Betavolt reveals battery of atomic proportions, may be solution to long-form energy storage on a micro-scale

Exploring alternate battery chemistries, Beijing-based Betavolt has unveiled a new battery that it claims can generate electricity for at least 50 years without the need for recharging or maintenance.

The catch – they are nuclear-powered, with diamond semiconductors, and only generate around 100 Microwatts at a size less than a five Jiao coin, which is about 25 millimeters wide.

Nuclear batteries are not a new technology, sometimes known as a radioisotope battery, an atomic battery, or a radioisotope generator. However, limited by the capabilities of miniaturization, among many other limitations, when it was first posited in 1913, the idea of utilizing the energy displaced with nuclear decay practically sat mum for over a century.

Now, however, Betavolt has come out with an innovation of atomic proportions, stating it is the first in the world to realize the miniaturization of atomic energy, fitting nickel-63 isotopes into a module roughly the size of a fingernail.

Measuring 15 by 15 by five millimeters, the three-volt BV100 delivers a whopping 100 μW, essentially one-millionth of a watt.

While logistically still far away from smartphone potential, which draws around five to 10 watts of power, the company claims it plans to launch a one-watt model in 2025, basically multiplying its current iteration's output by one million.

Mushroom-sized claims

Instead of relying on the heat emitted from nuclear fission, nuclear batteries instead use the natural decay of radioactive isotopes as energy – something that takes upwards of 4,500 million years for the uranium used in nuclear plants.

Once the isotope decays, it is converted into electrical energy through a semiconductor converter, an application that the United States and the former Soviet Union focused on heavily during the 1960s.

From this nuclear mobility race, thermoelectric nuclear batteries exist today but are typically only used in the aerospace sector. This type of battery is large in volume and weight, has a high internal temperature, is very expensive, and most likely will never be made available for consumer applications.

However, nuclear batteries are not electrochemical batteries. Having a purported energy density that is 10 times that of the ubiquitous three-part lithium-ion battery, Betavolt reports that its battery has a life of at least 50 years.

Further, during those 50 years, nuclear batteries will not adhere to the concept of cycles as typical batteries do, meaning no charging or discharging.

According to the company, the power generation of a nuclear battery is stable and will not change due to harsh environments or loads, meaning it is a constant power source for half a century that works in the range of 120 degrees above zero and minus 60 degrees, with no self-discharge.

Health and safety

While nuclear radiation is an appropriate concern, Betavolt says its device is safe and emits no external radiation.

Giving credibility to this claim, nickel-63 isotope as a nuclear reagent decays into copper, which is non-radioactive.

External gamma exposure is then not a concern because, according to the Health Physics Society, neither nickel-63 nor nickel-59 emit significant gamma radiation. Further, nickel-63 decays by emitting a beta particle and nickel-59 decays by electron capture, in which low-energy gamma radiation is emitted.

In simplest terms, for example, during our daily lives, the average amount of background radiation is around 0.1 to 0.2 microsieverts per hour. For comparison, around four to five sieverts of radiation received within a short period is enough to be lethal.

According to ionactive, a UK-based radiation protection advisor, nickel-63 produces no quantifiable measurement of microsieverts, no bremsstrahlung dose, and little to no Becquerel activity unless inhaled or ingested. (For further simplicity's sake, those are all just different types of nuclear measurements.)

Conversion conductor

The miniaturization, modularization, and civilianization of nuclear batteries have been pursued by U.S. and European researchers, but according to Betavolt, it is through China's 14th Five-Year Plan and Vision Goals for 2035 that put forward the future development trend of widespread nuclear technology use and the multi-purpose development of nuclear isotopes.

From this, the company needed a way to capture the decaying radioactive isotopes.

Betavolt nuclear batteries generate current through the semiconductor transition of beta particles (electrons) emitted by the radioactive source nickel-63. In order to accomplish this, the team developed its own unique crystal diamond semiconductor, only 10 microns thick.

Belonging to a class of semiconductors called the Ultra Wide Band Gap, diamond semiconductors exhibit greater durability in that their dielectric breakdown strength is at least three times higher than that of silicon carbide (SiC) devices and also offers superior thermal conductivity.

Betavolt

Built to be scalable and modular, a two-micron-thick sheet of radioactive nickel-63 is sandwiched between two 10-micron-thick sheets of diamond that catch decaying isotope particles and convert them to electricity.

For the BV100, a two-micron-thick nickel-63 sheet was placed between two of these diamond semiconductor converters to convert the decaying energy of the nickel into electric current and form a separate unit.

As they designed the battery to be modular, composed of dozens to hundreds of independent units that can be used in series and parallel, the batteries can eventually accommodate sizes more typically seen in things like laptops and smartphones.

With all the elements in play, Betavolt has registered its patents in Beijing and will begin registering global patents.

Not settling on just nickel, the company is also in talks with Chinese professional nuclear research institutes and universities to explore and study the possibility of strontium-90, promethium-147, and deuterium, as well as other isotopes to develop atomic energy batteries with higher power and service life between two to 30 years.