... if solving it is more profitable than shipping the toxic waste to $poor_country.

Batteries are not like plastic which can be manufactured on the cheap due to the abundant avability of resources. Natural lithium resources are available sparingly and mining it is not substantially easier than recycling it. It's like recycling aluminium and other metals, just the process consumes way more energy than it would be feasible. There are some advances already: https://spectrum.ieee.org/simple-energyefficient-recycling-p...