When clean energy is involved, there’s nothing quite as sweet as killing two environmentally-hazardous birds with one stone. Scientists at MIT have developed a technique that can create a solar cell from old car batteries. Not only are car batteries a great source of the materials needed to create the solar cell, but repurposing them also prevents toxic chemicals like lead from entering the environment when the batteries are thrown away. The research was led by Angela Belcher and Paula Hammond, and the paper was published in the journal Energy and Environmental Science.
Recent study has revealed that organolead halide perovskite is capable of making photovoltaic cells that are nearly as good as solar cells developed from silicon. Over the last 5 years, perovskite-based cells ballooned in efficiency from 3.8-19.3%. The team at MIT recognized that car batteries are a great source of the lead they need for their cells, and in only two years, their idea had been turned into a cell with good efficiency.
The vast majority of automotive batteries get recycled in the United States, and most of the lead from each old battery is used in new batteries. However, as technology progresses and the majority of batteries are made of safer materials, such as lithium ion batteries, there won’t be an immediate use for the lead in the batteries that are collected. There is a chance that the batteries could get discarded into landfills, where they could pose a huge pollution risk.
“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,” Belcher explained in a press release.
Such a huge stockpile of resources poses great potential for use in these solar cells. Obtaining perovskite from raw ore for solar cells can create toxic byproducts, but recycling the lead from old car batteries acts as a safer source of materials. The solar panels will safely encase the lead, minimizing any chance of pollution while generating clean, reliable electricity.
“The process to encapsulate them will be the same as for polymer cells today,” co-author Po-Yen Chen added. “That technology can be easily translated.”
Another great aspect to this technology is that the lead from one battery can go a long way. Each panel only needs a layer that is half a micrometer thick, so each battery can make enough panels to meet the needs of 30 American families. After the panels have been used for several years and need to be replaced, the perovskite can be recycled into new panels without diminished efficiency or new environmental threat.
“It is important that we consider the life cycles of the materials in large-scale energy systems,” Hammond says. “And here we believe the sheer simplicity of the approach bodes well for its commercial implementation.”
Check out this step-by-step walkthrough of perovskite production from lead obtained in car batteries: