Since the early 1900s, researchers have been working on ways to turn radioactive material into an electric current that lasts for decades. Yeah, that’s right. We’re talking about NUCLEAR BATTERIES! So, how close are we for Nuclear Batteries?
This class of batteries is known as betavoltaics, and they’re powered by the beta-decay of radioactive material, hence the name. Beta particles are basically just high-energy electrons. So setting a beta-emitting material up next to a semiconductor is virtually all you need to get an electric current in motion. Though their power output can be pretty low (less than an AA battery), they last as long as it takes the material to decay. And since radioactive materials can have half-lives of centuries to millennia, that means batteries that could last for decades without any noticeable power loss.
As an aside, betavoltaics is different from the Radioisotope Thermoelectric Generators (or RTGs) that NASA uses for space missions. Those are powered by the HEAT of radioactive materials, like plutonium, instead of beta particles directly and are also sometimes referred to as nuclear batteries. But betavoltaics can be made smaller and safer than RTGs, and with the incredibly long lifetimes that nuclear promises. Back in 1954, the Radio Corporation of America announced the development of their first betavoltaic battery. It was a big deal these days. RCA imagined them being used in wristwatches, hearing aids, and radios.
In the February 1954 issue of LIFE magazine, RCA even compared their invention to Edison’s lightbulb. But, while lightbulbs are literally everywhere, I would wager you probably don’t own a device that runs on nuclear batteries. Today, betavoltaics are mainly used in deep space and military applications far away from the average consumer. And there are a lot of factors involved as to why that is, but a big one is safety. Like I said before, betavoltaics is safer than other nuclear power systems, but some beta-emitting materials can still be pretty dangerous.
For example, RCA’s prototype from 1954 ran on Strontium-90, exposure to which can cause leukemia. And even though their battery was coated with radiation blocking materials, it still probably wasn’t the safest thing to hand off to anyone walking down the street. But we’ve come a long way! In recent years, several research teams have been looking for a way to safely harness the power of betavoltaics. And one team at the University of Bristol is making one out of diamonds (a new prototype made out of carbon-14).
The radioactive part is actually diamond as well And all of the radiation, all of the power of the device is completely absorbed by the diamond structure around it.” But perhaps one of the most impactful applications of this battery is for medical implants. Today, they largely rely on lithium-ion batteries, but those have limitations. So, today’s nuclear batteries might not be what scientists imagined back in the 1950s.