Researchers with Germany\u2019s J\u00fclich Research Centre in Erlangen said their new technique \u201cupcycles\u201d highly contaminated lead bullets into high-purity, commercial-grade lead iodide, a compound needed in bulk to manufacture the best of these perovskite solar cells. The team\u2019s results\u00a0produced solar panels capable of converting sunlight into electricity at a competitive 21% efficiency. For context<\/a>, topline perovskite solar cells made with more pristine starting ingredients currently harvest energy at just a little bit over 27% efficiency.<\/p>\n \u201cPerovskite solar cells rely on high-purity lead iodide,\u201d physicist and study coauthor Ian Marius Peters, said in a post on LinkedIn sharing the study<\/a>, \u201cbut lead is both toxic and resource-intensive to mine and refine.\u201d<\/p>\n \u201cMillions of tons of lead already exist in waste streams that remain underutilized,\u201d Peters added. \u201cThis work shows that toxic legacy waste can become a resource for clean energy.\u201d<\/p>\n Get the lead out <\/p>\n Peters and his colleagues selected this pile of time-ravaged ammunition from Renaissance-era muskets and arquebuses primarily as a proof of concept for their new method. According to their new study, published<\/a> this March in the journal Cell Reports Physical Science, they bought the \u201cmusket-ball fragments\u201d (like you would, probably) from someone on eBay. The bullets, they wrote, were intentionally chosen as \u201can exceptionally challenging model feedstock\u201d for manufacturing high-purity lead iodide. They did this, in other words, expressly to prove that their process would work even on really dirty old lead filled with chemical impurities.<\/p>\n Their upcycling method has two essential steps. First, two electrodes made out of the smelted and reshaped lead bullets were dipped into a mixture of acetonitrile solvent and dissolved iodine with an electrical current coursing through this liquid bath. The process, according to the team, produced lead iodide at remarkably high purity. The team also noted that this new method had ecological benefits too, limiting chemical use and producing less lead-contaminated wastewater.<\/p>\n In the second step, this mustard yellow and highly pure lead iodide powder was then used to grow perovskite crystals via a technique<\/a> known as inverse-temperature crystallization\u2014which uses heat, rather than cold, to induce the right formation of molecules and crystalline shapes.<\/p>\n According to Peters, this low-cost refinement method yielded perovskite solar cells that were \u201cstatistically indistinguishable from devices made with commercial 5N precursors.\u201d (5N here is industry jargon for a material with 99.999% purity. If you can believe it, and I will admit that I\u2019m having trouble myself, 5N is short<\/a> for \u201cfive nines.\u201d)<\/p>\n Closing the loop <\/p>\n The researchers said that they pursued this project as a means of capturing the \u201cestimated 30%\u201340% of lead waste\u201d that is effectively abandoned at the end of its industrial life cycle. An entirely new system, akin to the efficient recycling of lead-acid car batteries, would be needed to help boost production of perovskite solar cells (PSCs).<\/p>\n \u201cSustainable lead sourcing is imperative for scaling PSCs,\u201d the authors wrote.<\/p>\n Perovskites are a broad category of solar cells\u2014and they don\u2019t necessarily need lead in their crystalline structure to function\u2014but it has been these lead-based versions that have proven to be the most efficient at converting sunlight into electricity.<\/p>\n \u201cConsistently over time, the lead-based devices continue to improve in their performance,\u201d Tonio Buonassisi, director of MIT\u2019s Photovoltaics Research Laboratory, told<\/a> MIT News in 2022, \u201cnone of the other compositions got close in terms of electronic performance.\u201d<\/p>\n According to Buonassisi, lead halide perovskites solar cells have been the primary focus for perovskite researchers for over a decade. Among the material\u2019s many benefits over traditional silicon-based solar panels, perovskites can be easily woven into fabric-like solar cells, made of incredibly lightweight and flexible polymer materials<\/a>. Perovskites can be blended to make hybrid perovskite-silicon solar panels too, where they have achieved<\/a> impressive 36% efficiencies, greater than either alone.<\/p>\n \u201cYou can mix and match atoms and molecules into the structure,\u201d Buonassisi noted. \u201cPerovskites are highly tunable, like a build-your-own-adventure type of crystal structure.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"Materials scientists say they\u2019ve taken nearly 300-year-old toxic waste\u2014a stockpile of spherical lead bullets from the 16th and…\n","protected":false},"author":2,"featured_media":378208,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[181182,85,46,10860,181183,12055,125],"class_list":{"0":"post-378207","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-technology","8":"tag-hazardous-waste","9":"tag-il","10":"tag-israel","11":"tag-lead","12":"tag-perovskite-solar-cells","13":"tag-solar-cells","14":"tag-technology"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/378207","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/comments?post=378207"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/378207\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media\/378208"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media?parent=378207"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/categories?post=378207"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/tags?post=378207"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"Lead](\"https:\/\/www.newsbeep.com\/il\/wp-content\/uploads\/2026\/04\/lead-bullets-perovskite-solar-chart.jpg\")
Above, a flowchart illustrating how these old lead (Pb) bullets are refined into lead iodide (PbI2) for the perovskite solar cells. Credit: Sytnyk, Peters, et al., courtesy of Cell Reports Physical Science <\/p>\n![\"Perovskite](\"https:\/\/www.newsbeep.com\/il\/wp-content\/uploads\/2026\/04\/perovskite-structure-3d-model-e1775438566671.jpg\")
Above, a 3D model of perovskite\u2019s crystalline structure as seen in metal halides, like lead halide-based perovskite solar cells. Credit: John Labram, OSU College of Engineering, via a CC 2.0 license <\/p>\n