Published on October 23rd, 2020 | by Carolyn Fortuna0
Battery Recycling Researchers Develop New Electrochemical Process
October 23rd, 2020 by Carolyn Fortuna
Battery recycling is essential if we are to keep hazardous materials from entering the waste stream during the EV production process and at its end-of-life. Battery landfill disposal is reckless, as it can disperse significant amounts of heavy metals and other toxic substances into the air and water.
Given the backdrop of growing challenges and opportunities, Idaho National Laboratory (INL) aims to make the recycling of lithium-ion batteries easier, more efficient, and potentially greener. In their paper, the researchers reported proof-of-principle for a different approach to battery recycling, one that works at room temperature and significantly reduces the use of chemicals.
Lithium-ion is a low maintenance battery with high energy density and power-to-weight ratio, relatively low self-discharge, and low maintenance. Since we’re at the beginning of the electric vehicle (EV) revolution, only a small number of EVs have approached the end of their useful lives. Predictions are this year China alone will generate some 500,000 metric tons of used lithium-ion batteries, and, by 2030, the worldwide number will hit 2 million metric tons per year.
Lithium-ion batteries pose a significant environmental challenge: How do you dispose of a battery once it’s no longer useful?
Legislation to Support Battery Recycling
Senator Angus King, ME-independent, sponsored the “Battery and Critical Mineral Recycling Act of 2020.” The Act (which seems to be stalled in committee) calls on Congress to designate $150 million over the next 5 years to support research on state-of-the-art battery recycling approaches and to help establish of a national collection system.
The Act addresses:
- recycling processes
- the development of methods to promote the design and production of batteries that take into full account and facilitate the dismantling, reuse, recovery, and recycling of battery components and materials
- strategies to increase consumer acceptance of, and participation in, the recycling of batteries; and the integration of increased quantities of recycled critical minerals in batteries and other products to develop markets for recycled battery materials and critical minerals
Rapid growth in the market for EVs is imperative to meet global targets for reducing greenhouse gas emissions. as is the need to expand the current range of approaches to EV lithium-ion battery recycling and re-use. Today, only an estimated 5% of lithium-ion batteries are recycled due to the inefficient current process that involves high temperature and caustic chemicals.
Idaho National Laboratory Research into Battery Recycling
In the journal Resources, Conservation & Recycling, the INL team describes an electrochemical-based method for leaching valuable metals from the active materials of mixed shredded lithium-ion batteries. Instead of heat, the energy comes from electricity, which powers the reactions that leach the cobalt, lithium, manganese, and other materials out of the batteries. The researchers argue that the development of a circular economy for lithium-ion batteries is essential to realize decarbonization and an electrified energy market.
The INL scientists started with shredded lithium-ion batteries, with material supplied by Retriev Technologies of Lancaster, Ohio. A battery recycling and management company, Retriev also participated in the research, as did Solvay, a Brussels-based company that supplied the chemicals used for metals separation.
After developing the electrochemical process, the scientists tested it out, finding they could achieve high recycling recovery rates. They reported over 96% efficiency in terms of extracted cobalt, lithium, manganese and nickel, which exit the process in a single output stream. In contrast, copper — a metal with high commercial value — deposits on the cathode, which simplifies the downstream separation process, Lister said.
A preliminary cost analysis indicated a roughly 80% reduction in energy and chemical costs as compared to present recycling techniques.
In this process, the use of electrons as green reagent allowed the use and regeneration of Fe2+ in low concentrations as substitute for hydrogen peroxide as a reducing agent. Leaching in a membrane-separated 2-compartment electrochemical cell contributed to decrease the acid requirements as H+ can be generated electrochemically. With this design, leaching efficiencies over 96% for the active metals (Li, Co, Mn, and Ni) were demonstrated at pulp densities up to 240 g/L. Copper was recovered separately.
Preliminary cost analyses demonstrate ca. 80% reduction in energy and chemical costs as compared to traditional hydrometallurgical routes.
What’s Ahead for Battery Recycling?
In addition to being dangerous, disposing of batteries in landfills is also profligate, as dead batteries contain valuable elements such as cobalt, lithium, and manganese at higher concentrations than can be found in commercial ores. Recovering those metals after batteries lose their vitality is imperative.
All indications point to battery recycling as a soon-to-be big business, one that should grow commensurate with predictions for EVs to comprise 1/3 of passenger vehicles by 2040. — that’s 54 million EVs on the road, according to Bloomberg NEF. By then, the value of the raw materials in end-of-life lithium-ion batteries will have grown from about $0.3 billion in 2020 to $1.1 billion by 2025 and nearly $24 billion by 2040.
Future plans for the INL team, as reported by Hank Hogan for INL Communications & Outreach, include developing an electrochemical procedure to separate the leach process output into cobalt, lithium, manganese, and nickel. The team is also exploring reuse for another critical material, graphite, that remains and which has the potential to be recycled.
Both the leaching and separation processes then need to be scaled up to a size that is useful in an industrial setting. Part of this effort will include optimizing the leaching and separation processes by tweaking parameters to improve performance and efficiency. In addition to project partner Retriev, INL scientists are interested in working with commercial partners on these next steps.
Finally, this type of battery recycling could make use of the excess energy sometimes produced by utility-sized electricity plants.
Want to read more about battery recycling research that’s currently ongoing?
- The economic potential for battery reuse, or “second life,” can represent a market of low-cost storage for utilities and electricity consumers.
- The Union of Concerned Scientists offers an overview of the current state of battery recycling and highlights opportunities to close the loop on battery materials and create a sustainable value chain for lithium batteries.
- Researchers at Michigan Technological University are using century-old mining techniques to recycle lithium-ion batteries at low cost.
- Fortum, a Finland-based clean energy and electric vehicle charging company that is involved with a plan to install wireless EV chargers for taxis in Oslo, has also created a new process that makes more than 80% of EV battery materials recyclable.
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