What are batteries?
Batteries come to our rescue many times. Life would be difficult without them.Even though we depend, daily, on batteries most of us would be hard pressed to describe what a battery is. So what are batteries?
A battery is one or more electrically connected cells that are electrochemical. The cells have contacts or terminals that supply electrical energy.
If you have a primary battery these are a group of cells or a cell for the generation of electrical energy the purpose of which is to be used until it's exhausted, and then you throw it away. When you buy a primary battery it is already in a charged state. Discharge is the main process when the battery is in use.
A secondary battery is also a group of cells or one cell that can be restored to its original charge after it has been used. It is charged by an electric current that flows in the direction that is opposite to the flow current when the battery was being used or discharged. This is a rechargeable battery.
Batteries consist of three parts, including, the anode (which is depicted by the negative or minus sign), the cathode (plus or positive sign) and the electrolyte. The anode and cathode are the positive and negative sides at either end of the battery. They are hooked up to an electrical circuit.
Chemical reactions occur in the battery, and this results in a build up of electrons at the anode, which creates the difference between the anode and the cathode. The electrons need to rearrange themselves because they want to get rid of the difference but the rearranging occurs in a specific way. The electrons fend off each other and try to find a place where there are not as many electrons.
Electrons are the tiny parts of an atom that travel from one kind of chemical to another if the circumstances are right.
When the electrons move this creates an electric current that is capable of powering something. A battery puts the right chemicals into the right relationships and then places a wall between them. Only when the two sides of the battery are connected by a conductor or a wire can the electrons flow.
The only place the electrons can go is to the cathode. However, this is no easy trip. The electrolyte prevents the electrons from making a straight shot from the anode to the cathode. When the circuit is closed, which is the wire that connects the two, the electrons can get to the cathode.
Electrical current is the flow of electrons. The kind of flow that you get in batteries is direct current or DC. The electrons only travel in one direction. An AC or alternating current flow, which is found in household electrical outlets, allows electrons to flow from the positive terminal to the negative and vice versa, which is alternating directions.
There are nickel-hydride batteries such as those found in cell phones and laptop computers; rechargeable nickel-cadmium batteries that are used in spacecraft and single use alkaline batteries.
The next time you grab your camera or phone or try to turn on your laptop computer and realize, uh, oh, it's not working, think battery. It turns out your battery either needs replaced or recharged. That's when we are really, really grateful for batteries and how accessible they are and how convenient they make our lives. Let's give a high five to batteries!
Remember that batteries can be recycled, which makes batteries a green power source. Rechargeable batteries are an excellent source for living green.
Northwestern University: What are batteries?