New Industry Products

NEC Develops Ultra-Thin Rechargeable Battery.

January 26, 2006 by Jeff Shepard

NEC Corp. has demonstrated a prototype of a new organic radical (ORB) battery that uses a type of plastic called organic radical polymer as its cathode. The battery is thin, only 30 microns, which is expected to enable it to be embedded into objects such as smartcards and intelligent paper in the future.

NEC anticipates that its new and unique battery will be used extensively in the future to power all kinds of tiny ubiquitous terminals. The interconnection of networks with battery-powered next generation ubiquitous devices will enable all kinds of objects to become terminals, bringing us closer to a ubiquitous networked society by allowing access to the network anytime, anywhere.

Organic radical polymer assumes an electrolyte-permeated gel state (that is the state in which polymer suffused with solvent expands)and is the reason why the rechargeable battery is so remarkably flexible and pliant. In addition, the organic radical polymer electrode reaction is extremely fast and the supporting salts migrate through gel state polymer very smoothly. This results in little resistance to the charging reaction and an incredibly fast charging time of less than 30 seconds. Because the battery contains no metals such as mercury, lead or cadmium, it is environmentally friendly.

The new battery has an exceedingly thin structure (300 microns), which will enable it to be embedded into objects such as smartcards and intelligent paper in the future. It is pliant and bendable, as flexible plastic is used as the cathode material. And features high energy density of approximately 1 mWh per cm squared. This means, for example, that if the ORB is used in an active RFID device, it would support up to several tens of thousands of signal transmissions on a single charge.

Currently, NEC has no plans for commercial production. But the company will continueto carry out aggressive R&D in this area toward enhanced performance and reliability and reduced cost of thin, flexible rechargeable ORBs.

NEC's first proposed the use or an organic radical compound as a battery's electrode active material in 2000. Charging occurs through the oxidation-reduction (redox) reaction of the radical region. The ORB exhibits an extraordinarily high discharge rate (large current discharged at one time). NEC was commissioned by the New Energy and Industrial Technology Development Organization (NEDO) of Japan during the period from November 2002 to March 2005 to develop abattery for data backup on desktop PCs, which fully exploits the advantageous characteristics of ORBs.