiling enables high heat extraction, an immensely beneficial feature in a number of industrial systems. Herein, subcooled liquid enters the tube, and boiling commences at the wall, at a location where the temperature of the liquid adjacent to the wall exceeds the saturation temperature. This location is known as Onset of Nucleate Boiling (ONB). At a downstream location, the bubbles forming at the wall become more in number and start to depart from the wall, which is popularly known as the Onset of Significant Void (OSV) (Fig. 1).
Formulation of high new high energy density materials for use in rocket engines and other important applications
Rocket engines, gas generation mechanisms such as automobile air bags and explosive devices employ high energy density materials (HEDMs) as fuels. Formulating an HEDM having high specific impulse, high density, low production cost, low sensitivity to impact and friction and low toxicity all at the same time is extremely challenging. In this regard, cage compounds with their severely strained molecular structures look promising. Chemical synthesis of such compounds is expensive and tedious.
Electrochemical energy storage materials for powering electric vehicles
Majority of the portable electronic devices used in our day-to-day life, starting from basic cell phone, smart phone, laptop, digital camera, camcorder, tablet, power tools etc. use Li-ion batteries as the power source. Imagine the next generation automobiles also running on such batteries, instead of burning fossil fuels and causing environmental pollution. Yes, there is a definite possibility for the same, leading to saving our environment and having us breathe fresh air, even in the cities.
Plasmonics: The way to efficient photodevices via two-photon lithography
A photodiode is a device capable of converting light energy into electrical signal. The materials used to make these devices critically define the properties and performance of the photo-devices. Thus the materials primarily act as a detrimental factor in limiting the performance of these photo- devices. This bottleneck can be removed partially by using plasmonic structures which can be fabricated easily by two-photon lithography (TPL).
Energy extraction from vortex induced vibration of bi-stable structures
Any elastic structure vibrates in the presence of fluid flow; for instance, we can see leaves in a tree, attached to branches via elastic stems, oscillate furiously on a windy day. These vibrations often occur due to vortices, which are essentially regions of intense fluid rotation. Vortices are periodically shed behind any solid body placed in a fluid flow, and they tend to ‘kick’ the solid as they are shed.
Development of constant temperature microdevice
In several biological applications, it is required to maintain the cells above / below the room temperature implying the need for heating / cooling the microdevice. For instance, in polymerase chain reaction (PCR) a particular DNA sequence is amplified and used in applications such as pathogen detection and hereditary disorder diagnosis. The entire process takes place in 3 steps: denaturation, annealing and extension for which the different stations are required to be maintained at constant temperatures of 95°C, 55°C and 72°C, respectively.
Electricity from waste heat
More than 40% of energy in fossil fuels is lost in the form of ‘heat’ during different conversion processes. This results in not only inefficient usage of natural resources but also leads to environmental and water pollution. One of the techniques that can be used to recover this ‘waste heat’ is via a ‘thermoelectric generator’ which has no moving parts and converts heat directly into electrical power. Our research is focused on developing suitable materials for this purpose with the aim that they have high conversion efficiencies.
Intrinsically conducting polymers for energy storage
Intrinsically conducting polymers such as polyaniline, polythiophene, polypyrrole and polyethylenedioxy thiophene are not only good conductors of electricity, but also possess a property called pseudo-capacitance, which allows them to store electric charge through redox reaction. They therefore possess much higher power density than a battery and phenomenally higher energy density than a capacitor. This dual advantage makes them useful as ‘flywheels’ in energy storage systems. These ‘flywheels’ store surplus energy and provide it when needed.