Diamond: Paving the Way for a New Generation of Energy Storage Devices
What is a supercapacitor
Today, Supercapacitor, as a new energy saving device, has received much attention. Ultracapacitors, also known as electrochemical capacitors, double layer capacitors, gold capacitors, and Farad capacitors, developed in the 1970s and 1980s, are electrochemical components that store energy through polarized electrolytes. The supercapacitor has a positive electrode and a negative electrode, and there is a membrane between the two electrodes, which is filled with electrolyte. The porous electrode has a larger surface area to absorb the charge of electrolyte, so its capacity can reach a great extent. Since no chemical reaction occurs during the storage process, such capacitors can be charged and discharged hundreds of thousands of times.
Innovation
Today, as a safe, efficient and high-performance energy storage device, ultracapacitors have begun to replace traditional batteries, such as lithium-ion batteries. At the moment, however, it can store far less energy than ideal. To solve this problem, a team led by Dr. Takeshi Kondo of the Tokyo University of Science and The Daicel Corporation proposed to make a high-performance energy storage device (ultracapacitor) using conductive nano-diamond as electrode material. The device is suitable for rapid charging and discharging multiple times over a long period of time. In this innovation, diamond once again shines and stands out.
Technology
Kondo's team is exploring the use of a new material (boron-doped nanodiamond) as an electrode for supercapacitors. An electrode is a conductive material in a battery or capacitor that connects an electrolyte to an external wire, sending current out of the system. The team chose the electrode material because they realized that boron-doped nanodiamonds have a wide potential window, a feature that would allow high-energy storage devices to work steadily over long periods of time. "We considered that if we used conductive diamond as an electrode material, we could generate large voltages of water-based ultracapacitors," said Kondo. After this achievement, scientists began to explore whether the electrode material would produce the same results if the electrolyte were converted to a saturated sodium perchlorate solution, which produces a higher voltage than a conventional sulfuric acid electrolyte. In fact, in this configuration, the voltage generated is greatly increased. So, as Dr Kondo puts it: "Boron-doped nanodiamond electrodes are suitable for river supercapacitors, and they are suitable for high-energy storage devices that charge and discharge at high speeds."
