Researchers working to perfect quick release battery binder.(Credit: Marilyn Sargent/Berkeley Lab)

Berkeley National Lab Reveals New Battery Recycling Technique

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One of the beautiful things about the transition to clean transportation and clean energy is that battery recycling can reuse the raw materials inside again and again. When today’s batteries reach the end of the their useful life, the magic stuff that makes them work — lithium, cobalt, copper, manganese, nickel, and iron — can be reclaimed and used to make new batteries.

We didn’t actually know that much about battery recycling when electric cars first appeared in commercial quantities a dozen years ago. Back then, the focus was on reusing them for energy storage when they were no longer capable of powering vehicles. JB Straubel, former Tesla CTO, was actually one of the first to concentrate on battery recycling, but now many others are joining the battery recycling push.

Just a few years ago, many were astonished to learn that the reclaimed materials were every bit as good as new materials. People have been talking about building a circular economy where we don’t just throw our old stuff into landfills but reuse and recycle it again and again. In a perfect world, that would be the norm, not the exception.

A Battery Recycling Breakthrough

Researchers at Lawrence Berkeley National Lab announced on February 1 that they have developed what they call a Quick Release Binder that makes it simple and affordable to separate the valuable materials in lithium-ion batteries from the other components and recover them for reuse in new batteries.

“We’re getting to the point that recycling batteries will be a requirement,” said project leader Gao Liu, a senior scientist in Berkeley Lab’s Energy Technologies Area and a member of the Berkeley Lab Energy Storage Center. “If we don’t stop burning them and throwing them in the trash, we will run out of resources in the next ten years. It’s just impossible to keep up with the number of batteries the market is demanding otherwise. There’s just not enough cobalt, not enough nickel — we have to recycle.”

A battery made with Quick Release Binder simply needs to be opened, placed in room temperature alkaline water, and gently shaken. The separated elements are easily filtered out of the water and air dried. That’s in sharp contrast to current lithium ion recycling, which involves first shredding and grinding batteries, then burning them to separate the metals from the other constituents. Recycling companies aim to make their processes as efficient as possible, but due to the past and current design of most batteries, recovering the elements is still energy intensive, expensive, and releases toxic chemicals that must be carefully managed.

Just Add Water

Liu and his team at the Berkeley Lab Energy Storage Center were working on lithium-sulfur batteries — one of the possible alternatives to traditional lithium-ion that is being developed — when they created the Quick-Release Binder. Lithium-sulfur batteries are a hot concept in the battery research and development world because they can be made without rare cobalt and have a higher theoretical energy density than lithium-ion. But there are a lot of functionality problems that must be solved before the batteries can be adopted commercially. The Quick Release Binder would make lithium-sulfur batteries easily recyclable and might solve one of the major performance issues.

The group’s research findings were quite exciting on their own, but Chen Fang, a postdoctoral researcher in Liu’s lab, realized that the new binder material had even bigger potential — it could also be used in today’s lithium-ion batteries as well.

Binders are glue-like substances used in most types of batteries. Every battery has two electrodes — the positively charged cathode and the negatively charged anode. The electrodes are made from conductive chemicals that generate an electric current, and structural materials that hold the active ingredients in place for consistent and durable performance. Binders, as the name implies, bind these ingredients together and help maintain the architecture of the battery.

The new Quick Release Binder is made from two commercially available polymers — polyacrylic acid (PAA) and polyethylenimine (PEI) — that are joined together through a bond between positively charged nitrogen atoms in PEI and negatively charged oxygen atoms in PAA. When the solid binder material is placed in alkaline water containing sodium hydroxide, the sodium ion pops into the bond site, breaking the two polymers apart. The separated polymers dissolve into the liquid, freeing any embedded electrode components.

The binder can be used to make anodes and cathodes, and is about one-tenth of the price of two of the most commonly used commercial binders. “[In our recent research] we demonstrated that the whole process is very easy at the lab scale and we see no reason why it won’t work equally well at the industrial scale,” Fang said. He added that the team believes the material can be used for batteries of all sizes, from the small ones in cell phones to the extra large batteries being deployed to store back-up energy on the nation’s electric grid.

In late September, the technology was recognized by the R&D 100 Awards as one of the top 100 revolutionary technologies developed globally in 2022. The team is now working with Steve Sloop, a battery recycling developer and founder of OnTo Technology, to finish testing the product and bring it to the market. Past experiments demonstrated that the binder is highly stable at high and low voltages, and the researchers now plan to build prototype lithium-ion batteries with the revolutionary binder to analyze their performance and showcase their functionality.

Commercializing Is Next

Assuming the tests go well, the scientists foresee a smooth transition to commercial manufacturing. “There’s no fundamental obstacle in adapting the current manufacturing process to use the binder because it will actually simplify manufacturing for the same reason it simplifies recycling — you can use water instead of harsh solvents,” said Chen.

To make new batteries, manufacturers process binders with chemical solvents to create a slurry containing all the electrode components, which is then deposited in the desired shape and thickness on electrode sheets. “This means that current manufacturers need to set up extra instruments or facilities for protecting workers from toxic solvent vapor and for managing safe disposal of the solvent.” Chen says the Quick Release Binder would eliminate those steps.

According to Steve Sloop, the Quick Release Binder represents a paradigm shift in battery design. Instead of engineering advanced batteries and trying to create a recycling process after the fact, Liu’s team was the first to “design for recycling.”

“The binder has a great feature that it can be ‘un-zipped’ with low cost, environmentally benign processing, which benefits us all by improving the economic and environmental sustainability of advanced battery systems,” said Sloop.

“It’s also a great achievement that the batteries contain no perfluoroalkyl and polyfluoroalkyl substances (PFAS) — the family of compounds used to make non-stick coating and many other products, but it’s extraordinarily important for the future. Customers don’t want them due to the emerging link with health issues and I think soon regulators will agree that we can’t keep using these chemicals.”

Development of the Quick Release Binder was supported by the Department of Energy’s Office of Energy Efficiency and Renewable Energy and OnTo Technologies. The technology is now available for licensing by contacting ipo@lbl.gov.

The Takeaway

Is this research a proverbial “game changer?” No, it is part of a process that has been going on for generations. The internal combustion engine was not perfected overnight. Many people used to actually change gears in their cars by moving a piece of metal backward or forward and side to side. What this is, is a small step forward towards the goal of electrifying everything — which we need to do if humans are to survive in a hotter environment.

A circular economy will be a necessary part of the effort to keep the world habitable. If we take all the small breakthroughs like this one and add them together, we just might — might — survive for another millennium or two.


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Steve Hanley

Steve writes about the interface between technology and sustainability from his home in Florida or anywhere else The Force may lead him. He is proud to be "woke" and doesn't really give a damn why the glass broke. He believes passionately in what Socrates said 3000 years ago: "The secret to change is to focus all of your energy not on fighting the old but on building the new." You can follow him on Substack and LinkedIn but not on Fakebook or any social media platforms controlled by narcissistic yahoos.

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