What Are Three Important Parts Needed to Make a Battery?

You can make a battery using two electrodes and a potato.
••• Jupiterimages/Photos.com/Getty Images

A battery is a voltaic cell, also known as a galvanic cell (or a group of connected cells). It is a type of electrochemical cell used to provide electricity created by a chemical reaction. A simple battery can be constructed by placing electrodes of different metals in an electrolyte fluid. The chemical reaction that occurs produces an electric current. Thus, the three main parts of a battery are the two electrodes and the electrolyte.

Voltaic Cells

Some metals lose electrons more readily than other metals. This can be exploited to produce a flow of electrons from one piece of metal to another, by submerging two pieces of different metals in a conductive solution, such as a solution of metal salts. This is called a voltaic cell. Zinc and copper can be used to make a voltaic cell because zinc gives up electrons more readily than copper. The metal plates are called the electrodes: the anode and the cathode.

The Cathode

A cathode is one of the two electrodes in a polarized device such as a voltaic cell. Current flows out of the cathode. A useful mnemonic for remembering this is CCD: Cathode Current Departs. (Note that this refers to the direction of the conventional current, not the electron flow, which is in the opposite direction.) In a discharging battery the cathode is the positive electrode. In the case of a battery using copper and zinc electrodes, the cathode is the copper electrode.

The Anode

In a polarized electrical device, the anode is the terminal where current flows in. A mnemonic used to remember this is the word ACID: Anode Current Into Device. (Again, this refers to conventional current, not the electron flow.) In a device which provides power, such as a discharging voltaic cell, the anode is the negatively charged terminal. In a cell made with zinc and copper plates, the anode is the zinc plate.

The Electrolyte

In a voltaic cell, the electrolyte is a conductive fluid. A good current can be obtained by submerging a copper electrode in a solution of copper sulfate and a zinc electrode in a solution of zinc sulfate, with a conductive bridge between the two containers of electrolyte. When building a battery, however, any conductive fluid can be used. A glass of salty water is one possibility; other sources of electrolyte include fruit juices.

Making a Battery

A battery can be made using a piece of fruit or a vegetable such as a lemon or a potato to provide the electrolyte. The juice inside is conductive so when two pieces of metal, such as a copper penny and a zinc nail, are pushed into the fruit, an electric current is produced. This can be used to power a small electronic device with a low power requirement, such as a digital display.

Related Articles

What Are Some Possible Materials You Could Use to Make...
How to Make an Electrode
How Do Batteries Work? Parts, Types & Terminology (w/...
Making a Wet Cell Battery
What Fruits & Vegetables Conduct Electricity?
Why Does Citric Acid Produce Electricity?
What Is the Voltage of AA Battery?
Fun Facts About Simple Circuits
Making Electricity From Salt Water
How to Calculate Ohms
Why Do Citrus Fruits Produce Electricity?
Batteries Rely on What to Separate Positive & Negative...
How to Wire a Battery in Series
Why Salt in Water Can Conduct Electricity
How to Make a Battery With Coke & Vinegar
How to Electroplate at Home
How to Build a Clorox Bleach Battery
How to Make a Potato Lamp
How to Use a Magnet to Create Electricity
Parts of a Battery