Demystifying civilian nuclear batteries: 50 years of stable self-power generation, fantasy or reality?

Interface News Reporter | Dai Jingjing

Imagine a future where battery life is no longer limited: smartphones don't need to be recharged, drones can fly for a long time, and AI devices, medical devices, and micro-electromechanical systems can be used to their best without interruption.

Recently, a Beijing-based start-up, Beijing Betavolt New Energy Technology Co., Ltd. (hereinafter referred to as Beijing Betavolt), announced that the company has successfully developed a civilian micro atomic energy battery, which can generate electricity stably for 50 years without charging or maintenance, and the products introduced to the market in the future can help realize the above wonderful vision.

An atomic battery is a physical battery, also known as a nuclear battery or radioisotope battery, which is a device that converts the energy released when a radioisotope decays into electrical energy.

The first product the company will launch is the BV100, which has a power of 100 microwatts, a voltage of 3V, and a volume of 15x15x5 cubic millimeters, which is smaller than a coin.

Beijing Beta Volt said that this is the world's first nuclear battery that will be mass-produced. From a technical point of view, this also marks that China has made disruptive innovation in the two high-tech fields of atomic energy batteries and fourth-generation diamond semiconductors at the same time, "far ahead" of European and American scientific research institutions and enterprises.

The outlook looks promising, but there is still much to be left unanswered. What is the origin of this "born" Beijing Betavolt Company? Is this product really a breakthrough? How safe is it? Why has the civil process of nuclear batteries, which has long been available, been delayed in advancing the civilian process, and how can it subvert lithium batteries?

Component composition of the BV100, image source: Beijing Beta Volt

1. What is a nuclear battery?

Nuclear batteries are nothing new, they have been developed for more than a century and have been successfully used in aerospace and medicine.

Because the radioisotope decay process is continuous and not affected by the environment, nuclear batteries usually have the advantages of stability and reliability, no human intervention and high energy density, and some radioactive sources have a half-life of decades or hundreds of years, which can ensure a long working life of nuclear batteries.

The most mature and earliest type of nuclear battery is radioisotope thermoelectric generator (RTG), which has been deployed in many aviation projects, such as the "Voyager 1" spacecraft launched by the United States in 1977, which carried an RTG fueled by plutonium-238, helping it become the farthest and fastest artificial satellite from the Earth.

In 2013 and 2018, China's Chang'e-3 and Chang'e-4 lunar landers also carried RTG isotope batteries.

RTG is a heat-converting nuclear battery, which converts the thermal energy generated by decay into electrical energy. However, due to the large size, high cost and limited application field of RTG, scientists have begun to develop small RTGs and miniature nuclear batteries with other energy conversion modes, while pursuing higher conversion efficiency and safety.

2. What is the progress of civil nuclear energy batteries?

Non-thermal conversion nuclear battery refers to the direct or indirect conversion of charged particles or decay energy emitted by radioactive isotopes into electrical energy, among which the radiation volt effect nuclear battery has received more attention, with the development of semiconductor materials, it is considered to have the potential for commercialization, and β ray sources are usually used.

More than 10 years ago, the City Labs laboratory in Florida, USA, successfully developed a tritium-based radiovolt-effect nuclear battery called "Nano Tritium". Tritium is a hydrogen isotope that spontaneously undergoes β decay.

The battery, which claims to work continuously for at least 20 years without the need for recharging, even appeared on Chinese e-commerce platforms in 2013 for 6,980 yuan, labeled as a "radiation-free civilian nuclear battery."

According to City Labs' official website, its NanoTritium battery line can currently power nanowatt and microwatt devices for commercial or scientific use. The base price of each battery starts at $5,250 (about 37,700 yuan), and discounts are available for bulk orders.

At the same time, the company said that because nuclear batteries are currently used in limited use, there is no reason for the average person to buy them, so it usually deals with businesses or scientific organizations interested in the technology.

In addition, Arkenlight, a British company, and NDB, a new energy start-up based in California, both focus on carbon-14 isotopes to develop diamond nuclear batteries through the radiant volt effect.

Arkenlight admits that the battery has limited power capacity to power a phone or car, but hopes it can be used in high-power devices or sensors with low power consumption. The company plans to load battery products on equipment in 2024.

In 2020, NDB claimed that its battery could collect about 40% of the charge, and it could last for 28,000 years without recharging. But so far, the company has not announced the commercial use of the product.

Whether it is Arkenlight or NDB, the nuclear batteries they have developed are in the early stage of development.

