A battery, as you may already know, is primarily made of three components; the cathode (positive terminal), the anode, (negative terminal), and an electrolyte, a chemical medium which physically separates those two. When a battery is hooked up to an electrical circuit or a light bulb, chemical reactions in the electrolyte allows electricity to flow into the device.
Like most of the devices we use today, modern batteries are a result of countless researches and groundbreaking discoveries. The term ‘battery’ was first used back in 1748, when Benjamin Franklin described Leyden jar. Then in 1880, Alessandro Volta presented his Voltaic Pile, arguably the first electrical battery, to the world.
Batteries, we use today, can be classified based on their sizes and more importantly chemical composition, but the generally accepted classification of batteries is by their re-usability. The two battery forms are-
- Primary or non-rechargeable batteries, and
- Secondary cells or rechargeable batteries
Primary batteries are designed for one-time use. It means they cannot be charged because they are made of electrochemical cells whose reaction cannot be reversed.
Today, the world’s battery market is dominated by primary cells. They pose some serious threats to public health and the environment. Below, we have explained a few types of primary batteries which are in popular use.
10. Zinc-Carbon Battery
Cross section of a zinc-carbon battery Image Courtesy: Jerry Crimson Mann
Capacity: 400-1700 mAh
Voltage: 1.5 V
In a zinc-carbon battery, electricity is generated from a non-reversible electrochemical reaction between zinc and manganese oxide. The outer layer of such a battery is made of zinc. The next layer is comprised of ammonium chloride (acting as electrolyte) which is separated from manganese oxide by a single layer of paper.
At the center of the battery is a carbon rod which acts as the positive electrode. The carbon rod, basically, gathers all the current generated from a redox reaction between zinc and manganese oxide.
The idea of zinc-carbon batteries came from Leclanché cell, a wet cell which was invented in 1866. By early 1900s, zinc-carbon batteries became the first dry batteries to be commercially available. Zinc-carbon batteries popularized the use of portable devices like flashlights. Today, they are mostly used in radio transistors and remote controls.
A much higher overall performance is delivered by Zinc chloride batteries, an improvement over the original. Due to their much purer chemical set-up, zinc chloride batteries are able to produce a steadier voltage with longer service age.
9. Atomic Battery
All illustration of nuclear-powered pacemaker instrument developed by the USAEC (Atomic Energy Commission) Here Plutonium-238 has been used as a fuel
An atomic or nuclear battery generates electricity by harnessing energy from the radioactive isotopes decay (of certain elements), which is quite similar to nuclear reactors. The only difference here is that atomic batteries don’t use chain reaction. As expected, these batteries are much more expensive than others.
They, however, have high energy density output and are suitable for use in systems that must operate in isolated environments for an extended period of time, such as cardiac pacemakers, deep sea instruments, and spacecraft.
Based on the energy conversion approach, atomic batteries are classified into two broad groups; thermal and non-thermal. Thermal converters including radioisotope thermoelectric generator (RTG) and thermophotovoltaic cells generate power through temperature difference (heat is first generated from nuclear power then it’s used to produce electricity).
The non-thermal converters, such as betavoltaics, on the other hand, produce electricity by capturing high-energy electrons produced during the decay of a hydrogen isotope called tritium. The first atomic battery was developed by Henry Moseley in 1913 based on radium.
8. Silver-Oxide Battery
Silver Oxide batteries
Voltage: 1.55 V
Another type of primary cell is Silver-oxide batteries. For commercial uses, silver-oxide batteries are generally available in small-sized button cells due to related cost concerns.
However, in certain sectors (including military and space) where cost is not a major issue and high performance is necessary, large silver-oxide batteries with unconventional designs are used in numbers.
Silver-oxide batteries were initially developed for use in spacecraft launching vehicles, manned spacecraft and satellites due to their high energy density. From Soviet Sputnik satellites, Apollo Lunar module to torpedoes during WWII, all were powered by such batteries.
So far, thousands of researches have been conducted to assimilate silver-oxide batteries more into consumer based products.
7. Lithium Battery
Disassembled button cell (CR2032) battery
Voltage: 1.5 V to 3.7 V
The term ‘Lithium battery’ is collectively used to describe a specific group of batteries based on lithium-metal chemistry, in which multiple combinations of chemicals are used with only metallic lithium (for the anode) as the common substance. The most widely used lithium batteries employ manganese dioxide as the cathode, along with a dissolved lithium salt.
Another rare type of lithium cell is lithium-thionyl chloride battery. Invented in 1973, lithium-thionyl chloride batteries are suitable for low/moderate power electronics and are not available commercially, mostly.
Keep in mind that lithium batteries are non-rechargeable and different from secondary cell lithium-ion or lithium iron phosphate batteries.
Although lithium batteries are available in various shapes and sizes, the coin-type cells are the most popular. They are also capable of replacing ordinary alkaline cells in devices such as cameras.
On a different note, lithium batteries pose a much greater threat to the environment and human health than most other battery types. It has also been used in the illegal production of methamphetamine drug.
6. Nickel Oxyhydroxide Battery
A nickel oxyhydroxide battery manufactured by Panasonic
Voltage: 1.7 V
Nickel oxyhydroxide (NiOx) batteries are slightly different from the standard alkaline batteries. Instead of using just zinc and manganese dioxide for the cathode, they add nickel oxyhydroxide and graphite into the mix. This allows NiOx batteries to attain a relatively higher voltage per cell thus enabling battery operated devices to work much better.
