Recycling of precious metals from batteries of electric vehicles

Researchers have found a biological method, using bacteria, to recycle precious metals found in electronic waste, such as, for example, used batteries for electric vehicles

[By: Prof. Sebastian Farnaud, expert in innovation and entrepreneurship in the field of biology, University of Coventry. Translation by Dr. Moshe Nachmani]

Today there are more than 1.4 billion vehicles in the entire world, and this number is expected to double by 2036. If these vehicles are powered by oil or diesel, the consequences for the Earth's climate could be dire. Electric vehicles emit less pollutants into the air and if they can be powered by renewable energy, then these types of vehicles will not add greenhouse gases that cause global warming.

However, the production of such a large amount of electric vehicles in the coming decade may increase the demand for metals such as lithium, cobalt, nickel and manganese. These metals are essential for the production of batteries for electric vehicles, but they are not found everywhere. Most of the lithium metal is found in the Atacama Desert in South America (Chile-Peru), where the mining itself threatens the well-being and lives of the local residents and endangers the ecosystems. Leading electric vehicle manufacturers need to keep import costs low and find a reliable source for these raw materials. Mining in the depths of the sea is another option, but this method can also cause damage to habitats and endanger wildlife. At the same time, waste from electronic products full of precious metals accumulates in huge quantities in designated landfills in some of the poorest countries in the world - with an amount of 2.5 million tons added every year. Batteries for electric vehicles have a shelf life of only eight to ten years. Today, lithium-ion batteries are recycled at a paltry rate of less than five percent in the European Union. Instead of mining and destroying new sources of these metals, why not reuse the amounts that are already out there?

The largest factories in the world for recycling lithium ion batteries are located in China. While recycling is often seen as a corporate regulatory obligation in North America and Europe, competition for unused batteries is so fierce in China that recyclers are willing to pay for them.

Most of the batteries that do end up being recycled are melted down and the metals in them are extracted. This process is done in large commercial facilities that use a large amount of energy and therefore emit a large amount of carbon. These plants are expensive to set up and operate, and require sophisticated and expensive equipment designed to handle the harmful emissions created during the smelting process. Despite the high costs, these factories usually fail to recycle all the valuable materials inside the batteries. The value of the worldwide metal recycling market is expected to grow from $52 billion in 2020 to $76 billion by 2025. In the absence of less energy-intensive recycling methods, this growing industry could face more acute environmental problems. However, there is a natural process for extracting precious metals from waste, a process that has been in use for decades. 

Bioleaching, also called biomining, utilizes bacteria capable of oxidizing metals as part of their metabolism. This method has been widely used in the mining industry, where microorganisms are used to extract precious metals from lead. Recently, this method is used to clean and recycle materials from waste electronic components, especially computer printed circuits, solar panels, contaminated water and even uranium dumps.

The researchers found that it is possible to exhaust all the metals found in the batteries of electric vehicles with the help of this biological method. Certain bacteria, such as the strain Acidithiobacillus ferrooxidans , and other harmless strains, can focus and recycle the separated metals without the need for high temperatures or the use of toxic chemicals. These purified metals also include chemical elements that can be reused in many supply chains.                   

The capping stage (transferring the method to an industrial scale) of this process involves growing bacteria in incubation facilities at a temperature of 37 degrees Celsius, while also using carbon dioxide. The process does not consume a large amount of energy, so the carbon footprint is smaller than that typical of recycling plants, and in addition, the process itself emits less pollution. Such biological facilities not only reduce the amount of waste from electric vehicle batteries, but manufacturers can recycle these precious metals within their own country, relying on a smaller number of other countries.

The researchers from the academy working in this field do succeed in extracting all the precious metals from the electronic waste and making them float on the surface of a liquid solution. However, this method is not efficient enough for the industry. The researchers were able to combine the biological method with electrochemical methods capable of extracting these metals and making them useful for supply chains. Unfortunately, existing methods for the recycling of metals involve high energy requirements and toxic chemicals, and have been used for decades. The various industry sectors cannot always develop and create innovation in this area, so governments have the responsibility to promote changes and invest in the development of cleaner alternatives in this area. 

Batteries for electric vehicles are still a new technology, and the reuse of their components should be considered as part of their design. Instead of remaining an afterthought, biological recycling may become both the starting point and the end point of the life cycle of electric batteries, while obtaining quality raw materials for the development of new batteries with low environmental cost. 

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