NEC Corporation has announced the development of an ultra-thin, 0.3mm thick, organic radical battery (ORB) that is compatible within standard IC cards (cards with an integrated circuit such as credit cards) of 0.76mm thickness and suitable for use in electronic paper and other technologies. These new ORBs feature greater flexibility, higher power output and faster recharging speeds than existing rechargeable batteries, including lithium-ion batteries.
Conventional ORBs of 0.7mm thickness are difficult for IC cards of standard 0.76mm thickness to adopt. These new, 0.3mm ORBs are less than half the thickness of existing units, a size reduction that was accomplished by using printing technologies to integrate circuit boards with batteries. As a result, IC cards embedded with these batteries can be used for a wide range of functions, including displays, transmission and advanced encryption processing.
These batteries are externally wrapped with a polymer film of 0.05mm thickness that may also be used with circuit boards. Moreover, the 0.3mm thickness is achieved through printing technologies that enable negative electrodes to be directly formed on circuit boards. This is created in combination with separators (insulation) on the negative electrodes and laminated radical polymer cathodes. Conventional batteries use an aluminum laminate as external material that is 0.2mm thick.
Battery-equipped circuit boards can also be outfitted with small electronic components, such as antennae. Circuit boards that are equipped with these batteries and electronic components enable the production of standard size IC cards with built-in batteries.
Battery prototypes feature a 0.3mm edge, 3cm thickness, 3mAh capacity and 5kW / L high-output power density per unit volume. Prototypes are capable of 2,000 display screen updates, 360 consecutive flash firings and 35 location transmissions on a single charge. Furthermore, charge-discharge tests indicate that the batteries maintain 75% of their initial charge-discharge capacity after 500 cycles, equivalent to the performance of lithium-ion batteries for mobile phones.
Source and top image: NEC