Lithium-ion batteries have gradually established themselves in a large number of industrial sectors, from microelectronics to portable electronics, including transport (electric vehicles, soft mobility, rail and air transport) and the storage of alternative conversion energies. such as solar photovoltaic or wind power.
These batteries are considered today as one of the most efficient ways to store electrical energy. In the coming years, the lithium-ion battery market will be mainly driven by the field of transport (electric vehicles), and to a lesser extent by that of alternative energies. The outlook for industrial production is to increase these capacities by a factor of 10 by 2030, after growing by a factor of 6 between 2010 and 2018.
This technology currently represents the best compromise (compared to storage alternatives) between mass and volume energy density (quantity of energy that can be stored or transported for a given volume or mass), low self-discharge, long life life, low maintenance and use over a wide temperature range. Their cost and their unit carbon footprint having considerably decreased in recent years, lithium-ion batteries represent a key element in the decarbonization of transport: in France, electricity production is mainly based on nuclear power plants, the carbon footprint (manufacturing /uses/end of life) of a “mid-range” vehicle is divided by three, compared to its petrol equivalent.
So many elements that make lithium-ion batteries appear as a relevant technological solution for the ecological transition.
Cobalt and lithium, two essential ingredients but not very available compared to demand
Nevertheless, this technology consumes a lot of metals with a high “criticality”: by 2025, this technology should mobilize a large part of the world production of cobalt (which is used in the composition of the positive electrodes, for 65% of the production world) and lithium (for the positive and negative electrodes and the electrolyte, for 75% of world production), not to mention the other metals (nickel, copper, etc.) or carbon graphite that make up battery elements.
Read more: These metals that are running out, a challenge for the societies of tomorrow
For example, the global consumption of lithium increased by 283% between 2010 and 2021, the price per ton rose from $4,450 in 2012 to $78,000 in 2022. This strong growth in raw material needs could lead to tensions on the markets as well as major geopolitical risks, and increases the problem of the ecological impact of mining, which generally consumes fossil fuels and chemicals to separate the metals from the ore.
These tensions underline the importance of tackling, in parallel with technical solutions, societal questions concerning the relationship of the individual to the vehicle. For example, limiting the race for autonomy would reduce the size of batteries and therefore the consumption of raw materials.
In parallel with more virtuous practices, two research paths appear necessary in the short term: the development of battery recycling and the development of “post lithium-ion”.
Read more: Can electric vehicle batteries be recycled?
“Post lithium-ion” batteries to avoid lithium supply voltages
By “post lithium-ion”, we mean new battery technologies benefiting from the experience acquired over decades in the development of lithium-ion, or even completely disruptive technologies, for which everything has to be rethought. Worldwide academic research is currently in full swing in the development of these systems.
Thus, new ways are being explored to replace the element lithium with other much more abundant elements on earth, such as sodium, calcium, magnesium and potassium, which can, like lithium, act as an electrode. negative in a battery. These lines of research make it possible to anticipate possible future tensions on lithium supplies due to the very unequal distribution of this resource on Earth.
Sodium for example, very abundant and close to lithium in its chemical and electrochemical properties, does not have quite the same performance in terms of mass and volume energy density. On the other hand, it has been shown that sodium-ion batteries could have higher power performance than lithium-ion batteries, which, for certain applications, proves to be particularly interesting.
Batteries based on calcium, magnesium or potassium are currently facing significant scientific obstacles (availability and cost of positive electrode materials, reactivity at interfaces) which suggest a longer-term commercialization.
Replace flammable liquid constituents of Li-ion batteries
Furthermore, “post-lithium-ion” does not necessarily mean “end of lithium”, since among the new paths which benefit from the most significant industrial investments today are the so-called “all-solid” batteries, the purpose of which is not not to replace lithium itself, but the flammable liquid constituents of lithium-ion batteries (known as electrolytes) with non-flammable solid constituents, with the aim of increasing safety for users.
This route also offers prospects for increased performance in terms of energy density (i.e. lighter batteries and allowing longer range), through the use of metallic lithium (as opposed to lithium ions of lithium-ion batteries) as the negative electrode. This type of battery is particularly popular today with car manufacturers for whom safety and energy density are key elements.
This “all solid” technology also faces significant technological obstacles, but it is certain that, given the financial and human efforts made, considerable progress is to be expected in the years to come.
Diversification of technologies in response to needs
We are witnessing a diversification of technologies in response to specific needs depending on the nature of the application.
As long as lithium prices remain acceptable for a globalized world economic system, lithium-ion technology still has a bright future ahead of it, in the field of portable electronics in particular.
For the electric vehicle, it will rather be “all-solid” lithium technology, if all the scientific and logistical obstacles can be lifted. Alternatives to lithium remain slightly underperforming but could prove acceptable if the price of lithium were to rise sharply due to geopolitical tensions. Electric batteries are not the only technological solution. Energy storage using “green” hydrogen, for example, is a complementary solution.