Lithium Ion battery (Li-Ion)

Storage battery using lithium in ionic form

What is a lithium-ion (Li-Ion) battery ?

A lithium-ion (or Li-Ion) battery is a rechargeable battery whose operation is based on the exchange of lithium ions between two electrodes. We also talk about the lithium-ion accumulator (or Li-Ion battery) when the battery is composed of several cells.

Offering many advantages, Li-Ion batteries are now part of our daily lives. Indeed, they are used as a source of energy on many electronic devices or mobile electrical appliances (smartphones, laptops, vacuum cleaners...). They are also used in hybrid and electric vehicles.

The specificities of a lithium-ion battery (Li-Ion)

Lithium-ion batteries are rechargeable batteries:

  • they discharge when the equipment they supply with electricity is used ;
  • they recharge with energy when plugged into an electrical outlet using a charger.

Like all batteries, they exploit the electro-chemical principle of ion circulation between two electrodes: one positive (the cathode), and the other negative (the anode).

The exchange of positively charged atoms (ions) takes place through a conducting liquid called an electrolyte. By circulating between the two electrodes, the ions make it possible to discharge the battery by supplying electricity, or to recharge it, according to the reverse process.

Depending on their technology, batteries use different materials. Unlike a lead-acid battery used to start internal combustion engines (diesel, gasoline...), a lithium-ion battery uses lithium ions (Li+) to produce energy. Thus, we find today a wide variety of batteries with their own characteristics and adapted to different uses: lead batteries, lithium-ion (Li-Ion), and nickel-cadmium (Ni-Cd)...

In a Li-On battery, the positive electrode is often made of a metal oxide which can be cobalt-lithium dioxide for lithium-cobalt oxide batteries or manganese dioxide. The negative electrode is usually made of graphite.

In the discharge phase, lithium ions (Li+) detach from the graphite electrode and move through the electrolyte to the positive electrode. In the charging phase, it is the opposite: Li+ ions are released from the positive electrode to the graphite electrode.

Examples and practical application

Advantages of lithium-ion batteries

There are multiple advantages of lithium-ion (Li-Ion) batteries which make this technology one of the most attractive to date:

  • more efficient on load, they can be recharged more quickly ;
  • with a high energy density, they offer a good autonomy of use whilst being light ;
  • their life span is relatively long, with a moderate loss of efficiency over time ;
  • they are relatively easy to produce and are affordable considering their many advantages.

This is why Li-Ion batteries are widely present today in all our daily equipment (smartphones, laptops, household appliances...).

Disadvantages of Li-Ion batteries

The big weakness of Li-Ion batteries is their danger. In effect, they can explode suddenly if overloaded, causing property damage or even fire.

To secure their use, an electronic management is necessary to control their operation and to cut the circuits in case of anomaly (overload, over-voltage, temperature increase...). The management of the Li-Ion batteries is carried out by means of electronic components called the Battery Management System (or BMS).

Li-Ion batteries are also sensitive to shock and punctures which make them inflammable. This powerful technology can therefore be dangerous if misused: this restricts their use and requires special precautions for their storage and transport.


Lithium-ion (Li-Ion) batteries in figures

Strong growth in production

The production of Lithium-Ion batteries represents a major challenge for the manufacture of electric vehicles, which is currently booming. In this field, Asian countries dominate the market with:

  • Panasonic, the Japanese partner of the American Tesla, is the world’s leading manufacturer of battery cells, despite a sharp decline ;
  • Chinese companies CATL (ranked 2nd worldwide) and BYD (ranked 3rd) ;
  • The Korean's LG Chem (in 4th place), the Samsung SDI (in 5th place), and the SK Innovation.

In the United States, Tesla Group's Gigafactory 1 produces nearly 35 GWh/year. The company plans to build several more gigafactories to accelerate battery production in the coming years.

For the supply of the European and French market, the tendency is to establish Asian manufacturers in Europe. We also note the emergence of several Gigafactories on the European territory such as:

  • The Northvolt project developed in Sweden and supported by the European Union ;
  • And several Giga-factories are being developed in France with the manufacturers Stellantis (in Douvrin), Renault (in Douai), or independently, the start-up Verkor based in Grenoble.


Constantly decreasing manufacturing costs

In a 2020 battery pack price report, the Bloomberg NEF strategy research institute says that production costs have fallen in ten years (from 2010 to 2020) from over $1,000/kWh to just over $100/kWh. The adoption of lithium metal batteries could reduce current costs by 40% over the next 10 years.


Regulatory framework

Lithium ion cells and batteries are considered dangerous goods and are subject to strict storage and transportation regulations worldwide.

Different measures are then applied according to the modes of transport used: road, rail, river, sea or air.

In particular, it is appropriate to:

  • know and prevent the risks linked to the presence of lithium batteries on board goods transport vehicles ;
  • Identify the signs of a lithium battery fire ;
  • to know how to react appropriately during such an event.

Transportation regulations vary depending on the capacity and nature of the lithium batteries being carried.

Lithium batteries are tested for classification purposes prior to their first shipment. When they are picked up and shipped, they must then be packaged and the packages labelled accordingly.