Hot New Battery Powers IoT Devices Indefinitely

The proliferation of Internet of Things (IoT) devices and large sensor networks is already reshaping a number of industries by enabling unprecedented levels of data collection, analysis, and automation. These devices, equipped with advanced sensors and processing capabilities, have found applications in areas including agriculture, healthcare, manufacturing, smart cities, and environmental monitoring.

Despite their remarkable capabilities, the widespread adoption of IoT devices and sensor networks is presently being hindered by energy constraints. Most of these devices rely on batteries for power, which necessitates regular recharges and occasional battery replacements. This works well enough for a personal wearable device, for example, but when it comes to a large sensor network with hundreds or thousands of nodes, the level of maintenance needed quickly becomes impractical. That is especially true if the network spans a large geographical area that includes remote regions.

To unleash the full potential of IoT and distributed sensor networks, there is a pressing need for advancements in power sources. Many technologies, like solar and wind power, have been experimented with for this reason. While these energy sources are very valuable, they are not useful in every situation. Solar panels tend to get dirty and lose efficiency, which in turn requires that maintenance be performed. And wind may not be viable in some locations, like in a dense forest.

Another option was recently described by a team of engineers at the University of Utah. They developed a novel type of battery that can harvest electricity from a source of energy that is often available even when other sources fail — changes in temperature. When temperatures rise or fall, this battery can produce an electric current that it uses to recharge itself. At present, it is not able to generate a lot of power, but it is sufficient for many of today’s ultra-low-power microcontrollers and sensors.

The battery developed by the team is called a pyroelectrochemical cell. It consists of an electrochemical cell that is divided by a pyroelectric composite material made of porous polyvinylidene fluoride and barium titanate nanoparticles. As ambient temperatures go up or down, the polarization of the pyroelectric composite material increases or decreases. This results in the movement of ions, which creates an electric field inside the cell.

After a single cycle of heating and cooling, the battery can generate about 100 microjoules per square centimeter. This is by no means a lot of energy, but for certain types of IoT devices, it may be enough. Devices that make use of highly energy-efficient components and periodically wake to collect and process sensor readings, for example, might benefit from this type of technology.

To date, the battery has only been tested under laboratory conditions. Looking ahead, the researchers intend to carry out some real-world experiments to prove the value of their system in powering IoT devices. They also intend to tweak a number of parameters in an effort to optimize the battery’s performance. With a bit of luck, they might just be able to squeeze some extra juice out of it.