3. What is the origin of Beijing Betavolt?

According to Jiemian News, Beijing Betavolt was established in April 2021 and is registered in Yizhuang Economic Development Zone. THE LEGAL PERSON IS MUSOV ZAUR, A RUSSIAN NAMED ZHANG WEI IN Chinese, WHO ALSO SERVES AS CHAIRMAN AND CEO OF THE COMPANY.

Tianyancha APP shows that on January 15, Beijing Betavolt updated its registration information to show that the company's registered capital was 100 million yuan and the paid-in capital was 5.3 million yuan. Previously, the company had a registered capital of 1 billion yuan.

"At present, the CEO and the experts in charge of basic research and development have returned to Russia, and there will be a formal introduction to the outside world after the Spring Festival. An unnamed person in charge of Beijing Beta Volt told Jiemian News that specific products will be unveiled thereafter.

Judging from the patent applied for by Beijing Betavolt, the company's technology mainly comes from a Russian team. The person in charge said that the company is a domestic Chinese company, headquartered in Beijing, and will set up a branch in Moscow in the future.

The patent is titled "A Nuclear Battery and Its Manufacturing Method", and is currently in the state of substantive examination.

Image source: Tianyancha

Beijing Beta Volt said it is not only a new energy company, but also a fourth-generation semiconductor and ultra-long carbon nanotube new materials company.

"Nuclear batteries, diamond semiconductors and supercapacitors, the three major technologies and materials are linked and integrated, forming the core technology and innovation capabilities of Beta Volt. The company said.

In November last year, the official WeChat "Investment in Mianyang" of the Economic Cooperation Bureau of Mianyang City, Sichuan Province released a message showing that on the 7th of that month, the centralized signing ceremony of the project in the fourth quarter of 2023 was held in Youxian District, in which Youxian District and Beijing Betavolt Company signed a strategic cooperation agreement framework of 5 billion yuan for innovative high-tech projects.

Image source: Beijing Beta Volt official website

4. What are the products of Beijing Betavolt?

The nuclear battery developed by Beijing Beta Volt is also a radiated volt effect cell, which generates an electric current through the semiconductor transition of β particles (electrons) emitted by the radioactive source nickel-63.

To this end, the company has developed a single-crystal diamond semiconductor with a thickness of 10 microns, in which a 2-micron thick nickel-63 sheet is placed between two diamond semiconductor converters to convert the decay energy of the radioactive source into an electric current to form a separate unit.

Beijing Betavolt said that high-efficiency diamond converters are key to making nuclear batteries, and the core of the company's batteries is fourth-generation diamond semiconductors. The company is also the only company in the world that can be doped to make large-size diamond semiconductor materials.

"Nuclear batteries are modular, can be composed of dozens or hundreds of independent unit modules, and can be used in series and parallel, so battery products of different sizes and capacities can be manufactured. The company said.

This is basically in line with the technology previously announced by Russia.

IN 2018, A RUSSIAN RESEARCH TEAM PRODUCED A PROTOTYPE OF A NUCLEAR BATTERY INCLUDING A NICKEL-63 AND DIAMOND ENERGY CONVERTER, WHICH WAS PUBLISHED IN THE JOURNAL DIAMOND AND RELATED MATERIALS.

The team concluded that the nickel-63 layer was most effective when it was only 2 microns thick if nickel-63 was sandwiched between a diamond diode with a thickness of 10 microns. This nuclear battery prototype achieves a maximum output power of about 0.93 microwatts at 0.9 V and a volume of 5x5x3.5 cubic millimeters.

One microwatt is enough to power a pacemaker.

It is not yet confirmed that the relationship between Beijing Beta Volt and the above-mentioned Russian research team.

The BV100 of Beijing Beta Volt has a power of 100 microwatts, which is equal to one ten-thousandth of a watt. For comparison, the typical power consumption of current phones under heavy load is 8 watts, compared to about 5 watts in normal times.

The company plans to launch a 1-watt battery in 2025. If successfully launched, it will be the most powerful civilian nuclear battery at the moment.

The head of the company told Jiemian News that this will be achieved through the change in the size of diamond semiconductors, the change in nuclear isotope materials and the adoption of P-N junction technology.

"A 1-watt battery is definitely not 10,000 cells of 100 microwatts stacked together, it is an innovative combination of new technologies and new materials. The person in charge said.

Regarding the nuclear battery launched by Beijing Betavolt, a professor of physics at a university told Jiemian News that the management of radioactive sources is strict and the cost is high. In addition, the diamond semiconductor process is complex, and there is no technological breakthrough in the N-type doping process in China.

