While lead batteries are recycled into new ones, most dead lithium-based battery packs, like the ones in computers, are dropped in the regular trash, or placed in blue recycling bins with the best of intentions but generally end up in the landfill anyway.
Why the difference between lead and lithium batteries? Why can one battery can have 98 percent of its material recycled, while the other is cheaper to just toss? And what are the implications down the road, when battery packs from electric vehicles start to enter the waste stream in bulk?
Understanding the disparity between lead-acid and lithium-ion battery recycling boils down to two major factors: time and chemistry. Lead-acid batteries have over a century’s head start on t lithium-based ones. We’ve been using these things forever, and we’ve really dialed in their lifecycle management. From cradle to grave and back to cradle again, lead-acid batteries benefit from an extensive and highly integrated manufacturing and distribution system, one that the lithium-ion industry just has not yet had time to develop. The lead-acid infrastructure goes so far as to often use the exact same trucks that deliver batteries to retailers for the return trip to the recycler.
Time also plays into it via the rapid turnover of automotive batteries. The average car battery lasts about four years, give or take, and since the average lifetime of a car is now about eleven years, each car will likely see three or more batteries over its service life. For electric vehicles and hybrids, the battery pack is designed to last for pretty much the service life of the vehicle, so barring accidents that render the vehicle wrapped around them useless, lithium-ion packs are just not going to enter into the recycling stream nearly as often as lead-acid batteries do. This is somewhat negated by the number of lithium-ion battery packs from consumer products like laptops and power tools; those enter the waste stream far faster than lithium-ion batteries from electric and hybrid vehicles. But those numbers are a rounding error in the equation compared to the number of lead-acid batteries recycled every day.
As for chemistry, the simpler the mix of materials in an object, the easier it is to recycle. Aluminum cans, which are just aluminum and paint, are incredibly easy to reclaim with the addition of a little heat. Lead-acid batteries are not quite that simple, but they’re close: just lead, lead oxide, and sulfuric acid in a plastic case. Each material in the battery has a simple path from old to new: the lead plates melt easily at low temperatures and can be easily purified, ditto for the PVC that typically makes up the battery’s case, and the sulfuric acid electrolyte can either be diluted and disposed of as wastewater, or the sulfates can be recovered to manufacture new electrolytes or used in the production of other consumer items, such as soaps.
Lithium batteries, on the other hand, have much more complicated chemistries and a mix of materials that don’t work and play well together in an industrial recycling process. A lithium-ion battery is not just lithium but also has cobalt, manganese, iron phosphate, or nickel compounds, not to mention aluminum, copper, and graphite. Not only is the mix of metals more complicated, but their physical form as powders coated onto metal foil makes recovery of each component far more complicated than just throwing it in a furnace.
Read the full story at https://hackaday.com/2018/07/16/getting-the-lead-out-of-lithium-battery-recycling/.