Scientists claim to have made a breakthrough in the search for more powerful and lower-cost lithium-metal batteries by including common polymer nylon in the design.
Lithium-metal batteries have a higher energy density than their lithium-ion cousins used in laptops and electric vehicles. Non-rechargeable lithium-metal batteries are commonly used in watches, medical devices, and other small electronics. However, their widespread adoption is hindered by safety concerns, including dendrite formation, electrolyte instability, and the use of reactive materials that can degrade performance and pose fire risks.
Scientists at the Future Energy Technology Institute at King Abdulaziz City for Science and Technology (KACST) in Riyadh, Saudi Arabia, worked on the basis that additives help stabilize lithium-metal battery interfaces, which improves performance.
Two recent studies in ACS Energy Letters and Energy and Environmental Science suggest that nylon – a polymer used in clothing, other fabrics, and rope since the 1940s – as an additive has promise.
The researchers said their tests of lithium-metal batteries using nylon additives were more efficient, improved lifespans, and offered fewer adverse reactions.
Husam Alshareef, chair of the King Abdullah University of Science and Technology's Center of Excellence for Renewable Energy and Storage Technologies (CREST), who led the two studies, said in a statement that the discovery could lead to cheaper and safer additives, showcasing the benefits of fundamental scientific research.
According to a paper in ACS Energy Letters, most larger molecules were overlooked as candidates for lithium-metal battery additives because they are insoluble. However, the study found that nylon could be effectively solubilized in lithium electrolytes and utilized as a macromolecular additive, which is a large molecule that interacts with battery components.
An accompanying study published in Energy & Environmental Science said the battery incorporating nylon "significantly" reduces production costs and environmental impact compared with other lithium-metal units.
"Both the cathode and the polyamide matrix within the electrolytes are recyclable, enhancing considerable sustainability. This work offers new avenues for high-voltage polymer electrolytes and innovative chemistry for regenerating [nylon]," the paper said. ®