When it comes to increasing electric storage efficiency and electric breakdown strength — the ability of an electrical system to operate at higher voltage and temperatures with great efficiency — increasing one traditionally has led to a decrease in the other. Researchers have developed a scalable method that relies on engineered materials to increase both properties.
The team altered a dielectric capacitor, a device that stores and regulates energy and is commonly used in electronics and electric systems. Using dopants — small, engineered materials also called metamaterials — the researchers altered the dielectric capacitor to increase storage capacity while also increasing electric charge efficiency, meaning the capacitor can withstand greater voltage with very little energy loss at temperatures higher than 300 °F.
The team used interface effects in nano-dopants to increase both the storage efficiency and electric breakdown strength with a very small quantity of dopants and at a low cost. While previous work focused on filling the capacitor with a lot of fillers to achieve the greater energy storage efficiency, the new method accomplishes the task in the opposite direction; that is, by using very low-volume content fillers with very low-cost materials, which can also lead to greater breakdown strength. This keeps the cost low and makes this highly scalable.
Increasing the electric breakdown strength in a capacitor will enable the device to handle higher temperatures without a failure in the system. Hybrid electric vehicles now use a capacitor made of a material known as BOPP, which works well up to 80 °C (176 °F); however, vehicles can get very hot, so a cooling agent is needed, which increases cost and adds volume. The new capacitor can be used with metamaterials, which are smaller, to replace the existing capacitor.