A few months ago, I stumbled across an article that caught my attention. A Chinese start-up company, Betavolt, was able to produce a new battery that was capable of providing power for 50 years.1 The interesting part is that during those 50 years, the battery is said to require zero charging and maintenance. This battery is known as a betavoltaic battery, a type of nuclear battery (also commonly referred to as an atomic battery) that is currently in pilot testing stages. As the name suggests, nuclear batteries utilize nuclear energy to generate electricity from the decay of a radioactive isotope. A groundbreaking technology of its time, nuclear power can potentially revolutionize battery systems as we know them today.
The inklings of nuclear power
A topic of discussion for the past century, nuclear power became a reality in the 1940s after the discovery of nuclear fission in the late 1930s. In 1942, the construction of the first nuclear reactor, Chicago Pile-1, was spearheaded by a group of scientists led by Enrico Fermi.2 It wasn’t until the 1950s and 60s, however, that nuclear batteries began receiving in-depth research for long-life use in space.2
There are two groups of nuclear batteries: thermal converters and non-thermal converters. Thermal converters utilize the heat generated from nuclear decay to produce electricity, while non-thermal converters generate electricity from emitted radiation from the nuclear decay directly.
What are betavoltaic batteries?
A betavoltaic battery is a type of non-thermal converter nuclear battery. Betavoltaics convert the energy emitted from the decay of a beta-particle-emitting radioisotope into electrical energy using a semiconductor.3 Some of the most common beta particle sources are 63Ni, 3H (tritium), 147Pm, and titanium tritide.4 The beta electrons emitted from the radioactive decay hit the semiconductor body such as the p-n, p-i-n, or Schottky junction, resulting in impact ionization of the electrons, producing electron-hole pairs that produce electricity.3
Betavoltaic effects were first studied in 1953 by Paul Rappaport from Radio Corporation of America (RCA). He created a betavoltaic device that coupled semiconductors with 90Sr-90Y as the radioactive source. However, the first device had an efficiency of only 0.2% and degraded quickly due to radiation damage.4
It wasn’t until the 1970s when Larry Olsen of City Labs was able to pioneer the first commercially available betavoltaic battery, using 147Pm as the beta-emitting radioactive source and silicon p-n semiconductor junctions.4 Dubbed Betacel, these batteries were used to power cardiac pacemakers that were implanted into patients during clinical trials. However, due to concerns of gamma radiation emitted from the 146Pm contaminant of 147Pm (although shielded from leaking into the human body), the stigma around nuclear power, and the rise of lithium batteries (and their low cost), Betacel dwindled away.
Today, betavoltaics that are offered include the Nano-Tritium batteries produced by City Labs and Firefli by Widetronix, suitable for microelectronics. Both batteries utilize tritium as their beta particle source which has a half-life of 12.32 years. Some of the early NanoTritium batteries developed over 15 years ago are still operating efficiently, with simulations indicating that they may even last for over 20 years. The battery produced by Betavolt uses 63Ni and is smaller than a coin while delivering 100 microwatts of power and 3V.1
Why betavoltaic batteries?
One main advantage of betavoltaic batteries is their lifetime. Depending on the radioisotope used and its half-life, these batteries can provide electricity for many years. As a result, they require no charging or maintenance, and are suitable for long-term applications or extreme environments such as space or the deep sea. They also have a higher energy density compared to traditional batteries, making them suitable for areas where size and weight are a concern. Radiation leakage poses little to no risks as the penetration depth of beta radiation is small and can be prevented if proper shielding is designed for the battery.4 Some potential use cases of betavoltaic batteries include implantable medical devices and low-maintenance sensors, among others.
What the future holds
Although research is still being conducted on how to optimize betavoltaic batteries, a promising future awaits. By utilizing 63Ni, which has a half-life of 100 years — approximately eight times more than that of tritium — Betavolt is already taking steps toward improving this growing area of research. While we may not see these batteries being used in our daily lives in the near future, we can expect future generations to harvest the fruits of our labor.
This article is also featured in the ChE in Context column of the September 2024 issue of CEP. Members have online access to complete issues, including a vast, searchable archive of back-issues found at www.aiche.org/cep.
- Cuthbertson, A., “Nuclear Battery Produces Power for 50 Years Without Needing to Charge,” Independent, https://www.independent.co.uk/tech/nuclear-battery-betavolt-atomic-china... (Feb. 1, 2024).
- U.S. Dept. of Energy, “The History of Nuclear Energy,” DOE/NE-088, DOE Office of Nuclear Energy, Washington, DC (1995).
- Zhou, C., et al., “Review — Betavoltaic Cell: The Past, Present, and Future,” ECS Journal of Solid State Science and Technology, 10, 027005 (Feb. 17, 2021).
- Hughes, K., “Nuclear Power in Your Pocket? 50-year Battery Innovation,” CAS, https://www.cas.org/resources/cas-insights/nuclear-power-your-pocket-50-... (Mar. 11, 2024).