What is a Nuclear Battery : Working & Its Applications

At the beginning of 1950, a nuclear battery is developed when the beta cell was first demonstrated by Henry Moseley. The field received extensive research awareness for applications that needs power sources with long life for space requirements throughout 1950 to 1960.

Generally, chemical batteries need to replace frequently and they are bulky also. Similarly, solar cells and fuel are also expensive and solar needs sun energy correspondingly. To overcome these, we need a battery with features like lightweight, reliable, compact, long-lasting power supply like the nuclear battery. This article discusses an overview of a nuclear battery.

What is a Nuclear Battery?

The nuclear battery can be defined as, a device that uses electric energy from decomposing a radioactive isotope for producing electricity. So there is no panic about harmful radiation. The lifespan of these batteries is up to decades & very efficient as well.

Similar to nuclear reactors, they produce electrical energy using atomic energy however difference is that they do not utilize a chain reaction. An alternative name of nuclear battery is tritium battery, atomic, and radioisotope.

Nuclear Battery Working Principle

The amount of energy used by nuclear batteries is unbelievable which is generated naturally through small radioactive material bits without any fusion or fission charge occurred within the battery. These batteries work through slight radioactive films that set in energy which is higher than lithium-ion batteries

Conversion Techniques of Nuclear Battery

A radioisotopic material like a nuclear battery is just decay where Alpha & Beta emissions of this material are used for generating energy. The emission of alpha & beta particles provide the main battery source.

These emissions are established into the electrode to develop the potential disparity to make the current flow throughout the load. There are two methods to change this decaying radiation to functional electrical energy like the following

• Thermal Converters
• Non-thermal Converters

Thermal Converters

In the thermal conversion method, the o/p power is a task of the temperature. Thermal converters are again divided into different types which include the following.

Thermionic Converter

A thermionic converter includes two electrodes where one electrode thermionically emits electrons once it gets high temperature whereas the other electrode gets these electrons. Generally, there is a space between the two electrodes however sometimes it is packed with cesium vapor to enhance the efficiency of the electrodes.

RTC (Radioisotopic Thermoelectric Generator)

This kind of converter utilizes thermocouples for changing the energy from heat to electricity. The formation of each thermocouple can be done by using two different metal wires.

The change within temperature through the wire’s length generates a change in voltage from one wire end to the other. RTC is a stationary generator without rotating parts. It is mostly required after the source of energy for unmanned machines & remote site amenities.

Thermo Photovoltaic Cell

These converters mainly work on the principle of a PV cell apart from that they convert IR light generated through a hot surface to electricity.

The efficiency of PV cells is somewhat higher as compared to thermoelectric couples. The emissions like Alpha & Beta from the isotope are designed to drop on thermal emitter from which IR emission is given out and these emissions are made to drop on the Thermo PV cell to produce electricity.

AMTEC

AMTEC stands for “Alkali metal thermal to electric converter” is one kind of electrochemical system. This system mainly depends on the electrolyte utilized within the batteries like sodium beta alumina & sodium-sulfur. In the laboratory, AMTECH cells efficiency has achieved 16% & it is expected to reach 20%.

Stirling Radioisotope Generator

A Stirling engine drives by the difference of temperature generated through a radioscope. New progress has led to the formation of a more efficient version namely an advanced Stirling radioisotope generator.

Non-thermal Converters

In the nonthermal conversion method, the o/p power does not lie on the temperature difference.
These converters are classified into different types which include the following.

• Direct charging generators
• Betavoltaics
• Alphavoltaics
• Optoelectric
• Reciprocating Electromechanical Atomic Batteries

Direct Charging Generators

The primary generator includes a capacitor that is charged through the charged particles of current from a radioactive layer deposited on one of the electrodes. The spacing between the two terminals of a capacitor can be either a dielectric or a vacuum.

Betavoltaics

Betavoltaics generates electrical current by using energy from a radioactive source like hydrogen isotope which is known as tritium. These converters produce electricity by using a method like non-thermal conversion.

These converters utilize a PN-junction semiconductor for generating electricity. Once the Beta emission is given to the electrode, then it produces electron-hole pairs which cause the potential to enhance between the electrode & current flow.

Alphavoltaics

These power sources use a PN-junction semiconductor to produce electrical energy from high-energy-based alpha particles. It works on the same principle of Betavoltaics but they change like it utilizes a radioisotope to emit Alpha particles.

