What is the purpose of lithium in a battery?

Lithium-ion batteries are a benchmark in the world of electric vehicles, energy storage, portable devices, drones, green mobility, and more. As an essential component of these energy storage systems, lithium has become a strategic element both industrially and economically. So, what role does lithium play in batteries?

What is lithium?

Lithium is the lightest solid metal, making portable devices manageable and giving Li-ion batteries a significant advantage. On the periodic table, lithium is the first alkali metal and consists of the smallest atoms for a solid metal. This gives it its lightweight nature and very high heat capacity.

These chemical properties make lithium the preferred choice over other metals, such as lead. Lithium is known for its reactivity when in contact with water and air. For this reason, lithium-ion batteries required years of research to achieve safe and stable versions. This technology replaced Nickel-Cadmium and Nickel-Metal Hydride batteries.

The industrial production of lithium began in 1923, while commercial production started in 1991 with Sony. Initially designed for consumer electronics, Li-ion batteries have since become indispensable for any portable and rechargeable device. While lithium is most commonly associated with batteries, it is also essential in other industries such as ceramics, glass, pharmaceuticals, and metallurgy.

Lithium is abundant on Earth, but it is only extracted when present in high concentrations. Not all deposits are suitable for industrial exploitation. Market prices must justify extraction and other processing costs. The majority of lithium resources are found in the “Lithium Triangle” (Argentina, Bolivia, and Chile), which holds half of the world’s reserves. China, Australia, and the United States are also among the largest extractors.
In Europe, lithium deposits exist in countries like Portugal, Germany, Serbia, and France.

The importance of lithium in batteries

Lithium’s properties have enabled the development of high-performance batteries, making it the preferred choice for battery composition. This metal gives lithium batteries a critical advantage: lightweight design, essential for most portable devices and electric vehicles. Lithium also boasts a high electrochemical potential and exceptional energy density for its weight and volume. Compared to other metals, lithium enables more power in a smaller package.

For example, a lithium-ion battery has four times the energy density of a lead-acid battery. Regarding its composition, a lithium atom consists of three protons, three electrons, and one easily donated electron. When it donates this electron, it becomes an ion, explaining the term “lithium-ion.” This electrochemical potential is why lithium is used in batteries.

As a result, lithium-ion batteries are lightweight, compact, and capable of storing large amounts of energy.

Properties of a lithium-ion battery

The advantages of this technology

In addition to their light weight, lithium-ion batteries can store up to four times more energy per unit of mass compared to other battery technologies. Lithium-ion therefore offers excellent performance in terms of autonomy and power. They are not affected by the memory effect and have a low self-discharge rate.

How lithium-ion batteries work

Lithium-ion batteries convert chemical energy into electrical energy through the reversible exchange of lithium ions between the positive and negative electrodes. These electrodes are immersed in a conductive liquid known as the electrolyte. This movement generates electrical energy.