The problem is the same whether the batteries are used for cars, storage for solar, or storage for unreliable electric grid. But "solar" in the article title gets more clicks.
According to the linked report, the problem is that a great deal of the battery recycling is done by back-yard/garage operations that lose up to half of the lead into the environment. So the government needs to get involved somehow, stop the unregulated small operator recycling, and also do something about the other sources such as lead paint. Tragedy of the commons and that sort of thing. This is very much like the USA before the EPA was created in the 1970's, thank you President Nixon.