IIT Mandi develops safe, long-lasting, quicker battery

Charging battery is full of hassles. But, what if you get a permanent solution for charging? The thinker tank of IIT Mandi brings this never-ending issue of charging the battery to rest as they have developed a ‘perfect’ battery that can store large amounts of energy, and be charged rapidly and repeatedly. The lithium-ion battery that now powers almost all our consumer electronics devices such as mobile phones, laptops and even electric cars, has its own limitations. One of the disadvantages with batteries is that charging takes a lot of time, which results in extended down-times of operation. In addition, durability is another major concern.

This is an answer to regular battery

Viswanath Balakrishnan, Associate Professor, School of Engineering, Indian Institute of Technology Mandi, and his research scholar, Piyush Avasthi, have recently developed aligned carbon nanotube-based electrodes that could enable high energy supercapacitors.

“A promising route to improving the performance of energy storage devices, especially in terms of cycling life and charging times, is to move away from batteries towards supercapacitors”, says Balakrishnan. Supercapacitors can charge and discharge instantly and can ideally last across millions of charge-discharge cycles without performance degradation.

They also have a higher power density than batteries. Where they have fallen short so far, is in the area of energy density; supercapacitors have forty times less ability to store energy than the state-of-art lithium-ion battery.

What is supercapacitor?

A supercapacitor essentially consists of two conducting electrodes immersed in an electrolyte, which are separated by an electrically insulating layer to separate the charges.

While applying the current, potential difference develops between two electrodes and oppositely charged ions physically adsorb on the respective surfaces of electrodes.

This charge storage mechanism is highly reversible which makes supercapacitor to charge-discharge very quickly.

Carbon nanotubes, tiny tubes of carbon, a hundred thousand times thinner than the human hair, are used as electrodes, making supercapacitors’ energy density increase.

“Tuning wetting behaviour of supercapacitor electrode surface plays a crucial role in various interfacial processes as it directly affects mass transfer, formation of the electric double layer, and electron delivery at the interface”, the researchers write in their paper.

Process of making these batteries

IIT Mandi researcher Piyush Avasthi used a process called Chemical Vapor Deposition to produce ‘forests’ of vertically aligned carbon nanotubes that are wettable (hydrophilic) by the electrolyte.The perfectly aligned nanotubes, that were a few micrometers in height, were grown on a stainless-steel mesh and treated with two different ways to enhance their hydrophilic properties – in one, the forests were treated with potassium hydroxide (KOH), and in the other, they were coated with an ultrathin layer of titanium dioxide (titania), which made the nanotubes superhydrophilic.

While KOH treatment resulted in better energy density than randomly oriented carbon nanotubes, treating with titania resulted in a 102-fold increase in energy density, 20-fold increase in specific capacitance, and 13-fold increase in power density. With that kind of improvement, supercapacitors can certainly give lithium-ion batteries a run for their voltage.

The stainless-steel mesh on which the carbon nanotubes were grown, is physically flexible and would allow incorporation of the energy storage devices on wearable, miniaturized and portable electronic products and smart devices.

Their research papers have been published in Advanced Materials Interfaces and ACS Applied Nanomaterials.

Source: indiatoday.in