Published on October 18th, 2020 |
by Alex Voigt
October 18th, 2020 by Alex Voigt
What the heck is an anode and cathode in a battery, and why is that important?
A battery is nothing other than a medium in which you move electrons from one side to the other. While you do that, you charge or discharge a battery with energy. You either make energy available for whatever electric device you use it for, or you put energy in the medium to store it for later use. Forget all sophisticated technical terminology and measures, because that is all you need to know.
The anode and cathode are just the two names that describe the place where the electrons either move to or come from.
All and everything in our world has electrons, and all and everything has at a certain point in time more electrons or fewer electrons, behaving like a battery. Even we humans sometimes behave like a battery. Whoever has had their hair stand up or got an electric hit from a cow fence or another person knows how it feels when electrons suddenly flow – it can hurt.
Batteries surround us and we are sometimes batteries too, therefore, batteries are everywhere and normal. The reason why we call a battery a battery is simply because we designed them to be able to store more electrons than we usually find in nature to make use of it. Nature is diverse and some animals make use of electricity like for instance the electric eel but there are many more.
The famous inventor Nikola Tesla wanted to make nature a part of the electricity supply, and although he proved it works, he had too many enemies and no commercial model to scale it. Because having a few hundred electric eels in a tank in your car to power it is not a working plan, a different medium was searched for to hold electrons, and that was metal.
An anode and cathode are nothing other than a place where we have more or fewer electrons in a medium. What sounds like names out of a Greek drama is as simple as that. To make use of it for an electronic device, you need to choose a medium that is doing a good job at holding a lot of electrons and at making them flow to the other side, which creates what is called a current, like a river current that flows steadily in one direction. If the energy is the amount of water and your river is narrow, it needs to flow with higher speed or current to have the same energy/water supplied as if it’s a wide river but the current is flowing slowly. You just learned what Volt and Ampere are, two other members of our Greek drama.
To find a medium that creates a steady and reliable flow of electrons can be called finding good cell chemistry. Many materials, mostly metal we use on Earth, are suitable for it, and one of the best is lithium, which is nothing other than an ordinary metal that you find almost everywhere on earth.
To create a lot of current and to store a lot of energy with electrons requires a lot of surface area where the anode and cathode face each other. Think about it like a short or a long river, with more or less water. In a normal cylindrical household battery that you have at home for the remote control, for example, that large surface is created with a thin, long, paper-like material that is rolled up and put in a can. You would be surprised about the amazingly large surface area you have in a small household battery if you unrolled it. On each side of the paper, you put the material you want to use as a cathode and anode. You separate the two with something that acts neutral between the two parties, called a separator. Here you go, you have your battery.
All manufacturers apply the material on that paper in a wet form because it’s the easiest way to guarantee the material you choose is applied in a harmonized and equal way, and to make electrons flow well. To make it stick in a proper way, you need to dry it where you applied it before you can roll it up. Since you are trying to create an as-big-as-possible surface, you need an incredibly large space for just a few battery surfaces to dry, and if you have mass production like Tesla, the surface we are talking about is incredibly large. So large that Tesla intended to build the largest building on earth just to have enough battery supply.
The drying process takes time. Therefore, the only option you have to speed this up is to use ovens to dry them, and that’s why the Tesla Gigafactory in Nevada has such an enormous size. To invest in a lot of oven space, even if it’s in the Nevada desert, is expensive, and since it takes a long time to dry all this material even using ovens, the bottleneck of mass battery production that drives cost and time up is the drying process.
Imagine if all your laundry you wash every week needed to dry lying flat on the ground in your kitchen oven, and that it takes hours until dry before you can fold it and put in the wardrobe (or cupboard). To do all your laundry for the week will maybe take the entire week since your kitchen oven is small. To manage better, you buy 10 ovens and occupy the living room, which is expensive. Washing your clothes is now a very expensive exercise.
And now imagine you do laundry as a business for thousands of people. The dimensions of space, investment, and energy costs are outstanding and it would take you a long time even to build a factory with the required size to put all ovens needed in it.
But you want to improve and be smarter. You invent a dry way to make your laundry, and with that, you can get rid of all the ovens and factory space you thought you must invest in. All of a sudden, all the issues that made it impossible for you to scale the business fast, to offer the laundry service to more people, evaporates. With lower investment and less required space, you can do more, faster and cheaper. You can now offer lower prices, and with that, demand is increasing. Wouldn’t that be awesome?
The dry laundry invention is the dry electrode process Tesla invented and presented at Battery Day.
The so-called dry electrode from Tesla enables the company to apply the material without a drying process, which saves them all the space, time, and equipment they or outside suppliers previously had to invest in. With 75% lower investment, 10 times smaller footprint, and energy reduction, they are also able to increase the output 7 times.
That is an incredible achievement, which is a true revolution for the entire battery industry and could make all other battery manufacturers globally uncompetitive and obsolete in cost and volume in a very short time unless they do something similar.
Tesla just disrupted the entire battery industry, because it can produce better batteries cheaper and faster, and it seems no one took notice.
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