Lithium-ion batteries can't be recycled effectively, something that will stifle their wider use.
(I gave a keynote presentation last week at the 13th European Lead Battery Conference in Paris. This is the second in a series of articles for TheStreet that will highlight the principal issues that I touched on in that presentation.)
NEW YORK (TheStreet) -- Recycling is one of those warm and fuzzy, yet incredibly mushy, terms that people just love to abuse. The goal of all battery recycling is to recover valuable metals so they can be reused to make new products. Anything less is merely safe disposal that wastes metals by permanently removing them from the supply chain.
Recycling can be cheaper and more energy efficient than mining, but only if the waste stream would be a high-grade ore to begin with. Lead-acid batteries fit that definition because they're 70% lead. To recycle lead-acid batteries, you put them through a shredder and dump everything into a water bath where the plastic floats and the metal sinks. Then you neutralize the acid, melt the metal and remove the impurities. The reclaimed lead is perfectly suitable for use in battery manufacturing. The same is true for the reclaimed plastics. It's a closed-loop system where substantially all of the materials used to make a lead-acid battery can be recovered and reused.
The process is clean and cost-effective, which is why lead-acid battery recycling satisfies some 80% of U.S. lead demand.
Lithium-ion and other advanced batteries, in comparison, contain low concentrations of several different metals. They're a recycling nightmare because metallurgical complexity is "low grade" by definition. This schematic from LG Chem shows the basic architecture and construction of a typical lithium-ion cell.
The cathodes are usually complex formulations of very high purity metals that are applied as surface coatings on aluminum foil current collectors. The anodes are usually carbon compounds that are applied as surface coatings on copper foil current collectors. The battery cases, or cans, are usually steel, while the separators are plastic and the electrolytes are organic compounds. The biggest material cost in the cell is the cathode coating, which usually has high cobalt content.
If you put a lithium-ion battery through a shredder, the lithium will react violently with water in the air and ignite the electrolyte and separators. While there are cryogenic, vacuum and inert atmosphere techniques that can eliminate combustion risks, they're terribly expensive in practice. Even if you overcome the combustion risks, when you shred the batteries you end up with small pieces of different metals that are covered with exotic coatings. Once again, there are ways to separate shredded batteries into purer waste streams, but they're expensive. Between the costs of fire prevention, material separation and metal refining, all lithium-ion batteries and most other advanced batteries cost more to recycle than the metals are worth. That economic disequilibrium is not likely to change unless metal prices soar and energy costs plummet.
If you decide to shortcut the process and simply toss scrap batteries into a furnace, the separators and electrolytes contribute a modest amount of process heat and you end up with a complex alloy that contains several different metals. It can't be used to make new batteries and it's almost impossible to separate into pure metals. It's basically worthless.
From time to time, we see news stories about researchers who want to deploy used automotive battery packs to provide backup power for the grid. While five- to 10-year-old batteries might have some marginal utility in stationary applications where battery capacity and reliability are not mission-critical considerations, the larger, but usually unspoken, motivation for the work is knowing that there are no cost-effective recycling techniques for automotive battery packs. That reality makes it doubly important to find a plausible strategy to kick the can around the cul-de-sac and pretend that the absence of an efficient and cost-effective recycling solution isn't a fundamental block to the widespread implementation of electric-drive automobiles.
Many people are concerned about the potential environmental threats associated with the use of lead-acid batteries, but the concerns are overblown because lead-acid batteries do not pose the same kind of risks as lead fuel additives and paints that disperse lead into the environment. The lead in batteries can only be released at two points during the lifecycle of a normal battery. The first is during manufacturing and the second is during recycling. Since both of these activities are heavily regulated and carefully monitored, the risk in advanced societies is insignificant. While there are places in the world where environmental practices are inadequate, even less developed countries are rapidly improving regulations to prevent lead toxicity from the battery industry.
The bottom line is that the environmental record of major lead-acid battery manufacturers and recyclers like Johnson Controls (:JCI) and Exide Technologies (:XIDE) is admirable, while the claimed environmental advantages of lithium-ion and other advanced batteries are entirely illusory because those quarter-ton batteries cannot be efficiently recycled into useful metals and will almost certainly present massive disposal problems in years to come.