Batteries - The Redox Reactions to Power Our Future
We live in a world that is developing more and more ways to live off of electricity and machines. Televisions, smartphones and computers can be found in mostly every household in France. Lights and torches for seeing when the sun goes down, medical equipment able to revive someone from near death. We use these things to talk to people from across the world, research for tests without travelling to your local library, and watch what is happening halfway across the world using your televisions and smartphones.
But all of these things are dependant on one thing, electricity. We don’t have an unlimited amount of plugs that you can use to charge your equipment, some houses or apartments only have one or two plugs maximum. If these machines don’t get access to electricity, they are almost useless, you can’t interact or do anything on them until you get access to power. But scientists have found a solution to store energy inside the machine itself, meaning it can go wherever and still have a power source to use. Introducing, the battery.
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(“Different Types of Batteries” Internet Search)
The main purpose of the battery is to store electricity energy to be used when you activate the product you want to use. For example you use a battery for a torch, but it doesn’t activate until you activate the circuit via a switch or button. How the battery works uses a form of electrolysis. Electrolysis is used to break down a substance using electrodes (a material that can conduct electricity). There is an anode which is a positive electrode, and a cathode which is a negative electrode. Using a process of attracting the different iodes using charges we are able to split up the compound into its original elements. But electrolysis uses electricity to break the compound up, we want to store electricity and output it. So we have invented the Voltaic Cell, using anode, cathodes and the spontaneous redox reactions to create a cycle that can produce electricity. Redox reactions (or Oxidation and Reduction reactions) are spontaneous, meaning that the electrons start to move as soon as the reaction takes place. We can use the electrons to create an electric charge, and the Voltaic Cell is able to direct the electrons into an output before being put to use in another reaction. (Voltaic Cells) (Helmenstein)
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(Voltaic Cells)
Voltaic Cells are made up of an anode and a cathode in separate containers, in this example Nickel (Ni) is the anode, and this is where the oxidation reaction occurs. The oxidation reaction will make the anode have a negative charge, instead of like in an electrolysis anode which is positively charged. The Copper (Cu) is the cathode and is where the reduction reaction takes place. The cathode is positively charged because of the reduction reaction, again unlike an electrolysis cathode which is negative. Oxidation is the loss of electrodes and is what happens to the nickel, diffusing into the solution surrounding it as an ion. Then the 2 electrons travel along a copper wire and pass through the load (what you want to power), then travel into the copper electrode. The Cu electrode reacts with 2 electrons and forms a copper metal that rests on the surface of the electrode, which is a reduction reactions, the gain of electrons. But the light bulb doesn’t turn on, because there is an extra Nickel Ion from the oxidation in the right-hand beaker (the green Ni2+). We need to make the charges in each beaker equal, so that way the circuit is complete and the voltaic cell can work. The salt bridge does just that. The salt bridge leaves a conduit for ions to travel from one beaker to another. This particular salt bridge is a Potassium Sulphate mixture (K2SO4 (aq means aqueous) and Potassium ions will flow through into the cathode chamber, where they will replace the Copper ions that will attach to the cathode, and sulfate ions will negate the effects of the leftover Nickel ion, keeping everything in balance. Only then will the voltaic cell work and the lightbulb will turn on. (All of this is from Voltaic Cell)
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(“Diagram of a Battery” Internet Search)
Voltaic cells are used in batteries because of their ability to have a conduit where the electrodes will travel, which is able to power something we need to use. Common batteries use a voltaic cell with a different type of setup, often setup so that the reactions are separated with only a thin piece of material, and the cathode is connected to the positive terminal of the battery, and the anode with the negative side. The electrons from the oxidation reaction gather on the negative side of the battery, and once a circuit is formed they rush as fast as they can to the positive side, charging an object along the way. (Palermo) Depending on the battery, the materials will change so that there is more electrons being moved, or the duration of the reaction is longer (for longer-lasting batteries). Different combinations of electrodes are Zinc/Carbon, Zinc/Manganese-Oxide with an alkaline electrolyte (an electrolyte is a paste or material used to conduct electricity), and Lead/Lead-Oxide which is often used in car batteries. (Electrolyte)