Your watch, laptop, and laser-pointer are all powered by the same thing: chemistry…. There are a lot of different kinds of batteries, but they all function based on the same underlying concept. There are three main components of a battery: two terminals made of different chemicals typically metals , the anode and the cathode; and the electrolyte, which separates these terminals.
The electrolyte is a chemical medium that allows the flow of electrical charge between the cathode and anode. When a device is connected to a battery — a light bulb or an electric circuit — chemical reactions occur on the electrodes that create a flow of electrical energy to the device. Meanwhile, at the positive terminal, the cathode accepts electrons, completing the circuit for the flow of electrons. Batteries are often rated in terms of their output voltage and capacity. The capacity is how long a particular battery will last in Ah Ampere hours [2] :.
Batteries can also be rated by their energy capacity. This is either done in watt-hours or kilowatt-hours. The University of Colorado has graciously allowed us to use the following Phet simulation. This simulation explores how batteries work in an electric circuit :. Fossil Fuels. They are the oldest rechargeable batteries in existence.
Scientists developed lead-acid batteries in the mids. These batteries use old technology to store energy for conversion to electricity. Each volt lead-acid battery contains six 6 cells, and each cell contains a mixture of sulfuric acid and water. Each cell has a positive terminal and a negative terminal.
When the battery is generating power, it is discharging as it does so. The chemical reaction causes the sulfuric acid to break down into the water stored inside each cell for the purpose of diluting the acid.
So the use of power depletes the acid. This is the chemical equation for the negative plate that releases electrons. The HSO-4 is the acid that gets consumed when releasing electrons and hydrogen ions. That process is the storing of energy. Later, we convert the energy stored in the acid to electricity for use.
While there are many different types of lead-acid batteries, they all use the same chemical energy storage process. You may recall an earlier mention of the cathode positive side and the anode negative side of a battery. As it turns out, cathodes and anodes are capable of storing lithium ions. Energy is stored and released when lithium ions move from the cathode to the anode through the electrolyte.
Unlike all lead-acid batteries that use the same chemical reaction, lithium-ion batteries come in many different chemistries. A few of the most common types of lithium batteries are:. This question, which appears simple and direct, is actually filled with subtlety and complication. First, the definition of a battery must be established. There are a variety of chemical and mechanical devices that are called batteries, although they operate on different physical principles. A battery for the purposes of this explanation will be a device that can store energy in a chemical form and convert that stored chemical energy into electrical energy when needed.
These are the most common batteries, the ones with the familiar cylindrical shape. There are no batteries that actually store electrical energy; all batteries store energy in some other form. Even within this restrictive definition, there are many possible chemical combinations that can store electrical energy--a list too long to go into in this short explanation. There are two fundamental types of chemical storage batteries: the rechargeable, or secondary cell, and the non-rechargeable, or primary cell.
In terms of storing energy or discharging electricity, they are similar, it is simply a question of whether or not the chemical processes involved permit multiple charging and discharging. Before answering this question it is also necessary to distinguish between a galvanic cell and a battery, as I have defined it. The former is the fundamental unit of electrochemical storage and discharge.
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