Deep inside a laboratory in Golden, Colorado, researchers have learned to make batteries fail on purpose—and it's saving lives in space. The National Laboratory of the Rockies (NLR) and KULR Technology Group just won NASA's 2025 Invention of the Year for developing an internal short-circuit device (ISC-D) that allows scientists to trigger controlled battery failures before they send lithium-ion cells to the moon.
The stakes could hardly be higher. When four NASA astronauts circled the moon on Artemis II, lithium-ion batteries powered their communications, navigation, propulsion, and thermal systems for ten days. Any hidden manufacturing defect—a speck of dust creating a microscopic flaw—could have triggered thermal runaway, a chain reaction of venting gas and extreme heat that spreads from one cell to the next. In the harsh isolation of space, such a failure could bring down an entire spacecraft and its crew. On Earth, we can afford to learn from mistakes. In orbit, we cannot.
For more than a decade, NLR researchers have collaborated with NASA to solve this problem. The innovation came from understanding something counterintuitive: to design safer batteries, you must first understand exactly how they fail. Traditional abuse tests—nailing batteries, crushing them, overheating them—reveal only external damage. They cannot replicate the unique reactions that occur when an internal short circuit happens, something impossible to control or predict using external triggers alone.
The ISC-D is elegantly simple. Three layered metal discs insulated by a thin layer of wax sit precisely between the anode and cathode inside a cell. When researchers want to trigger a failure, they warm the cell to 57 degrees Celsius—slightly cooler than a fresh cup of coffee. The wax melts. The metal components touch. A short circuit fires in a controlled environment. "The ISC-D is similar to placing a wrench between the layers of a cell in a precise, repeatable, and controlled environment," explained Matthew Keyser, NLR's senior energy storage engineer. The triggered device acts as a conductor, rapidly discharging all the battery's energy as intense, concentrated heat that typically exits through a vent, transforming into what Keyser describes as "a blow torch to adjacent cells."
What makes this breakthrough revolutionary is what it revealed: properly designed batteries can tolerate a single-cell thermal runaway event in any location without the failure spreading to neighboring cells. The system degrades performance, yes, but survives. This knowledge has allowed NASA to establish some of the world's most rigorous battery safety standards. Eric Darcy, former battery technical discipline lead at NASA's Johnson Space Center, stated plainly: "Nearly all battery designs for manned spacecraft applications have been verified to resist propagation of thermal runaway from cell to cell thanks to test campaigns using trigger cells with the ISC-D."
The collaboration began in 2010 when Darcy took a sabbatical to work alongside Keyser and Emeritus Energy Storage Engineer Ahmad Pesaran. What started as an effort to solve a problem that had long frustrated the battery industry—creating a reliable way to replicate internal short circuits—became essential infrastructure for human spaceflight. Today, scientists can run ISC-D tests repeatedly until their battery designs can withstand the most demanding applications imaginable: a round trip to the moon.