Optoelectric

A beta-emitter like technetium-99 excites an excimer mixture & the light would influence a photocell. In this, an exact electrode assembly is not required & most of the particles of the beta will escape the lightly divided bulk material to supply the net power of a battery. It changes the emissions toward light & after that, it changes it into electrical energy

Reciprocating Electromechanical Atomic Batteries

These batteries use the buildup of energy among two plates to drag one flexible plate to the other until the two plates touch, discharge, leveling the electrostatic buildup & spring back.

The mechanical motion generated can be utilized to generate electricity through a linear generator or a piezoelectric material flexing.

Nuclear Battery Construction

A research team at MIPT developed a method to enhance the density of power 10 times for a nuclear battery. So, they designed a betavoltaic battery through nickel-63 like the radiation source & diamond diodes based on the Schottky barrier for energy change.

The nuclear prototype battery construction is shown below. This battery achieves 1 microwatt of o/p power whereas the density of power for every cubic centimeter was 10 microwatts. So this power is sufficient for a current artificial pacemaker.

The prototype of the nuclear battery includes 200 diamond converters which are interlaid through nickel-63 & constant nickel foil layers. The sum of power produced through the converter mainly depends on the width of the nickel foil & the converter. At present, nuclear battery prototypes are badly optimized, as they include extreme volume.

If the source of beta radiation is very thick, then electrons emitted by this cannot run away from it which is called self-absorption. However, whenever the power source is designed to thin, then several atoms go through beta decay for each unit time is proportionally decreased. The same principle is applied to the thickness of the converter.

The main objective of the researchers was to increase the density of power for the nickel-63 battery. To achieve this, they simulated numerically the way of electrons throughout the beta source & the converters.

It turned out that the source of nickel-63 is most efficient once it is two micrometers wide & the optimal width of the converter depending on Schottky barrier diamond diodes is approximately 10 micrometers.

Advantages

The advantages of nuclear batteries include the following.

• Reliable
• Less weight with high energy density
• Life span is decades
• The greenhouse effect can be reduced
• Obtained energy is maximum
• Waste generation is less
• Nuclear battery’s economic viability can be determined by balancing the power benefits & safety measures.

Disadvantages

The disadvantages of nuclear batteries include the following.

• When the battery is in the experimental phase, the production cost is high
• Conversion methods of energy are not advanced

Applications

The applications of nuclear batteries include the following.

Nuclear Battery for Cars

Nuclear batteries are used in neglected sources that should function for the long period. The best example of atomic batteries is underwater systems, space crafts, pacemakers, etc. The usage of nuclear batteries in automobiles is under process in the beginning stage, but it includes many benefits. The usage of this kind of battery in cars is restricted because of several reasons like the following.

• Under development technology
• As compared to other batteries, it generates more heat
• Expensive
• Ecological & health problems may occur because of the radioactive substance

Nuclear Battery Pacemaker

Generally, the pacemaker is mainly used to stimulate a normal heartbeat once the natural electrical pacing system of the body is not regular. For the past many years, pacemakers use different power sources like plutonium-238 (radioactive material).

But if we want to find out the pacemaker which is nonnuclear or nuclear powered, then different indicators are used on the pacemaker. We have to notice the markings on the body like Nuclear/Curies” to discover the radioactive material. So if the battery doesn’t have any of these markings, then the pacemaker is said to be non-nuclear & only includes a chemical-based battery.

Pacemakers with Nuclear-powered were designed by several companies like ARCO, Medtronic, Gulf General Atomic, American Optical, Cordis, Biocontrol Technology & Medical Devices

Nuclear batteries are used in different applications like a power source because of their enhanced reliability, high energy density & long lifetime.

• These are extensively used in military, space, medical & underwater applications.
• Pacemakers
• Spacecraft
• Underwater systems
• Automated scientific stations in remote areas
• Military & Medical applications

Thus, this is all about an overview of a nuclear battery or atomic battery and its working. Previously we have already familiar with the nuclear energy concept but not nuclear batteries. Nuclear batteries are nearer to nuclear power plants as compared to conventional batteries. These batteries use radioactivity for producing power in place of storing the energy. As evaluated to chemical batteries, these are divided through high volumetric energy density & endurance is stronger within harsh circumstances.

These devices are the long-lasting electricity source. The chance of utilizing nuclear batteries within automobiles is still being studied. Here is a question for you, what is nuclear energy?