How Supercapacitors Work - A step by step guide

welcome to Evy Tech explained today I'll be introducing super capacitors super capacitors are energy storage devices capable of delivering power at much higher rates than batteries and have been recently used in Toyotas TS zero for zero lamorne car in the energy recovery system this video will briefly explain what super capacitors are give a detailed step-by-step guide to how they function and discuss some typical uses of the technology super capacitors are charge storage devices that look similar to batteries in comparison to batteries super capacitors have low energy capacity typically ten to hundred times less than the state-of-the-art lithium-ion battery however they are able to deliver 10 200 times more power than a state-of-the-art lithium-ion battery I will briefly explain the difference between power and energy in in my following slides whilst batteries typically last 1,000 charge and discharge cycles before they lose much of their capacity super capacitors will typically last 1 million charge and discharge cycles because they function via the physical movement of ions and not via chemical reactions as a battery goes to help understand the difference between power and energy let's use an analogy of a bucket of water with a hole in it water can only leave the bucket via the hole the rate at which water can flow out of the Booker is analogous to the power the amount of water that can be held within the bucket is analogous to the energy capacity a larger hole in the bucket increases the power whilst increasing the volume of the book it increases the energy that can be stored therefore by this analogy a super capacitor is a small bucket with a big hole whereas a battery is a big bucket with a small hole before exploding how super capacitors function it is necessary to introduce its internal components a cross-section of a super capacitor is seen in the image on the left and on the right hand side is an illustration of a simplified structure the cell contains two identical carbon electrodes held apart by a paper-based separator and the electrodes are both connected to aluminium current collectors this simplified structure is redrawn in this schematic as well as the positive and negative ions from the liquid electrolyte the image on the Left shows the iron arrangement in an uncharged cell whereas the right-hand side shows the iron arrangement in a fully charged cell let's go through the charge storage process step by step to charge up our uncharged super capacitor we begin by connecting the positive and negative terminals to an energy source assuming we're looking at just the negative electrode the carbon electrode becomes negatively charged an electrical field is generated near the electrode attracting positive ions and repelling negative ions the opposite is happening simultaneously are the positive electrode be counter ions which in this case are the positive ions adsorbed to the surface of the electrode and a very intense electric field is now holding the electrons from the electrode and the ions in the electrolyte close to one another this intense electric field is where the cell is storing its energy as potential energy so to recap we apply potential to the electrodes an electric field is generated within sell the counter ions absorb to the electrode surface and the electrons and ions are subsequently held in an intense electric field which stores the energy which we are putting into the cell now if we were to discharge our cell by removing electrons through the external circuit on the electrode electrolyte interface we would have an excess of positive ions therefore a positive ion is repelled in order to return the interface to a state of charge neutrality that is the negative charge and the positive charge is balanced super capacitors are not a substitute for batteries their characteristics make them suitable for different applications so which applications are suitable applications requiring high power with moderate to low energy requirements such as cranes and elevators are very suitable they can also be used as voltage support of high energy devices such as fuel cells and batteries in fact Honda used a band of ultra capacitors in the under FCX fuel cell vehicle to protect the fuel cell from rapid voltage fluctuations furthermore because super capacitors are very reliable they are typically used in applications that are described as maintenance-free such as space travel and wind turbines they are also extensively used in smartphones to cover the camera flush and for uninterruptible power supplies as a power backup master also uses them to capture waste energy in their ie loop energy recovery system as used on the Mazda 6 and on the Mazda 3 if you'd like a detailed explanation of the where the ie loop system functions or any other Eevee tap please leave a comment and I will do my best to create a video on that topic

Channel: EV-Tech Explained

Views: 321,878

Keywords: Supercapacitor, Ultracapacitor, How capacitors work, How supercapacitors work, How ultracapacitors work, capacitor, super, guide, how, does, it, work, they, energy, storage, battery, EDLC, Electric Double Layer Capacitor, Double Layer, fast battery

Id: 6FG6JRHGFyQ

Length: 6min 56sec (416 seconds)

Published: Sat Jan 02 2016

Reddit Comments

[u/Atheists_Are_Annoyin]

I'm curious what the difference between a normal capacitor and super capacitor is. I could of course wikipedia this, and i probably will, but I went through the whole video waiting to hear that.

[u/emilvikstrom]

Thank you, just what I needed for my one of current projects!

Do you know if these cheap supercapacitors can really be 100F at that small size? It feels sketchy but my experience with supercapacitors is none so far.

[u/throw_bundy]

My only critique is that the narration is a bit boring sounding. The monotone delivery is the only flaw. I agree with the music bit someone else suggested. Pepper some inflection to keep my interest, unless you're going for a "corporate presentation" style.

To me, you sound like you're reading at me, rather than talking to me as a friend. Friendly voiceover tends to keep subjects interesting even if there are boring details or a bunch of unfamiliar technical data. Good info in there though, I didn't know much of that material.

[u/asoap]

Thank you! This is great.

I'm versed on what a super capactior is. But I have no clue how to hook up a super capacitor to a battery. And then how to use that in a system. And prevent stuff like crazy discharges and the such.

[u/USComponent2001]

Great post. Thank you

[u/kireol]

OK. It totally would not add 1 bit of technical information; but I'd like to have some music in the intro, or something to jazz it up a bit. I realize it's a dry subject, but try and add something sexy to draw us in.

Other than that, I learned something and thought it was laid out well

[u/RangerPretzel]

You said in your video (at the 1:16 mark): "Capacitors ... function by the physical movement of ions and not via chemical reaction as a battery does."

But actually, a battery also has movement of ions as well.

Reference: https://en.wikipedia.org/wiki/Lithium-ion_battery