Chinese startup Betavolt recently announced it developed a nuclear battery with a 50-year lifespan. While the technology of nuclear batteries has been available since the 1950s, today’s drive to electrify and decarbonize increases the impetus to find emission-free power sources and reliable energy storage. As a result, innovations like Betavolt’s are bringing renewed focus to nuclear energy in batteries.
Nuclear batteries — those using the natural decay of radioactive material to create an electric current — have been used in space applications or remote operations such as arctic lighthouses, where changing a battery is difficult or even impossible. The Mars Science Laboratory rover, for example, uses radioisotopic power systems (RPS), which convert heat from radioactive decay into electricity via a thermoelectric generator. Betavolt’s innovation, however, is a betavoltaic battery that uses beta particles rather than heat as its energy source.
Before expecting to find these long-lasting batteries in common devices, it’s important to understand some key tradeoffs. The long lifespan of betavoltaic batteries is counterbalanced by their relatively low power output per unit mass, known as power density. The power density of the current betavoltaic batteries is so low that they cannot power a cell phone or laptop.
There are additional challenges that hinder the wider usage of these and all types of nuclear batteries, particularly material supply & discomfort with the use of radioactive materials. Yet, the physical and materials science behind this technology could unlock important advances for CO2-free energy and provide power for applications where currently available energy storage technologies are insufficient.
Future applications of nuclear battery technology
If betavoltaic batteries can increase their power density while managing size and cost challenges, these batteries could power devices for many years without replacement. Because beta radiation’s penetration depth is relatively small, emitters are safer than other types of radioactive materials and can be shielded with simple materials to make them appropriate for consumer use.
Researchers in the UK have even developed a betavoltaic battery using radioactive carbon-14 from nuclear waste. They embedded the carbon-14 in the diamond to maximize efficiency, as opposed to keeping the emitter and absorber in separate layers. If produced at scale, these can help address issues with radioactive waste products while providing long-term, consistent power.
Another possible innovation is to use nanomaterials, such as carbon nanotubes or nanoporous structures, to increase the surface area of the absorbers. This would allow them to generate and efficiently separate more electron-hole pairs and hence produce a stronger current, while not increasing the size of the battery to an unsustainable degree. Increasing surface area through the use of nanomaterials has been applied to solar cells and electrochemical batteries such as lithium-ion.
If researchers can master this capability in betavoltaic batteries, it would open up this type of energy storage to even more applications and potentially lead to advances in renewable energy and energy storage to support decarbonization. To learn more about the future opportunities in green energy, see our recent article on fastest growing research trends, li-ion battery recycling breakthroughs, and key building blocks for green hydrogen economies.