Chinese researchers have developed a new method of recycling lithium ion batteries from electric cars. Their study was published in October in a scientific journal alemana Applied Chemistry. Unlike traditional techniques, the new method is “simple, cheap and environmentally friendly”. The main objective was to reduce the carbon footprint of the process. Let us remember that most of the emissions of an electric car come from the manufacturing of its battery and its subsequent recycling, which are offset by the zero emissions when driving.
In this new method it is not necessary to add more chemicals than the citric acid, the same one that is present in the effervescent tablets, to a battery in which metals such as nickel, manganese and cobalt already enter their composition. It would be enough to add lemon juiceso to speak.
Simple, cheap and environmentally friendly recycling
A team from China University of Mining and Technology in Beijing, Fuzhou University, Beijing University of Chemical Technology and Tsinghua University in Shenzhen, led by Guangmin Zhou and Ruiping Liu, has developed a novel citric acid-based method for the leaching, separation and recovery of metals from NMC cathodes. NMC is a mixed oxide containing nickel, cobalt and manganese in a lamellar structure. The lithium ions are enclosed between the layers or sheets of that compound.
The researchers explain that they used a “small amount” of citric acid, the same one found in large quantities in lemons, to extract and separate more than 99% of lithium, nickel, cobalt and manganese contained in NMC batteries.
They assure that “no other chemical product was used in the experiment.” This method resulted in a “new NMC laminar framework”, which can be used “as high quality material”. Thus, the resulting recycled material can be directly converted into electrodes for NMC batteries.
This method represents an important milestone since most recycling processes involve high energy consumption, high emissions and often limited or low quality recovered material. Other processes, which require less energy, involve large quantities of chemicals, are complicated and expensive processes that at the same time produce toxic gases and waste.
These conventional processes require a significant excess of acid, and the pH value must be constantly adjusted with ammonia, which is complicated and unfriendly to the environment. Let us remember that industrial ammonia is currently produced from natural gas and in its production process two tons of CO₂ are emitted for every ton of ammonia. About 185 million tons of ammonia are produced every year.
The leaching, or solid-liquid extractionwith biocompatible acids such as citric acid, is an alternative to these processes. This new technique not only is relevant to reduce CO₂ emissionssino also on an economic level.
Linium ion batteries with NMC chemistrythe favorites of Western electric car manufacturers, are more expensive than LFP batteries, commonly used in models manufactured in China. The cost of these batteries also takes into account the recycling process, which is mandatory by law and which, at least in the EU, will be more restrictive thanks to the Mandatory battery passport for all electric cars in 2027.
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Source: www.motorpasion.com
