One of the most challenging aspects that has hampered the more widespread adoption of clean energy solutions, especially the replacement of fossil fuel-guzzling cars with electric vehicles, is the way lithium batteries are recycled. The process is time-consuming and, in some quarters, is seen as one that does more harm than good to the environment as strong inorganic corrosives are used to extract potentially useful byproducts.
But researchers at the Chalmers University of Technology in Gothenburg, Sweden say that they have hit upon a more effective – and efficient – way to recover useful materials from spent EV batteries, and it is one that does not require potentially dangerous acids.
What’s the Difference?
In conventional hydrometallurgy, a spent battery cell is subjected to an acid bath which dissolves the bulk of the metals used in its production. Lesser metals like aluminum and copper are removed from the resulting slurry in order to recover cobalt, lithium, manganese, and nickel from the cell.
However, doing so requires numerous steps and, as a result, it is possible that the amount of lithium that could be extracted from the cell could be down to nil by the time the process is done.
The Chalmers team claims that their method effectively recovers up to 100% of the aluminum, and – more importantly – nearly 98% of the lithium. This is because the method takes the aluminum out first to ensure that other metals can be extracted with minimal to no loss.
Their method involves the placement of spent EV batteries and the pulverized metals within a fume cabinet. The resulting black powder is then dissolved in oxalic acid, an organic substance found in edible plants like spinach. This mixture is then blended, resulting in a liquid compound of lithium and aluminum separated from other metals which remain in a solid state.
The lithium is then separated from the aluminum through a secondary process.