How Battery Recycling Works, Step by Step

Most of what happens after drop-off is sorting, then breaking the battery down, then pulling out the metals. The details depend on the chemistry. EPA puts it this way: the type and chemistry of the battery "determines which of the various waste management options to use"¹.

Step 1: Collection and sorting

Your battery goes to a collection point, such as a recycler that accepts batteries or a household hazardous waste site². From there it travels to a plant. Batteries are sorted by chemistry first, because a lead-acid unit and a lithium-ion unit need different treatment¹.

Step 2: Making the battery inert

For lithium-ion batteries, the first listed step is deactivation or discharging, especially for large packs from electric vehicles³. Large packs may also be taken apart before anything else happens. A battery can look dead and still hold charge, which is why this step comes first.

Step 3: Breaking it down

Next come mechanical processes, which include crushing, sorting and sieving³. The same source lists electrolyte recovery as a further step in the chain. Electrolyte is the liquid inside a cell that lets current move.

Lead-acid batteries are handled more simply. They're ground up, the acid is neutralized, and the plastic is separated from the lead³.

Step 4: Getting the metals back

For lithium-ion batteries, recyclers use one or more metal recovery methods. Here are the two common ones:

• Hydrometallurgical. Metals are dissolved in a liquid, usually with acids, then separated out. The source notes low energy use but also safety concerns about the acids³.
• Pyrometallurgical. Material is heated at very high temperatures to produce a metal-rich alloy. One source calls it one of the most widely used techniques for lithium-ion recycling, though it uses a lot of energy³.

A third method, direct recycling, tries to restore the cathode material without breaking down its structure. The source describes it as emerging, so don't expect every plant to offer it³.

How much comes back

It varies. Today's processes recover approximately 25% to 96% of the materials of a lithium-ion cell, a wide range that reflects different plants and methods³. Don't read a single figure into it.

What you do

Almost nothing, beyond getting the battery to the right place. Take it to a recognized collection site, as laid out in the drop-off guide, and let the plant handle the rest. Don't try to strip it for parts first. Opening a battery is the plant's job, because the plant has the equipment and training to do it. Large installed batteries go through the maker or installer instead². For differences by chemistry, see recycling lithium-ion, LFP and lead-acid batteries compared.