Washington: Scientists have developed a micro-supercapacitor, just nanometres thick, which could help in the development of smaller, lighter and thinner mobile phones and cameras.
The tiny power supply measures less than half a centimetre across and is made from a flexible material, which has opened up the possibility for wearable electronics.
Supercapacitors are attractive power supplies because they can store almost as much energy as a battery, with the advantage of high-speed energy discharge. Supercapacitor electrodes are normally made from carbon or conducting polymers, but these can be relatively costly.
A team led by Professor Oliver G Schmidt at the Leibniz Institute for Solid State and Materials Research in Dresden (IFW-Dresden) examined the use of manganese dioxide as an alternative electrode material, which is more environmentally friendly and less expensive than the standard materials.
Manganese dioxide is not a natural choice for an electrode material because it isn`t very electrically conductive, nor is it naturally flexible or strong.
However, the scientists overcame this by vaporising the manganese dioxide using an electron beam and then allowing the gaseous atoms to precipitate into thin, bendy films. They incorporated very thin layers of gold into the films to improve the electrical conductivity of the material.
Tests on the new micro-supercapacitor showed that the tiny, bendy power supply can store more energy and provide more power per unit volume than state-of-the-art supercapacitors.
Dr Chenglin Yan, leader of the research group at IFW-Dresden, said that supercapacitors, as a new class of energy device, can store high energy and provide high power, bridging the gap between rechargeable batteries and conventional capacitors.
He said that the device could be applied to many miniaturised technologies, including implantable medical devices and active radio frequency identification (RFID) tags for self-powered miniaturised devices.
The research has been published in the Royal Society of Chemistry journal Energy and Environmental Science.