Electricity is produced when the ends of a battery are connected by a conducting wire, triggering chemical reactions that release the energy stored in chemical bonds.

During manufacturing, lithium-ion and alkaline batteries are tested for short-circuiting

Lithium-ion batteries are made by manufacturing anodes, cathodes, and electrolytes via chemical processes, assembling these components into cells, and enclosing multiple interconnected cells within a protective casing. Disposable alkaline battery production involves filling steel containers with preforms—rings of powdered cathode material—paper-based separators, electrolyte solution, and an anode gel.

If two strands of conducting materials are connected at two junctions, electricity can be generated if one junction is heated while the other is cooled—a phenomenon known as the Seebeck effect.

Hydrogen fuel cells, which combine hydrogen and oxygen to generate electricity and water, can be run in reverse to produce hydrogen fuel from water.

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

Nuclear batteries generate electrical currents using radioactive materials

Rather than using electrochemical reactions to produce the electrons that flow through a circuit, isotopes like nickel-63 undergo beta decay—emitting electrons—which a semiconducting material can absorb to establish a charge imbalance that generates current. Such batteries could provide low-power energy for decades.

Electrogenic animals generate their own electricity within an electric organ by changing the pattern of electrical charges in disc-shaped cells called electrocytes.

In the photovoltaic effect, light generates electricity by creating a charge imbalance after knocking electrons out of atoms in the semiconducting materials of solar cells.

Watch a timeline of the history of electricity, from observations of static electricity in antiquity to the War of the Currents—a rivalry to establish the ideal system for electric grids.

Gradual chemical build-up reduces the effectiveness of rechargeable batteries

During charge cycles, small chemical deposits gradually form a film on the electrodes where they make contact with the electrolyte, trapping ions that would otherwise facilitate the flow of electricity. Mechanical degradation from electrode wear and electrical shorting from structural instability can also reduce battery capacity.

A dispute about the origin of twitching frog legs led to the invention of the first battery

Experiments by Luigi Galvani on exposed frog leg nerves showed activity when they were hung from iron railings and brass hooks, suggesting the existence of "animal electricity" that discharged when connected to metals. Alessandro Volta's voltaic pile, which stacked metals with an inorganic electrolyte, showed that electricity originates from chemical reactions.

Explore how excitatory cells, such as neurons and muscle cells, transmit information in the body via electrochemical signals, which can travel up to 120 meters (390 feet) per second.

On average, the human body produces about 100 watts of electricity—enough to power a light bulb—but some people can produce over 2,000 watts in short bursts, such as when sprinting.

The world's largest lemon battery was made from nearly 3,000 lemons

By connecting lemons with a piece of zinc on one side and a piece of copper on the other, a team from the Royal Society of Chemistry created a fruit battery with a capacity of 2,307.8 volts.

Benjamin Franklin described a series of static electricity storage jars as 'batteries'

Discovered over 50 years before the first electrochemical cell was invented, Leyden jars stored electric charge between the metals inside and outside a liquid-filled container. Franklin was the first to use the term "battery" in an electrical sense, though his multiple-jar device—lacking chemical reactions—was actually a series of capacitors.

Thermal runaway reactions can cause batteries to catch fire or explode

If a lithium-ion battery is heated, punctured, crushed, or short-circuits due to manufacturing flaws or degradation, the cathode and anode can make contact without the resistance provided by a circuit. The ensuing spike in chemical reactions increases the temperature and can release oxygen, initiating and intensifying burning of the battery's interior.

Watch how metals are extracted from rechargeable devices during recycling

Recyclable batteries found in cars, phones, power tools, and other electronics contain lithium, cobalt, nickel, and other precious metals, whose reuse generates 70% fewer emissions than during their initial mining. Upon shredding these devices, a filter press squeezes the pieces through a proprietary fluid, which separates them for future reuse.

Visualize the minerals used in a lithium-ion battery

The lithium cathode includes nickel to increase energy storage per unit volume, as well as cobalt and manganese as stabilizing agents. Anodes are composed entirely of graphite, with aluminum and copper composing the current collectors for the cathode and anode, respectively. The battery is enclosed in a steel casing.

