Recovery of valuable metals
Lithium-Ion Battery Recycling
Hydrogen peroxide and persulfate are uniquely positioned to aide in the recovery of the rare and valuable metals during the LiB recycling process.
Why is recycling lithium-ion batteries important?
Lithium-ion batteries (LiBs) are widely used power source in, fo example, electric vehicles, computers, and smart portable devices.
As more and more lithium-ion batteries reach the end of their useful life, concerns are being raised about the economic and environmental implications. LiBs contain several different rare earth minerals such as lithium, cobalt and nickel. Recycling the batteries is thus critical to recovering and reusing these precious and rare metals.
The global lithium battery recycling market is expected to grow rapidly in the next few years.
LiB recycling technology with hydrogen peroxide
Among the various LiB recycling technologies, one widely implemented process is “wet hydrometallurgy”. In this process, hydrogen peroxide (H₂O₂) is used as a reducing agent in the leaching step to:
- Oxidize or reduce the metals such as Co, Mn, Ni, Li, and Fe to aide in their recovery from the LiB substrates
- Increase leaching efficiency and shorten leaching time
LiB recycling technology with ammonium and sodium persulfates
Persulfate is another peroxygen produced by Evonik. While hydrogen peroxide can either oxidize or reduce corresponding metals, persulfate offers a purely oxidative pathway. This pathway is used, for example, as a highly efficient method for recovering lithium from lithium iron phosphate (LFP) batteries, as shown in the process flow scheme below.
Persulfate is available in several salts that are used in LiB recycling, including ammonium persulfate and sodium persulfate. In the persulfate process, lithium is quickly and efficiently leached from the cathode powder.
Product Overview
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Product |
Application |
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HYPROX® hydrogen peroxide |
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Ammonium persulfate and sodium persulfate |
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Key characteristics
Hydrogen peroxide
Hydrogen peroxide decomposes to form oxygen and water via both oxidative and reductive processes, allowing for minimal end products while oxidizing certain metals or reducing others when needed.
Persulfate
With the oxidative pathway only, persulfate is highly efficient in recovering metals that are liberated oxidatively, such as lithium.
Sustainability aspects of LIB recycling with peroxides
Since hydrogen peroxide only breaks down into only water and oxygen, it leaves minimal trace in the environment. Hydrogen peroxide is also an effective and sustainable solution for wastewater treatment: It can be used alone or in combination with advanced oxidation processes (AOP) to break down organic chains and reduce the chemical oxygen demand of wastewater.
The persulfate process leaches lithium quickly and efficiently. The lithium is recovered into a reusable substance via several methods, including either high-quality lithium hydroxide (LiOH) following electrolysis of the Li2SO₄ solution, or as a high purity lithium carbonate with the addition of carbonate to the lithium sulfate solution.
