Phys.org  July 26, 2024 Single-walled carbon nanotubes (SWCNTs), which typically exhibit great toughness, have emerged as promising candidates for innovative energy storage solutions. An international team of researchers (Japan, USA – University of Maryland Baltimore County, Michigan State University, South Africa) produced SWCNT ropes wrapped in thermoplastic polyurethane elastomers, and demonstrated experimentally that a twisted rope composed of these SWCNTs possesses the remarkable ability to reversibly store nanomechanical energy. The gravimetric energy density of the twisted ropes reaches up to 2.1 MJ kg−1, exceeded the energy storage capacity of mechanical steel springs by over four orders of magnitude and surpassed advanced lithium-ion […]