While nuclear subjects appear regularly in the news, they are usually dealing with "big" things like nuclear reactors, nuclear weapons, nuclear treaties, nuclear waste, nuclear accidents, etc. The average person could very well be affected by these things but in day to day life, most people have little contact with nuclear materials. Other than radioisotopes used in medicine or industry, radioactive materials are not part of most people's lives. However, a new technology was announced in the fall of 2014 that may change all that.
Generating electricity from a radioactive material has been researched since the 1950s. Some approaches create electricity by converting the heat produced by radioactive decay to electricity. Other processes use the flow of charged particles created by radioactive decay. Beta particles (electrons), positrons (anti-electrons), alpha particles (helium nuclei) and other fission produces have been used to construct batteries. Generally, atomic batteries have an efficiency of about two percent and a life span of up twenty years. High efficiency betavoltaic batteries can reach efficiencies of up to eight percent.
Nuclear batteries have been developed and used in a number of applications because they are long lasting and have a high energy density. Because they have been very expensive, they have been used primarily for applications that require a long term unattended power source such as powering equipment in remote locations on land, in the sea and in space. Their cost has kept them out of consumer products.
The College of Engineering at the University of Missouri has developed a new type of betavoltaic battery. According to the CoE, the new battery utilizes strontium-90 to increase the electrochemical potential in a water-based solution. The electrodes consist of titanium oxide that has been arranged in a specific pattern at the nanometer level and then coated with platinum. The electrodes serve as catalysts for the breakdown of water into oxygen compounds. When high-energy electrons from the decaying strontium-90 pass through the electrodes, electron-hole pairs are created in the titanium dioxide which creates an electron flow and, thus, an electric current.
Surface plasmons are "coherent delocalized electron oscillations that exist at the interface between any two materials where the real part of the dielectric function changes sign across the interface," in this case, between the aqueous solution and the electrode. The surface plasmons in the new battery increase its efficiency.
Other methods of using the breakdown of water to produce electricity do not produce the abundance of free radicals produced by the CoE battery. The kinetic energy of the free radicals is trapped inside the water molecules which enhances the production of electricity from the radiation.
This new betavoltaic battery is efficient and considerably cheaper than other atomic batteries. The ionic solution can stay liquid over a wide range of temperatures and might be useful in spacecraft. The new battery was made possible by breakthroughs in nanotechnological fabrication. It may be used in automobiles and other vehicles. Setting aside cost and efficiency, it will be necessary to convince people that nuclear batteries are safe enough to be used in vehicles. Issues such as safety in accidents and disposal will have to be dealt with.
