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Lithium-ion battery

technology Maturity 7-9 Next article →

A lithium-ion battery, or Li-ion battery, is a rechargeable device that stores energy through a process called reversible intercalation. This process involves lithium ions (Li+) moving into and out of electronically conducting solids. These batteries are vital because they offer high specific energy and energy density. They also provide high energy efficiency and a long cycle life.

Liion-18650-AA-battery
Liion-18650-AA-battery

Because they can hold much energy in a small space, they have transformed modern life. In the thirty years following their commercial release in 1991, their volumetric energy density tripled. During that same period, their cost dropped by ten times.

To understand how they work, we must look at the internal components. A typical cell consists of a negative electrode, called the anode, and a positive electrode, called the cathode. Between these electrodes sits a separator to prevent a short circuit. The electrodes are connected to a circuit via metal pieces known as current collectors.

Lithium Ionen Akku Überwachungselektronik
Lithium Ionen Akku Überwachungselektronik

To allow ions to move, the battery contains an electrolyte. This is usually a lithium salt, such as lithium hexafluorophosphate (LiPF6), dissolved in organic solvents like ethylene carbonate. The LiPF6 is important because it helps protect the aluminum current collector at the cathode. When the battery discharges, lithium ions move from the anode to the cathode through the electrolyte. When the battery is charged, the ions move back to the anode.

Different chemistries allow these batteries to be optimized for different tasks. For example, handheld electronics often use lithium polymer batteries. These use a polymer gel as an electrolyte and typically feature a graphite anode and a lithium cobalt oxide (LiCoO2) cathode. This combination provides the high energy density needed for small devices.

Expanded lithium-ion polymer battery from an Apple iPhone 3GS
Expanded lithium-ion polymer battery from an Apple iPhone 3GS

Other chemistries, such as lithium iron phosphate (LiFePO4) or lithium manganese oxide (LiMn2O4), might offer a longer life. Lithium nickel manganese cobalt oxide (NMC) is another common type. NMC is widely used to power electric vehicles because it supports high discharge rates. Another high-energy option used in electric cars is lithium nickel cobalt aluminum oxide (NCA).

The history of this technology is a story of many scientific breakthroughs. In 1974, M. Stanley Whittingham developed an early version using a titanium disulfide (TiS2) cathode. This material had a layered structure that could accept lithium ions. However, these early batteries used metallic lithium anodes, which were unstable and prone to catching fire. In 1980, John Goodenough improved the design by using lithium cobalt oxide as the cathode. This material was much more stable in the air and provided a higher voltage.

Lithium Ionen Akku Überwachungselektronik
Lithium Ionen Akku Überwachungselektronik

Another major step occurred in 1985 when Akira Yoshino developed a prototype using a carbonaceous anode. Instead of using dangerous lithium metal, he used petroleum coke, which could safely hold lithium ions. This innovation made the batteries much safer for commercial use. In 1991, a team led by Yoshio Nishi at Sony successfully commercialized the first modern Li-ion battery. For their combined work, Whittingham, Goodenough, and Yoshino were awarded the 2019 Nobel Prize in Chemistry. This recognition highlighted how their research changed the world.

Today, the scale of Li-ion production is massive. In 2010, global production capacity was 20 gigawatt-hours (GWh). By 2020, that capacity had grown to 767 GWh, with China producing 75% of that amount. By late 2024, global demand had passed certain annual milestones, while production capacity was more than double that demand. These batteries power everything from cellular phones and laptops to massive grid-scale energy storage systems. They are also essential for electric cars, such as the Nissan Leaf.

Nissan Leaf 012
Nissan Leaf 012

Despite their benefits, there are challenges regarding safety and the environment. Li-ion batteries contain flammable electrolytes, which can pose a fire or explosion hazard. To solve this, researchers are developing solid-state batteries that eliminate flammable liquids. There are also environmental concerns regarding mining. Lithium mining is water-intensive, often occurring in arid regions. Additionally, some minerals like cobalt can be classified as conflict minerals. Researchers are now looking for alternatives, such as sodium-ion or iron-air batteries, to improve mineral efficiency and sustainability.

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🖼️ Images & Media (11)
File:Lithium-Ion Cell cylindric.JPG
Lithium-Ion Cell cylindric.JPG
File:Lithium Ionen Akku Überwachungselektronik.jpg
Lithium Ionen Akku Überwachungselektronik.jpg
File:Liion-18650-AA-battery.jpg
Liion-18650-AA-battery.jpg
File:Nissan Leaf 012.JPG
Nissan Leaf 012.JPG
File:GITT-2025-03-01a.png
GITT-2025-03-01a.png
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File:2022-Vermeer-F2.jpg
2022-Vermeer-F2.jpg
File:Expanded lithium-ion polymer battery from an Apple iPhone 3GS.jpg
Expanded lithium-ion polymer battery from...
File:1-7-12 JAL787 APU Battery.JPG
1-7-12 JAL787 APU Battery.JPG
File:ADR 9A.svg
ADR 9A.svg
File:Geographical distribution of the global battery supply chain.png
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