Solar Cells Recycled from Old Car Batteries

In a sort of win-win situation, researchers at MIT have found a way to create solar panels from old recycled car batteries, providing a source of long-lasting, emissions-free power.

This system of solar cells uses an up-and-coming compound called perovskite - specifically, organolead halide perovskite - that is more than 19 percent efficient, making it competitive with many commercial silicon-based solar cells on the market.

This technology used lead, which unfortunately can produce toxic residues. However, MIT researchers circumvented this drawback by using recycled lead from old car batteries instead. And given the thin film of photovoltaic material - just half a micrometer thick - the team's analysis shows that the lead from a single car battery could produce enough solar panels to provide power for 30 households.

And given the simplicity of the manufacturing process, these solar panels will be "easy to get to large scale cheaply," co-author Po-Yen Chen said in a statement.

One reason using lead in old car batteries is advantageous is because of the changing battery technology industry. New, more efficient types like lithium-ion batteries are swiftly taking over the market.

"Once the battery technology evolves, over 200 million lead-acid batteries will potentially be retired in the United States, and that could cause a lot of environmental issues," explained co-author Angela M. Belcher.

Belcher says that today about 90 percent of the lead recovered from the recycling of old batteries is used to produce new batteries. However, when the market for lead-acid batteries declines, as researchers predict it will, there will be a large pile of lead left sitting around. With this new solar panel technology, the lead can simply be recycled to create new panels.

"It is important that we consider the life cycles of the materials in large-scale energy systems," added MIT researcher Paula T. Hammond, who was involved in the research. "And here we believe the sheer simplicity of the approach bodes well for its commercial implementation."

The system is described in a paper in the journal Energy and Environmental Science.