Identification

• The battery's construction is actually quite simple. It consists of two terminals of a negative and positive. The negative terminal is also called an anode and the positive terminal is called a cathode. Each of these terminals is composed of a different metal and suspended in an electrolyte solution, such as sulfuric acid.
  
  

Effects

• A battery is actually like a test tube in which chemicals are mixed to create a reaction. It's the reaction among these chemicals that allows a battery to power a circuit. The molecular composition of the materials used in the terminals of the battery create a chemical reaction, which in turn serves as a catalyst that sends electrons from the negative (-) terminal of the battery through the circuit (where your device is powered) and on to the positive (+) terminal of the battery. The reaction does not begin until you connect the battery into a circuit.
  
  

Types

• You've probably noticed that there are a variety of types of batteries out there. Common alkaline batteries, lithium ion batteries and lead-acid (car) batteries are a few types that you're probably familiar with using. The differences among these batteries relate to their chemical composition and the materials used in their terminals and electrolyte solution. Different chemical reactions also produce different voltages, which is why batteries have a wide range of voltages.
  
  

History

• The first practical battery was invented by Alessandro Volta in 1800. His voltaic pile used alternating pieces of copper and zinc with brine-soaked cardboard in between each layer of metal. His configuration of different metals separated by a wet conductive solution was successful in creating electrical current and provided the basic archetype by which modern batteries are constructed today. During the decades that followed, different chemicals were used to improve upon Volta's design and in 1859 French inventor Gaston Plante designed the first lead-acid battery, which was also the first rechargeable battery. The invention of the nickel cadmium battery by Walmar Jungner and the alkaline battery by famed inventor Thomas Edison came in the early years of the twentieth century. The first mass-market alkaline battery that you are accustomed to today was produced by Lew Urry in 1959 for the Everready Battery Company (Energizer).
  
  

Features

• You've probably wondered why some batteries expire and some can be recharged. This is another characteristic of the specific chemical composition. Rechargeable batteries, such as nickel cadmium batteries common in cell phones, allow for a reverse reaction. Rather than the battery creating current through a chemical reaction, current is used to reverse the reaction and restore the electrons in the battery. When you put the battery in the charger, power from the electrical outlet reverses the flow of electrons and restores the batteries original chemical state so that it can be used again. In non-rechargeable, disposable batteries the chemical components are exhaustible and the reaction process is irreversible.