Supercapacitor vs Battery & Capacitor

In this era of climate change, there is a need to switch from fossil fuels to electric power. Electricity is a versatile form of electricity but it has one problem associated with it. As I had raised same concern in my last post that there is a problem to store electricity for a long time (https://imbibephysics5794.blogspot.com/2020/08/decarbonisation-and-storing-thermal.html). For capacitors and batteries we need to look for two different things, one is amount of charge stored and other is how quickly the energy is delivered. Capacitors deliver energy instantaneously but cannot able to store large amount of charge. Batteries have an ability to store large charge and cannot give energy quickly. So in order to overcome these drawbacks, we need to look for other alternatives. This problem can now be solved by supercapacitors.

SUPERCAPACITORS

Supercapacitor also known as ultracapacitor is an electronic device which is used to store large amount of electric charge. According to following formula, it is cleared that capacitance is directly proportional to surface area and is inversely proportional to distance between the plates.

C = Ɛ_oA/d

How supercapacitors are different from conventional capacitors and batteries?

    Supercapacitors consist of electrodes of large surface area and a thin dielectric plate between electrodes so to have large capacitance. Supercapacitors can store 100 times more charge than a conventional capacitors. Here, electrodes are made up of some porous substance which provides more surface area for storage of charge. In supercapacitors there is no dielectric material between the plates. Both electrodes are soaked in specific electrolyte and are separated by very thin layer of insulator. Plastic, paper or carbon can be used as insulator. That’s why supercapacitors could able to store larger charge because of large surface area of electrodes and lesser distance between them.

    Supercapacitors rely on static charges resting on solid electrodes while batteries rely on the charges which produced through chemical reactions of liquids present in batteries. Batteries have higher energy density while supercapacitors have higher power density. All these factors gave us conclusion that supercapacitors releases energy very quickly as compare to batteries.

Future of supercapacitors

Scientists believe that supercapacitors may replace lithium ion cells as it charges more quickly and can recharge multiple numbers of times.

Scientists are exploring the concept of designing lightweight supercapacitors by designing ECs with graphene which will have high storage capabilities.

Supercapacitors can widely be used in automobiles where regenerative braking is used, in wind turbines, motors and also it been employed in hybrid buses.

By looking its applications it seems that supercapacitors or ultracapacitors are a most promising energy storage device.

Black hole bagged Nobel Prize this time

Black holes, in simple language can be anything but an empty space. But in our universe black hole is super massive monster in which great amount of matter concentrated in a small region. In it, gravitational field is so strong that nothing can escape out of it, not even a light. Black hole forms when massive star collapses at the end of its life cycle. After its formation, it continues to grow by engulfing the matter around it. And in this way it grows in the form of supermassive black hole.

Three scientists share the Nobel Prize in Physics, 2020 for their discoveries about the black holes in universe. Roger Penrose showed that the general theory of relativity leads to the formation of black holes. Albert Einstein who gave general theory of relativity could not able to explain properly the existence of black holes. In 1965, Roger Penrose used various mathematical methods and in his proof tells that black holes are a direct consequence of Einstein’s general theory of relativity. He explains that black hole is a kind of situation in which all the laws of physics ceases. He tells that black hole would be a real and stable astrophysical object. He laid the theoretical foundation which explains the existence of black holes in outer universe.

Reinhard Genzel and Andrea Ghez both led the research that tracked stars at the centre of the Milky Way. Their orbits were bent by what known as supermassive black hole. Their study was mainly focussed on the region called Sagittarius A* at the centre of our galaxy. Both researchers claimed on finding extremely heavy and invisible object that pulls on the closest stars and cause them to orbit around at dizzying speeds. Sagittarius A*, weighs about millions of solar masses and is about 26000 light years away. Genzel and Ghez used world’s largest telescopes and various methods to see through the huge clouds of interstellar dust and gas to the centre of the Milky Way. In their study, they mapped the progress of a single star orbiting around Sagittarius A*. by studying such orbits, they draw out the conclusions of the presence of invisible object. Unique instruments and refined new technologies which reduce distortions and noise has lead us to give most convincing evidences of a supermassive black hole at the centre of our galaxy.

The discoveries of these researchers have open up new doors of the study of supermassive and invisible objects present in our universe. In the end, both these researches provided the strongest evidences of black holes and also lead to the development refined telescope methods and wonderful technologies. But still there are several questions which are still to be answerable by our future researchers.