5. Is this product safe?

Nuclear radiation is the primary consideration in the utilization of nuclear energy, and there are certain safety risks in the field of nuclear energy batteries. For example, plutonium-238, in addition to being radioactive in itself, is itself a highly toxic substance.

In 1964, the United States failed to launch the Transit-5BN-3 satellite, which burned the body during re-entry, and the plutonium-238 fuel in its isotope battery was released into the atmosphere, causing very serious pollution.

At present, the range of particles released during the decay of α and β decay nuclides is relatively short, and the radiation is relatively easy to block.

Beijing Betavolt said that the atomic batteries developed by the company are absolutely safe, have no external radiation, and are suitable for use in medical devices such as pacemakers, artificial hearts and cochlea in the human body. At the same time, after the decay period, the nickel-63 isotope as a radioactive source becomes a stable isotope of copper, which is not radioactive and does not pose any threat or pollution to the environment.

According to the above-mentioned physics professor, from the perspective of radioactivity alone, the range of pure β particles in beta radiation cells is very short, and there is no safety problem. If Beijing Betavolt uses nickel-63 to make batteries, the safety of the nuclear battery itself for radiation protection can be guaranteed.

6. Can it subvert lithium batteries?

Considering that nickel-63 has a half-life of 100 years, it is not impossible for BV100 to achieve a lifespan of 50 years.

According to an article published in the Nuclear Physics Review in December 2020 by Li Xiaoyi, Lu Jingbin and other scholars from Jilin University, the life of a nuclear battery with the β radiation volt effect mainly depends on two parts: one is the energy loss, which is determined by the characteristics of the radioactive source, which is called the theoretical life, and the other is the radiation damage, which is determined by the overall characteristics of the semiconductor material and the period, which is called the working life.

Beijing Beta Volt said that the nuclear batteries developed by the company have about 3,300 milliwatt hours of electricity per gram, and the energy density is more than 10 times that of ternary lithium batteries.

This has sparked discussions that nuclear batteries will disrupt the lithium battery industry.

The above-mentioned physics professor said that in principle, the energy density of nuclear batteries can be many times higher than that of lithium batteries, but it does not mean that nuclear batteries can effectively replace lithium batteries in all fields. In addition, there is a lot of research progress on lithium batteries, and for safety and cost considerations, nuclear batteries are unlikely to replace lithium batteries in civilian use in the short term.

Historically, lithium batteries have actually replaced nuclear batteries at one point due to their low cost performance and safety.

In the 70s of the last century, some companies used the promethium-147 isotope for pacemakers, although the promethium-147 isotope also belongs to the β decay, but the process will release γ rays, which requires a lot of cost to shield the radiation. In addition, the cremation of the patient after the death of the patient may also cause the leakage of radioactive materials, so lithium batteries are used in this field instead of nuclear batteries.

7. What is the prospect of mass production?

In addition to the technical uncertainties, the physics professor pointed out that the strict management of radioactive sources will make it a big problem to obtain them in mass production.

According to China's Regulations on the Safety and Protection of Radioisotopes and Radiation Devices and the Administrative Measures for the Safety Licensing of Radioisotopes and Radiation Devices, exemptions for radioactive sources must be accompanied by a filing certificate and subject to approval.

From the point of view of cost, the nickel-63 isotope does not exist in nature and needs to be obtained by irradiating nickel-62 in a nuclear reactor. According to an article on the website of the journal "International Nuclear Engineering", the price of 1 gram of radioactive nickel-63 is about 4,000 US dollars (about 28,700 yuan). As a result, if mass production is realized, the price of these nuclear batteries will be high.

However, nickel-63 is less radioactive, and the Ministry of Ecology and Environment has also granted exemptions to some corporate instruments in recent years.

In the face of recent doubts, the person in charge of the company told Jiemian News that FMCG products such as mobile phones are not the market that Beijing Beta Volt will serve in the past two or three years, and it is necessary to consider all aspects: one is to look at national regulations, standards and industrial policies, the second is to see the further breakthrough in the performance of the battery, and the third is to see how the cost continues to decrease.

"Pacemakers, micro-UAVs and micro-electromechanical systems also belong to the civilian sector. The person in charge said.

Beijing Betavolt said it has communicated with China's professional nuclear research institutes and universities and plans to continue research on the use of isotopes such as strontium-90, promethium-147 and deuterium to develop higher-power, two-to-30-year nuclear batteries.