There is a lot of talk about electricity, how it is cleaner, cheaper and together with other benefits, how it will be great to implement it in our everyday lives in forms such as electric cars etc. But mostly, for electric powered things to work, especially when they are mobile (cars, mobile phones, etc.), they need to have a source of that electricity, which in most cases is what we call a Battery.
The main components of a battery are a positive electrode – cathode, a negative electrode – anode, and an electrolyte that separates them. The positive and negative electrodes are not connected, however, when they get connected through an external connection – the electrical circuit, the anode reacts with the electrolyte and sets free the electrons, who travel to the cathode. On the way, they can trigger a reaction (producing light etc.).
One of the most important characteristics of a battery is the energy density. This is crucial nowadays since we want to store as much energy in as possible in the smallest volume possible. If we want to increase the energy density, we have to be careful since it may have negative effects, mostly on costs which can result in high prices for the battery and in safety issues.
The most common batteries for our everyday gadgets, such as smartphones, e-cigarettes, tablets etc. are lithium batteries. Lithium is one of the elements with favorable properties that allow it to deliver electrical energy in a great amount and at the same time being small in volume and being light – it has a low atomic weight. Although it is a metal, it actually floats on water. Since it is an alkali metal, as other alkali elements, it can give up an electron so it is perfect to be a negative electrode. It is also able to release a lot of energy in one moment if there is a fault, and then it can become really dangerous.
Other materials can also be used. With nuclear waste and artificial diamonds, it is possible to make a battery that will last for centuries. It is also possible to make a very weak battery from potatoes.
There is a battery-powered bell at Oxford University that has been continuously ringing for over 175 years. No one knows what the battery is composed of and no one wants to take the device apart in order to figure it out.