Stay In Charge: An Insight into Battery Technology

Nicholas Schleicher - Engineering Intern

In today's world, batteries are the unsung hero. We often overlook these bricks of inconvenience. With their large size and seemingly limited function, most people often don't bother to learn more about them and just go with the assumption that batteries are the way they are and we can't do anything to change that. As technology grows, more electricity is required to run them. One thing we need to find out is, do we really know what goes on behind the curtains of technological advancement? Is there a way to make batteries smaller? How do they work, and why do we need them in the first place? These are the questions we all have, so let's look deeper, and see if there is anything we can do to give batteries the understanding they deserve.

What are batteries? Batteries are a way to store electrical energy for use later. They are typically made up of cells, and inside of those cells are different types of chemicals. These chemicals take in electrons, which are the outside part of an atom and switch them between other chemicals. Then, when they are ready to be used, they convert the chemical energy back into electrical energy.

Here are a few main ways we store this energy: lead acid is the most common. Others include Lithium Ion, Nickel Metal Hydride and Nickel Cadmium (the main rechargeable battery types). For now, we will focus on the basics of lead acid batteries. These are the ones you find in your car, they are reliable and very heavy. In the cold, they tend to weaken. Inside of a battery is made up of an anode (-), electrolyte and a cathode (+). The energy coming in goes to the anode. The chemical reactions in the battery cause a build-up of electrons at the anode. This results in an electrical difference between the anode and the cathode. You can think of this difference as an unstable build-up of the electrons. The electrons want to rearrange themselves to get rid of this difference. But they do this in a certain way. Electrons repel each other and try to go to a place with fewer electrons. When a battery is ready to be used, a switch will get flipped allowing the electrons to flow out of the anode flow through the device and switch and travel to the cathode. This is called the flow of electrons. It is how all current works. When we want to recharge the battery, the directions of the electron flow reverses. Electrons then come from a power source to the anode and stay there.

Now that we have a basic understanding of electricity and how it flows and gets stored, we can look at why they choose those types of chemicals for storage. Since every device needs a different amount of electricity. We can follow a fundamental equation to find out. This is called Ohm's law. This version of Ohm's Law looks like this I = V/R (I = amps, V = voltage, R = resistance). My father put it best when he said “electricity is most easily understood if you look at it like throwing a punch. Voltage is the power of the punch, Amperage is the size of the fist and resistance is the air between you and your target. Put them together and you get the total wattage.” Electrochemical processes change the chemicals in anode and cathode to make them stop supplying electrons. So there is a limited amount of power available in a battery. If we want to store a large amount of energy that is easily accessible (ready for use), then we typically use the lead acid. If we need more of a steady flow of about 19 volts at 2 amps, the standard is the Lithium Ion type. These are the batteries you find in your laptop and cell phone. Modern electric cars use this type because it can provide a longer charge with half the weight. The downside to this is they can explode if they get too hot. This is the reason it has taken so long for electric cars to become practical and affordable. If you try to use a lead acid battery it weighs the car down so much that the available electricity to mileage ratio goes down.

Advancements in battery storage. Batteries have not advanced much in the last few decades. Now, with the help of the internet and collaborating with universities and major manufacturing companies, batteries are on the verge of a revolution. One such problem that is being worked out is how to charge and discharge a battery quickly without damaging the chemicals inside. Every time you charge your smartphone or laptop you are exciting the atoms causing a slow degradation of the anode and cathode. It's like stretching a rubber band. You can only do it so many times before you snap the band. Same is true for any material. As a result, some companies are working on a solid-state lithium-ion type that uses a sulfide super-ionic conductor. This means you can charge and discharge completely in seven minutes—without damaging the battery. This is ideal for cars.

At the end of the day, if more people can get informed and involved with this technology, it can help society curb the problem of energy consumption and reduce costs of everything in our modern world. It will also help us curb our addiction to petrol energy storage and move towards all electrical energy storage.

Thursday March 29th, 2018#batteries