How plasma is improving battery recycling
A new battery recycling process using microwave plasma and citric acid could recover up to 95% of critical materials while cutting energy demand and reducing the use of aggressive chemicals. The approach also makes it possible to regenerate graphite, strengthening the sustainability and value of the battery supply chain.
A new battery recycling process based on microwave plasma and citric acid makes it possible to recover nearly 95% of critical minerals while operating at room temperature and using mild solvents.
That is the conclusion of a study published in Advanced Materials, which introduces a pre-treatment capable of significantly increasing the efficiency of metal extraction from so-called black mass.
The method enables the recovery of lithium, cobalt, nickel and other strategic elements, while also regenerating graphite, a key battery component. This is an important step towards reducing environmental impact and improving the sustainability of the battery value chain.
The process relies on a 15-minute plasma treatment followed by a leaching stage with citric acid at room temperature. The result is recovery rates above 90% for all metals, reaching peaks of up to 95%, together with greater selectivity in lithium recovery.
How plasma changes black mass
The first stage involves shredding spent cells into a mixture known as black mass, which contains metals and graphite.
The plasma treatment, meaning a highly energised ionised gas, acts on this mixture by altering its structure. The particles are exposed to energetic bombardment that creates microfractures and increases the reactive surface area.
This step makes subsequent metal extraction easier. Unlike conventional methods, which require high temperatures and strong acids, the process works with weak solvents such as citric acid.
More specifically, the plasma helps break down the structures of metal oxides, making the materials easier to dissolve. It also enables more efficient lithium separation, with lithium recoverable even in water.
Traditional battery recycling
Current battery recycling technologies are based mainly on pyrometallurgical and hydrometallurgical processes.
The former require high temperatures, often above 700 to 900°C, with significant energy consumption. The latter rely on concentrated acids and complex processes, with considerable environmental impacts.
In both cases, recovery efficiency is not uniform. Some metals can be recovered with good yields, while others are harder to extract. In addition, many processes focus only on the most valuable materials, overlooking other important components.
The study highlights that current technologies still deliver low overall yields and do not allow full recovery of all the materials contained in batteries.
The new plasma-based approach overcomes these limits, improving both process efficiency and sustainability.
Graphite recovery in battery recycling
In battery recycling, graphite remains one of the main challenges. This material accounts for around 22% of the weight of a lithium-ion battery.
In traditional processes, graphite is often damaged by high temperatures and can no longer be reused in batteries. As a result, it is typically diverted to lower-value applications, leading to a loss of material value.
The plasma treatment changes that picture. The process removes residues and defects that build up during battery use, while preserving the material’s structure.
Tests show that the recovered graphite retains good electrochemical performance and can be reused as an anode. This reduces the need for virgin raw materials and improves the overall sustainability of the system.
The advantages of plasma-based battery recycling
A comparison with conventional processes shows important advantages for battery recycling.
The plasma pre-treatment takes just 15 minutes, compared with two hours or more for conventional thermal treatments.
Energy consumption is also lower. Industrial furnaces must maintain high temperatures over long periods, whereas plasma allows fast and controlled heating.
From a chemical perspective, the use of citric acid at around 30°C replaces the need for strong acids and elevated temperatures.
Comparative tests show that recovery of transition metals exceeds 90%, while thermal processes stop at around 86%.
In addition, the recovery of high-quality graphite increases the overall value of the materials obtained, improving the economic sustainability of the process.
Industrial prospects for battery recycling
The new battery recycling method has been designed to be integrated into existing industrial processes. Techno-economic analysis points to advantages in terms of costs, energy consumption and the value of recovered materials.
For scale-up, two main strategies are envisaged. The first is the development of plasma reactors capable of operating on larger volumes. The second is parallelisation, with multiple systems running at the same time.
The technology has already been patented and is now moving towards industrialisation.
Battery recycling is strategic for critical raw materials
Battery recycling is central to securing the supply of critical raw materials. Lithium, cobalt and nickel are limited resources concentrated in only a few parts of the world.
At the same time, less than 10% of end-of-life batteries are currently recycled, with large quantities of materials still ending up in landfill.
This creates environmental risks and leads to the loss of strategic resources. Technologies able to recover almost all materials therefore represent a key step for the energy transition.
The new method shows that it is possible to increase recovery efficiency while at the same time reducing environmental impact and operating costs.
