Long-life nuclear batteries could power remote missions such as deep-sea exploration.
EB Adventure Photography/Shutterstock
Nuclear batteries, which run on radioactive decay rather than chemical reactions, could last for decades, and their most efficient design to date may bring the concept closer to reality.
Researchers have been hoping to use radioactive atoms to create a battery that would last a very long time and be resistant to damage since the 1900s. Several prototypes have been built and even used on space missions, but they have not been very efficient. Now, Wang Shuai and his colleagues at China’s Soochow University have improved the efficiency of their nuclear battery design by 8,000 times.
They started with a small sample of the element americium, which is usually considered nuclear waste. Americium radiates energy in the form of alpha particles, which carry a lot of energy but are quickly lost to their surroundings. So the researchers embedded the americium in a polymer crystal, which converted this energy into a sustained, steady green glow.
Next, the researchers combined the americium-doped photonic crystal with a thin photovoltaic cell, which converts light into electricity, and finally packaged this tiny nuclear battery into a millimeter-sized quartz cell.
Wang said that over 200 hours of testing, the device provided steady power at a relatively high energy level with unprecedented efficiency and required minimal radioactive material to function. Americium has a half-life of 7,380 years, but the components surrounding the sample will eventually be destroyed by radiation, so the nuclear battery should last for decades.
Americium-doped crystal glowing under a light source (top) and americium-doped crystal glowing in a dark environment (bottom)
Kai Li et al.
Michael Spencer of Morgan State University in Maryland says the new battery has “significantly improved overall efficiency and power output” over previous designs, but it’s still much less powerful than conventional devices: It would take 40 billion batteries to power a 60-watt lightbulb, for example.
Researchers are already working to improve the efficiency and power output of their design, and they also want to make it easier to use and safer, since it contains potentially dangerous radioactive materials.
“Ideally, we envision our micronuclear batteries being used to power tiny sensors in remote or harsh environments where traditional power sources are impractical, such as in deep-sea exploration, space missions and remote monitoring stations,” Wang says.
topic:
