Waste car batteries could fuel solar panel manufacture

A team of academics at the US-based Massachusetts Institute of Technology (MIT) have proposed a system based on a recent technological development in solar cells that makes use of a compound called perovskite.

According to trials, perovskite-based photovoltaic cells have achieved power-conversion efficiency of more than 19%, which is close to that of many existing silicon-based solar cells. As such, the technology is at a point where it is almost commercially competitive.

The system is described in a paper in the journal Energy & Environmental Science. The perovskite technology utilises lead, which can be sourced from old car batteries.

As the perovskite photovoltaic material takes the form of a thin film just half a micrometre thick, researchers showed that the lead from a single car battery could produce enough solar panels to provide power for 30 households.

In a finished solar panel, the lead-containing layer would be fully encapsulated by other materials, limiting the risk of lead contamination into the wider environment. The paper points out that when the panels are eventually retired, the lead can be recycled into new solar panels.

As an added advantage, the production of perovskite solar cells is a relatively simple process. One of the paper’s co-authors Angela Belcher, professor of energy at MIT, said that the number of steps involved in its production was less than that compared with the manufacture of conventional solar cells.

She pointed out that the motivation for using lead from old car batteries is that battery technology is undergoing rapid change, with new, more efficient types, such as lithium-ion batteries, 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,” she said.

Belcher believes that the recycled perovskite solar cells will be embraced by other photovoltaics researchers looking to fine tune the technology for added efficiency.

According to the paper, some companies are already gearing up for commercial production of perovskite photovoltaic panels, which could otherwise require new sources of lead. Since this could expose miners and smelters to toxic fumes, introducing lead recycling as an alternative could provide immediate benefits.

Maxine Perella