Explore options for recycling batteries

Improper battery disposal can lead to fires and the leaching of harmful chemicals and toxic materials into local soil and water systems. Although many batteries contain metals that can be recycled with less energy than it takes to produce them, variability in regulations across municipalities and states can complicate efforts. (Some readers may experience a paywall.)

Nuclear fusion, where the nuclei of two atoms are combined, can produce near-limitless clean energy, but requires extreme conditions to kickstart because of the natural repulsion of atomic nuclei.

Iron rusts in the presence of water and oxygen because these ingredients enable the metal atoms to release energy and enter a more stable state.

Lightning forms when streams of rising and falling charged particles connect

In cloud-to-ground lightning, a buildup of negative charge at the bottom of clouds repels electrons on Earth's surface, leaving behind positively charged particles. When descending negatively charged air—the stepped leader—meets rising positively charged particles—the upward streamer—brightening runs up the connection, producing intense flashes known as return strokes.

Electromagnetic induction creates electricity from a changing magnetic field

The phenomenon was discovered in 1831 by Michael Faraday when an electric current was induced in a wire wrapped around an iron ring after a second wrapped wire not connected to the first was connected or disconnected from a battery.

Accidental ingestion of batteries can be life-threatening

Tissue in the body can serve as a circuit path between the anode and cathode of a battery, resulting in electrical burns and gradual tissue erosion. Stomach acid can corrode a battery and cause its toxic contents to leak, making a person sick. Batteries for internal use, such as in pacemakers, require special designs.

The 2019 Nobel Prize in Chemistry was awarded for lithium-ion battery development

Stanley Whittingham developed the first functional lithium battery in the early 1970s, while John Goodenough doubled its electrical potential in 1980 by replacing the cathode, thereby enhancing its commercial viability. Five years later, Akira Yoshino developed an anode using carbon material, reducing the risk of flammability.

Genetically modified viruses can help construct battery electrodes

MIT scientists' modifications caused the viruses to attract conductive materials, such as gold ions, which the viruses self-assembled into nanowires that could be used in batteries. These components allow batteries to be thinner and flexible enough to be constructed into new shapes.

The characteristic zigzag of lightning originates from columns of conductive oxygen

Energized electrons from the base of clouds collide with oxygen molecules, placing them in a "singlet delta state," which makes the air conductive. Collisions continue until more than 1% of nearby oxygen is in this state—about 0.00005 seconds—matching the electrical potential of the cloud and propogating electricity in a 50-meter "step."

Solid-state batteries substitute the fluid electrolyte layer with a solid

The non-flammable solid greatly reduces the risk of fire and explosion, as well as the release of toxic gases via leaks in the existing sulfide-based systems. These batteries use garnet-type solid electrolytes, which provide high ionic conductivity and chemical stability but require temperatures above 1,000 degrees Celsius (1,800 degrees Fahrenheit) for fabrication.

How brain cells carry information

At any moment, there is an electrical storm coursing through your body. Discover how chemical reactions create an electric current that drives our responses to everything from hot pans to a mother’s caress.

The outermost shell of electrons in an atom dictates how it bonds to other atoms, including those of the same element, and the properties of the materials composed of those atoms.

How chemical bonds between atoms form molecules and large geometric structures

In ionic bonding, one atom transfers at least one electron to another atom, forming two atoms of opposite charge. These atoms attract one another and can stack up in a 3D grid called a lattice. Covalent bonding, where electrons are instead shared, can produce enormous molecules, such as the two found in human chromosome 13, which each contain 37 billion atoms.

More batteries in the power grid would create an on-demand energy reservoir

Most power grids are inefficient because they require enough generation capacity at all times to avoid blackouts. This means at any given time, as much as 50% of generating capacity at power plants can go unused. Batteries would reduce this inefficiency and allow for real-time adjustments.

Lithium can store and deliver substantial energy for its cost and weight

When exploring which compounds would be best suited for batteries, scientists sought elements that were relatively inexpensive to mine, readily available, and that provided high energy density—how much chemical energy an element could store for its size. Lithium-ion batteries provide these benefits and discharge at very low rates when unused.

