Around eleven o’clock at night, practically everyone’s phone reaches that anxious eight percent. The half-dead portable charger at the bottom of a bag and the frantic search for a cable are so commonplace that we hardly notice them as issues anymore. However, a group of scientists is working on a project in a research lab at the Daegu Gyeongbuk Institute of Science and Technology in South Korea that would make that nightly ritual seem almost charming. They are developing a battery that should theoretically never require charging.
The key component of this work is a betavoltaic cell, a tiny nuclear-powered battery that uses beta radiation from radiocarbon, a carbon-14 isotope that is frequently produced as a byproduct of nuclear power plants, to generate energy. It sounds like science fiction. Anyone who has witnessed a dead phone incident will also find it to be something worth listening to.
The project’s leader, Professor Su-Il In, bluntly states that the performance of lithium-ion technology is “almost saturated.” He presented his team’s findings at the American Chemical Society’s Spring 2025 meeting. For a sector valued at hundreds of billions of dollars, the implication is unsettling. The majority of the battery chemistry that powers almost all portable devices on the planet has been squeezed to its limit, and the ceiling is approaching.
The material selection is what makes In’s approach truly intriguing and truly unique. Only beta particles, which can be stopped by something as thin as an aluminum sheet, are released by carbon-14. Compared to more severe forms of radiation, that is a significant safety difference. Additionally, it is cheap, readily available from the current nuclear infrastructure, and degrades so slowly that a battery built on it could theoretically outlive the devices it powers by centuries. No one seems to have a definitive answer to the question of whether that’s a selling point or a disposal nightmare.
In order to strengthen the molecular bond, the team’s prototype uses a titanium dioxide semiconductor, which is the same base material used in many solar cells, that has been sensitized with a ruthenium dye and treated with citric acid. When the radiocarbon’s beta rays hit the dye, they cause what scientists refer to as an electron avalanche, which is a series of charge transfers that the titanium dioxide layer then gathers into usable electricity. The energy conversion efficiency of earlier betavoltaic designs was, at most, moderate. This arrangement significantly raises that figure. In terms of raw power output, it is still inferior to lithium-ion. However, the longevity argument is difficult to reject, and the gap is closing.
It’s important to consider what “decades without charging” really entails. Think about a pacemaker. The gadget, which controls a person’s heartbeat, needs to be surgically replaced every five to ten years. This isn’t because the technology malfunctions, but rather because the battery does. It is not merely practical to have a nuclear cell that lasts a patient’s entire life. It completely alters the medical calculus. The same reasoning holds true for satellites in orbit, remote sensors buried in infrastructure, and monitoring equipment in locations that are simply inaccessible to a technician carrying a charging cable.
For years, the EV industry has been discussing solid-state batteries in parallel. Investment circles dubbed those batteries “forever batteries” because they were compressed, liquid-free, theoretically quicker to charge, and longer-lasting, but the term was always more optimistic than factual. Due to the promise, businesses such as QuantumScape have drawn significant investment. Nuclear betavoltaics is a completely different animal; it produces less power but has a longer lifespan than solid-state designs.
As this research progresses, it seems that use cases—rather than battery types—are the true competitors. Electric vehicles and other high-drain devices require quick, dense energy. Sensors, implants, and remote monitors are examples of low-drain devices that require endurance. The nuclear version of the forever battery appears to be specifically designed for the second category. It is genuinely unclear if it will ever cross into the first.
The researchers seem to be open about the difficulties that still exist. The power output of the current prototype is lower than that of a typical AA cell. A lab prototype does not present the same challenges as large-scale manufacturing. Furthermore, engineers cannot resolve the public’s discomfort with anything deemed “nuclear,” regardless of how secure the beta shielding is, in a white paper. It takes a while to go from a promising prototype to a product that is housed inside a consumer device. Before anything approaching widespread adoption, this technology might be used for years in specialized industrial and medical applications.
However, it seems difficult to disagree with the direction. The problem being solved—our collective weariness with dying batteries—is one of the few universal frustrations that cut across all demographics and income levels on the planet, and the materials are plentiful and the physics sound. The charging cable may already be outdated somewhere in that South Korean laboratory. Simply put, the world has not yet caught up.
