Companies like Apple and Samsung aren’t the only ones making high-tech devices that are difficult to take apart and recycle. The same is true for manufacturers of critical clean energy technologies like solar panels, wind turbines and electric vehicle (EV) batteries – and unlike the consumer tech industry, which is slowly beginning to reverse some of its unsustainable design practices, there is not much that can be done. done about it.
Batteries, solar panels and wind turbines are all essential tools in the fight against climate change. However, manufacturing these technologies requires considerable energy and resources, and the best way to ensure that we can continue to manufacture more of them in a sustainable way is to recycle these resources at their end of life. But today, clean energy recycling is limited by design choices that hinder disassembly, including the widespread use of ultra-strong adhesives. That could change, experts say, if companies making oversized batteries for electric vehicles and rare-earth magnets for wind turbines turn to new adhesives that can be ‘peeled off’ using light, heat , magnetic fields, etc. drawings.
“Designing for recycling hasn’t really arrived in this market yet,” says Andy Abbott, professor of chemistry at the University of Leicester, who recently co-authored a review article on peel-off adhesives and their potential use. in clean energy.
Instead, Abbott says, manufacturers tend to “overdesign” their products for safety and durability. Take EV batteries, which are made up of tens to thousands of hermetically sealed individual cells glued together inside modules and packs. Although the extensive use of adhesives helps to ensure that the batteries do not fall apart on the road, it can make them incredibly difficult to take apart in order to reuse individual cells or recycle critical metals like lithium, cobalt and nickel.
“At the moment, because it’s all connected, a lot of batteries end up being shredded,” said study co-author Gavin Harper, an expert in electric vehicle battery recycling at the University of Birmingham in the UK. -United. The edge. “The material is mixed, which complicates the later stages of the recycling process. ”
Solar panels and wind turbines are also built to last in a way that makes recycling difficult. Most solar panels are made up of silicon cells coated with layers of polymer sealants that bond the cells to glass and weather-resistant plastic covers. While this electronic sandwich design means the panels can last decades on a roof exposed to the elements, the adhesives and sealants used throughout the panel make it difficult to cleanly separate end-of-life components. Rare-earth magnets inside wind turbine generators, meanwhile, are coated in resins and glues that can create significant contamination for anyone looking to salvage and reuse the material. A single wind turbine can contain hundreds of pounds of rare earth elements, and demand for these metals is expected to skyrocket as the world builds more electric vehicles and more turbines.
Abbott says manufacturers are just beginning to realize that recovering critical materials in clean energy technologies is important to shore up long-term supplies — and that new design approaches are needed to facilitate that. “Really only in the last 18 months or so has this conversation started to lift its head,” he says.
Abbott and Harper’s new paper outlines a number of potential pathways to a more recyclable cleantech sector. While solar manufacturers are unlikely to phase out adhesives anytime soon, the authors suggest that manufacturers may be moving towards adhesives and sealants that can be removed with chemicals, magnetic fields or even a high frequency sonic pulse. For wind turbine magnets, an adhesive that loses its adhesion in the presence of a strong magnetic field will not work, but an adhesive that could be melted with heat or peeled off when exposed to ultraviolet light , could be viable.
Designs that use fewer adhesives could significantly improve EV battery recycling. If batteries were easier to break down to individual cells, Harper says it could make it easier to recover critical materials inside the cathode, including lithium, which is rarely recycled today. And at least one company is already marketing an adhesive-free battery design: In 2020, Chinese battery maker BYD announced a new “Blade Battery,” which features long, thin cells that clip into the main battery without using glue. “In terms of disassembly, it’s trivial,” says Abbott. “The cells just detach. “
For EV battery makers unwilling to abandon glue-based designs, there are “a lot of methods” that could lead to a more removable adhesive, says Jenny Baker, battery storage expert at Swansea University in Great Britain. The challenge, according to her, will be to develop adhesives that can be removed quickly, in a process that can be carried out on an industrial scale.
“The thing now is to take some of the science and try to move it into engineering so that we can prepare it for very large scale recycling, because we know there will be a lot of these batteries that will happen,” Baker said. Based on the projected growth of the electric vehicle and energy storage markets, Harper estimated that by 2040, there could be about 8 million metric tons of waste batteries to be recycled globally. A similar amount of solar e-waste could flood recycling plants by 2030.
To convince manufacturers (and consumers) to adopt more recycling-friendly adhesives and adhesive-free designs, Baker says they’ll need assurances that the alternatives don’t compromise the durability or lifespan of the products, which, in the cleantech sector, is often measured in decades. She suspects that many new designs will need to be “road tested” in shorter life products where premature failure is “less of a risk”.
That could include consumer tech markets, where sustainability-focused companies like Framework and Fairphone are already rolling out modular, adhesive-free laptops and phones meant for easy disassembly. Even industry giants like Apple and Dell have recently announced ambitious goals and product concepts focused on recyclability. Abbott has already had preliminary talks with a phone maker about glues that can peel off a screen much more easily, though he says the company has yet to embrace the idea.
Ultimately, manufacturers could be forced to overcome their reluctance to change product designs for recycling if policymakers start to impose it or if the world faces shortages of the metals and minerals needed for construction. of these technologies. As the clean energy transition drives up demand for high-tech metals, Baker says companies are going to have to start getting more creative about where to source them.
“If you can get [a resource] but it’s a really high price, it’s bad, but you can pass the price on to the consumer,” says Baker. “If you can’t get it at all, you don’t have to do anything.”