Nuclear Batteries

[Bruce Nunnally]

[full article]

Researchers have demonstrated a penny-sized "nuclear battery" that produces energy from the decay of radioisotopes.

As radioactive substances decay, they release charged particles that when properly harvested can create an electrical current.

Nuclear batteries have been in use for military and aerospace applications, but are typically far larger.

The University of Missouri team says that the batteries hold a million times as much charge as standard batteries.

They have developed it in an attempt to scale down power sources for the tiny devices that fall under the category of micro- and nano-electromechanical systems (Mems and Nems).

The means to power such devices has been a subject of study as vigorous as the development of the devices themselves.

Here was the release from Univ of Missouri: [release]

MU Researchers Create Smaller and More Efficient Nuclear Battery

Mizzou scientist develops a powerful nuclear battery that uses a liquid semiconductor

Oct. 07, 2009

Story Contact(s):

Kelsey Jackson, JacksonKN@missouri.edu, (573) 882-8353

COLUMBIA, Mo. – Batteries can power anything from small sensors to large systems. While scientists are finding ways to make them smaller but even more powerful, problems can arise when these batteries are much larger and heavier than the devices themselves. University of Missouri researchers are developing a nuclear energy source that is smaller, lighter and more efficient.

“To provide enough power, we need certain methods with high energy density,” said Jae Kwon, assistant professor of electrical and computer engineering at MU. “The radioisotope battery can provide power density that is six orders of magnitude higher than chemical batteries.”

Kwon and his research team have been working on building a small nuclear battery, currently the size and thickness of a penny, intended to power various micro/nanoelectromechanical systems (M/NEMS). Although nuclear batteries can pose concerns, Kwon said they are safe.

“People hear the word ‘nuclear’ and think of something very dangerous,” he said. “However, nuclear power sources have already been safely powering a variety of devices, such as pace-makers, space satellites and underwater systems.”

His innovation is not only in the battery’s size, but also in its semiconductor. Kwon’s battery uses a liquid semiconductor rather than a solid semiconductor.

“The critical part of using a radioactive battery is that when you harvest the energy, part of the radiation energy can damage the lattice structure of the solid semiconductor,” Kwon said. “By using a liquid semiconductor, we believe we can minimize that problem.”

Kwon has been collaborating with J. David Robertson, chemistry professor and associate director of the MU Research Reactor, and is working to build and test the battery at the facility. In the future, they hope to increase the battery’s power, shrink its size and try with various other materials. Kwon said that the battery could be thinner than the thickness of human hair. They’ve also applied for a provisional patent.

Kwon’s research has been published in the Journal of Applied Physics Letters and Journal of Radioanalytical and Nuclear Chemistry. In addition, last June, he received an “outstanding paper” award for his research on nuclear batteries at the IEEE International Conference on Solid-State Sensors, Actuators and Microsystems in Denver (Transducers 2009).

[Texas Jim]

Very interesting..

Wonder if that can be scaled to power a vehicle.

The statement...

quote...

"The radioisotope battery can provide power density that is six orders of magnitude higher than chemical batteries."

end quote...

sounds very good.

[BodybyFisher]

I just worry about disposal of these types of things...

In a related story from 49 years ago, this was in a June 1960 Time magazine, I always thought this was amazing, in 1960

http://caddyinfo.ipbhost.com/index.php?showtopic=12432

[Cadillac Jim]

From what I know of the numbers and the nature of ionizing radiation, alpha decay (spontaneous fission in which an unstable or radioactive nucleus decays into a helium nucleus and a nucleus with two fewer protons and two fewer neutrons) could spit out these positively charged particles through a vacuum which would "stick" to a battery cathode, which would provide two electrons and thus be a positive terminal of a battery. The support of the unstable nucleus would be the negative terminal of the battery. How to get rid of all that helium and thus maintain the vacuum is an issue, which might be self-solved in space vehicles.

Other mechanisms that might form the electrical base for a battery are electron capture, electron emission, and positron emission. This is beta and gamma emission.

Although Any of these will be fraught with hazardous radiation, such as gamma rays, neutrons, etc. Massive amounts of lead strike me as undesirable in, say, a sports car, and mass shielding may be a really big disadvantage in hilly terrain.

I think that these batteries may be important in very specialized niches, such as "keep alive" low power systems for spacecraft on long voyages. I do NOT want to see a massive proton or gamma ray source in my Chevy Volt.