Electricity can flow indefinitely along a ring of superconducting material, which provides zero resistance to the movement of charges due to quantum effects.

Batteries are likely to stop working sooner in cold temperatures

The electrolyte separating the cathode and anode of a battery can thicken, impeding ion flow. Lower temperatures also slow the rate of chemical reactions, further reducing battery capacity. Large draws of power, such as when using heaters, heated seats, etc., in a car during winter, exacerbate battery drain further.

Batteries range in size based on their purpose, cost, and manufacturability

Lead-acid batteries used in combustion vehicles are resilient to temperature extremes, low-cost, and provide high surge current, which is needed for initial ignition. Alkaline batteries, including AA, AAA, and B, have long shelf lives and supply the low, steady power required for electronics with minimal demand fluctuations.

Visualize how alternating currents—electricity that periodically changes direction—are generated by rotating magnetic fields, as occurs in turbine-generator systems.

In 1880, Jacques and Pierre Curie discovered that electricity could be produced by striking certain materials—the piezoelectric effect—a phenomenon that is seen in barbecue lighters.

Bath bombs can produce endothermic reactions that cool water

In bath bombs containing citric acid and sodium bicarbonate, water facilitates the reaction between the bicarbonate and acid, providing energy as the salt dissolves. The loss of energy in the water reduces the average speed of the water molecules, reducing the temperature of the bath.

Legacy electronics have prevented significant advancements in alkaline batteries

While lithium-ion batteries have increased in energy density multiple times since their commercialization in 1991 and can be sized to various capacities by connecting numerous electrochemical cells, disposable alkaline batteries have been forced to maintain their 1.5-volt standard and form factors for compatibility with existing devices.

The gradual loss of capacity in rechargeable batteries can be delayed by avoiding overnight charging, charging to 100%, fast charging, and exposing your device to excessive heat.

Wireless charging uses a magnetic field to move charged particles in a battery

Based on the concept of electromagnetic induction, when a compatible device is placed on a charging pad with correct alignment, the alternating current flowing through the pad creates a changing magnetic field. This magnetic field induces a current in the device, recharging the battery without a connecting wire.

In osmotic power systems, the natural movement of water from regions of low to high salt concentration is used to generate electricity from pressurized water.

Simulate the buildup and discharge of static electricity through friction by dragging the arm and leg of 'John Travoltage' along surfaces.

Battery and plug-in hybrid EVs can operate with zero tailpipe emissions

Battery electric vehicles only run on electricity, while plug-in hybrids incorporate a small internal combustion engine that recharges the battery or directly powers the wheels to improve driving range. Fuel cell electric vehicles convert hydrogen gas fuel into electricity.

Electricity can be lethal because it can disrupt the nervous system, which controls critical bodily functions that rely on electrical signals between cells, such as breathing and heart rate.

An overview of oxygenic photosynthesis, which releases oxygen from breaking down water

Within the membranes of chloroplasts, electrons in pigments are energized by light and transferred across a series of molecules until they create the energetic NADPH molecule. This transfer also powers a hydrogen pump, which creates an ion imbalance that, when relieved, produces energetic ATP molecules. Outside the membranes, both NADPH and ATP are used to synthesize G3Ps, which are funneled into other metabolic pathways to produce sugars.

Growing EV adoption requires battery management infrastructure

Despite rechargeable batteries' limited life cycle, companies like Spiers New Technologies have developed methods to repair, refurbish, repurpose and recycle these components to minimize environmental waste, lower demand for new critical minerals, and increase electric vehicle lifetimes.

Lightning is the sudden flow of electricity in the atmosphere as two oppositely charged regions seek to become balanced via the movement of electrons.

How to make your own DIY ionic thruster

In the search for more efficient, sustainable types of propulsive thrust, scientists have dabbled in developing engines using ionic thrust, a type of propulsion using the attractive force of oppositely charged ions. First introduced by a Russian...

The different energy levels of each element result in unique colors when burned

When heated, electrons absorb energy and move to excited states within an atom. They promptly drop back down and release light energy corresponding to the size of the drop, which is unique to each element.