Batteries - Production And The Uncertain Future Of Lithium

Lithium is a chemical element that is a soft, silvery-white metal commonly and most frequently used in lithium-ion batteries. Lithium also plays a role in various industrial applications, such as the manufacture of ceramics, glass and lubricants. In addition, it is used in pharmaceuticals, for example to treat bipolar disorder and depression.

Lithium is a rare element and the multitude of its uses means that natural supplies of the element are dwindling. In the upper layers of the Earth, lithium is present in an amount of about 0.0018%. This raises the questions: how long will lithium reserves last and what measures should be taken to reduce the consumption of its reserves? Will the continued production of batteries containing lithium make the use of this element uncertain or even at risk in the future? Exactly how much lithium is needed to produce a lithium or lithium-ion battery?

Demand is growing, resources are shrinking

Lithium batteries are manufactured by using lithium as the active material in the electrodes. The production process includes extracting lithium, refining it and then mixing it with other components such as metal oxides, electrolytes and separator to form the electrochemical cells of the battery. These cells are then assembled into a housing and tested for their performance and safety. Manufactured lithium batteries are widely used in consumer electronics, automotive and renewable energy applications. In addition, it is estimated that with the continued upward trend in the use of lithium in industry (mainly in the automotive industry to build batteries for electric cars), we will need to mine 20 times more lithium by 2050 than we do today, meaning that global production will increase to 11.2 million tonnes per year.

Multiple methods of regeneration

Lithium batteries, and more specifically lithium-ion batteries, can be repeatedly regenerated-recharged by a process called battery balancing, which aims to equalise the state of charge of each cell in the battery (pack) in order to maximise its capacity and extend its life. Balancing, i.e. evenly discharging and recharging all the cells in the battery, is carried out using special battery balancing equipment or by cyclically charging and discharging the battery. It is also important to clean the battery terminals regularly and to ensure that the correct ambient temperature and humidity are maintained to prevent degradation. If the lithium battery is already very worn out, it is best to replace it with a new one. Replacing a used battery with a new one seems trivial to the user, but looking at this from the point of view of a technologist or patent attorney and in the light of reducing the consumption of lithium reserves, the key aspect is to carry out processes aimed at recovering the "used lithium"

Here is a list of currently known ways to recover lithium from waste batteries:

1. a recycling (recovery) process, where used batteries are collected and treated in dedicated recycling facilities, where the lithium is extracted and subjected to purification processes,
2. a pyrometallurgical process in which waste batteries are subjected to a high-temperature melting process to separate the lithium from other components,
3. a hydrometallurgical process, where used batteries are dissolved in acids or bases and the lithium is then recovered through extraction and electrolysis processes,
4. an electrochemical process, where waste batteries are subjected to an electrolysis process that makes it possible to recover lithium in pure metal form.

Latest inventions

With rising raw material prices and environmental benefits, the recycling of used battery components is gaining increasing attention and importance. Overall, the recycling efficiency of materials from lithium-ion batteries is less than 50%, as recovered components such as lithium and graphite, as well as cobalt, nickel and manganese, are of low purity and not worth reusing. Among the inventions recently published in the European Patent Office database, attention should be drawn to patent application No EP4400616A2 to TADIOS TESFU, which relates to a method of recovering raw materials from primary and rechargeable batteries, but also from strong magnets and fuel cells. The method comprises a step of mechanical and chemical treatment of components containing at least cobalt and nickel compounds. The first step comprises in particular a physical preparation of the raw materials, decomposition of the charged cells and physical separation and grinding processes. When rechargeable batteries, e.g. lithium-ion batteries, are ground, the liquid electrolyte contained in them is additionally collected. Physical separation is followed by a chemical treatment step using acid, e.g. dilute sulphuric acid at 60 to 80°C, which can be controlled by adding potassium permanganate as an oxidising agent. The precipitation of cobalt from the sulphate solution can be carried out by reaction with caustic soda to produce cobalt(II) hydroxide, that of nickel can be carried out with multidentate ligands and that of manganese by electrochemical separation. After precipitation of Ni, Co and Mn ions, lithium ions usually still remain in the sulphate solution, and these can first be chemically precipitated out of the solution with sodium carbonate to obtain lithium carbonate, which is purified, e.g. by re-crystallisation. The lithium carbonate can then be dissolved in an aprotic solvent and electrochemically deposited as lithium metal. In the final process step, the remaining material is transferred to a neutralisation system, where acids and bases are neutralised and heavy metals are separated. By recovering the process water and using the hydrogen produced during electrolysis to generate energy, the proposed method can be largely self-sufficient and efficient, and the raw materials recovered are of high purity.

An interesting solution for improving the recycling of waste lithium-ion batteries is given in international patent application No. WO2024046889A1 to CYLIB GMBH; RHEINISCH-WESTFÄLISCHE TECHNISCHE HOCHSCHULE AACHEN, KÖRPERSCHAFT DES ÖFFENTLICHEN RECHTS, this being a method for processing energy storage batteries containing lithium, which includes at least the following steps: i) optional pre-treatment of the battery, namely thermal, mechanical and electrical treatment; ii) pyrolysis of the pre-treated battery with release of carbon dioxide and in a carbon dioxide atmosphere with at least partial carbonation of the contained lithium; iii) the separation of lithium in the separation step, and iv) hydrometallurgical treatment of the resulting mixture of step (iii) of the process with further carbonation of the contained lithium and its removal in a subsequent separation step, with the carbon dioxide released in step (ii) being recycled thus making it possible to reduce CO₂ emissions by re-circulating it, as well as to have a high lithium yield without any additional carbonation agents, which are necessary in a conventional process.

Finally, European Patent EP3517641B2 to DUESENFELD GMBH proposes a solution which involves digesting the comminuted lithium-containing material with concentrated sulphuric acid at a temperature of at least 100°C, discharging the waste gas, followed by wet chemical extraction of the metallic components of the lithium-containing material and re-leaching, graphite separation and digestion, an important aspect of the solution being that the resulting highly corrosive hydrogen fluoride migrates into the waste gas.

The vast majority of known processes recover lithium from waste batteries in a manner that is not sufficiently efficient and environmentally friendly for lithium to be fully reused in the production of new batteries. Consequently, and also because of the continuing depletion of the natural reserves of this element, there is a high demand for the provision of new diverse technologies to make the recovery of lithium, mainly from used lithium batteries, more widespread than the use of existing reserves of this element. Many scientists and informed entrepreneurs are conducting extensive research to develop such technologies and thus increase the sustainability of lithium use in the future. It is also equally important and necessary to spread knowledge and raise awareness in society about the problem and about measures for the effective recycling of batteries worldwide.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.