How Batteries Are Made
Date Posted:22 October 2017
We use batteries, whether at home or work, every day. But just how are they made?
What Makes Up A Battery?
In your typical alkaline household battery, which range in sizes from AAAA cell to D cell to even larger, you’ve got a particular design that allows it to be portable and yet charge a variety of devices.
Alkaline batteries are affordable, but this cost advantage is traded for lower power output and lower lifespan compared to lithium batteries. Alkaline batteries function based upon the reaction between zinc and manganese dioxide. The electrolyte used to conduct within the cell is an alkaline chemical called potassium hydroxide. Other battery types use acidic electrolytes. Alkaline batteries can be recharged, unlike most lithium batteries.
Most batteries are a series of linked cells, however we’ll look at what goes into producing a single-cell portable battery of the type commonly used in most household or office devices.
The two most important parts of a battery are the anode and cathode. Both are metals that oxidize when exposed to oxygen. The cathode is “oxidized” and the anode isn’t. The battery produces electricity when parts of the anode and cathode are linked in some form of a conductor substance (an electrolyte). The anode pulls oxygen atoms from the cathode, generating electricity.
This means that a battery, placed in a device, only generates electricity when the circuit allows electricity to flow from the cathode (the “top” of the battery) to the anode (the “bottom” of the battery). This electricity is used by the device to power the circuit, light a lamp, or any other uses of electricity.
The electrolytic substance in which the anode and cathode are placed is usually a chemical with strong alkaline properties, from whence the name “alkaline battery” comes.
Many factors of a battery’s design affects the amount of power, voltage, lifetime, and temperature variation that a battery can handle.
An alkaline battery is constructed with an enclosing cylinder made of nickel plated metal. A synthetic sleeve separates the anode and cathode. The cathode is a mixture of manganese dioxide and a few other materials, while the anode is zinc along with a few other materials.
The Steps of Manufacturing A Battery
The raw materials involved in manufacturing batteries are quite numerous. At a battery factory, the raw materials are shipped in by train or ship.
But first, they have to be mined. The specific materials needed for battery construction are manganese dioxide, graphite, potassium hydroxide, nickel-plated steel, and zinc. These are mined in various places all over the world.
Manganese, for example, is mined mostly in South Africa, which produces around 31% of all ore in the world, followed by Gabon, Australia, and Mexico. Manganese ore is reduced by firing in giant furnaces into pure materials needed for industrial use.
Graphite is found in many places around the world, primarily China, Brazil, India, Turkey, and North Korea. It is mined either by surface mining or by digging deep specifically for it, and then refined into pure graphite.
Potassium hydroxide is created by reacting sodium hydroxide with potassium. Potassium is created from potash, mined in places as wide-ranging as Canada, Russia, and Belarus, and sodium hydroxide is artificially produced all over the world through a process involving evaporation of water. Nickel and steel are mined and refined traditionally, and zinc is mined as well. More zinc comes from China, Australia, Peru, and India than anywhere else.
To make the cathode, manganese dioxide, graphite, and potassium hydroxide are blended together and formed into sleeves. These are put inside the nickel steel cylinder which makes up the outside part of the battery. A separator made of electrolyte-soaked paper is then inserted inside to keep the cathode and anode from touching. Then, the anode, which is a gel solution made of a mixture of zinc and potassium hydroxide. The battery is then sealed by adding a top to the cylinder. This top contains a seal, which prevents air from entering the cell, and also has differing levels of thickness to serve as a safety release in case of high pressure gases building up within the cell. The top and bottom of the battery are sealed in by a metal cap. Then, a label is applied to the battery. Usually, this is by surrounding the cylinder with a plastic label and heat-shrinking it to fit around the cylinder.
This is then a fully-functional alkaline battery. When placed in a device and a circuit is opened, this battery then generates electricity through the oxygen atoms attempting to transit from cathode to anode.
Other Types Of Battery Construction
Other types of batteries include lithium-ion batteries, which offer significant advantages over alkaline batteries. Some advantages include providing more power than alkaline, and a higher resistance to temperature. While traditional alkaline batteries cease to function at extreme temperatures of hot or cold, lithium batteries continue to work in a wider range of temperatures. Lithium batteries are also not as heavy as the equivalent alkaline battery, important for small devices relying upon small size for convenience. The downside of lithium is that these batteries are usually more expensive than alkaline. If the battery lasts significantly longer than alkaline, however, it could be more cost efficient over the battery’s lifespan.
If you're interested in different types of batteries, check out our entire range of batteries for any use!