The energy crisis caused by the war in the Middle East has brought the use of nuclear energy sources back into discussion. Thorium molten salt reactors are among those that are in the spotlight because they are seen as safer than uranium reactors that can be fused. At DARPA, the Rads to Watts program wants to realize high-power nuclear batteries that will allow laptops to operate continuously for several months for military use.
The use of computers in the battlefield and space is seen to be increasingly important in the near future. Existing batteries only last about a day before needing to be charged. This makes it difficult to use them in the field or remote locations without a power source to charge.
DARPA's Rads to Watts project wants to convert high-power nuclear radiation into electrical energy on the kilowatt scale. The goal is to develop a nuclear power battery with a power of 10 W/kg. Existing nuclear batteries such as those used in the Perseverance and Curiosity robots on Mars only provide 2.6W/kg of power.
Avalanche Energy has been awarded a $5.2 million contract to develop a solid-state battery that can convert alpha particles into electricity (alphavoltaics). Alpha particles are easy to block, but more dangerous to humans.
Nuclear batteries have been developed since 1914 with two versions, one converting heat generated from the radioactive decay process into electrical power using thermocouples. The other uses beta particles to move electrons in semiconductor materials to produce current.
In China, the Betavolt company announced the success of building a nuclear battery that can last up to 50 years without needing to be charged in 2024. This battery uses the Nickel-63 isotope which produces 100 microwatts of power and a voltage of 3V. It is only 15x15x15 millimeters in size, which is very compact.
