Researchers at Tohoku University have successfully increased the capability, lifetime durability, and cost-effectiveness of a capacitor of their pursuit of a more power-efficient future. A capacitor is a tool used as a part of a circuit that may store and release energy, similar to a battery. What makes a capacitor different from a battery is that it takes much less time to charge. For instance, your cellphone battery will power your phone immediately, but charging that battery back as much as 100% when it dies is much from instantaneous.
While this makes capacitors sound just like the superior selection, they’ve some big drawbacks that must be overcome. Firstly, their capability is way smaller than batteries, in order that they cannot store large amounts of energy directly. Secondly, they will be quite expensive. Lately, supercapacitors (capacitors with increased capability and performance) have been developed using nanocarbon materials, equivalent to carbon nanotubes (CNTs), which increase the surface area and overall capability. Nevertheless, because of the expensive nature of nanocarbon materials, large-scale production using this system will not be cost-effective.
With the intention to tackle these specific concerns to enhance the general performance of capacitors, a research group consisting of Professor Hiroshi Yabu (Tohoku University), AZUL Energy Co., Ltd. (a enterprise company from Tohoku University), and the AZUL Energy x Tohoku University Bio-Inspired GX Co-Creation Center was formed. Their findings were published in ACS Applied Materials & Interfaces On June 20, 2024.
The team succeeded in increasing the capability of capacitors by 2.4 times (to 907 F/gAC) in comparison with carbon alone by “sprinkling” iron azaphthalocyanine (FeAzPc-4N), a form of blue pigment, onto activated carbon. This method allows the molecule to adsorb on the molecular level, utilizing its redox capabilities. Moreover, the study demonstrated that 20,000 charge-discharge cycles are possible even in high-load regions of 20 A/gAC, making it feasible to power LEDs.
“This increased lifespan in comparison with batteries may help reduce waste, as the identical capacitor will be reused many more times,” comments Yabu, “The components of capacitors are also significantly less toxic than batteries.”
The capacitor electrode developed on this research can increase capability to the extent of supercapacitors using CNTs while utilizing commonly available and cheap activated carbon, making it a possible option for next-generation energy devices. What’s the subsequent step for the team after this? To make the supercapacitor much more super-powered.
