Can old batteries really be recycled?

Yes, old batteries can really be recycled, but how well depends on the kind. Most types of batteries can be recycled, and lead–acid car batteries are recycled most readily: nearly all of them. Lithium-ion batteries, the kind in phones and electric cars, are harder, and the honest answer for them is that today's recycling is partial, disputed and not fully measured.

Why bother? Batteries contain heavy metals and toxic chemicals, and putting them in household waste has raised concerns about soil contamination and water pollution. The recycling itself is not risk-free, because it can release harmful materials to the environment and to the workers doing it.

Lead–acid is the success story. These batteries are ground up, the acid is neutralized, and the plastic is separated from the lead, and the recovered materials go into new batteries. In some places a refundable deposit is charged on them, which encourages people to bring old ones back rather than abandon them. A 2019 study commissioned by the battery industry's own Battery Council found that, for 2014 to 2018, 99.0 percent of the lead from lead–acid batteries in the United States was reclaimed. That figure comes from an industry group, and the US Environmental Protection Agency reported in 1987 that rates had once fallen as low as 61 percent in 1983.

The everyday cell is the opposite. Disposable alkaline batteries make up most consumer battery use, yet there is currently no cost-neutral recycling option for them.

For lithium-ion, there are three main routes: furnaces that melt the metals into an alloy, acid baths that dissolve them, and direct recycling that reconditions the electrode itself. Today these recover somewhere between 25 and 96 percent of a cell's materials, which is a wide range. How many lithium batteries reach them is disputed: the US government and others estimated in 2021 that at most 15 percent were recycled at end of life in 2019, while some recycling advocates claim most were.