Well, the high voltage output is not entirely due to their new, improved chemical composition but also due to a vacuum manufacturing process that packs more electrolyte into the battery.
The higher voltage, however, may cause malfunctions in instruments with incandescent light involvement like torches and flashlights. It can also mess with battery life indicator showing incorrect battery health.
5. Alkaline Battery
A side-by-side lineup of alkaline batteries of different sizes Image courtesy: Wikimedia
Capacity: 700 mAh at 1-ampere load (Standard sized cell)
Voltage: 1.5 V (fresh battery)
Alkaline batteries are one of the most widely used primary cell batteries in the world which rely on the chemical reaction between zinc and manganese dioxide to generate electricity. They use potassium hydroxide, also known as caustic potash, as the electrolyte.
While there are other battery types that use alkaline electrolytes, notably rechargeable alkaline battery, they use different substances in electrodes than alkaline batteries. Such cells are generally used in easily portable items such as digital cameras, electric toys, radios, and MP3 players.
Almost 80% of all the batteries produced in the United States are alkaline batteries. In Switzerland, this ratio is near 68%, about 60% in the United Kingdom with an EU average of 47%. Annually, more than 10 billion units of alkaline batteries are produced worldwide (2010 data).
Unlike primary batteries, secondary batteries are rechargeable and can be used after numerous discharges. Technically, secondary batteries are those whose electrochemical reaction can be reversed. There are more than two dozen secondary cells, but we have included only the most popular ones.
4. Lead-acid Battery
A lead-acid car battery
Voltage: 2.1 V nominal
Before all the eco-friendly, energy saving batteries got popular, lead-acid batteries were leading the market. Originally invented by French physicist Gaston Planté in 1859 lead-acid batteries were a hit with early electric cars.
A fully charged lead-acid battery carries gelled lead at the negative end (electrode) and Lead dioxide at the positive end with sulfuric acid as electrolyte. Electricity is produced when ions from the negative terminal move to the electrolyte and then absorbed into the positive terminal. Reverse reaction occurs at charging.
Lead-acid batteries are generally used in automobile industry for ignition and lighting purposes. Other uses include a backup power supply in telephone towers and data centers. They are also utilized in submarines to power utilities when totally submerged (underwater).
However, these batteries are much harmful than others. Toxic compounds released from lead-acid batteries have been in the focus of environmental agencies worldwide over the past couple of decades.
3. Nickel-Cadmium Battery
Sub C nickel-cadmium battery Image Courtesy: Wikimedia Commons
Voltage: 1.2 V
Another type of rechargeable cell is Nickel-Cadmium (NiCd) battery that uses metallic cadmium and nickel oxide hydroxide as electrodes and an alkaline electrolyte, mostly potassium hydroxide (KOH). It was invented in 1899 by Swedish inventor Waldemar Jungner as an alternative to lead-acid batteries.
Nickel-cadmium batteries are not suitable for many electronic devices since its nominal voltage (1.2 V) is lower than that of standard zinc-carbon and alkaline batteries. However, unlike others, NiCd cell’s voltage degrades only slightly as it discharges. Many portable appliances are designed to operate in low voltages (0.90 to 1.0 V/cell).
Nickel-cadmium cells are one of the very few known batteries that have the potential to suffer from a ‘memory effect,’ a temporary condition in which the battery losses its maximum capacity after being repeatedly discharged partially (only up to a certain percentage for a long period time).
Such batteries are vastly used in the toy industry and were, once widely utilized in portable tools, electronic devices, cameras, and torch lights.
2. Nickel-metal hydride Battery
Disassembled Nickel-metal hydride battery 1. positive terminal 2. negative terminal 3. positive electrode 4. negative electrode with current collector 5. electrode separator
Voltage:1.2 V nominal
Nickel-metal hydride (NiMH) batteries are basically an upgrade over nickel-cadmium cells. They both use the same alkaline electrode (potassium hydroxide) and nickel hydroxide as the positive electrode. The only difference is, instead of cadmium, nickel-metal hydride uses hydrogen ions for the negative electrode.
This allows a NiMH battery to have almost thrice the capacity as compared to a nickel-cadmium battery. In many cases, their energy density reaches the level of lithium-ion batteries.
Nickel-metal hydride batteries replaced once popular nickel-cadmium batteries in almost all areas, especially in consumer electronics where double A batteries are used. They also have an advantage over standard alkaline batteries due to high durability and lower internal resistance.
They are also used in various electric vehicles, though less common than lithium-ion batteries.
1. Lithium-Ion Battery
Lithium-ion battery Image Courtesy: Claus Ableiter
Voltage: 3.2 V (Lithium iron phosphate) , 3.6-3.7 V nominal
Capacity: 3,000 mAh
The remarkable rise of lithium-ion batteries (LIBs) is attributed to its high performance, overall safety standards and more than four decades of continuous research. They’re almost everywhere; in our smartphones, laptops, tablets, power tools, cars and even in various aerospace systems.
Lithium-ion batteries come in various shapes, sizes, and chemical configurations. One of the most popular LIBs, which are used in high energy density handheld electronics, is based on lithium cobalt oxide. Other types such as lithium-ion manganese oxide and lithium iron phosphate battery provide lower energy density but are less prone to explosion.
These batteries are charged at an over-voltage condition, in which a slightly higher voltage is applied than what the battery produces. During a charging process, the current within the battery flows from the positive electrode to the negative electrode. The flow direction reverses during battery discharge.